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Fresh biomass production and partitioning of aboveground growth in the three botanical varieties of Cynara cardunculus L.
Industrial Crops and Products 37 (2012) 253–258
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Fresh biomass production and partitioning of aboveground growth in the three botanical varieties of Cynara cardunculus L. Vanina Cravero a,∗ , Eugenia Martin a , Ignacio Crippa a , Fernando López Anido b , Stella Maris García c , Enrique Cointry d a
CONICET, CC 14, (S2125ZAA) Zavalla, Argentina Cátedra de Genética, Facultad de Ciencias Agrarias (UNR) Parque J.F. Villarino, (S2125ZAA) Zavalla, Argentina c Cátedra de Cultivos Intensivos, Facultad de Ciencias Agrarias (UNR) Parque J.F. Villarino, (S2125ZAA) Zavalla, Argentina d Cátedra de Mejoramiento Vegetal y Producción de Semillas, Facultad de Ciencias Agrarias (UNR) Parque J.F. Villarino, (S2125ZAA) Zavalla, Argentina b
a r t i c l e
i n f o
Article history: Received 4 May 2011 Received in revised form 30 November 2011 Accepted 18 December 2011 Available online 11 January 2012 Keywords: Biomass Dry matter Fresh matter Biomass partition
a b s t r a c t Fourteen accessions of Cynara cardunculus were compared with the aim to evaluate the fresh biomass production and its partition, aiming at its potential use for industrial purposes. At anthesis stage, when plants have the maximum vegetative development, stalks, leaves and capitula were weighed separately. The percentage of dry matter per gram of fresh biomass was also calculated. The first capitulum components of each plant: bracts, flowers and remnant receptacle were also weighed separately. The total fresh biomass ranged between 1188 and 3235 g/plant, with variable values within each botanical variety, whereas the partition of the aboveground biomass was strongly affected by botanical variety. In both cardoons varieties, the percentage of dry matter ranged between 30 and 35% for all components of aboveground biomass, whereas in globe artichoke values ranged between 20% for capitula and 40% for leaves. Regarding capitula components, receptacle weight was of greatest importance in globe artichoke and cultivated cardoon. In wild cardoon flowers weight was more important than the other components. Results suggest that Cynara cardunculus var. scolymus and C. cardundulus var. cardunculus, might be considered as double purpose crops if after the capitula (in globe artichoke) or leaves (in cardoon) harvest, the fresh matter remaining is artificially dried and cut. On the other hand, Cynara cardunculus var. sylvestris, might be incorporated into the culture system as an industry or energy crop due the low inputs management that it requires, its adaptability to the local conditions and its aboveground biomass production. © 2012 Published by Elsevier B.V.
1. Introduction Cynara cardunculus L. is a perennial species with an annual reproductive cycle, which is completed each year by the end of the spring. It is native to the Mediterranean Basin (Sonnante et al., 2007) and comprises three botanical varieties, Cynara cardunculus var. scolymus (globe artichoke), C. cardunculus var. cardunculus (cultivated cardoon) and Cynara cardunculus var. sylvestris (wild cardoon) (Lanteri and Portis, 2008). They are completely interfertile and their F1 hybrids are also fertile (Lanteri and Portis, 2008). Globe artichoke is mainly grown in Mediterranean countries but its cultivation is also extended in South America, North America and, more recently, in China (FAO, 2008). The immature capitulum (head) is the consumed organ. Although mostly destined to the fresh market, is also frozen, pickled, cooked and canned or
∗ Corresponding author. Tel.: +54 341 4970080/85; fax: +54 341 4970080/85. E-mail address: [email protected] (V. Cravero). 0926-6690/$ – see front matter © 2012 Published by Elsevier B.V. doi:10.1016/j.indcrop.2011.12.028
preserved in oil. In general, this crop has high sale values generating important economic returns to horticulturists, however, by the end of the productive cycle (late spring), when harvests are discontinued, stalks and leaves are cut and discarded as leftovers. The cultivated cardoon has been grown from remote times (even before that globe artichoke), nevertheless, the cultivated area is relatively small and limited to Italy, Spain, South of France and a few countries with Italian immigration. The commercial product is the fleshy petiole and part of the central leaf nervure, consumed as a typical ingredient of the northern Italy “Bagna cauda” dish. Leaves are usually cut once a year, in late winter, when capitula still have not been developed. Stalks of uncut plants are usually discarded and remain as stubble. Wild cardoon is considered the common ancestor of both cultivated varieties (Rottemberg and Zohary, 2005). It is a nondomesticated perennial plant and shows a wide distribution around the world where in some places is naturalized and considered a weed. The plant has spiny leaves and small spiny capitula. It is not cultivated as a commercial crop, nevertheless, capitula are
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sometimes gathered and sold in local markets in Sicily (Ierna and Mauromicale, 2010). The adult plants of all C. cardunculus botanical varieties exhibit vigorous growth along their natural growth cycle; suggesting that this species could be useful for biomass production. The whole plant can be divided into aboveground parts which dry up in summertime, and the underground parts which stay alive along all the perennial life-cycle (Fernández et al., 2006). In the aboveground part of the plant; fresh biomass is suitable to be used as winter forage for livestock feeding (Cajarville et al., 1999; Fernández et al., 2006), whereas as dry biomass it could destined for energy production. The crop characteristics that support these applications are: relatively low crop input, large biomass productivity, mainly of lignocellulosic composition and high heating value (Fernández et al., 2006). This affirmation in true only under Mediterranean climatic conditions; in South America, especially in Argentine, agrometeorological conditions are quite different. Summer is rainy, with some rainfalls over 100 mm. The humidity excess right after the end of the productive stage generates the rotting of the aboveground biomass, not enabling for biomass harvest at this stage. To employ the aboveground biomass for energy production or other industrial purposes it would be necessary then, the application of some desiccant product as paraquat (1,1 -dimethyl4,4 -bipyridylium dichloride) when plants are still at full growth, for example, at anthesis stage. Cynara pulp shows, for hemicellulose, cellulose and lignin contents, similar properties as eucalypt pulp (Antunes et al., 2000; Gominho et al., 2001); therefore it is seen as an interesting alternative for fibre supply in pulp and paper industries (Antunes et al., 2000; Gominho and Pereira, 2000, 2006; Gominho et al., 2001; Villar et al., 1999). Crude extracts of Cynara flowers have been used in some regions of Spain and Portugal, since ancient times, as a natural rennet substitute to make traditional sheep cheese (Freni et al., 2001; Pires et al., 1994). Plant fruits (achenes) can be utilized for oil production for human consumption (Curt et al., 2002; Maccarrone et al., 1999), and also to prepare biodiesel (Benjelloun-Mlayah et al., 1997; Encinar et al., 1999; Fernández and Curt, 2004a; Fernández et al., 2006; Lapuerta et al., 2005). After oil extraction, seed cake could be used for animal feed (Fernández and Manzanares, 1990a). The benefits of the application of Cynara extracts in pharmacology are also known; they have antimicrobial, hepatoprotector and antioxidant properties, which are attributed to cynarin, silymarin and other minor compounds (Gebhardt, 1997, 1998; Lombardo et al., 2010). The use of these polyphenolic compounds in cosmetics was more recently reported (Lupo, 2001; Peschel et al., 2006). Studies of the potential of C. cardunculus for biomass production started in the 1980s (Fernández, 1990; Fernández and Manzanares, 1990a,b). The evaluation of Cynara as an energy and industrial crop requires the knowledge not only of the produced biomass but also the partition of this biomass. Several studies developed in Europe showed that the average annual production of Cynara varieties varies from 15 to 20 t/ha depending on soil and rainfall, with the following biomass partitioning: 40% stalks, 25% leaves and 35% capitula (Dalianis et al., 1996; Fernández, 1992, 1993a,b), showing that Cynara can be considered as a renewable source of energy in the European agriculture systems. The aim of this work was to evaluate the three botanical forms of C. cardunculus regarding fresh biomass production and its partition, aiming at its potential use for industrial purposes.
2. Materials and methods The field experiments were carried out at the Experimental Field Station of Rosario’s National University, Argentina (33◦ 01 S;
Table 1 Accessions of C. cardunculus L. included in the study and their origin. Accession
Origin
C. cardunculus var. cardunculus (cultivated cardoon) Florensa Commercial seed Semence Commercial seed Cereseto Local horticulturist Local horticulturist Schiavoni Local horticulturist Zavalla C. cardunculus var. sylvestris (wild cardoon) Pergamino Locally collected Entre Ríos Locally collected Locally collected Route 9 Route 2 Locally collected C. cardunculus var. scolymus (globe artichoke) Commercial seed Feltrin Verde Commercial seed Feltrin Roxa Commercial seed Violeta precocce Commercial seed Estrella del Sur FCA Commercial seed Imperial Star
Country Argentine Argentine Argentine Argentine Argentine Argentine Argentine Argentine Argentine Brazil Brazil Italy Argentine USA
60◦ 53 W). The station has a temperate climate, loamy soil, an average annual rainfall of 950 mm. Fourteen accessions of C. cardunculus L. (Table 1) were compared in a randomized design with three replications. Plants at the stage of four true developed leaves were transplanted in April 2008. Each plot consisted in 20 plants arranged in three rows with between six and seven plants each one. Plant spacing was 140 cm between rows and 80 cm within plants in the row. Fertilization was conducted prior planting incorporating urea at a 150 kg ha−1 dose. Herbicides linuron at a 600 g ai ha−1 dose (ai = active ingredient), applied a month after plantation and haloxyfop-R-metil-ester at a 30 g ai ha−1 dose applied 6 months after plantation were used. Monthly temperature and rainfall recorded during 2008 and 2009 at the site of the experiment are shown in Table 2. The anthesis stage of the second growth cycle is the moment in which the plants have the maximum vegetative development. At this time, at the end of October, 2009, six plants of the middle row of each plot were cut down and weighed in the open field to determine the total fresh biomass, plants bordering the plot were discarded. Then, stalks, leaves and capitula of each plant were weighed separately. The first capitulum produced for each plant was manually divided into its components: bracts, flowers (including ovaries, pappi and floret scales) and remnant receptacle (eatable portion) which were also weighed separately. Those variables that did not present a normal distribution (leaves, capitula, flowers and receptacle weights) were transformed √ by x. Data were subjected to a one-way analysis of variance (ANOVA) and mean values were compared by Duncan’s multiplerange test, using the SAS software (SAS Institute and Inc., 1999). A multiple linear regression analysis was performed to estimate the relationship between the dependent variable total fresh biomass and the independent variables stalks, leaves and capitula weights. The regression model was: Y = ˛ + ˇ1 x1 + ˇ2 x2 + ˇ3 x3 where Y = dependent variable; ˛ = intercept; ˇ1 , ˇ2 , ˇ3 = partial regression coefficients; x1 , x2 , x3 = independent variables. The same analysis was performed to compare the first capitulum weight (dependent variable) and its components: bracts, flowers and receptacle weights (independent variables). For each aboveground fresh biomass fraction (stalks, leaves and capitula), 5 samples of 100 g each one for each botanical variety were taken and dried in a thermoventilated oven at 60 ◦ C, until constant weight. The percentages of dry matter were calculated.
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Table 2 Weather parameters during the experimental period at the experimental site. Jan 2008 Max T◦ (◦ C) Min T◦ (◦ C) Rainfall (mm) 2009 Max T◦ (◦ C) Min T◦ (◦ C) Rainfall (mm)
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
30.6 17.5 101.5
29.7 17.2 77.4
27.8 14.6 54.3
25.8 9.4 26.7
21.6 7.4 0.0
17.0 2.6 1.7
19.2 7.0 9.5
20.9 2.9 0.0
21.4 5.4 43.6
26.2 10.6 32.4
28.2 16.0 145.2
30.4 16.7 18.3
31.0 16.7 45.9
28.6 16.2 313.1
29.3 15.6 104.3
26.7 13.2 41.3
22.3 8.8 13.6
17.8 3.2 0.0
16.7 2.1 36.1
22.7 6.9 1.7
18.5 6.5 93.0
25.1 9.5 70.2
26.8 15.2 148.7
27.2 15.9 178.1
Table 3 Mean fresh weight (in g) of aboveground biomass and its components of Cynara cardunculus L. belonging to three botanical varieties (values expressed in a plant basis). Botanical variety and accessions
C. cardunculus var. cardunculus Florensa Semence Cereseto Schiavoni Zavalla C. cardunculus var. sylvestris Pergamino Entre Ríos Route 9 Route 2 C. cardunculus var. scolymus Feltrin Verde Feltrin Roxa Violeta precocce Estrella del Sur FCA Imperial Star
Mean fresh weight (g) Leaves
Stalks
Capitula
Total biomass
1138.33a 1088.33a 695.00b 353.30cde 508.35bcd
1223.30a 793.35bc 785.00bc 366.70de 868.30b
873.33bc 903.30bc 816.67c 468.33d 620.05cd
3235.00a 2785.00abc 2296.70bcdef 1188.30g 1996.70cdefg
665.00b 606.33bc 751.67b 501.67bcd
305.00e 325.00e 450.00de 408.30de
401.67d 415.00d 580.02cd 593.33cd
1371.70g 1346.30g 1781.70defg 1503.30fg
565.05bcd 495.00bcd 361.69cde 311.65de 248.35e
751.70bc 873.30b 643.30bcd 520.00cde 441.70de
1291.67ab 1525.00a 1443.30a 813.30c 915.00bc
2608.30abcd 2893.30ab 2448.30abcde 1645.00efg 1605.00fg
Values followed by the same letter in the same column are not significantly different at p < 0.05.
3. Results Results of the analysis of variance for all traits concerning the total fresh biomass showed significant differences among genotypes (p < 0.001). Mean values are showed in Table 3. The total fresh biomass ranged between 1188 and 3235 g/plant, with variable values within each botanical variety, whereas the partition of the aboveground biomass was strongly affected by botanical variety. In the wild variety, the leaves weight represented about 42% of the total fresh biomass, whereas capitula and stalks weights represented the 33 and 25%, respectively. In the cultivated cardoon, the three evaluated components of the aboveground biomass have approximately the same weight. In globe artichoke, capitula weight was the most important
constituent of the fresh biomass determination (about 54%), whereas stalks and leaves represented 29% and 17%, respectively (Fig. 1). Multiple regression analysis showed that about 70% of the total biomass in wild cardoon was explained by the regression on leaves weight (R2 = 0.696); when the capitula weight was included in the model, R2 increased up to 0.937. In cultivated cardoon, when only leaves weight was included in the model, the percentage of the variance of total biomass explained was 82% (R2 = 0.818), when stalk weigh was added to the model this value increased to 97% (R2 = 0.971). On the other hand, almost all biomass variance in globe artichoke was represented by the capitula weight (R2 = 0.914), when leaves weight was added to the model, the explained percentage of variance only increased 7% (R2 = 0.985).
Fig. 1. Partitioning of the total fresh aboveground biomass as a funtion of the Cynara cardunculus L. botanical variety. The dry matter percentage of each fraction is included in the figure.
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Table 4 Mean fresh weight (in g) of the first capitula and its components for fourteen accesions of Cynara cardunculus L. belonging to three botanical varieties. Botanical variety and accessions
Mean fresh weight (g) Bracts
C. cardunculus var. cardunculus Florensa Semence Cereseto Schiavoni Zavalla C. cardunculus var. sylvestris Pergamino Entre Ríos Route 9 Route 2 C. cardunculus var. scolymus Feltrin Verde Feltrin Roxa Violeta precocce Estrella del Sur FCA Imperial Star
8.00d 10.00d 7.50d 7.62d 7.50d 4.83d 3.00d 5.17d 3.00d 147.33a 102.50b 139.00a 147.00a 75.17c
Flowers
Receptacle
First capitulum
89.67cd 99.86cd 54.5ef 106.07c 74.16de
107.50d 113.65d 64.67e 115.30d 87.21de
205.17def 223.50de 126.67g 229.00d 168.85defg
74.17de 58.67ef 78.86cde 38.68f 242.83a 212.17a 239.47a 228.08a 138.75b
78.17de 57.50ef 61.67e 31.84f 378.41ab 299.70b 443.17a 374.67ab 209.88c
157.17efg 119.17g 145.70fg 73.50h 768.60a 614.90b 821.65a 749.75a 423.80c
Values followed by the same letter in the same column are not significantly different at p < 0.05.
In both cardoons varieties, the percentages of dry matter were similar for all components of aboveground biomass, and ranged between 30 and 35% for each one. In contrast, in globe artichoke, these values varied; for stalks and capitula were scarcely superior to 20%, whereas for leaves, the dry matter represented over 40% of the total aboveground biomass (Fig. 1). This could be explained by the domestication towards tender, less fibrous heads in globe artichoke. The analysis of variance performed for the weight of the first capitulum and its components, also showed significant differences among accessions (p < 0.001) (Table 4). Globe artichoke capitulum weight ranged between 423.80 g (Imperial Star) and 821.65 g (Violeta preccoce), whereas in cardoons (cultivated and wild) this trait value ranged between 73.50 g (Route 2) and 229.00 g (Schiavoni). The same pattern was observed for the capitulum components, globe artichokes accessions were clearly separated from cardoons by showing the highest values for bracts, receptacle and flowers weights. Regarding capitulum components, receptacle weight was the most important trait in globe artichoke and cultivated cardoon representing more than 50% of total capitula weight (Fig. 2); less influence presented the flowers weight (44% and 31% in cultivated cardoons and globe artichoke, respectively). In wild cardoon flowers weight was more important than receptacle weight in the determination of the first capitula total weight (50% and 46%, respectively). In all botanical forms, the bracts weight was the minor component. Multiple regression was applied considering as independent variables those three components to describe the first capitula
weight. In globe artichoke, R2 value of 0.944 was obtained when only the receptacle weight was included in the model as independent variable, which indicates that about 95% of the variance of the first capitula weight was explained by the regression with this trait. When a second variable (flowers weight) was included in the model, R2 increased to 0.98. In cultivated cardoon both receptacle and flowers weight were sufficient by themselves to explain almost all the variation of capitula weight, when only one of this variables was included in the model (R2 = 0.98 and 0.97, respectively). These values are almost the same as 0.999 achieved when both variables were included simultaneously. In the wild cardoon, the same pattern was observed, since both flowers and receptacle weight were able to explain 91% of the variation when they were considered separately in the regression model (R2 = 0.916 and 0.914, respectively); whereas this value rose up to 0.999 when both variables were included together into the model. In all the cases, bracts weight contributed scarcely to the regression model. 4. Discussion Most of the current energetic sources are limited and generates environmental problems, thus, obtaining of renewable, not pollutant energy sources is one of the most important current global goals. In this sense, energy crops represent a sustainable alternative. Likewise, new crops incorporation into the agricultural system as well as the additional utilization of the stubble leftover, usually rejected material, represent an interesting alternative to increase the horticulturist economic profits.
Fig. 2. Partitioning of first capitula fresh weight as a function of the Cynara cardunculus L. botanical variety.
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C. cardunculus is a perennial crop that can remain in the field for at least 10 years. It is characterized by its positive energy balance between energy input and output. The energy input is higher in first year than in the followings, and it is mostly represented by field preparation and crop implantation costs, decreasing afterward because these operation costs are not longer needed. The energy outputs considerably increase during the first 3 years due to the increments of the biomass and to its high calorific value (Angelini et al., 2009). An efficient utilization of C. cardunculus L. as an energy and industrial crop requires the knowledge of alternative utilization of all parts of the aboveground plant. In this context, only one report is available regarding the pattern of biomass partition in this species, considering the three botanical varieties (Ierna and Mauromicale, 2010). Nevertheless, in this work, the authors show results obtained under European conditions. Analysis were carried out at the second growth year because at the first year the aboveground biomass production is usually low (Fernández et al., 2006), biomass production usually increases and became more stable over the following years (Fernández et al., 2006; Raccuia and Melilli, 2007). Likewise, under Mediterranean conditions, plants remain in the field still after the productive period is finished and maintain the total biomass until the senescence stage. At this time, the dry biomass can be cut to be used for industrial purposes. In Argentina, after the productive stage (September–October) an important loss of biomass occurs due to the climatic conditions, especially strong rainfalls that cause an environmental dampness increase which promote biomass rotting. Chemical desiccants applications would be an alternative to allow the whole biomass use. These desiccants should be applied when the aboveground biomass still has its maximum vigor, for example, at anthesis stage. In the present work, fresh biomass quantification and its partition is used to infer the amount of dry biomass that might be obtained with this practice. The fresh aboveground biomass of the accessions ranged between 12 and 32 t/ha/year, considering a plant density of about 10,000 plants ha−1 , with a dry matter percentage, ranging between 29.50 and 33.80%. Raccuia and Melilli (2007) obtained an average yield of 50 t/ha of dry biomass accumulated during a 3-year trial under Sicilian conditions. Angelini et al. (2009) reported average values between 14 and 15 t/ha/year in central Italy. Similar values of dry biomass were reported also by Fernández et al. (2006) in the Mediterranean area. The lowest values observed in this work can be attributed to the different accessions evaluated and to the climatic differences. Likewise, there must be taken into account that data was collected in only one growth cycle. Results of the analysis of variance for all traits showed a great range of variability. Aboveground total fresh biomass of C. cardunculus L. was affected by accessions, nevertheless, it was not possible to establish differences between botanical varieties. On the other hand, the biomass partitioning into leaves, stalk and capitula depended on the botanical variety. In globe artichoke almost all the aboveground biomass was destined towards capitula due the domestication aimed at this consumed organ. Cardoon, in the other hand, is cultivated for its succulent leaves, for that reason, domestication derived in forms where leaves and stalks comprised the principal component of biomass weight, nevertheless, capitula weight was also an important destination since they represented, in average, 30% of the total fresh biomass. In the wild form, leaves weight was the most important component of biomass, nevertheless stalks and capitula weights together explained more than 50% of the mean total biomass. Significant differences among genotypes for aboveground biomass yield and its partitioning were also observed by Raccuia and Melilli (2007) in a 3-year trial performed with wild and cultivated cardoons accessions.
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Several components also can be distinguished in the C. cardunculus capitula at anthesis stage: bracts, receptacle and flowers, each of them with different potential uses. Scarce information is available regarding the partition of the capitula biomass. Fernández and Curt (2005) showed that the dry capitula biomass in cardoon is partitioned on average as: receptacle 18%, bracts 25%, fruits 32% and light material 25% (hairs, pappi, and remains of corolla, stamens and styles). Similar values were recorded by Piscioneri et al. (2000). Gominho et al. (2009) found that the capitula biomass partitioning is a function of capitulum size. Our results showed that the receptacle was the most important component independently of the capitula size, both in globe artichoke and cardoon, receptacle weight accounted for 50% of the total biomass, nevertheless, in wild cardoon this value was similar to flowers weight. The partition towards receptacle was relatively constant, whereas the proportion accounted for bracts increased with capitula size. The lower heating value (LHV) of whole C. cardunculus biomass is about 3795 kcal kg−1 of dry matter, whereas the higher heating value (HHV) is higher than 4000 kcal kg−1 . Both LHV and HHV can vary with the different parts of the plant showing the achenes the highest values (5208 and 5576 kcal kg−1 of dry matter for LHV and HHV, respectively) and basal leaves, the lowest values (3390 and 3652 kcal kg−1 , respectively) (Fernández et al., 2006). Also, the plant material harvested by conventional mechanical methods results in a high biomass contamination by soil particles. A high percentage of ash in basal leaves could by attributable to this phenomenon. In this sense, further experiments are needed to improve the characteristics of Cynara biomass for solid fuel production (Fernández and Curt, 2004b). Harvest time and condition of aboveground biomass (fresh or dry) must be also considered taking into account the application proposed. Also, the whole aboveground biomass might be cut to be used by thermal purposes or it might be destined to a selective separation process of the eatable parts and those plants parts with other destinations such as forage, pulp and paper production, pharmacological and cosmetic industry, cheese production (flowers). Likewise, if the aboveground biomass is cut at the end of the vegetative cycle, achenes might be used as raw material for oil or biodiesel production. 5. Conclusions In Argentine, both C. cardunculus var. scolymus and C. cardundulus var. cardunculus, are cultivated as horticultural crops. Nevertheless, results observed in this work, suggest that after the capitula (in globe artichoke) or leaves (in cardoon) collection, the fresh matter remaining can artificially desiccated to be destined for other purposes, as energy production or industry, enabling a double purpose (vegetable and industrial) destination. On the other hand, C. cardunculus var. sylvestris, is not considered as a crop in our region, nevertheless, it grows in wild form in fields and road sides. The low inputs management required for this botanical variety and its adaptability to the local conditions, added to their aboveground biomass production indicate that this variety might be incorporated into the culture system as an industry or energy crop. References Angelini, L., Ceccarini, L., Nassi, N., Bonari, E., 2009. Long-term evaluation of biomass production and quality of two cardoon (Cynara cardunculus L.) cultivars for energy use. Biomass Bioenergy 33, 810–816. Antunes, A., Amaral, E., Belgacem, M.N., 2000. Cynara cardunculus L.: chemical composition and soda-antraquinone cooking. Ind. Crop Prod. 12, 85–91. Benjelloun-Mlayah, B., Lopez, S., Delmas, M., 1997. Oil and paper pulp from Cynara cardunculus: preliminary results. Ind. Crop Prod. 6, 233–236. Cajarville, C., González, J., Repetto, J.L., Rodriguez, C.A., Martinez, A., 1999. Nutritive value of green forage and crop by products of Cynara cardunculus. Ann. Zootech. 48, 353–365.
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Curt, M.D., Sánchez, G., Fernández, J., 2002. The potential of Cynara cardunculus L. for seed oil production in a perennial cultivation system. Biomass Bioenergy 23, 33–46. Dalianis, C., Panoutsou, C., Dercas, N., 1996. Spanish thisle artichoke Cynara cardunculus L., under Greek conditions. In: Chartier, P., Ferrero, G.L., Henius, U.M., Hultberg, S., Sachau, J., Wiinblad, M. (Eds.), Proceedings of the 9th European Bioenergy Conference, Biomass for Energy and the Environment. Pergamon, Oxford, pp. 663–668. Encinar, J.M., Gonzalez, J.F., Sabio, E., Ramiro, M.J., 1999. Preparation and properties of biodiesel from Cynara cardunculus L. oil. Ind. Eng. Chem. Res. 38, 2927–2931. FAO, 2008. Food and Agricultural Organization (FAO). http://www. faostat.fao.org (accessed 23.4.08). Fernández, J., 1990. Lignocellulosic biomass production from annual energy crops. Report EUR 12631 EN-C. Commission of the European Communities, Luxembourg. Fernández, J., 1992. Production and Utilization of Cynara cardunculus L. Biomass for Energy, Paper-Pulp and Food Industry. Final Report JOUB 0030-ECCE, Brussels. Fernández, J., 1993a. Production and utilisation of Cynara cardunculus L. biomass for energy, paper-pulp and food industry. In: Grassi, G., Colina, A., Zibetta, H. (Eds.), Biomass for Energy, Industry and Environment. Elsevier Applied Science Publishers, London, pp. 312–316. Fernández, J., 1993b. Production and Utilization of Cynara cardunculus L. Biomass for Energy, Paper-Pulp and Food Industry. Final Report JOUB 0030-ECCE, Brussels. Fernández, J., Curt, M.D., 2004. Low cost biodiesel from cynara oil. In: Van Swaaij, W.P.M., Fjällstrom, T., Helm, P., Grassi, A. (Eds), Proceeding of the 2nd World Biomass Conference on Biomass for Energy, Industry and Climate Protection. ETA-Florence and WIP-Munich pub, pp. 109–112. Fernández, J., Curt, M.D., 2004. State-of-the-art of Cynara cardunculus as an energy crop. In: Van Swaaij, W.P.M., Fjällstrom, T., Helm, P., Grassi, A. (Eds), Proceeding of the 2nd World Biomass Conference on Biomass for Energy, Industry and Climate Protection. ETA-Florence and WIP-Munich pub, pp. 22–27. Fernández, J., Manzanares, P., 1990a. Cynara cardunculus L., a new crop for oil, paper pulp and energy. In: Grassi, G., Gosse, G., Dos Santos, G. (Eds.), Proceedings of the 5th International Conference on Biomass for Energy and Industry. Lisbon, Portugal. Elsevier Science Publishers Ltd., Barking, pp. 1184–1189. Fernández, J., Manzanares, P., 1990b. Lignocellulosic biomass production from annual energy crops. Report CCE EUR 12631. EN-C. Fernández, J., Curt, M.D., 2005. State of the art of Cynara cardunculus L. as an energy crop. In: Proceedings 14th. European Biomass Conference & Exhibition. Biomass for Energy, Industry and Climate Protection, Paris, France, pp. 22–27. Fernández, J., Curt, M.D., Aguado, P.L., 2006. Industrial applications of Cynara cardunculus L. for energy and other uses. Ind. Crop Prod. 24, 222–229. Freni, K.T., Sousa, M.J., Malcata, F.X., 2001. Storage and lyophilization effects of extracts of Cynara cardunculus on the degradation of ovine and caprine caseins. Food Chem. 72, 79–88. Gebhardt, R., 1997. Antioxidative and protective properties of extracts from leaves of the artichoke (Cynara scolymus L.) against hydroperoxide-induced oxidative stress in cultured rat hepatocytes. Tox. Appl. Pharm. 144, 279–286. Gebhardt, R., 1998. Inhibition of cholesterol biosynthesis in primary cultured rat hepatocytes by artichoke (Cynara scolymus L.) extracts. J. Pharmacol. Exp. Ther. 286, 1122–1128.
Gominho, J., Pereira, H., 2000. An overview of the research on pulping aptitude of Cynara cardunculus L. In: Kyritsis, S., Beenackers, A.A.C.M., Helm, P., Grassi, A., Chiaramonti, D. (Eds.), Proceedings of First World Conference and Exhibition on Biomass for Energy and Industry. Science Publishers Ltd., UK/Seville, Espain, pp. 1187–1190. Gominho, J., Pereira, H., 2006. Influence of raw material and process variables in the kraft pulping of Cynara cardunculus L. Ind. Crop Prod. 24, 160–165. Gominho, J., Fernández, J., Pereira, H., 2001. Cynara cardunculus L.: a new fibre crop for pulp and paper production. Ind. Crop Prod. 13, 1–10. Gominho, J., Lourenc¸, O.A., Curt, M.D., Fernández, J., Pereira, H., 2009. Characterization of hairs and pappus from Cynara cardunculus capitula as a fibre raw material. Ind. Crop Prod. 29, 116–125. Ierna, A., Mauromicale, G., 2010. Cynara cardunculus L. genotypes as a crop for energy purposes in a Mediterranean environment. Biomass Bioenergy 34, 754–760. Lanteri, S., Portis, E., 2008. Globe Artichoke and Cardoon. In: Prohens, J., Nuez, F. (Eds.), Vegetables. I. Asteraceae, Brassicaceae, Chenopodiaceae, and Cucurbitaceae. Handbook of Plant Breeding, Springer, pp. 49–74. Lapuerta, M., Armas, O., Ballesteros, R., Fernández, J., 2005. Diesel emissions from biofuels derived from Spanish potential vegetable oils. Fuel 84, 773–780. Lombardo, S., Pandino, G., Mauromicale, G., Knodler, M., Carle, R., Schieber, A., 2010. Influence of genotype, harvest time and plant part on polyphenolic composition of globe artichoke [Cynara cardunculus L. var. scolymus (L.) Fiori]. Food Chem. 119, 1175–1181. Lupo, M.P., 2001. Antioxidant and vitamins in cosmetics. Clin. Dermatol. 19, 467–473. Maccarrone, E., Fallico, B., Fanella, F., Mauromicale, G., Raccuia, S.A., Foti, S., 1999. Possible alternative utilization of Cynara spp. II. Chemical characterization of their grain oil. Ind. Crop Prod. 10, 229–237. Peschel, W., Sanchez-Rabaneda, F., Diekmann, W., Plescher, A., Gartzia, I., Jimenez, D., Lamuela-Raventos, R., Buxaderas, S., Codina, C., 2006. An industrial approach in the search of natural antioxidants from vegetable and fruit wastes. Food Chem. 97, 137–150. Pires, E.F.C., Macedo, I., Esteves, C., Morgado, M., Veríssimo, P., Pereira, D., Gomes, D., 1994. Flor do cardo versus quimosina no fabrico de queijos artesanais. Química Bol. Soc. Port. Química 54, 66–68. Piscioneri, I., Sharma, N., Baviello, G., Orlandini, S., 2000. Promising industrial energy crop, Cynara cardunculus: a potential source for biomass production and alternative energy. Energy Conv. Manage. 41, 1091–1105. Raccuia, S.A., Melilli, M.G., 2007. Biomass and grain oil yields in Cynara cardunculus L. genotypes grown in a Mediterranean environment. Field Crops Res. 101, 187–197. Rottemberg, A., Zohary, D., 2005. Wild genetic resources of cultivated artichoke. Acta Hort. 681, 307–313. SAS, 1999. SAS User’s Guide: Statistics Versión 6.12. SAS Institute Inc., Cary, NC, USA. Sonnante, G., Pignone, D., Hammer, K., 2007. The domestication of artichoke and cardoon: from Roman times to the genomic age. Ann. Bot. 100, 1095–1100. Villar, J., Poveda, P., Tagle, L., 1999. Obtención de pastas al sulfato a partir del cardo (Cynara cardunculus L.). Influencia del troceado sobre la calidad de las pastas. Invest. Agr. Sist. Recur. For. 8 (2), 305–317.
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Industrial Crops and Products journal homepage: www.elsevier.com/locate/indcrop
Fresh biomass production and partitioning of aboveground growth in the three botanical varieties of Cynara cardunculus L. Vanina Cravero a,∗ , Eugenia Martin a , Ignacio Crippa a , Fernando López Anido b , Stella Maris García c , Enrique Cointry d a
CONICET, CC 14, (S2125ZAA) Zavalla, Argentina Cátedra de Genética, Facultad de Ciencias Agrarias (UNR) Parque J.F. Villarino, (S2125ZAA) Zavalla, Argentina c Cátedra de Cultivos Intensivos, Facultad de Ciencias Agrarias (UNR) Parque J.F. Villarino, (S2125ZAA) Zavalla, Argentina d Cátedra de Mejoramiento Vegetal y Producción de Semillas, Facultad de Ciencias Agrarias (UNR) Parque J.F. Villarino, (S2125ZAA) Zavalla, Argentina b
a r t i c l e
i n f o
Article history: Received 4 May 2011 Received in revised form 30 November 2011 Accepted 18 December 2011 Available online 11 January 2012 Keywords: Biomass Dry matter Fresh matter Biomass partition
a b s t r a c t Fourteen accessions of Cynara cardunculus were compared with the aim to evaluate the fresh biomass production and its partition, aiming at its potential use for industrial purposes. At anthesis stage, when plants have the maximum vegetative development, stalks, leaves and capitula were weighed separately. The percentage of dry matter per gram of fresh biomass was also calculated. The first capitulum components of each plant: bracts, flowers and remnant receptacle were also weighed separately. The total fresh biomass ranged between 1188 and 3235 g/plant, with variable values within each botanical variety, whereas the partition of the aboveground biomass was strongly affected by botanical variety. In both cardoons varieties, the percentage of dry matter ranged between 30 and 35% for all components of aboveground biomass, whereas in globe artichoke values ranged between 20% for capitula and 40% for leaves. Regarding capitula components, receptacle weight was of greatest importance in globe artichoke and cultivated cardoon. In wild cardoon flowers weight was more important than the other components. Results suggest that Cynara cardunculus var. scolymus and C. cardundulus var. cardunculus, might be considered as double purpose crops if after the capitula (in globe artichoke) or leaves (in cardoon) harvest, the fresh matter remaining is artificially dried and cut. On the other hand, Cynara cardunculus var. sylvestris, might be incorporated into the culture system as an industry or energy crop due the low inputs management that it requires, its adaptability to the local conditions and its aboveground biomass production. © 2012 Published by Elsevier B.V.
1. Introduction Cynara cardunculus L. is a perennial species with an annual reproductive cycle, which is completed each year by the end of the spring. It is native to the Mediterranean Basin (Sonnante et al., 2007) and comprises three botanical varieties, Cynara cardunculus var. scolymus (globe artichoke), C. cardunculus var. cardunculus (cultivated cardoon) and Cynara cardunculus var. sylvestris (wild cardoon) (Lanteri and Portis, 2008). They are completely interfertile and their F1 hybrids are also fertile (Lanteri and Portis, 2008). Globe artichoke is mainly grown in Mediterranean countries but its cultivation is also extended in South America, North America and, more recently, in China (FAO, 2008). The immature capitulum (head) is the consumed organ. Although mostly destined to the fresh market, is also frozen, pickled, cooked and canned or
∗ Corresponding author. Tel.: +54 341 4970080/85; fax: +54 341 4970080/85. E-mail address: [email protected] (V. Cravero). 0926-6690/$ – see front matter © 2012 Published by Elsevier B.V. doi:10.1016/j.indcrop.2011.12.028
preserved in oil. In general, this crop has high sale values generating important economic returns to horticulturists, however, by the end of the productive cycle (late spring), when harvests are discontinued, stalks and leaves are cut and discarded as leftovers. The cultivated cardoon has been grown from remote times (even before that globe artichoke), nevertheless, the cultivated area is relatively small and limited to Italy, Spain, South of France and a few countries with Italian immigration. The commercial product is the fleshy petiole and part of the central leaf nervure, consumed as a typical ingredient of the northern Italy “Bagna cauda” dish. Leaves are usually cut once a year, in late winter, when capitula still have not been developed. Stalks of uncut plants are usually discarded and remain as stubble. Wild cardoon is considered the common ancestor of both cultivated varieties (Rottemberg and Zohary, 2005). It is a nondomesticated perennial plant and shows a wide distribution around the world where in some places is naturalized and considered a weed. The plant has spiny leaves and small spiny capitula. It is not cultivated as a commercial crop, nevertheless, capitula are
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sometimes gathered and sold in local markets in Sicily (Ierna and Mauromicale, 2010). The adult plants of all C. cardunculus botanical varieties exhibit vigorous growth along their natural growth cycle; suggesting that this species could be useful for biomass production. The whole plant can be divided into aboveground parts which dry up in summertime, and the underground parts which stay alive along all the perennial life-cycle (Fernández et al., 2006). In the aboveground part of the plant; fresh biomass is suitable to be used as winter forage for livestock feeding (Cajarville et al., 1999; Fernández et al., 2006), whereas as dry biomass it could destined for energy production. The crop characteristics that support these applications are: relatively low crop input, large biomass productivity, mainly of lignocellulosic composition and high heating value (Fernández et al., 2006). This affirmation in true only under Mediterranean climatic conditions; in South America, especially in Argentine, agrometeorological conditions are quite different. Summer is rainy, with some rainfalls over 100 mm. The humidity excess right after the end of the productive stage generates the rotting of the aboveground biomass, not enabling for biomass harvest at this stage. To employ the aboveground biomass for energy production or other industrial purposes it would be necessary then, the application of some desiccant product as paraquat (1,1 -dimethyl4,4 -bipyridylium dichloride) when plants are still at full growth, for example, at anthesis stage. Cynara pulp shows, for hemicellulose, cellulose and lignin contents, similar properties as eucalypt pulp (Antunes et al., 2000; Gominho et al., 2001); therefore it is seen as an interesting alternative for fibre supply in pulp and paper industries (Antunes et al., 2000; Gominho and Pereira, 2000, 2006; Gominho et al., 2001; Villar et al., 1999). Crude extracts of Cynara flowers have been used in some regions of Spain and Portugal, since ancient times, as a natural rennet substitute to make traditional sheep cheese (Freni et al., 2001; Pires et al., 1994). Plant fruits (achenes) can be utilized for oil production for human consumption (Curt et al., 2002; Maccarrone et al., 1999), and also to prepare biodiesel (Benjelloun-Mlayah et al., 1997; Encinar et al., 1999; Fernández and Curt, 2004a; Fernández et al., 2006; Lapuerta et al., 2005). After oil extraction, seed cake could be used for animal feed (Fernández and Manzanares, 1990a). The benefits of the application of Cynara extracts in pharmacology are also known; they have antimicrobial, hepatoprotector and antioxidant properties, which are attributed to cynarin, silymarin and other minor compounds (Gebhardt, 1997, 1998; Lombardo et al., 2010). The use of these polyphenolic compounds in cosmetics was more recently reported (Lupo, 2001; Peschel et al., 2006). Studies of the potential of C. cardunculus for biomass production started in the 1980s (Fernández, 1990; Fernández and Manzanares, 1990a,b). The evaluation of Cynara as an energy and industrial crop requires the knowledge not only of the produced biomass but also the partition of this biomass. Several studies developed in Europe showed that the average annual production of Cynara varieties varies from 15 to 20 t/ha depending on soil and rainfall, with the following biomass partitioning: 40% stalks, 25% leaves and 35% capitula (Dalianis et al., 1996; Fernández, 1992, 1993a,b), showing that Cynara can be considered as a renewable source of energy in the European agriculture systems. The aim of this work was to evaluate the three botanical forms of C. cardunculus regarding fresh biomass production and its partition, aiming at its potential use for industrial purposes.
2. Materials and methods The field experiments were carried out at the Experimental Field Station of Rosario’s National University, Argentina (33◦ 01 S;
Table 1 Accessions of C. cardunculus L. included in the study and their origin. Accession
Origin
C. cardunculus var. cardunculus (cultivated cardoon) Florensa Commercial seed Semence Commercial seed Cereseto Local horticulturist Local horticulturist Schiavoni Local horticulturist Zavalla C. cardunculus var. sylvestris (wild cardoon) Pergamino Locally collected Entre Ríos Locally collected Locally collected Route 9 Route 2 Locally collected C. cardunculus var. scolymus (globe artichoke) Commercial seed Feltrin Verde Commercial seed Feltrin Roxa Commercial seed Violeta precocce Commercial seed Estrella del Sur FCA Commercial seed Imperial Star
Country Argentine Argentine Argentine Argentine Argentine Argentine Argentine Argentine Argentine Brazil Brazil Italy Argentine USA
60◦ 53 W). The station has a temperate climate, loamy soil, an average annual rainfall of 950 mm. Fourteen accessions of C. cardunculus L. (Table 1) were compared in a randomized design with three replications. Plants at the stage of four true developed leaves were transplanted in April 2008. Each plot consisted in 20 plants arranged in three rows with between six and seven plants each one. Plant spacing was 140 cm between rows and 80 cm within plants in the row. Fertilization was conducted prior planting incorporating urea at a 150 kg ha−1 dose. Herbicides linuron at a 600 g ai ha−1 dose (ai = active ingredient), applied a month after plantation and haloxyfop-R-metil-ester at a 30 g ai ha−1 dose applied 6 months after plantation were used. Monthly temperature and rainfall recorded during 2008 and 2009 at the site of the experiment are shown in Table 2. The anthesis stage of the second growth cycle is the moment in which the plants have the maximum vegetative development. At this time, at the end of October, 2009, six plants of the middle row of each plot were cut down and weighed in the open field to determine the total fresh biomass, plants bordering the plot were discarded. Then, stalks, leaves and capitula of each plant were weighed separately. The first capitulum produced for each plant was manually divided into its components: bracts, flowers (including ovaries, pappi and floret scales) and remnant receptacle (eatable portion) which were also weighed separately. Those variables that did not present a normal distribution (leaves, capitula, flowers and receptacle weights) were transformed √ by x. Data were subjected to a one-way analysis of variance (ANOVA) and mean values were compared by Duncan’s multiplerange test, using the SAS software (SAS Institute and Inc., 1999). A multiple linear regression analysis was performed to estimate the relationship between the dependent variable total fresh biomass and the independent variables stalks, leaves and capitula weights. The regression model was: Y = ˛ + ˇ1 x1 + ˇ2 x2 + ˇ3 x3 where Y = dependent variable; ˛ = intercept; ˇ1 , ˇ2 , ˇ3 = partial regression coefficients; x1 , x2 , x3 = independent variables. The same analysis was performed to compare the first capitulum weight (dependent variable) and its components: bracts, flowers and receptacle weights (independent variables). For each aboveground fresh biomass fraction (stalks, leaves and capitula), 5 samples of 100 g each one for each botanical variety were taken and dried in a thermoventilated oven at 60 ◦ C, until constant weight. The percentages of dry matter were calculated.
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Table 2 Weather parameters during the experimental period at the experimental site. Jan 2008 Max T◦ (◦ C) Min T◦ (◦ C) Rainfall (mm) 2009 Max T◦ (◦ C) Min T◦ (◦ C) Rainfall (mm)
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
30.6 17.5 101.5
29.7 17.2 77.4
27.8 14.6 54.3
25.8 9.4 26.7
21.6 7.4 0.0
17.0 2.6 1.7
19.2 7.0 9.5
20.9 2.9 0.0
21.4 5.4 43.6
26.2 10.6 32.4
28.2 16.0 145.2
30.4 16.7 18.3
31.0 16.7 45.9
28.6 16.2 313.1
29.3 15.6 104.3
26.7 13.2 41.3
22.3 8.8 13.6
17.8 3.2 0.0
16.7 2.1 36.1
22.7 6.9 1.7
18.5 6.5 93.0
25.1 9.5 70.2
26.8 15.2 148.7
27.2 15.9 178.1
Table 3 Mean fresh weight (in g) of aboveground biomass and its components of Cynara cardunculus L. belonging to three botanical varieties (values expressed in a plant basis). Botanical variety and accessions
C. cardunculus var. cardunculus Florensa Semence Cereseto Schiavoni Zavalla C. cardunculus var. sylvestris Pergamino Entre Ríos Route 9 Route 2 C. cardunculus var. scolymus Feltrin Verde Feltrin Roxa Violeta precocce Estrella del Sur FCA Imperial Star
Mean fresh weight (g) Leaves
Stalks
Capitula
Total biomass
1138.33a 1088.33a 695.00b 353.30cde 508.35bcd
1223.30a 793.35bc 785.00bc 366.70de 868.30b
873.33bc 903.30bc 816.67c 468.33d 620.05cd
3235.00a 2785.00abc 2296.70bcdef 1188.30g 1996.70cdefg
665.00b 606.33bc 751.67b 501.67bcd
305.00e 325.00e 450.00de 408.30de
401.67d 415.00d 580.02cd 593.33cd
1371.70g 1346.30g 1781.70defg 1503.30fg
565.05bcd 495.00bcd 361.69cde 311.65de 248.35e
751.70bc 873.30b 643.30bcd 520.00cde 441.70de
1291.67ab 1525.00a 1443.30a 813.30c 915.00bc
2608.30abcd 2893.30ab 2448.30abcde 1645.00efg 1605.00fg
Values followed by the same letter in the same column are not significantly different at p < 0.05.
3. Results Results of the analysis of variance for all traits concerning the total fresh biomass showed significant differences among genotypes (p < 0.001). Mean values are showed in Table 3. The total fresh biomass ranged between 1188 and 3235 g/plant, with variable values within each botanical variety, whereas the partition of the aboveground biomass was strongly affected by botanical variety. In the wild variety, the leaves weight represented about 42% of the total fresh biomass, whereas capitula and stalks weights represented the 33 and 25%, respectively. In the cultivated cardoon, the three evaluated components of the aboveground biomass have approximately the same weight. In globe artichoke, capitula weight was the most important
constituent of the fresh biomass determination (about 54%), whereas stalks and leaves represented 29% and 17%, respectively (Fig. 1). Multiple regression analysis showed that about 70% of the total biomass in wild cardoon was explained by the regression on leaves weight (R2 = 0.696); when the capitula weight was included in the model, R2 increased up to 0.937. In cultivated cardoon, when only leaves weight was included in the model, the percentage of the variance of total biomass explained was 82% (R2 = 0.818), when stalk weigh was added to the model this value increased to 97% (R2 = 0.971). On the other hand, almost all biomass variance in globe artichoke was represented by the capitula weight (R2 = 0.914), when leaves weight was added to the model, the explained percentage of variance only increased 7% (R2 = 0.985).
Fig. 1. Partitioning of the total fresh aboveground biomass as a funtion of the Cynara cardunculus L. botanical variety. The dry matter percentage of each fraction is included in the figure.
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Table 4 Mean fresh weight (in g) of the first capitula and its components for fourteen accesions of Cynara cardunculus L. belonging to three botanical varieties. Botanical variety and accessions
Mean fresh weight (g) Bracts
C. cardunculus var. cardunculus Florensa Semence Cereseto Schiavoni Zavalla C. cardunculus var. sylvestris Pergamino Entre Ríos Route 9 Route 2 C. cardunculus var. scolymus Feltrin Verde Feltrin Roxa Violeta precocce Estrella del Sur FCA Imperial Star
8.00d 10.00d 7.50d 7.62d 7.50d 4.83d 3.00d 5.17d 3.00d 147.33a 102.50b 139.00a 147.00a 75.17c
Flowers
Receptacle
First capitulum
89.67cd 99.86cd 54.5ef 106.07c 74.16de
107.50d 113.65d 64.67e 115.30d 87.21de
205.17def 223.50de 126.67g 229.00d 168.85defg
74.17de 58.67ef 78.86cde 38.68f 242.83a 212.17a 239.47a 228.08a 138.75b
78.17de 57.50ef 61.67e 31.84f 378.41ab 299.70b 443.17a 374.67ab 209.88c
157.17efg 119.17g 145.70fg 73.50h 768.60a 614.90b 821.65a 749.75a 423.80c
Values followed by the same letter in the same column are not significantly different at p < 0.05.
In both cardoons varieties, the percentages of dry matter were similar for all components of aboveground biomass, and ranged between 30 and 35% for each one. In contrast, in globe artichoke, these values varied; for stalks and capitula were scarcely superior to 20%, whereas for leaves, the dry matter represented over 40% of the total aboveground biomass (Fig. 1). This could be explained by the domestication towards tender, less fibrous heads in globe artichoke. The analysis of variance performed for the weight of the first capitulum and its components, also showed significant differences among accessions (p < 0.001) (Table 4). Globe artichoke capitulum weight ranged between 423.80 g (Imperial Star) and 821.65 g (Violeta preccoce), whereas in cardoons (cultivated and wild) this trait value ranged between 73.50 g (Route 2) and 229.00 g (Schiavoni). The same pattern was observed for the capitulum components, globe artichokes accessions were clearly separated from cardoons by showing the highest values for bracts, receptacle and flowers weights. Regarding capitulum components, receptacle weight was the most important trait in globe artichoke and cultivated cardoon representing more than 50% of total capitula weight (Fig. 2); less influence presented the flowers weight (44% and 31% in cultivated cardoons and globe artichoke, respectively). In wild cardoon flowers weight was more important than receptacle weight in the determination of the first capitula total weight (50% and 46%, respectively). In all botanical forms, the bracts weight was the minor component. Multiple regression was applied considering as independent variables those three components to describe the first capitula
weight. In globe artichoke, R2 value of 0.944 was obtained when only the receptacle weight was included in the model as independent variable, which indicates that about 95% of the variance of the first capitula weight was explained by the regression with this trait. When a second variable (flowers weight) was included in the model, R2 increased to 0.98. In cultivated cardoon both receptacle and flowers weight were sufficient by themselves to explain almost all the variation of capitula weight, when only one of this variables was included in the model (R2 = 0.98 and 0.97, respectively). These values are almost the same as 0.999 achieved when both variables were included simultaneously. In the wild cardoon, the same pattern was observed, since both flowers and receptacle weight were able to explain 91% of the variation when they were considered separately in the regression model (R2 = 0.916 and 0.914, respectively); whereas this value rose up to 0.999 when both variables were included together into the model. In all the cases, bracts weight contributed scarcely to the regression model. 4. Discussion Most of the current energetic sources are limited and generates environmental problems, thus, obtaining of renewable, not pollutant energy sources is one of the most important current global goals. In this sense, energy crops represent a sustainable alternative. Likewise, new crops incorporation into the agricultural system as well as the additional utilization of the stubble leftover, usually rejected material, represent an interesting alternative to increase the horticulturist economic profits.
Fig. 2. Partitioning of first capitula fresh weight as a function of the Cynara cardunculus L. botanical variety.
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C. cardunculus is a perennial crop that can remain in the field for at least 10 years. It is characterized by its positive energy balance between energy input and output. The energy input is higher in first year than in the followings, and it is mostly represented by field preparation and crop implantation costs, decreasing afterward because these operation costs are not longer needed. The energy outputs considerably increase during the first 3 years due to the increments of the biomass and to its high calorific value (Angelini et al., 2009). An efficient utilization of C. cardunculus L. as an energy and industrial crop requires the knowledge of alternative utilization of all parts of the aboveground plant. In this context, only one report is available regarding the pattern of biomass partition in this species, considering the three botanical varieties (Ierna and Mauromicale, 2010). Nevertheless, in this work, the authors show results obtained under European conditions. Analysis were carried out at the second growth year because at the first year the aboveground biomass production is usually low (Fernández et al., 2006), biomass production usually increases and became more stable over the following years (Fernández et al., 2006; Raccuia and Melilli, 2007). Likewise, under Mediterranean conditions, plants remain in the field still after the productive period is finished and maintain the total biomass until the senescence stage. At this time, the dry biomass can be cut to be used for industrial purposes. In Argentina, after the productive stage (September–October) an important loss of biomass occurs due to the climatic conditions, especially strong rainfalls that cause an environmental dampness increase which promote biomass rotting. Chemical desiccants applications would be an alternative to allow the whole biomass use. These desiccants should be applied when the aboveground biomass still has its maximum vigor, for example, at anthesis stage. In the present work, fresh biomass quantification and its partition is used to infer the amount of dry biomass that might be obtained with this practice. The fresh aboveground biomass of the accessions ranged between 12 and 32 t/ha/year, considering a plant density of about 10,000 plants ha−1 , with a dry matter percentage, ranging between 29.50 and 33.80%. Raccuia and Melilli (2007) obtained an average yield of 50 t/ha of dry biomass accumulated during a 3-year trial under Sicilian conditions. Angelini et al. (2009) reported average values between 14 and 15 t/ha/year in central Italy. Similar values of dry biomass were reported also by Fernández et al. (2006) in the Mediterranean area. The lowest values observed in this work can be attributed to the different accessions evaluated and to the climatic differences. Likewise, there must be taken into account that data was collected in only one growth cycle. Results of the analysis of variance for all traits showed a great range of variability. Aboveground total fresh biomass of C. cardunculus L. was affected by accessions, nevertheless, it was not possible to establish differences between botanical varieties. On the other hand, the biomass partitioning into leaves, stalk and capitula depended on the botanical variety. In globe artichoke almost all the aboveground biomass was destined towards capitula due the domestication aimed at this consumed organ. Cardoon, in the other hand, is cultivated for its succulent leaves, for that reason, domestication derived in forms where leaves and stalks comprised the principal component of biomass weight, nevertheless, capitula weight was also an important destination since they represented, in average, 30% of the total fresh biomass. In the wild form, leaves weight was the most important component of biomass, nevertheless stalks and capitula weights together explained more than 50% of the mean total biomass. Significant differences among genotypes for aboveground biomass yield and its partitioning were also observed by Raccuia and Melilli (2007) in a 3-year trial performed with wild and cultivated cardoons accessions.
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Several components also can be distinguished in the C. cardunculus capitula at anthesis stage: bracts, receptacle and flowers, each of them with different potential uses. Scarce information is available regarding the partition of the capitula biomass. Fernández and Curt (2005) showed that the dry capitula biomass in cardoon is partitioned on average as: receptacle 18%, bracts 25%, fruits 32% and light material 25% (hairs, pappi, and remains of corolla, stamens and styles). Similar values were recorded by Piscioneri et al. (2000). Gominho et al. (2009) found that the capitula biomass partitioning is a function of capitulum size. Our results showed that the receptacle was the most important component independently of the capitula size, both in globe artichoke and cardoon, receptacle weight accounted for 50% of the total biomass, nevertheless, in wild cardoon this value was similar to flowers weight. The partition towards receptacle was relatively constant, whereas the proportion accounted for bracts increased with capitula size. The lower heating value (LHV) of whole C. cardunculus biomass is about 3795 kcal kg−1 of dry matter, whereas the higher heating value (HHV) is higher than 4000 kcal kg−1 . Both LHV and HHV can vary with the different parts of the plant showing the achenes the highest values (5208 and 5576 kcal kg−1 of dry matter for LHV and HHV, respectively) and basal leaves, the lowest values (3390 and 3652 kcal kg−1 , respectively) (Fernández et al., 2006). Also, the plant material harvested by conventional mechanical methods results in a high biomass contamination by soil particles. A high percentage of ash in basal leaves could by attributable to this phenomenon. In this sense, further experiments are needed to improve the characteristics of Cynara biomass for solid fuel production (Fernández and Curt, 2004b). Harvest time and condition of aboveground biomass (fresh or dry) must be also considered taking into account the application proposed. Also, the whole aboveground biomass might be cut to be used by thermal purposes or it might be destined to a selective separation process of the eatable parts and those plants parts with other destinations such as forage, pulp and paper production, pharmacological and cosmetic industry, cheese production (flowers). Likewise, if the aboveground biomass is cut at the end of the vegetative cycle, achenes might be used as raw material for oil or biodiesel production. 5. Conclusions In Argentine, both C. cardunculus var. scolymus and C. cardundulus var. cardunculus, are cultivated as horticultural crops. Nevertheless, results observed in this work, suggest that after the capitula (in globe artichoke) or leaves (in cardoon) collection, the fresh matter remaining can artificially desiccated to be destined for other purposes, as energy production or industry, enabling a double purpose (vegetable and industrial) destination. On the other hand, C. cardunculus var. sylvestris, is not considered as a crop in our region, nevertheless, it grows in wild form in fields and road sides. The low inputs management required for this botanical variety and its adaptability to the local conditions, added to their aboveground biomass production indicate that this variety might be incorporated into the culture system as an industry or energy crop. References Angelini, L., Ceccarini, L., Nassi, N., Bonari, E., 2009. Long-term evaluation of biomass production and quality of two cardoon (Cynara cardunculus L.) cultivars for energy use. Biomass Bioenergy 33, 810–816. Antunes, A., Amaral, E., Belgacem, M.N., 2000. Cynara cardunculus L.: chemical composition and soda-antraquinone cooking. Ind. Crop Prod. 12, 85–91. Benjelloun-Mlayah, B., Lopez, S., Delmas, M., 1997. Oil and paper pulp from Cynara cardunculus: preliminary results. Ind. Crop Prod. 6, 233–236. Cajarville, C., González, J., Repetto, J.L., Rodriguez, C.A., Martinez, A., 1999. Nutritive value of green forage and crop by products of Cynara cardunculus. Ann. Zootech. 48, 353–365.
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Curt, M.D., Sánchez, G., Fernández, J., 2002. The potential of Cynara cardunculus L. for seed oil production in a perennial cultivation system. Biomass Bioenergy 23, 33–46. Dalianis, C., Panoutsou, C., Dercas, N., 1996. Spanish thisle artichoke Cynara cardunculus L., under Greek conditions. In: Chartier, P., Ferrero, G.L., Henius, U.M., Hultberg, S., Sachau, J., Wiinblad, M. (Eds.), Proceedings of the 9th European Bioenergy Conference, Biomass for Energy and the Environment. Pergamon, Oxford, pp. 663–668. Encinar, J.M., Gonzalez, J.F., Sabio, E., Ramiro, M.J., 1999. Preparation and properties of biodiesel from Cynara cardunculus L. oil. Ind. Eng. Chem. Res. 38, 2927–2931. FAO, 2008. Food and Agricultural Organization (FAO). http://www. faostat.fao.org (accessed 23.4.08). Fernández, J., 1990. Lignocellulosic biomass production from annual energy crops. Report EUR 12631 EN-C. Commission of the European Communities, Luxembourg. Fernández, J., 1992. Production and Utilization of Cynara cardunculus L. Biomass for Energy, Paper-Pulp and Food Industry. Final Report JOUB 0030-ECCE, Brussels. Fernández, J., 1993a. Production and utilisation of Cynara cardunculus L. biomass for energy, paper-pulp and food industry. In: Grassi, G., Colina, A., Zibetta, H. (Eds.), Biomass for Energy, Industry and Environment. Elsevier Applied Science Publishers, London, pp. 312–316. Fernández, J., 1993b. Production and Utilization of Cynara cardunculus L. Biomass for Energy, Paper-Pulp and Food Industry. Final Report JOUB 0030-ECCE, Brussels. Fernández, J., Curt, M.D., 2004. Low cost biodiesel from cynara oil. In: Van Swaaij, W.P.M., Fjällstrom, T., Helm, P., Grassi, A. (Eds), Proceeding of the 2nd World Biomass Conference on Biomass for Energy, Industry and Climate Protection. ETA-Florence and WIP-Munich pub, pp. 109–112. Fernández, J., Curt, M.D., 2004. State-of-the-art of Cynara cardunculus as an energy crop. In: Van Swaaij, W.P.M., Fjällstrom, T., Helm, P., Grassi, A. (Eds), Proceeding of the 2nd World Biomass Conference on Biomass for Energy, Industry and Climate Protection. ETA-Florence and WIP-Munich pub, pp. 22–27. Fernández, J., Manzanares, P., 1990a. Cynara cardunculus L., a new crop for oil, paper pulp and energy. In: Grassi, G., Gosse, G., Dos Santos, G. (Eds.), Proceedings of the 5th International Conference on Biomass for Energy and Industry. Lisbon, Portugal. Elsevier Science Publishers Ltd., Barking, pp. 1184–1189. Fernández, J., Manzanares, P., 1990b. Lignocellulosic biomass production from annual energy crops. Report CCE EUR 12631. EN-C. Fernández, J., Curt, M.D., 2005. State of the art of Cynara cardunculus L. as an energy crop. In: Proceedings 14th. European Biomass Conference & Exhibition. Biomass for Energy, Industry and Climate Protection, Paris, France, pp. 22–27. Fernández, J., Curt, M.D., Aguado, P.L., 2006. Industrial applications of Cynara cardunculus L. for energy and other uses. Ind. Crop Prod. 24, 222–229. Freni, K.T., Sousa, M.J., Malcata, F.X., 2001. Storage and lyophilization effects of extracts of Cynara cardunculus on the degradation of ovine and caprine caseins. Food Chem. 72, 79–88. Gebhardt, R., 1997. Antioxidative and protective properties of extracts from leaves of the artichoke (Cynara scolymus L.) against hydroperoxide-induced oxidative stress in cultured rat hepatocytes. Tox. Appl. Pharm. 144, 279–286. Gebhardt, R., 1998. Inhibition of cholesterol biosynthesis in primary cultured rat hepatocytes by artichoke (Cynara scolymus L.) extracts. J. Pharmacol. Exp. Ther. 286, 1122–1128.
Gominho, J., Pereira, H., 2000. An overview of the research on pulping aptitude of Cynara cardunculus L. In: Kyritsis, S., Beenackers, A.A.C.M., Helm, P., Grassi, A., Chiaramonti, D. (Eds.), Proceedings of First World Conference and Exhibition on Biomass for Energy and Industry. Science Publishers Ltd., UK/Seville, Espain, pp. 1187–1190. Gominho, J., Pereira, H., 2006. Influence of raw material and process variables in the kraft pulping of Cynara cardunculus L. Ind. Crop Prod. 24, 160–165. Gominho, J., Fernández, J., Pereira, H., 2001. Cynara cardunculus L.: a new fibre crop for pulp and paper production. Ind. Crop Prod. 13, 1–10. Gominho, J., Lourenc¸, O.A., Curt, M.D., Fernández, J., Pereira, H., 2009. Characterization of hairs and pappus from Cynara cardunculus capitula as a fibre raw material. Ind. Crop Prod. 29, 116–125. Ierna, A., Mauromicale, G., 2010. Cynara cardunculus L. genotypes as a crop for energy purposes in a Mediterranean environment. Biomass Bioenergy 34, 754–760. Lanteri, S., Portis, E., 2008. Globe Artichoke and Cardoon. In: Prohens, J., Nuez, F. (Eds.), Vegetables. I. Asteraceae, Brassicaceae, Chenopodiaceae, and Cucurbitaceae. Handbook of Plant Breeding, Springer, pp. 49–74. Lapuerta, M., Armas, O., Ballesteros, R., Fernández, J., 2005. Diesel emissions from biofuels derived from Spanish potential vegetable oils. Fuel 84, 773–780. Lombardo, S., Pandino, G., Mauromicale, G., Knodler, M., Carle, R., Schieber, A., 2010. Influence of genotype, harvest time and plant part on polyphenolic composition of globe artichoke [Cynara cardunculus L. var. scolymus (L.) Fiori]. Food Chem. 119, 1175–1181. Lupo, M.P., 2001. Antioxidant and vitamins in cosmetics. Clin. Dermatol. 19, 467–473. Maccarrone, E., Fallico, B., Fanella, F., Mauromicale, G., Raccuia, S.A., Foti, S., 1999. Possible alternative utilization of Cynara spp. II. Chemical characterization of their grain oil. Ind. Crop Prod. 10, 229–237. Peschel, W., Sanchez-Rabaneda, F., Diekmann, W., Plescher, A., Gartzia, I., Jimenez, D., Lamuela-Raventos, R., Buxaderas, S., Codina, C., 2006. An industrial approach in the search of natural antioxidants from vegetable and fruit wastes. Food Chem. 97, 137–150. Pires, E.F.C., Macedo, I., Esteves, C., Morgado, M., Veríssimo, P., Pereira, D., Gomes, D., 1994. Flor do cardo versus quimosina no fabrico de queijos artesanais. Química Bol. Soc. Port. Química 54, 66–68. Piscioneri, I., Sharma, N., Baviello, G., Orlandini, S., 2000. Promising industrial energy crop, Cynara cardunculus: a potential source for biomass production and alternative energy. Energy Conv. Manage. 41, 1091–1105. Raccuia, S.A., Melilli, M.G., 2007. Biomass and grain oil yields in Cynara cardunculus L. genotypes grown in a Mediterranean environment. Field Crops Res. 101, 187–197. Rottemberg, A., Zohary, D., 2005. Wild genetic resources of cultivated artichoke. Acta Hort. 681, 307–313. SAS, 1999. SAS User’s Guide: Statistics Versión 6.12. SAS Institute Inc., Cary, NC, USA. Sonnante, G., Pignone, D., Hammer, K., 2007. The domestication of artichoke and cardoon: from Roman times to the genomic age. Ann. Bot. 100, 1095–1100. Villar, J., Poveda, P., Tagle, L., 1999. Obtención de pastas al sulfato a partir del cardo (Cynara cardunculus L.). Influencia del troceado sobre la calidad de las pastas. Invest. Agr. Sist. Recur. For. 8 (2), 305–317.