Production of muskmelon (Cucumis melo L.) under controlled deficit irrigation in a semi-arid climate

Agricultural Water Management 54 (2002) 93±105

Production of muskmelon (Cucumis melo L.) under controlled de®cit irrigation in a semi-arid climate C. Fabeiro*, F. MartõÂn de Santa Olalla, J.A. de Juan Regional Water Research Center, University of Castilla-La Mancha, E.T.S. de Ingenieros Agronomos, Campus Universitario s/n, E-02071 Albacete, Spain Accepted 9 August 2001

Abstract Controlled de®cit irrigation (CDI) was studied in a muskmelon crop cultivated in semi-arid climate. Nine drip irrigation treatments were differentiated by the level to which the water requirements were met. The effect of de®cit irrigation at three crop stages (blooming, setting and ripening) was studied. Fruit yield and its components were highly in¯uenced by the total volume of irrigation water. The treatments with a de®cit during the blooming stage had the lowest production. The de®cit imposed during blooming stage affected mainly to quantity (yield), at setting stage both quantity and quality, and the de®cit imposed at ripening stage affected principally to quality (sugar content). The mathematical function that better ®ts the relation between production and water volume received is a second-degree polynomial. Adequate production rates may be reached with no more of 400 mm, provided that the fruit setting stage is not subjected to water stress, particularly in its early stages. Under this conditions, the fruit obtained would be fairly rich in sugar content. # 2002 Elsevier Science B.V. All rights reserved. Keywords: Cucumis melo; Controlled de®cit irrigation; Production functions

1. Introduction The world production of muskmelon is over 6 million t in a total surface area of 311,000 ha. Turkey is the country with the greatest production, taking up about 30% of the total world surface and production. It is followed by USA with 21% and Spain and Romania with 17 and 16%, respectively (FAO, 1998). The area dedicated to the muskmelon crop in Spain in the past was traditionally around 70,000 ha (Navarro and Manjavacas, 1993) and has decreased over the past few years, the current figure having stabilised at about 45,000 ha (MAPA, 1998). Its production is * Corresponding author. Tel.: ‡34-967-599200; fax: ‡34-967-599238. E-mail address: [email protected] (C. Fabeiro).

0378-3774/02/$ ± see front matter # 2002 Elsevier Science B.V. All rights reserved. PII: S 0 3 7 8 - 3 7 7 4 ( 0 1 ) 0 0 1 5 1 - 2

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close to 1 million t, while its average yield ranges from 4 t/ha on dry farmland to just over 20 t/ha on irrigated land (Valls, 1984a,b; Zapata et al., 1988; Sobrino Illescas and Sobrino Vesperinas, 1989; Siviero et al., 1995). Under protected cropping (greenhouse, plastic mulching) conditions this figure may readily exceed 30 t/ha (Robles, 1992). The largest cropping surface areas correspond to the Smooth Rind and Tendril types though other varieties, such as the Cantaloupe, which has reached 12% of the cropping surface area over the last few years, have become increasingly more important. About 40% of the overall production is intended for exports (Almendros, 1987; Pleguezuelo, 1992; Palomar and GoÂmez, 1994, 1995; Palomar, 1995; Navarro et al., 1999). The largest areas are concentrated in the southern half of the Peninsula, where conditions are more favourable. About 30% of the national area dedicated to this crop is found in Castilla-La Mancha, in a semi-arid climate, and basically on irrigated land (Blanca, 1992; GonzaÂlez et al., 1992; MartõÂnez, 1994; Navarro et al., 1999; Ribas et al., 1998). Various experiments carried out under rainwater deficiency conditions during the crop's growth cycle have shown its positive response to irrigation in terms of both yield and quality. The literature available to date, though not extensive, seems to point clearly in this direction (Detar et al., 1983; Bhella, 1985; De Juan and MartõÂn de Santa Olalla, 1993; Pier and Doerge, 1995; Meiri et al., 1995). Controlled deficit irrigation (CDI) attempts to go one step further in this direction by relating the water stress which takes place in the plant at a certain phenological stage to losses in production and quality. The results obtained through CDI experiments enable us to select more productive irrigation scheduling strategies with water consumption adjusted to the physiology of yield development in the plant (Mitchell et al., 1984; English, 1990; English et al., 1990; SaÂnchez Blanco and Torrecillas, 1995). This paper attempts to analyse this kind of situation. The plant is subjected to moderate water stress at one or several phenological stages and the results obtained are analysed in terms of both production and fruit quality, as well as of water use efficiency. 2. Materials and methods The experiment was carried out during the growing season of 1998, between the months of June and September on the estate of `Las Tiesas', situated in Albacete (Spain). Its coordinates are latitude 398140 N and longitude 2850 W. Its altitude is 695 m a.s.l. According to Papadakis' agro-climatic classification, the climate is Temperate Mediterranean (MeTE) with Cool Oats Winter (av), Maize Summer (M), with a thermal regime of Temperate Warmth (TE) and a humidity regime of a Dry Mediterranean type (Me) (MartõÂn de Santa Olalla, 1994). Data are available on thermal and water characteristics of the area over a long period of time (1974±1993). Moreover, the data correspond to the year in which the experiment took place, were obtained, as the long-term record, from automated agro-climatic stations. Fig. 1 shows the data related to temperatures, rainfall and evapotranspiration corresponding to these periods. From this figure, it can be seen that the evolution of

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Fig. 1. Environmental conditions: year 1998 and period 1974±1993.

temperatures was similar, though with slightly higher values for 1998, with an average of 23 8C as compared to 22.1 8C, whereas rainfall during the testing period was significantly lower, 12.4 mm as opposed to 91.2 mm in the period (1974±1993). The average reference monthly evapotranspiration (ET0) obtained through Penman± Monteith's formula had a behaviour throughout the year of the test similar to that of the average shown. Its mean value in millimetre per day during the period of the whole experiment was 5.4, with a maximum of 6.4 in July and a minimum of 4.0 in September. According to the seventh approximation of the American Taxonomic Classification (USDA) the soil of the field tested is classified as Calcixerrollic±Petrocalcic± Xerochrepts. The average soil depth of the plot undergoing the experiment was 50 cm and limited by the development of the petrocalcic horizon which is found to be more or less fragmented. The texture is sandy-clay-loam, alkaline pH, poor in organic matter and total nitrogen and with a high active lime and potassium content. In order to obtain the hydrological characteristics of the soil profile, the empirical methods of Gupta and Larson (1979) and Rawls et al. (1982) were used as mentioned by Kern (1995). This methodology determines the total available water (TAW) as the difference between field capacity (FC) and permanent wilting point (PWP). In our case, taking into account 50 cm of depth of the root zone, the results obtained were TAW ˆ 59 mm according to Gupta and Larson and TAW ˆ 55 mm according to Rawls et al. A mean value of TAW ˆ 57 mm was adopted. To obtain the readily available water (RAW) the following expression was used: RAW ˆ TAW  p

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where p is the fraction of TAW that can be depleted from the root zone before moisture stress occurs. In our case the average value of 0.35, expressed as a rate per unit, was adopted. As a result of the above, RAW ˆ 20 mm. This value was taken as the maximum irrigation dose to be applied during the experimental period. For daily irrigation scheduling, in each of the water treatments which are mentioned further on, the method used was the simplified water balance in the root zone, by means of a software program devised by our own team (De Juan and MartõÂn de Santa Olalla, 1993), developed according to the methodology formulated by Doorenbos and Pruitt (1984), Doorenbos and Kassam (1986) and Allen et al. (1998). ET0 was calculated on a daily basis by means of Penman±Monteith's semi-empirical formula (Smith, 1991). The expression of the simplified water balance used was I n ˆ ET Pe  Dw, where In is the net irrigation requirements, ET the actual crop evapotranspiration calculated for each treatment as shown later, Pe the effective precipitation, and Dw is the soil water reserve variation. The experimental field used on the estate of `Las Tiesas' for these tests had a total surface area of 9.68 ha, 648 m2 of which was set apart for this work, divided into 18 elementary plots of 31.5 m2 each. These plots included three planting rows placed 1.5 m apart with a distance of 1 m between plants. The experimental design was developed in random blocks, with two replications for each of the nine treatments shown in Table 1. The statistical study has been made with SPSS package (SPSS, 1999). The vegetable material chosen was the `Sancho' hybrid from the Piel de Sapo cv. The following procedure was used to define the water treatments. The phenological cycle was divided into the five stages which are considered to be the most relevant from the point of view of their response to irrigation, i.e. Stage A: crop establishment; Stage B: from the onset of blooming to early fruit setting; Stage C: from early fruit setting to setting of the first two fruits; Stage D: fruit swelling; Stage E: from fruit ripening to harvesting. The total duration of the cycle was 99 days allocated to each phenological stage as shown in Table 1. For each water treatment, the value used as ET was the result of the expression ET ˆ ETc  C. The value of C is the variation expressed as a rate per unit by which the crop's evapotranspiration (ETc) is modified in each test. This modification was applied selectively to each phenological stage as shown in Table 1. From the above table, we can see the criteria according to which the design of the nine treatments has been conceived: Table 1 Design of CDI schedulinga Stage

Duration (days)

T1

T2

T3

T4

T5

T6

T7

T8

T9

A B C D E

35 14 7 15 28

1 1 1 1 0.6

1 1 1 0.7 0.6

1 1 0.8 1 0.6

1 1 0.8 0.7 0.6

1 0.8 0.9 0.85 0.6

1 0.6 1 1 0.6

1 0.6 1 0.7 0.6

1 0.6 0.8 1 0.6

1 0.6 0.8 0.7 0.6

a

Value of coefficient C in each treatment.

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 A test treatment (T1) is maintained with a value of C ˆ 1 throughout every stage.  During both crop establishment (Stage A) and ripening (Stage E) the values of C are kept constant in every treatment. In the first case without producing any water deficit in order to ensure good crop implantation and in the second instance keeping a water deficit level likely to guarantee a minimum standard of fruit quality.  As far as the intermediate (Stages B±D) phenological stages are concerned, only one of them is subjected to restriction in three treatments (T2, T3 and T6), two of them in another three (T4, T7 and T8) and the three of them in the remaining two (T5 and T9).  The restrictions are more significant in Stage B (C ˆ 0:6) than in Stage C (C ˆ 0:8), an average value (C ˆ 0:7) being taken for Stage D.  Treatment T5 with mean value restrictions across the three stages is mainly devised to allow, with the values obtained from it, a better adjustment in the production and efficiency functions we wish to obtain. This design is intended to test the effect of ET variations at different phenological stages on an isolated or combined basis (Box et al., 1989). 3. Results 3.1. Total water received Table 2 shows the volume of water actually received through irrigation for each treatment. Moreover, it shows the effective precipitation (Pe) value. The only value taken into account was that of Pe ˆ 12:4 mm received by the crop in Stage D. This was the only value during the whole period which exceeded the minimum threshold of 5 mm without reaching the maximum threshold, i.e. the value which would have caused the soil to exceed its field capacity. The total amount of irrigation water applied ranged from 407 mm in T1 to 339 mm in T9 and the number of irrigation events ranged from 26 to 22 in the various treatments. The Pe value showed a low percentage when compared to that of water applied through irrigation, namely 3.66% in the case of the least irrigated treatment (T9) and 3.04% in the Table 2 Volume of water (mm) from irrigation and effective precipitation (Pe) Stage

Pe

Treatments T1

T2

T3

T4

T5

T6

T7

T8

T9

A B C D E

0 0 0 12.4 0

120 82 50 83 72

120 82 52 54 72

120 82 42 83 72

120 82 42 54 72

120 65 46 70 72

120 50 52 83 72

120 50 52 53 72

120 50 42 83 72

120 50 41 56 72

Total No. of irrigation events

12.4 ±

407 26

380 24

399 26

370 24

373 24

377 24

347 22

367 24

339 22

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Table 3 Actual scheduling of CDIa Stage

A B C D E

Actual ETc fulfilment percentage for each treatment T1

T2

T3

T4

T5

T6

T7

T8

T9

100.5 100.7 96.9 99.5 59.8

100.5 100.7 100.8 69.2 59.8

100.5 100.7 81.4 99.5 59.8

100.5 100.7 81.4 69.2 59.8

100.5 79.7 89.1 85.9 59.8

100.5 61.4 100.2 99.5 59.8

100.5 61.4 100.8 68.2 59.8

100.5 61.4 81.4 99.5 59.8

100.5 61.4 79.5 71.3 59.8

91.5

86.2

88.4

82.3

83.0

84.7

78.1

80.5

74.5

Average a

Irrigation ‡ effective precipitation.

one that received the largest amount of water (T1). The crop's development can therefore be considered to have depended essentially on the application of irrigation water. This fact will be taken into account when conclusions are drawn from the results obtained. Table 3 shows the actual CDI scheduling carried out during the season expressed as the ETc fulfilment rate. The actual levels of water applied do not differ significantly from those scheduled. This can be accounted for by the fact, mentioned earlier, that the rainfall was extremely low during the experiment. Bearing in mind these actual data on the fulfilment of water requirements, we analysed the results. 3.2. Yield Table 4 shows the quantitative yield obtained as well as its main components. The number of plants per ha was the same in each and every case, which was to be expected as Table 4 Quantitative yield and its componentsa Treatments

Plant density (103 plants/ha)

Melons (unit per plant)

Fresh weight (g per unit)

Fresh production (t/ha)

T1 T2 T3 T4 T5 T6 T7 T8 T9

6.66 6.66 6.66 6.66 6.66 6.66 6.66 6.66 6.66

2.93 2.57 2.70 2.40 2.40 2.40 2.30 2.40 2.25

2575.0 2537.5 2562.0 2325.5 2337.5 2487.5 2275.0 2300.0 2275.0

51.25 43.43 46.07 37.17 37.36 39.76 34.85 36.76 34.09

NS

*

(100/100/97/99/60) (100/100/100/69/60) (100/100/81/99/60) (100/100/81/69/60) (100/80/89/86/60) (100/61/100/99/60) (100/61/101/68/60) (100/61/81/99/60) (100/61/79/71/60)

SSL

a b abc bc bc bc bc bc c

*

a a a bc bc b c c c

a ab ab bc bc abc c bc c

**

a The values with the same letter are statistically homogeneous in Duncan's test. SSL: statistical significance level; NS: not significant (P > 0:05). * P < 0:05. ** P < 0:01.

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99

all the treatments were initiated under identical conditions. The number of fruits per plant ranged from 2.93 in T1 to 2.25 in T9. From the analysis of variance, it can be seen that there are significant differences among the various treatments. The Duncan's multirange test enables us to detect differences on a two by two basis between certain treatments with 95% probability. This is the case of the extreme treatments (T1 and T9) as compared to their remaining counterparts. The intermediate treatments, T3±T8, do not show any difference between each other when this test is applied to them. According to Barlow et al. (1980), the fruit number per plant is defined during Stages A and B, which is when the differentiation of vegetative and reproductive structures takes place, this period being highly sensitive to water deficit. The results obtained seem to confirm this fact. The effect of water stress during Stage B (blooming) on the number of melons per plant can be obtained from the following equation (Box et al., 1989): Y ˆ …1=4†‰…T1 ‡ T2 ‡ T3 ‡ T4†

…T6 ‡ T7 ‡ T8 ‡ T9†Š

(1)

where T1±T4 are the treatments which did not undergo water stress in the above stages and T6±T9 are those which withstood it, all of them having the same intensity (C ˆ 0:6). The value resulting from the application of Eq. (1) was, in our case, 0.91 fruits per plant. If we follow the analysis of yield components, Table 4 shows the fresh weight per unit for each fruit expressed in grams per unit. As in the previous case, significant differences are reported between the values obtained, which range from 2575 in T1 to 2275 in T9. The application of Duncan's test also enables us to establish a number of homogeneous groups. T1±T3 show significant differences with 95% probability as compared to the remaining treatment. The same significant differences can be seen, in turn, between treatment T6 and T7, and T8 and T9. The effect of water stress in the fruit swelling period (Stage D) can be determined with the same criteria as in the above case through the expression Y ˆ …1=4†‰…T1 ‡ T3 ‡ T6 ‡ T8†

…T2 ‡ T4 ‡ T7 ‡ T9†Š

(2)

By applying Eq. (2), we obtain as a result the difference in fruit weight per unit between the treatments which do not undergo de®cit and those which do is 121.7 g per unit. Finally, Table 4 contains the fresh fruit production (t/ha) which ranges from 51.25 in T1 to 34.09 in T9, once again with significant differences. Duncan's test enables us to differentiate certain homogeneous groups. Treatment T1 is statistically different from T4, T5, T7, T8 and T9, at 5%. Differences at the same level are also to be found between the groups T2 and T3, and the groups T7 and T9. The effect of the total water deficit undergone in Stages B (blooming) and D (fruit swelling) on the actual yield can be obtained, as in the previous cases, from the expression Y ˆ …1=2†‰…T1 ‡ T3†

…T7 ‡ T9†Š

(3)

From expression (3) it can be seen that the treatments which did not undergo de®cit during blooming and fruit swelling obtained a yield 14.14 t/ha higher than those which did.

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3.3. Fruit quality In this experiment, different parameters related to fruit quality were assessed (Siviero et al., 1995). Some of them refer to morphological aspects of the actual fruit, such as its perimeter, both crosswise and length-wise, thickness of pulp and rind, or size of seminal cavity. The results obtained did not show any significant differences or enable us to establish homogeneous groups in the application of Duncan's test. For this reason their inclusion in this text is not considered to be relevant. We do, however, consider the presentation of the results on pulp sugar content in degrees Brix to be of some interest. Measurements were taken close to both the rind and the seminal cavity and average values were obtained for both. In the three cases, the results were highly significant, the homogeneous groups also becoming differentiated in the application of Duncan's test. In this article, the values shown in Table 5 only relate to those corresponding to average degrees Brix of pulp sugar. From the above, it can be seen that the values ranged from 12.24 in T1 to 13.24 in T9. With a lower irrigation intake, the concentration of sugars in the fruit becomes higher. According to Duncan's test, T1±T3 show highly significant differences as compared to T7 and T9. 3.4. Production functions In the experiment, various production functions have been studied (Solomon, 1985; Howell et al., 1990) which relate production components and parameters to the volume of irrigation water applied. From these, we have selected for presentation in this paper that which links irrigation water to total production of fresh fruit and that which relates this parameter to average degrees Brix of pulp sugar. Through regression analysis, we have sought second- and third-degree polynomial functions and determined, in each case, their coefficients, standard error, determination Table 5 Average degrees Brix of pulp sugara Treatments

Degrees Brix

T1 T2 T3 T4 T5 T6 T7 T8 T9

12.24 12.63 12.32 13.03 13.00 12.95 13.14 13.07 13.24

(100/100/97/99/60) (100/100/100/69/60) (100/100/81/99/60) (100/100/81/69/60) (100/80/89/86/60) (100/61/100/99/60) (100/61/101/68/60) (100/61/81/99/60) (100/61/79/71/60)

SSL

a a a ab ab ab b ab b

**

a The values with the same letter are statistically homogeneous in Duncan's test. SSL: statistical significance level. ** P < 0:01.

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101

Fig. 2. Relationship between muskmelon production (kg/ha) and irrigation volume.

coefficient (R2), statistical significance level and residual analysis, which includes variance, typical deviation and average. With regard to fresh fruit weight, the mathematical function obtained, a second-degree polynomial, shows a highly significant determination factor (R2) of 0.950. Fig. 2 represents this function. The curve shows a markedly upward trend which entails clear response of production to irrigation. Nevertheless, it can also be seen that the slope of this curve is rather smooth up to 360 mm, which is where it becomes considerably steeper. With regard to the function which relates degrees Brix to irrigation volume, it was also adjusted to a second-degree polynomial with a high determination coefficient (R2) of 0.939, as shown in Fig. 3. In this function we can see an initial slope, here too, up to an irrigation volume of 360 mm, with a smooth decrease in degrees Brix, whereas for higher water values the slope becomes steeper and reaches its minimum values above 400 mm. One aspect which, in our opinion, should be interesting to assess is the extent to which the volume of irrigation water received by the plant affects the quality of its fruit at each

Fig. 3. Relationship between average degrees Brix and irrigation volume (mm).

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phenological stage, which can be done by analysing all of them together as a whole. For this purpose, leaving aside both Stages A and E, as in both cases the same volume was applied to all the treatments, multiple regressions were made by taking as independent variables the irrigation water applied at each stage and as dependent variables the yield in one case and the degrees Brix in the other. The equations obtained were as follows: yield …kg=ha† : 284; 186x1 ‡ 356; 024x2 ‡ 70; 288x3 ;

R2 ˆ 99:71

average degrees Brix : 0:0084x1 ‡ 0:2155x2 ‡ 0:0324x3 ;

2

R ˆ 98:66

(4) (5)

where x1, x2 and x3 express the irrigation volumes in mm applied in Stages B±D, respectively. The signi®cance of the adjustments made was 95%. The coefficient values of the independent variables show the effect of irrigation corresponding to each phenological stage, one point to be singled out in this respect being the considerable effect of irrigation in Stage C (setting) in terms of both quantity and quality of fruit obtained. Stage B (blooming) shows a greater effect than Stage D (ripening) as far as harvesting quantities are concerned, but the reverse happens when it comes to fruit quality, as represented by sugar content. 3.5. Water use efficiency Water use efficiency (WUE) is defined as the relationship between units produced and volume of irrigation water applied (Sinclair et al., 1984). Fig. 4 shows the WUE value in our experiment expressed as grams of fresh fruit weight produced per cubic metre of irrigation water applied and represented versus irrigation water (mm). The adjustment of the values obtained in the various treatments to a second-degree polynomial function is highly significant, with a correlation coefficient R2 ˆ 0:873.

Fig. 4. Water use efficiency expressed in grams of fruit per cubic metre of irrigation water.

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The values obtained range from 125:481  102 in T1 to 100:664  102 in T9, though the differences between the various treatments have not proved to be significant. The application of Duncan's test has only enabled us to distinguish T1 from T4, T5, T7, T8 and T9 with a significance level of 5%. 4. Conclusions In a semi-arid climate, the muskmelon crop which is the object of our experiment (Saccaharinus variety, Piel de Sapo cv.) shows positive response to irrigation in terms of both production and pulp sugar content. The experiment was carried out with irrigation levels ranging from 339 to 407 mm throughout the season. The differences in production expressed as tonnes per hectare have not proved to be significant, but in contrast, the effect of irrigation on fruit quality, shown as degrees Brix, was significant. The experiment does not enable us to know what the response of the actual production or quality would have been above the 407 mm applied in the treatment which received the highest amount of irrigation water. The analysis of the irrigation doses applied in the various phenological stages has enabled us to assess the effect of each of them on yield patterns and quality. The deficit imposed at blooming stage affects mainly the quantity (yield), at setting stage affects both quantity and quality, and lastly the deficit imposed at ripening stage affects principally the quality (sugar content). The water use efficiency values found in this experiment show results which are somewhat different from those which might have been expected. The most deficient strategies often prove to be the most efficient. This did not happen in our case, in which the greatest efficiency was found in the treatment which was subjected to no water restrictions, which may be accounted for by the larger production obtained. When we attempt to select a strategic course of action recommendable for CDI, we can point out that, with total volumes of water applied ranging from 370 to 410 mm we can obtain production rates which exceed 40 t/ha provided the fruit setting period is not affected by water stress, particularly in its early stages. Under these conditions, the fruit obtained would be fairly rich in sugar content. It would be interesting to assess the crop's response to applications of irrigation water above those used in the experiment, though its practical relevance would be limited to non-restrictive irrigation conditions. References Allen, R.G., Pereira, L.S., Raes, D., Smith, M., 1998. Crop evapotranspiration. Guidelines for computing crop water requirements. Paper 56, FAO irrigation and chain. Almendros, P., 1987. El cultivo moderno del meloÂn y la sandõÂa. De Vecchi S.A., Barcelona. Barlow, E.W.R., Munns, R.E., Brady, J.C., 1980. Drought responses of apical meristems. In: Turner, N.C., Kramer, P.J. (Eds.), Adaptation of Plants to Water and High temperatures Stress. Wiley, New York, pp. 191± 205.

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Bhella, H.S., 1985. Muskmelon growth, yield and nutrient as influenced by planting method and trickler irrigation. J. Am. Soc. Hortic. 110, 793±796. Blanca, I., 1992. Perspectivas del cultivo de meloÂn en Ciudad Real. Hortofruticultura 3, 41±43. Box, G.E.P., Hunter, W.G., Hunter, J.S., 1989. EstadõÂstica para investigadores. Reverte, Barcelona, p. 675. De Juan, J.A., MartõÂn de Santa Olalla, F.J., 1993. El estreÂs hõÂdrico en las plantas. In: MartõÂn de Santa Olalla, J.F., de Juan, J.A. (Coordinadores). AgronomõÂa del Riego. Mundi-Prensa S.A., Universidad de Castilla-La Mancha, Madrid, pp. 126±238. Detar, W.R., Kibler, D.F., Grenoble, D.W., Cok, R.H., Tukey, D., Hampson, S.H., Geller, S.C., 1983. Trickler irrigation versus no irrigation of five horticultural crops in Pennsylvania. Trans. ASAE 26, 82±86. Doorenbos, J., Kassam, A.H., 1986. Efectos del agua sobre el rendimiento de los cultivos. Estudio FAO Riego y Drenaje, Vol. 33. FAO, Rome. Doorenbos, J., Pruitt, W.O., 1984. Las necesidades de agua de los cultivos. Estudio FAO Riego y Drenaje, Vol. 24. FAO, Rome, p. 194. English, M.J., 1990. Deficit irrigation. Analytical framework. J. Irrig. Drain. Eng. 116, 399±412. English, M.J., Musick, J.T., Murty, V.V.N., 1990. Deficit irrigation. In: Hoffman, G.J., Howell, T.A., Solomon, K.H. (Eds.), Management of Farm Irrigation Systems. ASAE, St. Joseph, MI, pp. 631±663. FAO, 1998. http://www.fao.org/default.htm. GonzaÂlez, A., Vicente, F., FernaÂndez, J.A., BotõÂa, A., 1992. El meloÂn en la regioÂn de Murcia. Hortofruticultura 3, 34±40. Gupta, S.C., Larson, W.E., 1979. Estimating soil water retention characteristics from particle size distribution, organic matter content, and bulk density. Water Resources 15, 1633±1635. Howell, T.A., Cuenca, R.H., Solomon, K.H., 1990. Crop yield response. In: Hoffman, G.J., et al. (Eds.), Management of Farm Irrigation System. Monography, Vol. 9. St. Joseph, MI, pp. 93±122. Kern, J.S., 1995. Evaluation of soil water retention models based on basic soil physical properties. Soil Sci. Am. J. 59, 1134±1141. MAPA, 1998. http://www.mapya.es/indices/pags/info/index.htm. MartõÂn de Santa Olalla, F.J., 1994. DesertificacioÂn en Castilla La-Mancha. En: MartõÂn de Santa Olalla, J.F. (Coordinador). El proyecto EFEDA. Universidad de Castilla-La Mancha, p. 254. MartõÂnez, J., 1994. El cultivo del meloÂn en Castilla-La Mancha. Hortofruticultura 12, 24±26. Meiri, A., Lauter, D.J., Sharabani, N., 1995. Shoot growth and fruit development of muskmelon under saline and non-saline soil water deficit. Irrig. Sci. 16, 15±21. Mitchell, P.D., Jerie, P.H., Chalmers, D.J., 1984. Effects of regulated water deficits on pear tree growth, flowering, fruit growth and yields. J. Am. Soc. Hortic. Sci. 109, 604±606. Navarro, A., Manjavacas, M., 1993. El cltivo del meloÂn. Hortofruticultura 12, 26±28. Navarro, J.M., Botella, M.A., GarcõÂa, F., 1999. Rendimiento de plantas de meloÂn sometidas a estreÂs salino bajo diferente fertilizacioÂn de foÂsforo y calcio. VIII Congreso Nacional de Ciencias HortõÂcolas, Murcia, pp. 333± 338. Palomar, F., 1995. Cultivo del meloÂn Piel de sapo y Rochet. Poniente 357, 60±67. Palomar, F., GoÂmez, M.C., 1994. Cultivo del meloÂn galia y Cantalupo. Poniente 352, 84±93. Palomar, F., GoÂmez, M.C., 1995. Cultivo del meloÂn amarillo. Poniente 355, 24±31. Pier, J.W., Doerge, T.A., 1995. Nitrogen and Water Interactions in Trickle-Irrigated Watermelon. Soil Sci. Am. J. 59, 145±150. Pleguezuelo, P., 1992. El meloÂn de los 90. Hortofruticultura 3, 31±33. Rawls, W.L., Brakensiek, D.L., Saxton, K.E., 1982. Estimation of soil water properties. Trans. ASAE 25, 1316± 1320. Ribas, F., Moreno, M., Cabello, M.J., Moreno, A., 1998. Influencia del riego y del abonado potaÂsico en el contenido de azuÂcar del meloÂn en Ciudad Real. XVI Congreso Nacional de Riegos, Palma de Mallorca. Robles, J., 1992. CoÂmo se cultiva en invernadero. De Vecchi, Barcelona. SaÂnchez Blanco, M.J., Torrecillas, A., 1995. Aspectos relacionados con la utilizacioÂn de estrategias de riego deficitario controlado en cultivos lenÄosos. En Riego Deficitario Controlado. Cuadernos VALUE, MundiPrensa S.A., Madrid, pp. 45±65. Sinclair, T.R., Tanner, C.B., Bennett, J.M., 1984. Water use efficiency in crop production. Biol. Sci. 34, 36±40. Siviero, P., Macchiavelli, L., Eoni, M., 1995. Valutazione chimico fisica di ibridi di melone L.S.L. Rev. Culture Proteife. 11, 83±92.

C. Fabeiro et al. / Agricultural Water Management 54 (2002) 93±105

105

Smith, M. (Ed.), 1991. Report on the Expert Consultation on Procedures for Revision of FAO Guidelines for Prediction of Crop Water Requirements. FAO, Rome, p. 45. Sobrino Illescas, E., Sobrino Vesperinas, E., 1989. MeloÂn. En Tratado de Horticultura HerbaÂcea. I. Hortalizas de Flor y de Fruto. Aedos, Barcelona, pp. 155±182. Solomon, K.H., 1985. Typical crop water production functions. In: Proceedings of the Winter Meeting, Vol. 85. ASCE, Chicago, pp. 17±20. SPSS Inc., 1999. SPSS 9.0 Syntax Reference Guide. SPSS Inc., Chicago, p. 600. Valls, J., 1984a. Algunas ideas sobre el meloÂn. AgrõÂcola Vergel 27, 149±158. Valls, J., 1984b. Algunas ideas sobre el meloÂn. AgrõÂcola Vergel 30, 334±347. Zapata, M., Cabrera, P., BanÄoÂn, S., Roth, P., 1988. El MeloÂn. Mundi-Prensa S.A., Madrid.