- Email: [email protected]
Comparison of Opuntia ficus indica varieties of Mexican and Argentine origin for fruit yield and quality in Argentina
ARTICLE IN PRESS Journal of Arid Environments
Journal of Arid Environments 60 (2005) 405–422 www.elsevier.com/locate/jnlabr/yjare
Comparison of Opuntia ficus indica varieties of Mexican and Argentine origin for fruit yield and quality in Argentina P. Felkera,b,, S. del C. Rodriguezc, R.M. Casolibac, R. Filippinid, D. Medinad, R. Zapatae a
Universidad Catolica de Santiago del Estero, 4200 Santiago del Estero, Plantation Specialty, Felda, Florida, USA b INSIBIO, Universidad Nacional de Tucuman, Tucuman, Argentina c ICyTA-ICQ- Facultad de Agronomia y Agroindustrias, Argentina d Facultad de Agronomia y Agroindustrias, Universidad Nacional de Santiago del Estero. Av. Belgrano (S) 1912, 4200 Santiago del Estero, Argentina e Facultad de Ciencias Agropecuarias, Universidad Nacional de Cordoba Received 21 July 2003; received in revised form 13 April 2004; accepted 15 June 2004 Available online 24 August 2004
Abstract A randomized complete block field design for Opuntia ficus indica fruit production and quality in Argentina compared 19 of the most promising fruit accessions identified from previous Texas field trials to 8 individual selections of the naturalized Argentine ‘‘Santiaguen˜a variety’’ and one South African clone. The genetic material originating from Texas consisted of recently collected fruit varieties from high elevation sites in northern Mexico which should possess increased cold hardiness and the best accessions from among 100 accessions evaluated over a 15 year period in Kingsville, Texas. The Argentine accessions were selected for high yield from on-farm field trials and university field plots. The Argentine varieties were established about half a growing season after the Texas varieties. The yields ranged from 3000 to 22,000 kg ha 1 for the 4th growing season for the accessions from North America and from 2100 to 6400 kg ha 1 in the 3rd growing season for the Argentine naturalized genetic materials. The Argentine varieties had the greatest fruit pulp firmness (about 2 kg) and sugar contents (13.4–15.2) but had a lower percentage pulp Corresponding author. Current address: D’Arrigo Bros Co., 383 W Market Street, P.O. Box 850, Salinas, CA 93902, USA. E-mail address: [email protected] (P. Felker).
0140-1963/$ - see front matter r 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.jaridenv.2004.06.003
ARTICLE IN PRESS 406
P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
(40–47%) than the North American materials. For the first time this work demonstrated significant differences in yield and sugar content among the naturalized Argentine varieties leading the way to the first selected varieties. In some of the accessions, even at maturity, the inner pulp lacked structural integrity and easily broke apart on peeling. These accessions had both a low pulp firmness (less than 1 kg) and a low percentage of pulp to peel firmness. The ratio of pulp to peel fruit firmness at maturity varied greatly among the accessions obviating the possibility of evaluating pulp firmness from peel firmness measurements. The highly significantly negative correlation between fruit firmness (p=0.005) and pH among the accessions is reminiscent of auxin-induced pH decreases that lead to increased cell wall plasticity. Two of the spineless Texas accessions (1279 and 1300) with dark purple fruit could not be distinguished on the basis of cladode or fruit color or overall plant morphology. In agreement with prior Texas evaluations, clone 1300 had significantly greater yield but significantly lower sugar than the other indistinguishable clone 1279. These significant quantitative intravarietal differences in clones 1279 and 1300, combined with intravarietal differences in the externally indistinguishable Santiaguen˜a clones, points to the need to select and maintain individual plant selections within morphologically indistinguishable varieties. r 2004 Elsevier Ltd. All rights reserved. Keywords: Cactus pear; Fruit firmness; Intravarietal
1. Introduction The specialized photosynthetic system in cacti known as Crassulacean Acid Metabolism (CAM) provides greater water to dry matter conversion than C3 and C4 photosynthetic pathways (Nobel, 1988; Han and Felker, 1997). The combination of this conversion efficiency and the great biodiversity in fruit colors (red, orange, purple, pink, yellow, and lime-green) (Griffiths and Hare, 1907; Pimienta, 1990; Barbera et al., 1995; Inglese et al., 1995; Parish and Felker, 1997), results in great potential for the flat stemmed Opuntias in arid lands. While there are many excellent general descriptions of the variability in Opuntia fruit types (Griffiths and Hare, 1907; Monjauze and LeHouerou, 1965; Russell and Felker, 1987; Nobel, 1988; Wessels, 1988; Pimienta, 1990; Barbera et al., 1995), there are few journal articles that report yields and fruit quality measurements on genetically broadly based selections from replicated field trials. Gutierrez-Acosta et al. (2002) reported used cluster analyses to distinguish 3 main fruit groups from 24 accessions in Mexico but did not list individual fruit measurements for the accessions. Nieddu et al. (2002) listed general descriptions of 6 Italian cultivars but did not provide quantitative data on yields or fruit quality. Barbera et al. (1992) reported on the changes in fruit quality during ripening of the 3 major Sicilian Opuntia cultivars in commercial orchards but did not report yield data. From Israel, there is considerable data on fruit maturity and use of N fertilization to stimulate off season Opuntia fruit production (Nerd et al., 1991, 1993), and discovery of a low seedy parthenocarpic fruit (Weiss et al., 1993), but as far as we are aware no comparisons of fruit quality/yield from replicated field trials. There are reports of fruit yield/quality from a broad based germplasm collection in Texas (Gregory et al., 1993; Parish and Felker, 1997; Cowan and Felker, 1999; Wang et al.,
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
407
1998) and the resultant comparison of 12 of these clones in Argentina (Felker et al., 2002a). Due to 3 days of continuous below freezing weather in Texas in December 1989 (minimums of 12 1C on 2 days), that killed all Opuntia ficus indica accessions (Wang et al., 1998), the germplasm collections by the Texas group after 1989 emphasized freeze hardiness. Felker and Nerd made a major germplasm collection at high elevation sites in northern Mexico whose initial fruit quality was reported by Cowan and Felker (1999). Of special interest was the germplasm selected by Martinez (1968) in which 32 seedlings out of 200,000 seedlings planted survived a 1963 freeze of 16 1C in Saltillo, Mexico. Other interesting materials were those reported by Borrego-Escalente et al. (1990) that were reported to survive 16 1C. In 1999, eighteen accessions representative of the Texas collection, with emphasis on recently collected high elevation sites in northern Mexico were established in a randomized complete block trial in Argentina. It would be presumptuous to assume that the imported germplasm was superior to the naturalized local Santiaguen˜a cactus variety, as our measurements of fruit quality and yield in local farmers fields indicated great variability in yield (Felker et al., 2002b). Thus individual plant selections of the local variety were made from farmer’s fields and university research plots and established one year later in the replicated trial with the 18 accessions from Texas. For the first time in Argentina this trial was able to compare fruit quality/ yield of the local variety in a replicated field trial. Our Texas work (Parish and Felker, 1997) reported on fruits from spiny and spineless species such as O. ficus indica, O. hyptiacantha, O. amyclea etc and that spine characters were in part, used to distinguish the species. However DNA molecular marker data has raised significant doubts on the validity of the traditional taxonomic approaches to the classification of the commercial O. ficus indica fruit types. Wang et al. (1999) examined RAPD patterns in what were presumed to be 8 very contrasting Opuntia clones. The two most similar clones were the spiny O. hyptiacantha 1287 and the spineless O. ficus indica clone 1281. Moreover, O. ficus indica clone 1281 had a greater genetic affinity to O. hyptiacantha clone 1287 than the other spineless O. ficus indica clones 1279, 1321 and 1294. The major distinguishing feature between O. ficus indica clone 1281 and O. hyptiacantha clone 1287 was the presence of spines. This data has cast doubt on the traditional taxonomy, such as described by Scheinvar (1995) that used spine characters to distinguish species. A recent traditional taxonomic work (Kiesling, 1999) based on segregation of morphological characters within Opuntia progeny (among other characters) has also come to the conclusion that spine characters should not be used to differentiate species among the commercial Opuntia fruit types and lists all flat stemmed fruit types as simply O. ficus indica. We concur with this opinion and thus in this paper simply use O. ficus indica for these commercial fruit types.
2. Materials and methods The experimental design consisted of a randomized complete block design of 28 accessions with 4 replicates, each replicate consisting of a row of 3 plants. The plant
ARTICLE IN PRESS 408
P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
spacing was 2 5 m. The total fruit number on all plants was counted at mid-season. For yield calculations the mean fruit yield (fruit number times maximum fruit weight) of the 3 plants per rep was used to calculate a rep mean. Confidence intervals (95%) for fruit yield were based on the means of the 4 reps in the trial. In contrast for fruit quality measurements, the individual fruit was used as the experimental unit. The justification for this is as follows. In a trial with 5 fertilization treatments on O. ficus indica plantations with 10 single plant reps and 4 fruit measurements per rep, there was little difference in fruit quality among treatments (Galizzi et al., 2004). In a trial comparing 11 Opuntia clones grown in Texas, USA and Santiago del Estero, Argentina, there was remarkably little difference in the ranking of the varieties for fruit quality measurements such as Brix, pH and surprisingly the absolute values of the fruit quality indicators were very similar in Argentina and the USA (Felker et al., 2002a). Thus it seems as if the major variation in fruit quality is not related to environment or edaphic factors but rather genetic factors. The majority of the variation in the field for fruit quality seems to be due to random error. Thus in this situation it seems more logical to compute the confidence intervals on the basis of the means of all individual fruits in the field, rather than to compute the block means. Since all the varieties were randomly assigned to 4 blocks, any bias due to field position should be eliminated. The fruit quality measurements were based on the means (and confidence intervals) of 16 fruits coming from 4 fruits per replicate (of three plants) and 4 replicates. Due to difficulty in selecting the mean fruit size of the 3 plants, we chose to select 4 of the largest fruits per replicate because (1) we assumed there would be less error in choosing the largest fruits than in the mean fruit size per plant and (2) the ranking of fruit size would be the same whether based on the largest or the mean fruit size per accession. The origin and rationale for inclusion of the accessions in this trial is provided in Table 1. No single clone had the optimum combination of fruit yield, high sugar, lack of thorns, cold hardiness, fruit colors and low quantity of seeds. Thus accessions were selected that contained at least one of these characteristics. The largest US importer of cactus pears has stated that the highest priority should be given to selection of less-seedy varieties (Caplan, 1990) and thus the low-seedy clone 1319 was included. As provided in detail in Table 1, the trial contained; some of the most interesting clones resulting from an 18 year evaluation in Kingsville, Texas 1277, 1279, 1280, 1281, 1287, 1300, 1319, 1320; clones 1379 and 1380 reported by BorregoEscalente et al. (1990) to have survived 16 1C in Saltillo, Mexico; clones recently (1990) collected in farmers fields in high elevation in northern Mexico 1392, 1402, 1403, 1404, 1405, 1406 and 1458; clones from the naturalized Argentine ‘‘Santiaguen˜a’’ variety AR1–AR8, and a good fruit variety Meyer from South Africa. While the field trial for 4 blocks of 28 entries was laid out in early 1999, not all of the desired accessions were available for planting at the same time. When the materials became available, they were inserted into the preplanned design. The first 17 accessions from Texas were established on 22 April 1999 which is fall in Argentina. Following fruit yield measurements of mature naturalized Santiaguen˜a plants in farmer’s fields and research plots additional selections were made. AR1 and
Origin of accession
Spines
Reason for inclusion in this trial
1260
Obtained courtesy of H.N. LeHouerou from Algiers, North Africa
No
1277
Collected by C. Russell in Milpa Alta, Mexico where it was used for vegetable production Collected by C. Russell in Universidad Autonoma de Chapingo where it was labeled for vegetable use Collected by C. Russell in Universidad Autonoma de Chapingo where it was labeled for fruit use Collected by C. Russell in Universidad Autonoma de Chapingo where its common name was rojo vigor Collected by C. Russell in Agua Prieta, Mexquite, San Luis Potosi A misidentified selection received from the Texas A&M Univ Kingsville (TAMUK), collection not 1288 of the TAMUK collection Collected by C. Russell in Universidad Autonoma Chapingo where its use was for forage Collected by C. Russell in Nipas, Chile (near Chillan) in plantation of Carlos Gruebler Darel Collected by C. Russell in Nipas, Chile (near Chillan) in plantation of Carlos Gruebler Darel ANV4 of Fernando Borrego of Universidad Autonoma Agraria Antonio Narro in Saltillo, Mexico reported to survive 16 1C (Borrego-Escalente et al., 1990) ANV5 of Fernando Borrego of Universidad Autonoma Agraria Antonio Narro in Saltillo, Mexico reported to survive 16 1C (Borrego-Escalente et al., 1990) Collected P. Felker in farmers field in Saltillo, Mexico after severe freeze of 1990/1991
No
High yield of yellow fruits. Very erect habit High yield of yellow fruits
No
Purple fruits suitable for export
No
High yield of yellow/orange fruit
No
High yield of red fruit
Yes Yes
Orange fruit of exceptional quality —
No
Purple fruits suitable for export
No
High sugar fruits but low yield
No
High yield of yellow orange fruits
No
Non-dehiscing pink fruits under water stress High yield of yellow orange fruits
1279 1280 1281 1287 1288 1300 1319 1320 1379 1380 1392
No No
409
Non-dehiscing pink fruits under drought stress with cold hardiness
ARTICLE IN PRESS
Accession number
P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
Table 1 Description of O. ficus indica clones used in this trial
410
Table 1 (continued ) Spines
Reason for inclusion in this trial
1402
Collected by P. Felker in village of Escobedo, Mexico about 10 km east of Highway 54, about 50 km south of Saltillo, Mexico at 2200 m elevation known as chapeada Collected by P. Felker in village of Escobedo, Mexico about 10 km east of Highway 54, about 50 km south of Saltillo, Mexico at 2200 m elevation known as amarilla Collected by P. Felker in village of Escobedo, Mexico about 10 km east of Highway 54, about 50 km south of Saltillo, Mexico at 2200 m elevation known as morado Collected by P. Felker in village of Escobedo, Mexico about 10 km east of Highway 54, about 50 km south of Saltillo, Mexico at 2200 m elevation known as roja Collected by P. Felker in village of Escobedo, Mexico about 10 km east of Highway 54, about 50 km south of Saltillo, Mexico at 2200 m elevation known as pelon Collected by Nerd and P. Felker in on Hwy 10 in Constitucion, Province of Chihuahua between El Sueco and Flores Magon FAA3 of UNSE from town of Ampimpa, Province of Tucuman, Argentina at 2300 m with ripe fruit on 5 May FAA4 of UNSE from town of Ampimpa, Province of Tucuman, Argentina at 2300 m with ripe fruit on 5 May FAA18 of UNSE Zanjon, Highest yielding 8 year old plant (180 fruit) in row 15 of 26 O. ficus indica plants FAA19 of UNSE Zanjon, Highest yielding 8 year old plant (117 fruits) in row 11 of 90 plants from open pollinated progeny of spineless O. ficus indica from Maco, Argentina FAA 20 of UNSE Zanjon, Highest yielding 8 year old plant (234 fruits) in row 9 of 64 plants from open pollinated progeny of spiny O. ficus indica from Isla Verde, Argentina FAA 24 of UNSE from farmer Celiz in Village of Pampa Muyoj, 15 km from city of Santiago del Estero FAA 26 of UNSE from farmer Celiz in Village of Pampa Muyoj 15 km from city of Santiago del Estero in control treatment of Galizzi et al. (2004) FAA 27 of UNSE from farmer Escobedo in Village of Pampa Muyoj 15 km from city of Santiago del Estero Republic South Africa, Johan Potgieter
Yes Yes
Cold hardy yellow fruits with banana type flavor Cold hardy orange fruits
Yes
Cold hardy purple fruits
Yes
Cold hardy purple fruit
No
Cold hardy pink fruit
No
Early maturing yellow fruit
No
Cold tolerant
Yes
Cold tolerant
No
High productivity
No
High productivity
No
High productivity
No
High yield of fruits (180 plant 1)
No
High yield of fruits (600 plant 1)
No
High yield of fruits (1000 plant 1) on old mature plant Good quality red fruit
1403 1404 1405 1406 1458 AR1 AR2 AR3 AR4 AR5 AR6 AR7 AR8 Meyer
No
ARTICLE IN PRESS
Origin of accession
P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
Accession number
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
411
AR2 were planted in 8 July 1999, 1458 on 3 November 1999, AR 3–8 on 15 February 2000 and the Meyer on 2 October 2001. Thus the majority of the accessions were planted either in the fall of 1999 (April) or in the following summer of 2000 (February). Water became available to the drip irrigation system in December 2000, ten months after all but the Meyer accessions were established. The plants were only drip irrigated a few times in the early spring and late fall when the plants were without rainfall for more than 6 weeks. The cultural operations included combinations of glyphosate, diuron and disking to provide complete weed control in the rows and between the rows. After either glyphosate or disking produced virtually bare ground, diuron was applied in a pressure related backpack sprayer with a boom of 4 low volume nozzles (8001) spaced 50 cm apart at a concentration of 35 g l 1 of 85% active compound. Diuron was typically applied once in the spring at the onset of rains, once in mid-summer in the middle of the rainy season and once in late summer/fall to provide residual for the coming year. The plants were fertilized yearly with 110 g of 15–15–15 per plant as suggested by Potgieter (1996 pers comm). Control of the burrowing insect cactoblastis (Cactoblastis cactorum) was achieved with about 4 yearly sprays of the insecticide carbaryl (Sevin) at a dose of 1 g l 1 active ingredient with a coadjuvant. We believe the coadjuvant is responsible for the death of some of the larvae we have observed within the cladode 2 weeks after spraying. The nematicide carbofuran (Furadan) was applied to the base of the stems to control bacteriophagous nematodes that occurred above the soil line (Doucet et al., 2002). In the summer of 2002/2003 (4th growing season) the tallest accessions were about 3.5 m tall. The local Santiaguen˜a accessions were substantially damaged by high winds, with many vertical cladodes breaking midway between the joint and the cladode apex. To avoid confounding effects of maturation on fruit quality, the first fruits of the season were harvested at the same stage of maturity. For the light yellow (1320, 1277), red (1281) and dark purple varieties (1279, 1300) that are overmature at full peel color, we harvested at about 40% peel color. For the Santiaguen˜a varieties that can be harvested at full color, we harvested at peel color of about 75%. The following fruit characters were measured; total weight, weight of pulp and peel, soluble solids with a refractometer and pH with a pH meter. The latter measurements were made on a homogenate of 5 g of the pulp. The firmness (kg) of the fruit was measured with an 8 mm diameter penetrometer on the peel after removing the outer approximate 1 mm of epidermis with a knife, and also on the inner pulp.
3. Results The fruit yields in Table 2 are the product of the number of fruits per plant times the weight of the 4 largest size class of fruits per replicate. Even should one discount 25% of the yield for a change in fruit size from 210 to 157 g for clone 1287, the yields still were in the 16,000 kg ha 1 range, which for plants in their 4th season (less than 5
ARTICLE IN PRESS 412
P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
Table 2 Fruit yield of Opuntia accessions grown in Santiago del Estero, Argentina in the 2nd/3rd or 3rd/4th growing seasons
Accession number
Growing season 2 or 3
Growing season 3 or 4
Mean
95% confidence interval
Mean
95% confidence interval
1650 7650 4070 4550 5030 1750 5910 2230 1400 2810 480 70 1560 33 90 1460 25 0 410 200 620 340 70 28 38 47 39 0
22800 22700 18300 18000 16900 16600 14900 13300 12900 12500 10400 8340 8150 6830 6380 6300 5940 5420 5190 4960 4660 4390 3940 3730 2980 2110 1060 0
7150 1480 3490 6710 3600 8310 8600 5900 6080 5640 3910 4120 5410 4240 3490 5810 4050 2940 2250 5110 4360 3000 1800 4100 2210 1160 620 0
Yield (kg ha 1) 1458 4490 1287 7710 1281 6380 1320 7720 1288 4850 1280 1680 1403 4510 1277 7080 1380 2900 1260 4770 1392 360 1402 36 1300 1000 1406 29 AR7 120 1319 790 1379 13 AR3 0 AR1 210 AR6 160 1405 310 1404 250 AR5 60 AR4 25 1279 31 AR8 63 AR2 35 Meyer 0
The imported accessions with numbers in the 1300 and 1400 series were planted in the fall of 1999, while the AR accessions were planted in the summer of 2000 and thus the latter are in their 3rd growing season while the former are in their 4th growing season.
years old) is high. The low confidence interval in clone 1287 (1480) as compared to the other clones with similar yields (3500–7000) is noteworthy and shows promise for yield stability. The range in yield for the imported accessions, from 2980 kg ha 1 for 1279 to 22,800 kg ha 1 for accession 1458 and from 2110 kg ha 1 for AR8 to 6380 kg ha 1 for AR7 is impressive. Since the AR clones are about half a growing season younger than the imported accessions, their yields are understandably lower. However the maximum yield of the Santiaguen˜a clone AR7 of 6380 kg ha 1 in growing season 3 compares very favorably to the maximum yield of 7720 kg ha 1 for clone 1320 in season 3.
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
413
The highest yielding clone 1458 was planted 7 months later than the other 1400/ 1300 series and only 3 months earlier than the majority of the AR varieties. Thus its high productivity is exceptional. We have repeatedly considered clone 1319 from Chile, which is virtually identical in taste, color and appearance to the Santiaguen˜a naturalized clones, to have outstanding fruit quality with its only detracting factor being its low yield (Parish and Felker, 1997). The fact that Santiaguen˜a clone AR7 had a slightly higher yield than 1319 despite the fact that it was almost a growing season younger, shows much promise for improving yields for this type of fruit. For the first time in Argentina, we have demonstrated large clonal differences in yield (from 2110 to 6380 kg ha 1) within the ‘‘Santiaguen˜a’’ type variety. There is also considerable clonal variation in productivity within two other variety classes. Clones 1379, 1406 and 1392 with round, pinkish fruits are indistinguishable from each other in plant and fruit color/morphology but have an almost 2-fold difference in yield. Similarly indistinguishable clones 1279 and 1300 with dark purple fruits are statistically different in yields i.e. 2980 vs. 8150 kg ha 1 respectively. Possibly these differences will narrow as the plants become more mature. The ranking in yields of the clones in the 4th growing season in Argentina reported here are similar to the ranking of the same clones in the 5th growing season in Texas (Parish and Felker, 1997). In the Texas study the clones that ranked 1, 2, 3 and 4 were 1380, 1277, 1281 and 1300 with yields of 52,000, 41,000, 30,000 and 25,000 kg ha 1, respectively. Intermediate in yield in Texas was clone 1287 (12,000 kg ha 1 while low yielding accessions in the Texas study were clones 1319 (7000 kg ha 1) and 1279 (5600 kg ha 1). The variety with round pinkish fruits (clones 1379, and 1392) had low yields in the 5th growing season in the Texas study (2200 kg ha 1 and 6500 kg ha 1). However, their yields dramatically increased at 8 years of age (Felker, unpub obs). This latter class of clones were apparently more drought tolerant than yellow fruited clones such as 1277, 1380, etc. since in an extreme drought year, all fruits of 1277, 1380 abscised while fruits of the clones 1392, 1379, etc. remained on the plant (Felker, unpub. obs.). These accessions ranged in maximum commercial fruit weight from 212 g fruit 1 for accession 1287 to 112 g fruit 1 for accession AR8 (we did not consider fruit size of Meyer as it was less than 1 year old) (Fig. 1). Using the suggested size classes of Inglese et al. (1995) at least 5 accessions could produce fruit of the extra large size4160 g and virtually all the accessions have fruits that would fall into the second class of 120–160 g. AR5 was selected for inclusion in these trials due to a large fruit size of 197 g in a non-replicated trial. However in these trials this accession was ranked close to the bottom with a fruit size of 120 g. Approximately 9 of these accessions would meet the minimum percentage of flesh or edible pulp of 55–60% as suggested by Inglese et al. (1995) (Fig. 2). There were statistically significant differences among the Santiaguen˜a types which are known for their thick peel and low pulp percentage. AR4 had the highest pulp with 47.2%, while AR8 had the lowest with 40.3%. The Santiaguen˜a type with the highest yield, AR7 had 47.1% pulp.
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
414
220.0
Fruit weight (g)
200.0
180.0
160.0
140.0
120.0
AR9
AR8
AR5
AR2
AR3
1280
AR6
AR4
1319
AR7
1320
1277
1300
1404
1402
AR1
1405
1279
1406
1458
1288
1392
1260
1380
1281
1403
1379
1287
100.0
Accession
Fig. 1. A comparison of the maximum fruit weight of O. ficus indica clones when grown in Santiago del Estero, Argentina. Bars are 95% confidence intervals.
As previously reported (Felker et al., 2002a) in spite of acceptable fruit sugar concentrations and fruit juice content, some high yielding varieties, such as the Italian Gialla, have very low pulp firmness which leads to poor consumer acceptance. While firmness is the parameter measured, really the objectionable quality is that pulps with low firmness value lacks structural integrity and breaks apart when the peel is separated from the pulp. We have previously suggested that a pulp firmness of about 1 kg be the minimum acceptable for cactus fruit (Felker et al., 2002a). Fig. 3 compares the firmness of the outer peel (after removing the cuticle) to the inner pulp and illustrates that the Santiaguen˜a varieties only had an approximate 25% decrease in pulp firmness vs. outer peel firmness. Other accessions such as 1320, 1392 and 1458 had a pulp firmness much less than half of peel firmness. Clearly the Santiaguen˜a (AR) varieties, and clones 1287, 1288, and 1403 belonged to one category with a pulp firmness of nearly 2 kg while the other clones had pulp firmness values of about 1 or less. Thus we would suggest that the firmness of all the Santiaguen˜a clones and 1287, 1288, 1403, 1319 be considered excellent, that clones barely above one, i.e. 1406, 1404, 1281, 1405, 1279 and 1380 be deemed acceptable but that the other clones with less 1 kg firmness be deemed questionable or unacceptable. The tendency of the pulp firmness for these 28 clones to be either 1 or 2 kg, suggests that firmness could be a simply inherited trait. While the differences in fruit pH were small, these differences were significant (Fig. 4). There was a tendency for the Santiaguen˜a clones and those with higher pulp firmness to also have higher pH and indeed the correlation between fruit pH and pulp firmness was highly significant (r=0.47, n=27, p=0.005).
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
415
70.0
65.0
Fruit pulp percentage
60.0
55.0
50.0
45.0
40.0
35.0
AR8
1404
AR2
1402
AR6
1405
AR1
1406
AR9
AR3
1458
AR5
AR4
1319
1403
AR7
1300
1379
1392
1279
1277
1287
1281
1380
1320
1280
1288
1260
30.0
Accession
Fig. 2. A comparison of the percentage of edible pulp to entire fruit weight of O. ficus indica clones when grown in Santiago del Estero, Argentina. Bars are 95% confidence intervals.
Fig. 3. A comparison of the firmness measured on the outer peel to that of the inner edible pulp O. ficus indica clones when grown in Santiago del Estero, Argentina. Bars are 95% confidence intervals.
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
416 6.2
6.1
Fruit pH
6.0
5.9
5.8
1277
1392
1281
1380
1406
1458
1379
1320
1260
AR1
1405
1280
1404
AR2
Meyer
AR7
1300
AR8
AR5
AR3
1288
AR6
1403
AR4
1279
1402
1319
1287
5.7
Accession
Fig. 4. A comparison of the pH of a homogenate of the edible pulp portion of O. ficus indica clones when grown in Santiago del Estero, Argentina. Bars are 95% confidence intervals.
There were highly significant differences in fruit sugar concentrations with the Santiaguen˜a varieties having the greatest sugar levels (Fig. 5). This is in agreement with earlier work in Texas (Parish and Felker, 1997) and Argentina (Felker et al., 2002a) where clone 1319, which is a ‘‘Santiaguen˜a type’’ had the greatest sugar concentration. In the same range as the Santiaguen˜a types, were clones 1280 (14.1), 1380 (13.6 ) and 1260 (13.6), all of which had high yields. However even within the Santiaguen˜a accessions there were significant differences. If one excludes the spiny AR2 clone with very low yields, the spineless Santiaguen˜a clones ranged in fruit sugar from 15.2 for AR7 to 13.4 for AR1. It is promising that clone AR7 was also the Santiaguen˜a clone with the highest yield. Clones 1279 and 1300 which are identical in fruit color (dark purple), pad color (bluish green) and overall plant morphology were significantly different in Brix with clone 1279 having 13.0 and clone 1300 having 11.9. Similar results occurred in Texas with clone 1279 having 12.870.7 Brix and clone 1300 having 11.370.4 Brix (Parish and Felker, 1997). In contrast the clones 1379, 1392 and 1406 with similar rose colored fruit and indistinguishable overall plant morphology had mean Brix values of 12.08, 12.13 and 12.19 and were not significantly different. Slightly more than half of the clones would fall into the optimum Brix value at harvest of 13–15% as suggested by Inglese et al. (1995). However other authors report marketable fruits with lower Brix concentrations of 12% in Sicily (Schirra et al., 2002) and 12.8% for the Israeli summer crop (Nerd et al., 1991). In spite of the
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
417
16.0 15.5 15.0
Soluble solids (˚Brix)
14.5 14.0 13.5 13.0 12.5 12.0 11.5
1300
1392
1379
1406
1403
1402
1281
1277
1405
1287
1320
AR1
1288
1279
1404
1458
AR4
Meyer
1260
AR6
1380
AR5
AR8
1319
AR3
1280
AR7
AR2
11.0
Accession
Fig. 5. A comparison of the fruit sugar as measured with a refractometer of a homogenate of the edible portion of O. ficus indica clones when grown in Santiago del Estero, Argentina. Bars are 95% confidence intervals.
low sugar concentration (12.8) in clone 1287, we, and field workers familiar with cactus, feel that this clone is an exceptionally good tasting variety.
4. Discussion The maximum fruit production levels for the introduced varieties were 6000 kg ha 1 and 16,000 kg ha 1in the 3rd and 4th seasons respectively. The maximum fruit production was 6000 kg ha 1 in the 3rd season for the highest producing Santiaguen˜a variety. Using the economic analyses of as Felker and Guevara (2001) as a guideline, these productivities are indeed promising. For example for the lowest priced market, when cactus fruits used for juice ($0.12 kg 1), these authors calculated that a production of 10,000 would kg ha 1 be the break even point in the 5th year of the plantation. However at a price of $2.0 kg 1 for the local fresh fruit market, a production of only 1000 kg ha 1 would be required to break even in the third year of the plantation. There is a paucity of information on fruit yield as a function of plant age. Most reviews (Inglese et al., 1995; Pimienta, 1990) have suggested that yields as high as we observed are only possible in mature orchards—which presumably are more than 4 years old. Parish and Felker (1997) reported that fruit production in Texas for 22
ARTICLE IN PRESS 418
P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
accessions under dryland production, but with intensive weed control, ranged from about 1500 kg ha 1 to 50,000 kg ha 1. We attribute the rapid growth (many of these 4 yr old plants are 4 m tall with yields on the order of 16,000 kg ha 1) to the summer rainfall and to the intensive weed control. Fine cactus roots are highly visible several mm below the completely bare, herbicide treated soil surface that could take advantage of low rainfall events. With regard to fruit quality, this study confirms our earlier work (Felker et al., 2002a) on the importance of measuring the firmness on the pulp in addition to the peel. The great variability in the ratio of pulp to peel firmness among the accessions eliminates the possibility of assessing pulp firmness from peel firmness measurements. More importantly the pulp firmness is an indicator of the tendency of the pulp to remain intact upon peeling. This latter characteristic is a different phenomenon than peel softness that occurs during ripening. The correlation of decreasing pulp firmness with decreasing fruit pH might be related to the acid induction of low molecular weight expansins that are responsible for an increase in cell wall plasticity (Cosgrove, 1998). Hiwasa et al. (2003) reported an increase in cDNA coding for expansin homologues with the softening of pears during the ripening process. This might support involvement of an acid-induced stimulation of expansin and softening in cactus pears. We are in general agreement with Inglese et al. (1995) on the ideal cactus cultivar but we would add the following attributes; spineless cladodes, glochids easily removable by mechanical brushing techniques, tolerance to 9 1C with minimal damage, pulp percentage455%, Brix413%, pulp firmness41 kg, mature yield420,000 kg ha 1, post harvest shelf life at 2 1C44 weeks, seedinesso3.5 g seeds per 100 g pulp (Felker et al., 2002a) and in a variety of colors (yellow, orange, pink and purple). As of yet no accession meets all of these goals. Our ongoing evaluation of 20 hybrid crosses (Wang et al., 1998) whose parents collectively possess these traits is an attempt to develop such a series of new commercial varieties. Clone 1287 with the second highest yield, was far from the highest Brix with a value of 12.8. Nevertheless, farmers, field hands and professionals who have tasted the fruits of this clone, feel that it has exceptional quality (Unfortunately this accession has large thorns and glochids). Perhaps it has different flavor compounds than the common 2 methyl butanoic acid ethyl ester and 2, 6-nonadien-1-ol identified by Arena et al. (2001) as responsible for the flavor in cactus fruits. Alternatively it is possible that the higher pH or firmness in combination with the sugars was responsible for fruit quality. We feel it will be important to develop more quantitative models for overall consumer acceptability based on flavor compounds, firmness, pH, acidity, Brix concentrations, ratios of common sugars, and seediness. In addition to these traditional uses of cactus fruit for fresh consumption, Stintzing et al. (2001, 2003) have made a strong argument for use of cactus for natural food colorants since betalains present in some cactus pears do not have the earthy flavor of the betalains from red beets. The genetic material collected from the high elevation site in northern Mexico, which may have greater cold tolerance than normal commercial types, i.e. 1402–1406, are somewhat below the standards for commercial fruit types. Of these
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
419
high elevation materials, accessions 1404 and 1405 with dark purple fruit have the highest sugar of 13.0 and 12.8 but a very thick peel which leads to low pulp percentages of 38% and 41%. The yellowish pink 1402 is an attractive fruit but is mediocre in sugar (12.4%), firmness (0.95) and percent pulp (40.3%). Accession 1406 is very similar to the to the other rose colored fruit types, 1392 and 1379. Perhaps the most commercially acceptable is 1403 whose orange colored fruits had 12.4% sugar, 46.8% pulp and a high pulp firmness of 1.98. Should these accessions prove to able to be grown at 2200 m in Argentina in the same latitude as Mexico, their maturity probably will be delayed 30–60 days after the zero elevation stands and thus have fruit available in March and April. Thus in spite of somewhat lower quality (although this may change at higher elevations), they should command a good price on the international market since no other fruit in the world is available at this time (Moreno and Flores, 1996). This is the first report of fruit yield and quality measurements from a replicated trial of individual plant selections within the ‘‘Santiaguen˜a’’ type fruit variety in Argentina. Although the only selection criterion for Santiaguen˜a clones for inclusion in this trial, were for high yields, there was more than a 3-fold difference in yield. Despite the fact that this varietal type (i.e. clones 1319 and 1321 in Texas) has been reported to have low yields in Texas 1500–7000 kg ha 1 (Parish and Felker, 1997) and Chile 6000–9000 kg ha 1 (Inglese et al., 1995), the best yielding clone AR7 produced 6300 kg ha 1 in the third season which by any standards is high yield for cactus. All of these types had high firmness (from 1.8 to 2.7 kg). The pulp percentage was on the low side ranging from 41.4 to 47.2. However, the fruit sugar concentrations, which were significantly different among clones, were exceptional in ranging from 13.4 to 15.2. Accession AR7, which unfortunately was located in the control fertilizer treatment in a farmers field (Galizzi et al., 2004), had both the highest yield and highest sugar among the non-spiny types. Should this trend continue for several more years, AR7 should be released as a commercial type. At present all of the planting stock for new plantings is a mixture of highly variable clones from existing farmer’s fields. Thus these selections should be tested to see if they could provide significant yield increases. For the purposes of this study, we assume that an Opuntia variety could be defined as one that was indistinguishable from other strains based on internal or external appearance of the fruit or overall plant morphology. On this basis we would have several varieties with multiple accessions, i.e. a variety with dark purple spiny fruits with accessions 1404 and 1405, a variety with spineless cladodes and roundish pink fruits with accessions 1392, 1406 and 1379, a variety with spineless dark purple fruits with accessions 1279 and 1300 and the Santiaguen˜a varieties AR1–AR8 that includes the Chilean accession 1319. It is also to be noted that clone 1279 has been used in physiological studies of high and low temperature stress (Nobel and De La Barrera, 2003) and studies on the cold induction for fruit production (Nobel and Castaneda, 1998). Within the morphological indistinguishable Santiaguen˜a type variety and within the dark purple variety (1279 and 1300) there were quantitative differences in yield and fruit sugar but not in the variety composed of clones 1379, 1392 and 1406 with
ARTICLE IN PRESS 420
P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
rose colored fruits. This reinforces the need to make and maintain indistinguishable clonal selections within ‘‘varieties’’ for quantitative characters such as fruit yield and quality. In summary, the important features of this work are that we have: (a) identified new clones adapted to Argentine conditions with high yield, moderately high Brix and high pulp firmness, (b) demonstrated quantitative differences in yield and Brix for cactus clones indistinguishable from external appearances, (c) demonstrated significant differences in both pulp/peel firmness and pulp firmness among clones suggesting that peel firmness is not appropriate for varietal evaluations, and (d) identified clones within the naturalized Santiaguen˜a variety with significantly greater Brix and yield. This works stresses the importance of using replicated field trials to look for quantitative differences in yield and fruit quality from visually indistinguishable cactus fruit clones.
Acknowledgements The authors gratefully acknowledge Ing. Horacio Ochoa’s contribution in establishing the seedling population used to select some of the local Santiaguen˜a clones.
References Arena, E., Campisi, S., Fallico, B., Lanza, M.C., Maccarone, E., 2001. Aroma value of volatile compounds of prickly pear (Opuntia ficus indica (L) Mill Cactaceae). Italian Journal of Food Science 3, 311–319. Barbera, G., Inglese, P., Pimienta-Barrios, E., 1995. Agroecology, cultivation and uses of cactus pear. FAO Plant Production and Protection Paper 132, Rome, 216pp. Borrego-Escalente, F., Murillo-Soto, M., Parga-Torres, V.M., 1990. Potencial de produccion en el norte de Mexico de variedades de nopal (Opuntia spp.) tolerantes al frio. In: Felker, P. (Ed.), Proceedings of the First Annual Texas Prickly Pear Council. Caesar Kleberg Wildlife Research Institute, Kingsville, 95pp. Caplan, K., 1990. Marketing strategies for cactus pears and cactus leaves for the 1990’s. Proceedings of First Annual Texas Prickly Pear Council. Kingsville, Texas, pp. 85–89. Cosgrove, D.J., 1998. Cell wall loosening by expansins. Plant Physiology 118, 333–339. Cowan, R., Felker, P., 1999. Fruit quality of new cold hardy Opuntias from northern and high elevation sites in Mexico. Journal of Professional Association for Cactus Development 3, 75–86. Doucet, M.E., Weht, S., Felker, P., 2002. Nematodes as a possible cause of damage to Opuntia ficus-indica. Journal Professional Association for Cactus Development 4, 84–89. Felker, P., Guevara, J.C., 2001. An economic analyses of dryland fruit production Opuntia ficus indica in Santiago del Estero, Argentina. Journal of Professional Association for Cactus Development 4, 20–30 www.jpacd.org. Felker, P., Soulier, C., Leguizamon, G., Ochoa, J., 2002a. A comparison of the fruit parameters of 12 Opuntia clones grown in Argentina and the United States. Journal of Arid Environments 52, 361–370. Felker, P., Galizzi, F., Soulier, S., 2002b. Genetic variability within Opuntia ficus indica Mill. cv. ‘‘yellow fruit without spines’’ in Santiago del Estero, Argentina and individual plant selection for improved yield and fruit characteristics. Acta Horticulturae 581, 95–103.
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
421
Galizzi, F., Felker, P., Gardiner, G., 2004. Correlations between soil and cladode nutrient concentrations and fruit yield and quality in Opuntia ficus indica in a traditional farm setting in Santiago del Estero, Argentina. Journal of Arid Environments 59, 115–132. Gregory, R.A., Kuti, J.O., Felker, P., 1993. A comparison of Opuntia fruit quality and winter hardiness for use in Texas. Journal of Arid Environments 24, 37–46. Griffiths, D., Hare, R.F., 1907. The tuna as a food for man. USDA Bur. Plant Industry Bulletin 116. Gutierrez-Acosta, F., Valdez-Cepeda, R.D., Blanco-Macias, F., 2002. Multivariate analyses of cactus pear (Opuntia spp) fruits from a germplasm collection. Acta Horticulturae 581, 111–118. Han, H., Felker, P., 1997. Field validation of water use efficiency of a CAM plant Opuntia ellisiana in South Texas. Journal of Arid Environments 36, 133–148. Hiwasa, K., Rose, J.K., Nakano, R., Inaba, A., Kubo, Y., 2003. Differential expression of seven alphaexpansin genes during growth and ripening of pear fruit. Physiologia Plantarum 117, 564–572. Inglese, P., Barbera, G., La Mantia, T., 1995. Research strategies and improvement of cactus pear (Opuntia ficus-indica) fruit quality and production. Journal of Arid Environment 29, 455–468. Kiesling, R., 1999. Origen, domesticacion y distribucion de Opuntia ficus indica. Journal Professional Association for Cactus Development 3, 50–59. Martinez, L.M., 1968. Estudios del nopal rastrero forrajero y del nopal frutal. In: Box, T.W., RojasMendoza, P. (Eds.), Proceedings of International Symposium on Increasing Food Production in Arid Lands, Vol. 3. Lubbock, TX, ISCALS pub., pp. 39–344. Monjauze, A., LeHouerou, H.N., 1965. Le role des Opuntia dans l’Economie agricole de Nord Africaine. Extrait du Bulletin de l’Ecole Nationale Superieure d’Agriculture de Tunis. 85–165pp. Moreno, P.R., Flores, C.F., 1996. The world cactus pear market. Journal of Professional Association for Cactus Development 1, 75–86. Nerd, A., Karady, A., Mizrahi, Y., 1991. Out of season prickly pear: fruit characteristics and effect of fertilization and short droughts on productivity. HortScience 26, 337–342. Nerd, A., Mesika, R., Mizrahi, Y., 1993. Effect of N fertilizer of autumn flush and cladode N in prickly pear (Opuntia ficus-indica (L.) Mill.). Journal of Arid Environments 68, 337–342. Nieddu, G., Chessa, I., Satta, D., De Pau, L., Pala, M., 2002. Description of six cactus pear (Opuntia ficusindica Mill) fruit cultivars from Italy. Acta Horticulturae 581, 125–129. Nobel, P.S., 1988. Environmental Biology of Agaves and Cacti. Cambridge University Press, Cambridge 270pp. Nobel, P.S., Castaneda, M., 1998. Seasonal light, and temperature influences organ initiation for unrooted cladodes of the prickly pear cactus Opuntia ficus-indica. Journal of the American Society for Horticultural Science 123, 47–51. Nobel, P.S., De La Barrera, E., 2003. Tolerances and acclimation to low and high temperatures for cladodes, roots and fruits of a widely cultivated cactus Opuntia ficus indica. New Phytologist 157, 271–279. Parish, J., Felker, P., 1997. Fruit quality and production of cactus pear (Opuntia spp) clones selected for increased frost hardiness. Journal of Arid Environments 37, 123–143. Pimienta, E., 1990. El Nopal Tunero. Univ. Guadalajara Publisher, Guadalajara, Mexico 246pp. Russell, C.E., Felker, P., 1987. The prickly pears (Opuntia spp): a source of human and animal food in semiarid regions. Economic Botany 41 (3), 433–445. Scheinvar, L., 1995. Taxonomy of utilized Opuntias. In: Barbera, G., Inglese, P., Pimienta-Barrios, E. (Eds.), Agroecology, Cultivation and Uses of Cactus Pear. FAO Plant Production and Protection Paper 132, Rome, Italy, pp. 20–27. Schirra, M., Brandolini, V., Cabras, P., Angioni, A., Inglese, P., 2002. Thiabendazole uptake and storage performance of cactus pear (Opuntia ficus indica (L) Mill. Cv. Gialla) fruit following postharvest treatments with reduced doses of fungicide at 521C. Journal of Agriculture and Food Chemistry 50, 739–743. Stintzing, F.C., Scheiber, A., Carle, R., 2001. Phytochemical and nutritional significance of cactus pear. European Food Research and Technology 212, 396–407. Stintzing, F.C., Scheiber, A., Carle, R., 2003. Evaluation of colour properties and chemical quality parameters of cactus juices. European Food Research and Technology 216, 303–311.
ARTICLE IN PRESS 422
P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
Wang, X., Felker, P., Paterson, A., 1998. Environmental influences on cactus pear fruit yield, quality and cold hardiness and development of hybrids with improved cold hardiness. Journal of Professional Association for Cactus Development 2, 48–59. Wang, X., Felker, P., Burrow, M.D., Paterson, A.H., 1999. Assessment of genetic diversity among Opuntia genotypes, reflected by DNA markers. Journal Professional Association for Cactus Development 3, 3–14. Weiss, J., Nerd, A., Mizrahi, Y., 1993. Vegetative parthenocarpy in the cactus pear (Opuntia ficus-indica (L.) Mill. Annals of Botany 72, 521–526. Wessels, A.B., 1988. Spineless Prickly Pears. Perskor, Johannesburg, South Africa, 61pp.
Journal of Arid Environments 60 (2005) 405–422 www.elsevier.com/locate/jnlabr/yjare
Comparison of Opuntia ficus indica varieties of Mexican and Argentine origin for fruit yield and quality in Argentina P. Felkera,b,, S. del C. Rodriguezc, R.M. Casolibac, R. Filippinid, D. Medinad, R. Zapatae a
Universidad Catolica de Santiago del Estero, 4200 Santiago del Estero, Plantation Specialty, Felda, Florida, USA b INSIBIO, Universidad Nacional de Tucuman, Tucuman, Argentina c ICyTA-ICQ- Facultad de Agronomia y Agroindustrias, Argentina d Facultad de Agronomia y Agroindustrias, Universidad Nacional de Santiago del Estero. Av. Belgrano (S) 1912, 4200 Santiago del Estero, Argentina e Facultad de Ciencias Agropecuarias, Universidad Nacional de Cordoba Received 21 July 2003; received in revised form 13 April 2004; accepted 15 June 2004 Available online 24 August 2004
Abstract A randomized complete block field design for Opuntia ficus indica fruit production and quality in Argentina compared 19 of the most promising fruit accessions identified from previous Texas field trials to 8 individual selections of the naturalized Argentine ‘‘Santiaguen˜a variety’’ and one South African clone. The genetic material originating from Texas consisted of recently collected fruit varieties from high elevation sites in northern Mexico which should possess increased cold hardiness and the best accessions from among 100 accessions evaluated over a 15 year period in Kingsville, Texas. The Argentine accessions were selected for high yield from on-farm field trials and university field plots. The Argentine varieties were established about half a growing season after the Texas varieties. The yields ranged from 3000 to 22,000 kg ha 1 for the 4th growing season for the accessions from North America and from 2100 to 6400 kg ha 1 in the 3rd growing season for the Argentine naturalized genetic materials. The Argentine varieties had the greatest fruit pulp firmness (about 2 kg) and sugar contents (13.4–15.2) but had a lower percentage pulp Corresponding author. Current address: D’Arrigo Bros Co., 383 W Market Street, P.O. Box 850, Salinas, CA 93902, USA. E-mail address: [email protected] (P. Felker).
0140-1963/$ - see front matter r 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.jaridenv.2004.06.003
ARTICLE IN PRESS 406
P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
(40–47%) than the North American materials. For the first time this work demonstrated significant differences in yield and sugar content among the naturalized Argentine varieties leading the way to the first selected varieties. In some of the accessions, even at maturity, the inner pulp lacked structural integrity and easily broke apart on peeling. These accessions had both a low pulp firmness (less than 1 kg) and a low percentage of pulp to peel firmness. The ratio of pulp to peel fruit firmness at maturity varied greatly among the accessions obviating the possibility of evaluating pulp firmness from peel firmness measurements. The highly significantly negative correlation between fruit firmness (p=0.005) and pH among the accessions is reminiscent of auxin-induced pH decreases that lead to increased cell wall plasticity. Two of the spineless Texas accessions (1279 and 1300) with dark purple fruit could not be distinguished on the basis of cladode or fruit color or overall plant morphology. In agreement with prior Texas evaluations, clone 1300 had significantly greater yield but significantly lower sugar than the other indistinguishable clone 1279. These significant quantitative intravarietal differences in clones 1279 and 1300, combined with intravarietal differences in the externally indistinguishable Santiaguen˜a clones, points to the need to select and maintain individual plant selections within morphologically indistinguishable varieties. r 2004 Elsevier Ltd. All rights reserved. Keywords: Cactus pear; Fruit firmness; Intravarietal
1. Introduction The specialized photosynthetic system in cacti known as Crassulacean Acid Metabolism (CAM) provides greater water to dry matter conversion than C3 and C4 photosynthetic pathways (Nobel, 1988; Han and Felker, 1997). The combination of this conversion efficiency and the great biodiversity in fruit colors (red, orange, purple, pink, yellow, and lime-green) (Griffiths and Hare, 1907; Pimienta, 1990; Barbera et al., 1995; Inglese et al., 1995; Parish and Felker, 1997), results in great potential for the flat stemmed Opuntias in arid lands. While there are many excellent general descriptions of the variability in Opuntia fruit types (Griffiths and Hare, 1907; Monjauze and LeHouerou, 1965; Russell and Felker, 1987; Nobel, 1988; Wessels, 1988; Pimienta, 1990; Barbera et al., 1995), there are few journal articles that report yields and fruit quality measurements on genetically broadly based selections from replicated field trials. Gutierrez-Acosta et al. (2002) reported used cluster analyses to distinguish 3 main fruit groups from 24 accessions in Mexico but did not list individual fruit measurements for the accessions. Nieddu et al. (2002) listed general descriptions of 6 Italian cultivars but did not provide quantitative data on yields or fruit quality. Barbera et al. (1992) reported on the changes in fruit quality during ripening of the 3 major Sicilian Opuntia cultivars in commercial orchards but did not report yield data. From Israel, there is considerable data on fruit maturity and use of N fertilization to stimulate off season Opuntia fruit production (Nerd et al., 1991, 1993), and discovery of a low seedy parthenocarpic fruit (Weiss et al., 1993), but as far as we are aware no comparisons of fruit quality/yield from replicated field trials. There are reports of fruit yield/quality from a broad based germplasm collection in Texas (Gregory et al., 1993; Parish and Felker, 1997; Cowan and Felker, 1999; Wang et al.,
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
407
1998) and the resultant comparison of 12 of these clones in Argentina (Felker et al., 2002a). Due to 3 days of continuous below freezing weather in Texas in December 1989 (minimums of 12 1C on 2 days), that killed all Opuntia ficus indica accessions (Wang et al., 1998), the germplasm collections by the Texas group after 1989 emphasized freeze hardiness. Felker and Nerd made a major germplasm collection at high elevation sites in northern Mexico whose initial fruit quality was reported by Cowan and Felker (1999). Of special interest was the germplasm selected by Martinez (1968) in which 32 seedlings out of 200,000 seedlings planted survived a 1963 freeze of 16 1C in Saltillo, Mexico. Other interesting materials were those reported by Borrego-Escalente et al. (1990) that were reported to survive 16 1C. In 1999, eighteen accessions representative of the Texas collection, with emphasis on recently collected high elevation sites in northern Mexico were established in a randomized complete block trial in Argentina. It would be presumptuous to assume that the imported germplasm was superior to the naturalized local Santiaguen˜a cactus variety, as our measurements of fruit quality and yield in local farmers fields indicated great variability in yield (Felker et al., 2002b). Thus individual plant selections of the local variety were made from farmer’s fields and university research plots and established one year later in the replicated trial with the 18 accessions from Texas. For the first time in Argentina this trial was able to compare fruit quality/ yield of the local variety in a replicated field trial. Our Texas work (Parish and Felker, 1997) reported on fruits from spiny and spineless species such as O. ficus indica, O. hyptiacantha, O. amyclea etc and that spine characters were in part, used to distinguish the species. However DNA molecular marker data has raised significant doubts on the validity of the traditional taxonomic approaches to the classification of the commercial O. ficus indica fruit types. Wang et al. (1999) examined RAPD patterns in what were presumed to be 8 very contrasting Opuntia clones. The two most similar clones were the spiny O. hyptiacantha 1287 and the spineless O. ficus indica clone 1281. Moreover, O. ficus indica clone 1281 had a greater genetic affinity to O. hyptiacantha clone 1287 than the other spineless O. ficus indica clones 1279, 1321 and 1294. The major distinguishing feature between O. ficus indica clone 1281 and O. hyptiacantha clone 1287 was the presence of spines. This data has cast doubt on the traditional taxonomy, such as described by Scheinvar (1995) that used spine characters to distinguish species. A recent traditional taxonomic work (Kiesling, 1999) based on segregation of morphological characters within Opuntia progeny (among other characters) has also come to the conclusion that spine characters should not be used to differentiate species among the commercial Opuntia fruit types and lists all flat stemmed fruit types as simply O. ficus indica. We concur with this opinion and thus in this paper simply use O. ficus indica for these commercial fruit types.
2. Materials and methods The experimental design consisted of a randomized complete block design of 28 accessions with 4 replicates, each replicate consisting of a row of 3 plants. The plant
ARTICLE IN PRESS 408
P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
spacing was 2 5 m. The total fruit number on all plants was counted at mid-season. For yield calculations the mean fruit yield (fruit number times maximum fruit weight) of the 3 plants per rep was used to calculate a rep mean. Confidence intervals (95%) for fruit yield were based on the means of the 4 reps in the trial. In contrast for fruit quality measurements, the individual fruit was used as the experimental unit. The justification for this is as follows. In a trial with 5 fertilization treatments on O. ficus indica plantations with 10 single plant reps and 4 fruit measurements per rep, there was little difference in fruit quality among treatments (Galizzi et al., 2004). In a trial comparing 11 Opuntia clones grown in Texas, USA and Santiago del Estero, Argentina, there was remarkably little difference in the ranking of the varieties for fruit quality measurements such as Brix, pH and surprisingly the absolute values of the fruit quality indicators were very similar in Argentina and the USA (Felker et al., 2002a). Thus it seems as if the major variation in fruit quality is not related to environment or edaphic factors but rather genetic factors. The majority of the variation in the field for fruit quality seems to be due to random error. Thus in this situation it seems more logical to compute the confidence intervals on the basis of the means of all individual fruits in the field, rather than to compute the block means. Since all the varieties were randomly assigned to 4 blocks, any bias due to field position should be eliminated. The fruit quality measurements were based on the means (and confidence intervals) of 16 fruits coming from 4 fruits per replicate (of three plants) and 4 replicates. Due to difficulty in selecting the mean fruit size of the 3 plants, we chose to select 4 of the largest fruits per replicate because (1) we assumed there would be less error in choosing the largest fruits than in the mean fruit size per plant and (2) the ranking of fruit size would be the same whether based on the largest or the mean fruit size per accession. The origin and rationale for inclusion of the accessions in this trial is provided in Table 1. No single clone had the optimum combination of fruit yield, high sugar, lack of thorns, cold hardiness, fruit colors and low quantity of seeds. Thus accessions were selected that contained at least one of these characteristics. The largest US importer of cactus pears has stated that the highest priority should be given to selection of less-seedy varieties (Caplan, 1990) and thus the low-seedy clone 1319 was included. As provided in detail in Table 1, the trial contained; some of the most interesting clones resulting from an 18 year evaluation in Kingsville, Texas 1277, 1279, 1280, 1281, 1287, 1300, 1319, 1320; clones 1379 and 1380 reported by BorregoEscalente et al. (1990) to have survived 16 1C in Saltillo, Mexico; clones recently (1990) collected in farmers fields in high elevation in northern Mexico 1392, 1402, 1403, 1404, 1405, 1406 and 1458; clones from the naturalized Argentine ‘‘Santiaguen˜a’’ variety AR1–AR8, and a good fruit variety Meyer from South Africa. While the field trial for 4 blocks of 28 entries was laid out in early 1999, not all of the desired accessions were available for planting at the same time. When the materials became available, they were inserted into the preplanned design. The first 17 accessions from Texas were established on 22 April 1999 which is fall in Argentina. Following fruit yield measurements of mature naturalized Santiaguen˜a plants in farmer’s fields and research plots additional selections were made. AR1 and
Origin of accession
Spines
Reason for inclusion in this trial
1260
Obtained courtesy of H.N. LeHouerou from Algiers, North Africa
No
1277
Collected by C. Russell in Milpa Alta, Mexico where it was used for vegetable production Collected by C. Russell in Universidad Autonoma de Chapingo where it was labeled for vegetable use Collected by C. Russell in Universidad Autonoma de Chapingo where it was labeled for fruit use Collected by C. Russell in Universidad Autonoma de Chapingo where its common name was rojo vigor Collected by C. Russell in Agua Prieta, Mexquite, San Luis Potosi A misidentified selection received from the Texas A&M Univ Kingsville (TAMUK), collection not 1288 of the TAMUK collection Collected by C. Russell in Universidad Autonoma Chapingo where its use was for forage Collected by C. Russell in Nipas, Chile (near Chillan) in plantation of Carlos Gruebler Darel Collected by C. Russell in Nipas, Chile (near Chillan) in plantation of Carlos Gruebler Darel ANV4 of Fernando Borrego of Universidad Autonoma Agraria Antonio Narro in Saltillo, Mexico reported to survive 16 1C (Borrego-Escalente et al., 1990) ANV5 of Fernando Borrego of Universidad Autonoma Agraria Antonio Narro in Saltillo, Mexico reported to survive 16 1C (Borrego-Escalente et al., 1990) Collected P. Felker in farmers field in Saltillo, Mexico after severe freeze of 1990/1991
No
High yield of yellow fruits. Very erect habit High yield of yellow fruits
No
Purple fruits suitable for export
No
High yield of yellow/orange fruit
No
High yield of red fruit
Yes Yes
Orange fruit of exceptional quality —
No
Purple fruits suitable for export
No
High sugar fruits but low yield
No
High yield of yellow orange fruits
No
Non-dehiscing pink fruits under water stress High yield of yellow orange fruits
1279 1280 1281 1287 1288 1300 1319 1320 1379 1380 1392
No No
409
Non-dehiscing pink fruits under drought stress with cold hardiness
ARTICLE IN PRESS
Accession number
P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
Table 1 Description of O. ficus indica clones used in this trial
410
Table 1 (continued ) Spines
Reason for inclusion in this trial
1402
Collected by P. Felker in village of Escobedo, Mexico about 10 km east of Highway 54, about 50 km south of Saltillo, Mexico at 2200 m elevation known as chapeada Collected by P. Felker in village of Escobedo, Mexico about 10 km east of Highway 54, about 50 km south of Saltillo, Mexico at 2200 m elevation known as amarilla Collected by P. Felker in village of Escobedo, Mexico about 10 km east of Highway 54, about 50 km south of Saltillo, Mexico at 2200 m elevation known as morado Collected by P. Felker in village of Escobedo, Mexico about 10 km east of Highway 54, about 50 km south of Saltillo, Mexico at 2200 m elevation known as roja Collected by P. Felker in village of Escobedo, Mexico about 10 km east of Highway 54, about 50 km south of Saltillo, Mexico at 2200 m elevation known as pelon Collected by Nerd and P. Felker in on Hwy 10 in Constitucion, Province of Chihuahua between El Sueco and Flores Magon FAA3 of UNSE from town of Ampimpa, Province of Tucuman, Argentina at 2300 m with ripe fruit on 5 May FAA4 of UNSE from town of Ampimpa, Province of Tucuman, Argentina at 2300 m with ripe fruit on 5 May FAA18 of UNSE Zanjon, Highest yielding 8 year old plant (180 fruit) in row 15 of 26 O. ficus indica plants FAA19 of UNSE Zanjon, Highest yielding 8 year old plant (117 fruits) in row 11 of 90 plants from open pollinated progeny of spineless O. ficus indica from Maco, Argentina FAA 20 of UNSE Zanjon, Highest yielding 8 year old plant (234 fruits) in row 9 of 64 plants from open pollinated progeny of spiny O. ficus indica from Isla Verde, Argentina FAA 24 of UNSE from farmer Celiz in Village of Pampa Muyoj, 15 km from city of Santiago del Estero FAA 26 of UNSE from farmer Celiz in Village of Pampa Muyoj 15 km from city of Santiago del Estero in control treatment of Galizzi et al. (2004) FAA 27 of UNSE from farmer Escobedo in Village of Pampa Muyoj 15 km from city of Santiago del Estero Republic South Africa, Johan Potgieter
Yes Yes
Cold hardy yellow fruits with banana type flavor Cold hardy orange fruits
Yes
Cold hardy purple fruits
Yes
Cold hardy purple fruit
No
Cold hardy pink fruit
No
Early maturing yellow fruit
No
Cold tolerant
Yes
Cold tolerant
No
High productivity
No
High productivity
No
High productivity
No
High yield of fruits (180 plant 1)
No
High yield of fruits (600 plant 1)
No
High yield of fruits (1000 plant 1) on old mature plant Good quality red fruit
1403 1404 1405 1406 1458 AR1 AR2 AR3 AR4 AR5 AR6 AR7 AR8 Meyer
No
ARTICLE IN PRESS
Origin of accession
P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
Accession number
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
411
AR2 were planted in 8 July 1999, 1458 on 3 November 1999, AR 3–8 on 15 February 2000 and the Meyer on 2 October 2001. Thus the majority of the accessions were planted either in the fall of 1999 (April) or in the following summer of 2000 (February). Water became available to the drip irrigation system in December 2000, ten months after all but the Meyer accessions were established. The plants were only drip irrigated a few times in the early spring and late fall when the plants were without rainfall for more than 6 weeks. The cultural operations included combinations of glyphosate, diuron and disking to provide complete weed control in the rows and between the rows. After either glyphosate or disking produced virtually bare ground, diuron was applied in a pressure related backpack sprayer with a boom of 4 low volume nozzles (8001) spaced 50 cm apart at a concentration of 35 g l 1 of 85% active compound. Diuron was typically applied once in the spring at the onset of rains, once in mid-summer in the middle of the rainy season and once in late summer/fall to provide residual for the coming year. The plants were fertilized yearly with 110 g of 15–15–15 per plant as suggested by Potgieter (1996 pers comm). Control of the burrowing insect cactoblastis (Cactoblastis cactorum) was achieved with about 4 yearly sprays of the insecticide carbaryl (Sevin) at a dose of 1 g l 1 active ingredient with a coadjuvant. We believe the coadjuvant is responsible for the death of some of the larvae we have observed within the cladode 2 weeks after spraying. The nematicide carbofuran (Furadan) was applied to the base of the stems to control bacteriophagous nematodes that occurred above the soil line (Doucet et al., 2002). In the summer of 2002/2003 (4th growing season) the tallest accessions were about 3.5 m tall. The local Santiaguen˜a accessions were substantially damaged by high winds, with many vertical cladodes breaking midway between the joint and the cladode apex. To avoid confounding effects of maturation on fruit quality, the first fruits of the season were harvested at the same stage of maturity. For the light yellow (1320, 1277), red (1281) and dark purple varieties (1279, 1300) that are overmature at full peel color, we harvested at about 40% peel color. For the Santiaguen˜a varieties that can be harvested at full color, we harvested at peel color of about 75%. The following fruit characters were measured; total weight, weight of pulp and peel, soluble solids with a refractometer and pH with a pH meter. The latter measurements were made on a homogenate of 5 g of the pulp. The firmness (kg) of the fruit was measured with an 8 mm diameter penetrometer on the peel after removing the outer approximate 1 mm of epidermis with a knife, and also on the inner pulp.
3. Results The fruit yields in Table 2 are the product of the number of fruits per plant times the weight of the 4 largest size class of fruits per replicate. Even should one discount 25% of the yield for a change in fruit size from 210 to 157 g for clone 1287, the yields still were in the 16,000 kg ha 1 range, which for plants in their 4th season (less than 5
ARTICLE IN PRESS 412
P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
Table 2 Fruit yield of Opuntia accessions grown in Santiago del Estero, Argentina in the 2nd/3rd or 3rd/4th growing seasons
Accession number
Growing season 2 or 3
Growing season 3 or 4
Mean
95% confidence interval
Mean
95% confidence interval
1650 7650 4070 4550 5030 1750 5910 2230 1400 2810 480 70 1560 33 90 1460 25 0 410 200 620 340 70 28 38 47 39 0
22800 22700 18300 18000 16900 16600 14900 13300 12900 12500 10400 8340 8150 6830 6380 6300 5940 5420 5190 4960 4660 4390 3940 3730 2980 2110 1060 0
7150 1480 3490 6710 3600 8310 8600 5900 6080 5640 3910 4120 5410 4240 3490 5810 4050 2940 2250 5110 4360 3000 1800 4100 2210 1160 620 0
Yield (kg ha 1) 1458 4490 1287 7710 1281 6380 1320 7720 1288 4850 1280 1680 1403 4510 1277 7080 1380 2900 1260 4770 1392 360 1402 36 1300 1000 1406 29 AR7 120 1319 790 1379 13 AR3 0 AR1 210 AR6 160 1405 310 1404 250 AR5 60 AR4 25 1279 31 AR8 63 AR2 35 Meyer 0
The imported accessions with numbers in the 1300 and 1400 series were planted in the fall of 1999, while the AR accessions were planted in the summer of 2000 and thus the latter are in their 3rd growing season while the former are in their 4th growing season.
years old) is high. The low confidence interval in clone 1287 (1480) as compared to the other clones with similar yields (3500–7000) is noteworthy and shows promise for yield stability. The range in yield for the imported accessions, from 2980 kg ha 1 for 1279 to 22,800 kg ha 1 for accession 1458 and from 2110 kg ha 1 for AR8 to 6380 kg ha 1 for AR7 is impressive. Since the AR clones are about half a growing season younger than the imported accessions, their yields are understandably lower. However the maximum yield of the Santiaguen˜a clone AR7 of 6380 kg ha 1 in growing season 3 compares very favorably to the maximum yield of 7720 kg ha 1 for clone 1320 in season 3.
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
413
The highest yielding clone 1458 was planted 7 months later than the other 1400/ 1300 series and only 3 months earlier than the majority of the AR varieties. Thus its high productivity is exceptional. We have repeatedly considered clone 1319 from Chile, which is virtually identical in taste, color and appearance to the Santiaguen˜a naturalized clones, to have outstanding fruit quality with its only detracting factor being its low yield (Parish and Felker, 1997). The fact that Santiaguen˜a clone AR7 had a slightly higher yield than 1319 despite the fact that it was almost a growing season younger, shows much promise for improving yields for this type of fruit. For the first time in Argentina, we have demonstrated large clonal differences in yield (from 2110 to 6380 kg ha 1) within the ‘‘Santiaguen˜a’’ type variety. There is also considerable clonal variation in productivity within two other variety classes. Clones 1379, 1406 and 1392 with round, pinkish fruits are indistinguishable from each other in plant and fruit color/morphology but have an almost 2-fold difference in yield. Similarly indistinguishable clones 1279 and 1300 with dark purple fruits are statistically different in yields i.e. 2980 vs. 8150 kg ha 1 respectively. Possibly these differences will narrow as the plants become more mature. The ranking in yields of the clones in the 4th growing season in Argentina reported here are similar to the ranking of the same clones in the 5th growing season in Texas (Parish and Felker, 1997). In the Texas study the clones that ranked 1, 2, 3 and 4 were 1380, 1277, 1281 and 1300 with yields of 52,000, 41,000, 30,000 and 25,000 kg ha 1, respectively. Intermediate in yield in Texas was clone 1287 (12,000 kg ha 1 while low yielding accessions in the Texas study were clones 1319 (7000 kg ha 1) and 1279 (5600 kg ha 1). The variety with round pinkish fruits (clones 1379, and 1392) had low yields in the 5th growing season in the Texas study (2200 kg ha 1 and 6500 kg ha 1). However, their yields dramatically increased at 8 years of age (Felker, unpub obs). This latter class of clones were apparently more drought tolerant than yellow fruited clones such as 1277, 1380, etc. since in an extreme drought year, all fruits of 1277, 1380 abscised while fruits of the clones 1392, 1379, etc. remained on the plant (Felker, unpub. obs.). These accessions ranged in maximum commercial fruit weight from 212 g fruit 1 for accession 1287 to 112 g fruit 1 for accession AR8 (we did not consider fruit size of Meyer as it was less than 1 year old) (Fig. 1). Using the suggested size classes of Inglese et al. (1995) at least 5 accessions could produce fruit of the extra large size4160 g and virtually all the accessions have fruits that would fall into the second class of 120–160 g. AR5 was selected for inclusion in these trials due to a large fruit size of 197 g in a non-replicated trial. However in these trials this accession was ranked close to the bottom with a fruit size of 120 g. Approximately 9 of these accessions would meet the minimum percentage of flesh or edible pulp of 55–60% as suggested by Inglese et al. (1995) (Fig. 2). There were statistically significant differences among the Santiaguen˜a types which are known for their thick peel and low pulp percentage. AR4 had the highest pulp with 47.2%, while AR8 had the lowest with 40.3%. The Santiaguen˜a type with the highest yield, AR7 had 47.1% pulp.
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
414
220.0
Fruit weight (g)
200.0
180.0
160.0
140.0
120.0
AR9
AR8
AR5
AR2
AR3
1280
AR6
AR4
1319
AR7
1320
1277
1300
1404
1402
AR1
1405
1279
1406
1458
1288
1392
1260
1380
1281
1403
1379
1287
100.0
Accession
Fig. 1. A comparison of the maximum fruit weight of O. ficus indica clones when grown in Santiago del Estero, Argentina. Bars are 95% confidence intervals.
As previously reported (Felker et al., 2002a) in spite of acceptable fruit sugar concentrations and fruit juice content, some high yielding varieties, such as the Italian Gialla, have very low pulp firmness which leads to poor consumer acceptance. While firmness is the parameter measured, really the objectionable quality is that pulps with low firmness value lacks structural integrity and breaks apart when the peel is separated from the pulp. We have previously suggested that a pulp firmness of about 1 kg be the minimum acceptable for cactus fruit (Felker et al., 2002a). Fig. 3 compares the firmness of the outer peel (after removing the cuticle) to the inner pulp and illustrates that the Santiaguen˜a varieties only had an approximate 25% decrease in pulp firmness vs. outer peel firmness. Other accessions such as 1320, 1392 and 1458 had a pulp firmness much less than half of peel firmness. Clearly the Santiaguen˜a (AR) varieties, and clones 1287, 1288, and 1403 belonged to one category with a pulp firmness of nearly 2 kg while the other clones had pulp firmness values of about 1 or less. Thus we would suggest that the firmness of all the Santiaguen˜a clones and 1287, 1288, 1403, 1319 be considered excellent, that clones barely above one, i.e. 1406, 1404, 1281, 1405, 1279 and 1380 be deemed acceptable but that the other clones with less 1 kg firmness be deemed questionable or unacceptable. The tendency of the pulp firmness for these 28 clones to be either 1 or 2 kg, suggests that firmness could be a simply inherited trait. While the differences in fruit pH were small, these differences were significant (Fig. 4). There was a tendency for the Santiaguen˜a clones and those with higher pulp firmness to also have higher pH and indeed the correlation between fruit pH and pulp firmness was highly significant (r=0.47, n=27, p=0.005).
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
415
70.0
65.0
Fruit pulp percentage
60.0
55.0
50.0
45.0
40.0
35.0
AR8
1404
AR2
1402
AR6
1405
AR1
1406
AR9
AR3
1458
AR5
AR4
1319
1403
AR7
1300
1379
1392
1279
1277
1287
1281
1380
1320
1280
1288
1260
30.0
Accession
Fig. 2. A comparison of the percentage of edible pulp to entire fruit weight of O. ficus indica clones when grown in Santiago del Estero, Argentina. Bars are 95% confidence intervals.
Fig. 3. A comparison of the firmness measured on the outer peel to that of the inner edible pulp O. ficus indica clones when grown in Santiago del Estero, Argentina. Bars are 95% confidence intervals.
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
416 6.2
6.1
Fruit pH
6.0
5.9
5.8
1277
1392
1281
1380
1406
1458
1379
1320
1260
AR1
1405
1280
1404
AR2
Meyer
AR7
1300
AR8
AR5
AR3
1288
AR6
1403
AR4
1279
1402
1319
1287
5.7
Accession
Fig. 4. A comparison of the pH of a homogenate of the edible pulp portion of O. ficus indica clones when grown in Santiago del Estero, Argentina. Bars are 95% confidence intervals.
There were highly significant differences in fruit sugar concentrations with the Santiaguen˜a varieties having the greatest sugar levels (Fig. 5). This is in agreement with earlier work in Texas (Parish and Felker, 1997) and Argentina (Felker et al., 2002a) where clone 1319, which is a ‘‘Santiaguen˜a type’’ had the greatest sugar concentration. In the same range as the Santiaguen˜a types, were clones 1280 (14.1), 1380 (13.6 ) and 1260 (13.6), all of which had high yields. However even within the Santiaguen˜a accessions there were significant differences. If one excludes the spiny AR2 clone with very low yields, the spineless Santiaguen˜a clones ranged in fruit sugar from 15.2 for AR7 to 13.4 for AR1. It is promising that clone AR7 was also the Santiaguen˜a clone with the highest yield. Clones 1279 and 1300 which are identical in fruit color (dark purple), pad color (bluish green) and overall plant morphology were significantly different in Brix with clone 1279 having 13.0 and clone 1300 having 11.9. Similar results occurred in Texas with clone 1279 having 12.870.7 Brix and clone 1300 having 11.370.4 Brix (Parish and Felker, 1997). In contrast the clones 1379, 1392 and 1406 with similar rose colored fruit and indistinguishable overall plant morphology had mean Brix values of 12.08, 12.13 and 12.19 and were not significantly different. Slightly more than half of the clones would fall into the optimum Brix value at harvest of 13–15% as suggested by Inglese et al. (1995). However other authors report marketable fruits with lower Brix concentrations of 12% in Sicily (Schirra et al., 2002) and 12.8% for the Israeli summer crop (Nerd et al., 1991). In spite of the
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
417
16.0 15.5 15.0
Soluble solids (˚Brix)
14.5 14.0 13.5 13.0 12.5 12.0 11.5
1300
1392
1379
1406
1403
1402
1281
1277
1405
1287
1320
AR1
1288
1279
1404
1458
AR4
Meyer
1260
AR6
1380
AR5
AR8
1319
AR3
1280
AR7
AR2
11.0
Accession
Fig. 5. A comparison of the fruit sugar as measured with a refractometer of a homogenate of the edible portion of O. ficus indica clones when grown in Santiago del Estero, Argentina. Bars are 95% confidence intervals.
low sugar concentration (12.8) in clone 1287, we, and field workers familiar with cactus, feel that this clone is an exceptionally good tasting variety.
4. Discussion The maximum fruit production levels for the introduced varieties were 6000 kg ha 1 and 16,000 kg ha 1in the 3rd and 4th seasons respectively. The maximum fruit production was 6000 kg ha 1 in the 3rd season for the highest producing Santiaguen˜a variety. Using the economic analyses of as Felker and Guevara (2001) as a guideline, these productivities are indeed promising. For example for the lowest priced market, when cactus fruits used for juice ($0.12 kg 1), these authors calculated that a production of 10,000 would kg ha 1 be the break even point in the 5th year of the plantation. However at a price of $2.0 kg 1 for the local fresh fruit market, a production of only 1000 kg ha 1 would be required to break even in the third year of the plantation. There is a paucity of information on fruit yield as a function of plant age. Most reviews (Inglese et al., 1995; Pimienta, 1990) have suggested that yields as high as we observed are only possible in mature orchards—which presumably are more than 4 years old. Parish and Felker (1997) reported that fruit production in Texas for 22
ARTICLE IN PRESS 418
P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
accessions under dryland production, but with intensive weed control, ranged from about 1500 kg ha 1 to 50,000 kg ha 1. We attribute the rapid growth (many of these 4 yr old plants are 4 m tall with yields on the order of 16,000 kg ha 1) to the summer rainfall and to the intensive weed control. Fine cactus roots are highly visible several mm below the completely bare, herbicide treated soil surface that could take advantage of low rainfall events. With regard to fruit quality, this study confirms our earlier work (Felker et al., 2002a) on the importance of measuring the firmness on the pulp in addition to the peel. The great variability in the ratio of pulp to peel firmness among the accessions eliminates the possibility of assessing pulp firmness from peel firmness measurements. More importantly the pulp firmness is an indicator of the tendency of the pulp to remain intact upon peeling. This latter characteristic is a different phenomenon than peel softness that occurs during ripening. The correlation of decreasing pulp firmness with decreasing fruit pH might be related to the acid induction of low molecular weight expansins that are responsible for an increase in cell wall plasticity (Cosgrove, 1998). Hiwasa et al. (2003) reported an increase in cDNA coding for expansin homologues with the softening of pears during the ripening process. This might support involvement of an acid-induced stimulation of expansin and softening in cactus pears. We are in general agreement with Inglese et al. (1995) on the ideal cactus cultivar but we would add the following attributes; spineless cladodes, glochids easily removable by mechanical brushing techniques, tolerance to 9 1C with minimal damage, pulp percentage455%, Brix413%, pulp firmness41 kg, mature yield420,000 kg ha 1, post harvest shelf life at 2 1C44 weeks, seedinesso3.5 g seeds per 100 g pulp (Felker et al., 2002a) and in a variety of colors (yellow, orange, pink and purple). As of yet no accession meets all of these goals. Our ongoing evaluation of 20 hybrid crosses (Wang et al., 1998) whose parents collectively possess these traits is an attempt to develop such a series of new commercial varieties. Clone 1287 with the second highest yield, was far from the highest Brix with a value of 12.8. Nevertheless, farmers, field hands and professionals who have tasted the fruits of this clone, feel that it has exceptional quality (Unfortunately this accession has large thorns and glochids). Perhaps it has different flavor compounds than the common 2 methyl butanoic acid ethyl ester and 2, 6-nonadien-1-ol identified by Arena et al. (2001) as responsible for the flavor in cactus fruits. Alternatively it is possible that the higher pH or firmness in combination with the sugars was responsible for fruit quality. We feel it will be important to develop more quantitative models for overall consumer acceptability based on flavor compounds, firmness, pH, acidity, Brix concentrations, ratios of common sugars, and seediness. In addition to these traditional uses of cactus fruit for fresh consumption, Stintzing et al. (2001, 2003) have made a strong argument for use of cactus for natural food colorants since betalains present in some cactus pears do not have the earthy flavor of the betalains from red beets. The genetic material collected from the high elevation site in northern Mexico, which may have greater cold tolerance than normal commercial types, i.e. 1402–1406, are somewhat below the standards for commercial fruit types. Of these
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
419
high elevation materials, accessions 1404 and 1405 with dark purple fruit have the highest sugar of 13.0 and 12.8 but a very thick peel which leads to low pulp percentages of 38% and 41%. The yellowish pink 1402 is an attractive fruit but is mediocre in sugar (12.4%), firmness (0.95) and percent pulp (40.3%). Accession 1406 is very similar to the to the other rose colored fruit types, 1392 and 1379. Perhaps the most commercially acceptable is 1403 whose orange colored fruits had 12.4% sugar, 46.8% pulp and a high pulp firmness of 1.98. Should these accessions prove to able to be grown at 2200 m in Argentina in the same latitude as Mexico, their maturity probably will be delayed 30–60 days after the zero elevation stands and thus have fruit available in March and April. Thus in spite of somewhat lower quality (although this may change at higher elevations), they should command a good price on the international market since no other fruit in the world is available at this time (Moreno and Flores, 1996). This is the first report of fruit yield and quality measurements from a replicated trial of individual plant selections within the ‘‘Santiaguen˜a’’ type fruit variety in Argentina. Although the only selection criterion for Santiaguen˜a clones for inclusion in this trial, were for high yields, there was more than a 3-fold difference in yield. Despite the fact that this varietal type (i.e. clones 1319 and 1321 in Texas) has been reported to have low yields in Texas 1500–7000 kg ha 1 (Parish and Felker, 1997) and Chile 6000–9000 kg ha 1 (Inglese et al., 1995), the best yielding clone AR7 produced 6300 kg ha 1 in the third season which by any standards is high yield for cactus. All of these types had high firmness (from 1.8 to 2.7 kg). The pulp percentage was on the low side ranging from 41.4 to 47.2. However, the fruit sugar concentrations, which were significantly different among clones, were exceptional in ranging from 13.4 to 15.2. Accession AR7, which unfortunately was located in the control fertilizer treatment in a farmers field (Galizzi et al., 2004), had both the highest yield and highest sugar among the non-spiny types. Should this trend continue for several more years, AR7 should be released as a commercial type. At present all of the planting stock for new plantings is a mixture of highly variable clones from existing farmer’s fields. Thus these selections should be tested to see if they could provide significant yield increases. For the purposes of this study, we assume that an Opuntia variety could be defined as one that was indistinguishable from other strains based on internal or external appearance of the fruit or overall plant morphology. On this basis we would have several varieties with multiple accessions, i.e. a variety with dark purple spiny fruits with accessions 1404 and 1405, a variety with spineless cladodes and roundish pink fruits with accessions 1392, 1406 and 1379, a variety with spineless dark purple fruits with accessions 1279 and 1300 and the Santiaguen˜a varieties AR1–AR8 that includes the Chilean accession 1319. It is also to be noted that clone 1279 has been used in physiological studies of high and low temperature stress (Nobel and De La Barrera, 2003) and studies on the cold induction for fruit production (Nobel and Castaneda, 1998). Within the morphological indistinguishable Santiaguen˜a type variety and within the dark purple variety (1279 and 1300) there were quantitative differences in yield and fruit sugar but not in the variety composed of clones 1379, 1392 and 1406 with
ARTICLE IN PRESS 420
P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
rose colored fruits. This reinforces the need to make and maintain indistinguishable clonal selections within ‘‘varieties’’ for quantitative characters such as fruit yield and quality. In summary, the important features of this work are that we have: (a) identified new clones adapted to Argentine conditions with high yield, moderately high Brix and high pulp firmness, (b) demonstrated quantitative differences in yield and Brix for cactus clones indistinguishable from external appearances, (c) demonstrated significant differences in both pulp/peel firmness and pulp firmness among clones suggesting that peel firmness is not appropriate for varietal evaluations, and (d) identified clones within the naturalized Santiaguen˜a variety with significantly greater Brix and yield. This works stresses the importance of using replicated field trials to look for quantitative differences in yield and fruit quality from visually indistinguishable cactus fruit clones.
Acknowledgements The authors gratefully acknowledge Ing. Horacio Ochoa’s contribution in establishing the seedling population used to select some of the local Santiaguen˜a clones.
References Arena, E., Campisi, S., Fallico, B., Lanza, M.C., Maccarone, E., 2001. Aroma value of volatile compounds of prickly pear (Opuntia ficus indica (L) Mill Cactaceae). Italian Journal of Food Science 3, 311–319. Barbera, G., Inglese, P., Pimienta-Barrios, E., 1995. Agroecology, cultivation and uses of cactus pear. FAO Plant Production and Protection Paper 132, Rome, 216pp. Borrego-Escalente, F., Murillo-Soto, M., Parga-Torres, V.M., 1990. Potencial de produccion en el norte de Mexico de variedades de nopal (Opuntia spp.) tolerantes al frio. In: Felker, P. (Ed.), Proceedings of the First Annual Texas Prickly Pear Council. Caesar Kleberg Wildlife Research Institute, Kingsville, 95pp. Caplan, K., 1990. Marketing strategies for cactus pears and cactus leaves for the 1990’s. Proceedings of First Annual Texas Prickly Pear Council. Kingsville, Texas, pp. 85–89. Cosgrove, D.J., 1998. Cell wall loosening by expansins. Plant Physiology 118, 333–339. Cowan, R., Felker, P., 1999. Fruit quality of new cold hardy Opuntias from northern and high elevation sites in Mexico. Journal of Professional Association for Cactus Development 3, 75–86. Doucet, M.E., Weht, S., Felker, P., 2002. Nematodes as a possible cause of damage to Opuntia ficus-indica. Journal Professional Association for Cactus Development 4, 84–89. Felker, P., Guevara, J.C., 2001. An economic analyses of dryland fruit production Opuntia ficus indica in Santiago del Estero, Argentina. Journal of Professional Association for Cactus Development 4, 20–30 www.jpacd.org. Felker, P., Soulier, C., Leguizamon, G., Ochoa, J., 2002a. A comparison of the fruit parameters of 12 Opuntia clones grown in Argentina and the United States. Journal of Arid Environments 52, 361–370. Felker, P., Galizzi, F., Soulier, S., 2002b. Genetic variability within Opuntia ficus indica Mill. cv. ‘‘yellow fruit without spines’’ in Santiago del Estero, Argentina and individual plant selection for improved yield and fruit characteristics. Acta Horticulturae 581, 95–103.
ARTICLE IN PRESS P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
421
Galizzi, F., Felker, P., Gardiner, G., 2004. Correlations between soil and cladode nutrient concentrations and fruit yield and quality in Opuntia ficus indica in a traditional farm setting in Santiago del Estero, Argentina. Journal of Arid Environments 59, 115–132. Gregory, R.A., Kuti, J.O., Felker, P., 1993. A comparison of Opuntia fruit quality and winter hardiness for use in Texas. Journal of Arid Environments 24, 37–46. Griffiths, D., Hare, R.F., 1907. The tuna as a food for man. USDA Bur. Plant Industry Bulletin 116. Gutierrez-Acosta, F., Valdez-Cepeda, R.D., Blanco-Macias, F., 2002. Multivariate analyses of cactus pear (Opuntia spp) fruits from a germplasm collection. Acta Horticulturae 581, 111–118. Han, H., Felker, P., 1997. Field validation of water use efficiency of a CAM plant Opuntia ellisiana in South Texas. Journal of Arid Environments 36, 133–148. Hiwasa, K., Rose, J.K., Nakano, R., Inaba, A., Kubo, Y., 2003. Differential expression of seven alphaexpansin genes during growth and ripening of pear fruit. Physiologia Plantarum 117, 564–572. Inglese, P., Barbera, G., La Mantia, T., 1995. Research strategies and improvement of cactus pear (Opuntia ficus-indica) fruit quality and production. Journal of Arid Environment 29, 455–468. Kiesling, R., 1999. Origen, domesticacion y distribucion de Opuntia ficus indica. Journal Professional Association for Cactus Development 3, 50–59. Martinez, L.M., 1968. Estudios del nopal rastrero forrajero y del nopal frutal. In: Box, T.W., RojasMendoza, P. (Eds.), Proceedings of International Symposium on Increasing Food Production in Arid Lands, Vol. 3. Lubbock, TX, ISCALS pub., pp. 39–344. Monjauze, A., LeHouerou, H.N., 1965. Le role des Opuntia dans l’Economie agricole de Nord Africaine. Extrait du Bulletin de l’Ecole Nationale Superieure d’Agriculture de Tunis. 85–165pp. Moreno, P.R., Flores, C.F., 1996. The world cactus pear market. Journal of Professional Association for Cactus Development 1, 75–86. Nerd, A., Karady, A., Mizrahi, Y., 1991. Out of season prickly pear: fruit characteristics and effect of fertilization and short droughts on productivity. HortScience 26, 337–342. Nerd, A., Mesika, R., Mizrahi, Y., 1993. Effect of N fertilizer of autumn flush and cladode N in prickly pear (Opuntia ficus-indica (L.) Mill.). Journal of Arid Environments 68, 337–342. Nieddu, G., Chessa, I., Satta, D., De Pau, L., Pala, M., 2002. Description of six cactus pear (Opuntia ficusindica Mill) fruit cultivars from Italy. Acta Horticulturae 581, 125–129. Nobel, P.S., 1988. Environmental Biology of Agaves and Cacti. Cambridge University Press, Cambridge 270pp. Nobel, P.S., Castaneda, M., 1998. Seasonal light, and temperature influences organ initiation for unrooted cladodes of the prickly pear cactus Opuntia ficus-indica. Journal of the American Society for Horticultural Science 123, 47–51. Nobel, P.S., De La Barrera, E., 2003. Tolerances and acclimation to low and high temperatures for cladodes, roots and fruits of a widely cultivated cactus Opuntia ficus indica. New Phytologist 157, 271–279. Parish, J., Felker, P., 1997. Fruit quality and production of cactus pear (Opuntia spp) clones selected for increased frost hardiness. Journal of Arid Environments 37, 123–143. Pimienta, E., 1990. El Nopal Tunero. Univ. Guadalajara Publisher, Guadalajara, Mexico 246pp. Russell, C.E., Felker, P., 1987. The prickly pears (Opuntia spp): a source of human and animal food in semiarid regions. Economic Botany 41 (3), 433–445. Scheinvar, L., 1995. Taxonomy of utilized Opuntias. In: Barbera, G., Inglese, P., Pimienta-Barrios, E. (Eds.), Agroecology, Cultivation and Uses of Cactus Pear. FAO Plant Production and Protection Paper 132, Rome, Italy, pp. 20–27. Schirra, M., Brandolini, V., Cabras, P., Angioni, A., Inglese, P., 2002. Thiabendazole uptake and storage performance of cactus pear (Opuntia ficus indica (L) Mill. Cv. Gialla) fruit following postharvest treatments with reduced doses of fungicide at 521C. Journal of Agriculture and Food Chemistry 50, 739–743. Stintzing, F.C., Scheiber, A., Carle, R., 2001. Phytochemical and nutritional significance of cactus pear. European Food Research and Technology 212, 396–407. Stintzing, F.C., Scheiber, A., Carle, R., 2003. Evaluation of colour properties and chemical quality parameters of cactus juices. European Food Research and Technology 216, 303–311.
ARTICLE IN PRESS 422
P. Felker et al. / Journal of Arid Environments 60 (2005) 405–422
Wang, X., Felker, P., Paterson, A., 1998. Environmental influences on cactus pear fruit yield, quality and cold hardiness and development of hybrids with improved cold hardiness. Journal of Professional Association for Cactus Development 2, 48–59. Wang, X., Felker, P., Burrow, M.D., Paterson, A.H., 1999. Assessment of genetic diversity among Opuntia genotypes, reflected by DNA markers. Journal Professional Association for Cactus Development 3, 3–14. Weiss, J., Nerd, A., Mizrahi, Y., 1993. Vegetative parthenocarpy in the cactus pear (Opuntia ficus-indica (L.) Mill. Annals of Botany 72, 521–526. Wessels, A.B., 1988. Spineless Prickly Pears. Perskor, Johannesburg, South Africa, 61pp.