Utilization of grafting technique for sustaining cantaloupe productivity and quality under deficit irrigation water

Abstract

Background

Water use efficiency (WUE) is becoming a decisive factor for agricultural expansion to face water shortage. To meet the needs of high population density in Egypt, we have to use modern irrigation systems and new cultivation technologies. The current study is aiming to apply grafting technique for ameliorating the impact of deficit water on cantaloupe productivity and fruit quality. Two commercial cultivars (Ideal and Veleta) were grafted on two rootstocks (Cobalt and Strong-Tosa) and self-grafting. The seedlings were treated with three different irrigation levels: 100, 75, and 50% of Class A pan Evapotranspiration (ETc).

Results

The results showed that moderate irrigation level (75% ETc) increased the early yield, fruits number, by 15.3 and 17.4%, respectively, compared to control irrigation treatment (100% ETc). No significant variation was found concerning total yield between 100 and 75% ETc, so this led to an increase in WUE of moderate irrigation level (75% ETc) by 34.3%, compared to control irrigation treatment (100% ETc). Increasing deficit levels up to 50% ETc reduced the total yield by 47.4%, but it increased the WUE by 8.8%, compared to the non-deficit irrigation level (100% ETc). Meanwhile, grafting both cultivars on Cobalt rootstock improved the fruit number, total yield, and WUE by 39.2%, 26.9%, and 24.1%, respectively when irrigated with the moderate irrigation level (75% ETc), as compared to the non-grafted plants which recorded the highest decrease when irrigated with deficit irrigation level (50% ETc).

Conclusion

Finally, the combination treatments of Ideal/Strong-Tosa, Veleta/Cobalt, or Ideal/Cobalt irrigated with moderate irrigation level (75% ETc) increased the WUE by 97.3, 83.4, and 65%, respectively, compared to the control treatment (non-grafted plants of the same cv. at 100% ETc) and recorded higher flesh thickness, TSS and firmness.

Background

Cantaloupe (Cucumis melo L.) is a high economic vegetable crop in many countries including Egypt. It is grown in practically every country in the world under outdoor fields or greenhouses (Glala et al. 2010). The cultivated area of cantaloupe in Egypt is 66,434 feddan with a total production of 846,936 tons and an average of 12.749 ton per fed, while exports of cantaloupe fruits amounted 2689.88 ton per year (Ministry of Agric, Egypt 2015). Fruits are consumed in summer period and are popular because the pulp of the fruit is very refreshing, high nutritional, and sweet with a pleasant aroma.

The most important problems facing the horizontal expansion of cantaloupe in greenhouses or in open field are the water shortage, especially in the new reclaimed lands. Whereas, deficit irrigation had an opposite influence on production of fruits (Al-Mefleh et al. 2012; de Azevedo 2016; Elvis et al. 2017) and physical fruit quality expressed as weight, length, diameter average weight, and size are severely decreased (Zeng et al. 2009; de Azevedo 2016 as well as on watermelon Ibrahim 2012 and Elvis et al. 2017). This leads the researcher to use some new trends to mitigate these negative impacts. The grafting technique is one of the most modern trends used to improve the productivity of vegetable plants, especially under adverse environmental conditions. The advantages of grafting depend on using suitable rootstock capable to reduce the effects of biotic and abiotic stresses (Colla et al. 2014). Grafting vegetables on to resistant rootstocks offers numerous advantages on growth and yield, i.e., improving water use efficiency and tolerance to deficit irrigation (Wahb-Allah 2014; Özmen et al. 2015) and increase yield and fruit quality in many crops such as cucumber (Hsiu-Fung and Yung-Fu 2013), melon (Liu et al. 2011), and watermelon (Mohamed et al. 2014). Accordingly, the present study was conducted to investigate the possibility of using grafting as a new promising technique for ameliorating the negative effects of deficit irrigation water on cantaloupe yield and fruit quality.

Material and methods

This study was carried out in a private farm, Kalyobiya Governorate, Egypt during 2015 and 2016 autumn seasons to investigate the possibility of improving production and quality of cantaloupe yield under deficit of irrigation water by using grafting technique. Commercial cantaloupe cultivars (Cucmis. melo var. reticulates) Veleta RZ (Rijk-Zwaan Co.) and Ideal (Syngenta Co.) were used as scions while the Cobalt (Rijk-Zwaan Co.) and Strong-Tosa (Syngenta Co.) were used as rootstocks. A modified tongue approach grafting method was used to produce the grafted seedlings. The grafted seedling and the control (non-grafted) were transplanted under net house condition, on the 21st of July in both investigation seasons. The plants were transplanted on ridges of 1.5 m width, on one side of the ridge at 50 cm apart.

Experimental soil was clay soil in texture with pH of 8.0 and EC of 1.3 ds/m. Underground water with pH of 7.8 and EC of 0.8 ds/m was used in the experimental site. Three irrigation levels were used, i.e., 100% crop water requirement (ETc) “as a control treatment,” 75% ETc “as a moderate treatment,” and 50% ETc “as a deficit water treatment.” Class A pan evapotranspiration equation was used to calculate the daily amount of irrigation water. The total amount of added water through the drip irrigation system was measured by ginger for each water regime treatment. The average amounts of applied irrigation water in 100% ETc treatment were 1.500, 3.400, 4.250, and 3.600 litter in August, September, October, and November, respectively. Then, amounts were reduced to 75% and 50% to apply 75% ETc and 50% ETc treatments. A split split-plot designed was adopted with three replicates where water regimes were placed in main plots; meanwhile, cultivars in sub plots and rootstocks in sub-sub plots.

Yield of the first tow pickings was considered as early yield as well as number of fruits per plant and total yield per plant (g) were calculated in the end of the growing season. Water use efficiency (WUE) was calculated as the total yield divided by the amount of irrigation water applied according to Howell et al. (1990). The fruit length and diameter were measured to calculate fruit shape index (fruit length/fruit diameter). Finally, average fruit weight (g), flesh thickness of fruit (cm), and seed cavity diameter (cm) as well as fruit firmness and total soluble solids percentage (A.O.A.C. 1990) were measured. Data were subjected to the statistical analysis by the method of Duncan’s multiple range tests as reported by Gomez and Gomez (1984). Statistical analysis was performed with SAS computer software.

The obtained results of both seasons were used to evaluate the effect of deficit stress. Drought resistance indices were defined according to Ibrahim (2011) by the following formula:

• 1. Stress susceptibility index = (1-Ys/Yw)/D (Fisher and Maure 1978).

• 2. Relative yield reduction = 1-Ys/Yw (Hiller and Clark 1971).

Where Ys is the mean of yield under a deficit water, Yw is the mean of yield under well-watered conditions, and D is the environmental stress intensity = 1-(mean yield of all varieties under deficit/mean yield of all treatments under well-watered conditions). The relative yield under deficit water was calculated as the yield of a specific genotype under deficit irrigation divided by that of the highest yielding genotype in the population of the experiment.

Based on the average of two seasons, the total yield was used to calculate the costs, benefits, and saving of using grafted and non-grafted cantaloupe plants grown under deficit irrigation water.

Results

Effect of grafting technique (cultivars “scions” and rootstocks) under deficit of irrigation on the physical quality of cantaloupe fruits

Data presented in Tables 1, 2, and 3 showed the effect of deficit irrigation rates, cultivars, rootstocks, and their interaction on fruit shape index, average fruit weight, flesh thickness of fruit, seed cavity diameter, fruit firmness, and total soluble solid (TSS), respectively.

Table 1 Effect of deficit irrigation rates (% ETc), cultivars, and rootstocks on fruit shape index and average fruit weight (g) of cantaloupe plants during 2015 and 2016 seasons

Table 2 Effect of deficit irrigation rates, cultivars and rootstocks on flesh thickness (cm) and seed cavity diameter of fruit for cantaloupe plants during 2015 and 2016 seasons

Table 3 Effect of deficit irrigation rates, cultivars and rootstocks on firmness and TSS of fruit for cantaloupe plants during 2015 and 2016 seasons

All fruits quality parameters except for fruit shape index (average fruit weight (g), flesh thickness of fruit, seed cavity diameter, fruit firmness, and TSS) were positively affected by irrigation levels. Where, average fruit weight and flesh thickness of fruit were decreased by increasing deficit rates, and the opposite trend with regard to fruit firmness and TSS, which were increased by increasing deficit rates. These results are in agreement with those of Ibrahim (2012), Li et al. (2012), and de Azevedo (2016). Most fruits quality parameters, i.e., fruit shape index, average fruit weight, flesh thickness of fruit, and fruit firmness, were significantly affected by the cvs. Veleta and Ideal. Where, Ideal cultivar fruits recorded the highest values of all fruits quality parameters, except for fruit shape index. In general, Ideal cultivar fruits were bigger and heavier than those of cv. Veleta, while Veleta fruits were the longer little than those of Ideal, and the opposite trend at the fruit diameter all over the growing seasons, this led to increase in the value of fruit shape index with cv. Veleta. Fruit quality expressed as average fruit weight, flesh thickness, and seed cavity diameter were positively affected by Cobalt rootstock, while there were no significant responses regarding to other parameters (fruit shape index, fruit firmness, and TSS). The obtained results are matched with those reported by Rouphael et al. (2012) and Proietti et al. (2008).

Effect of grafting technique (cultivars and rootstocks) under deficit irrigation on fruit yield and its components of cantaloupe plants

Data presented in Tables 4 and 5 indicate the effect of deficit irrigation rates, cultivars, rootstocks, and their interaction on early yield, fruits number, total yield (g/plant), and WUE, respectively.

Table 4 Effect of deficit irrigation rates (% ETc), cultivars and rootstocks on early yield (g/plant) and fruits number/plant of cantaloupe plants during 2015 and 2016 seasons

Table 5 Effect of deficit irrigation rates, cultivars and rootstocks on fruit yield (g/plant) and WUE of cantaloupe plants during 2015 and 2016 seasons

The effect of deficit irrigation levels was very clear, where the moderate level (75% ETc) showed higher significant positive effects on early yield, fruits number, and WUE. Whereas irrigation with moderate level (75% ETc) increased the early yield, fruits number by 15.3 and 17.4%, respectively, comparing with control of irrigation water (100% ETc). No significant effect was found between 100 and 75% ETc on the total yield, so that this led to increase the WUE of moderate level (75% ETc) by 34.3%, compared to non-deficit irrigation level (100% ETc). Meanwhile, increasing deficit levels up to 50% ETc reduced the fruits number and total yield by 9.9% and 47.4%, respectively, but increased the WUE by 8.8%, comparing with non-deficit irrigation level (100% ETc). The obtained results are matched with those reported by Yildirim et al. (2009) and Al-Mefleh et al. (2012), who reported that there were no significant differences on total yield between high level and medium level of irrigation water. Concerning the effect of cultivars, cv. Ideal recorded the highest values of early yield, fruits number, total yield, and WUE, compared with cv. Veleta. The effect of rootstocks was very clear, where Cobalt showed higher significant positive effect on early yield, fruits number, total yield, and WUE. Grafting on Cobalt rootstock increased the fruits number, total yield, and WUE by 18.0%, 33.3%, and 36.3%, respectively, comparing with non-grafted plants. The obtained results are matched with those reported by Rouphael et al. (2012), Proietti et al. (2008), and Özmen et al. (2015), who noticed that grafted watermelon plants gave the highest fruit yields, comparing with non-grafted plants.

The early yield, fruits number, total yield, and WUE were not significantly affected by the interaction between cultivars and irrigation levels treatments. Even so, Ideal cv. recorded the highest increase at two levels 100 and 75% ETc and the lowest decrease at 50% ETc (high deficit irrigation level). Such results have coincided with those found by EL-Tawashy (2016) who reported that cv. Magenta produced higher yield per plant, compared to cv. Visa when irrigated by 20 m³, compared to 10 m³ water/fed. The interaction between rootstocks and deficit irrigation rates treatments improved the early yield, fruits number, total yield, and WUE. The highest increase on early yield (21%), fruits number (39.2%), total yield (26.9%), and WUE (24.1%) was represented in Cobalt rootstock when irrigated by the moderate level (75% ETc). Meanwhile, non-grafted plants recorded the highest decrease when irrigated with high deficit irrigation level (50% ETc). Also, the interaction between cultivars and rootstocks treatments improved fruits number, total yield, and WUE by grafted Ideal cv. on Strong-Tosa rootstock and combination of Veleta/Cobalt. Where, Ideal/Strong-Tosa combination improved fruits number, total yield, and WUE by 35.6, 75.6, and 33.8%, respectively, comparing with non-grafted plants of cv. Ideal, but this increase was 22.6, 47.4, and 42.8% by the combination of Veleta/Cobalt, comparing with non-grafted plants of cv. Veleta. The obtained results are matched with those reported by Rouphael et al. (2012), Proietti et al. (2008), Özmen et al. (2015), and Hussien (2016), who showed that grafted watermelon plants gave the highest fruit yields, comparing with non-grafted plants under various levels of irrigation water.

The best interaction effects among the three studied factors could be summarized in the combination of Ideal/Strong-Tosa or Veleta/Cobalt, followed by Ideal/Cobalt with non-deficit irrigation level (100% ETc) and medium (75% ETc) of deficit irrigation levels as shown in Tables 4 and 5. The total yield of cantaloupe plants was decreased when non-grafted and grafted plants were grown under high deficit irrigation level (50% ETc). However, the % decline varied according to the rootstock used. In this respect, the lowest decrease of the total yield was in the graft combination Ideal/Strong-Tosa or Veleta/Cobal, followed by Ideal/Cobalt. While, the graft combination Veleta/Strong-Tosa and non-grafted plants for both cultivars recorded the highest % decline, as compared to the general control (non-grafted plants at 100% ETc). Concerning fruits number and WUE, combination of Ideal/Strong-Tosa, Veleta/Cobalt, and Ideal/Cobalt recorded increase on fruits number and not decline on WUE at the high deficit irrigation level (50% ETc) as shown in Table 5.

In general, the sharp deficit water (50% ETc) reduced the fruits number and total yield by 9.9 and 47.4%, respectively, but increased the WUE by 8.8%, compared to non-deficit irrigation level (100% ETc). Meanwhile, grafting both cultivars on rootstocks improved fruit number, total yield, and WUE. Where, the highest increase on fruit number (39.2%), total yield (26.9%), and WUE (24.1%) were represented in Cobalt rootstock when irrigated with the moderate level (75% ETc). Meanwhile, non-grafted plants recorded the highest decrease when irrigated by high deficit irrigation level (50% ETc).

Evaluation of deficit resistance

Yield losses from the normal level due to water stress are useful in assessing drought resistance. A larger value of relative yield reduction (RY) may show more sensitivity to stress, thus a smaller value of relative yield reduction is favored. Presented data in Table 6 explain that cv. Ideal had the smallest relative yield reduction value (RY = 45%), as compared to cv. Veleta, which recorded the largest relative yield reduction value (RY = 52%), so cv. Ideal was the best cultivar based on this index. The obtained results coincide with those obtained by Ibrahim (2011), who noticed that cv. Ananas El-Dokki had the smallest relative yield reduction value (26%), comparing with Ismaelawi cv. (28%). Concerning the test of rootstocks, Cobalt rootstock had the smallest relative yield reduction value (RY = 44%), comparing with non-grafted of both cvs, which recorded the largest relative yield reduction value (RY = 54%), so Cobalt rootstock was the best rootstock to use as rootstock for grafting cantaloupe plants based on this index. Moreover, grafting cv. Ideal on rootstock Cobalt or Strong-Tosa recorded the lowest relative yield reduction values (39 and 44%, respectively).

Table 6 Average yields of grafted and non-grafted cantaloupe plants (based on the average of two seasons) under normal (Yw) and stress (Ys) conditions, stress susceptibility index (SSI), relative yield reduction, and relative yield under water stress (RY_S)

The stress susceptibility index (SSI) appeared to be a suitable selection index to distinguish resistant cultivars or rootstocks as well as their interaction. Genotypes with low SSI values (less than 1) can be considered to be drought resistant (Fisher and Maure 1978), because they exhibited smaller yield reductions under water stress, comparing with well-watered conditions. The cultivar Ideal and rootstock Cobalt as well as the interaction of their (Ideal/Cobalt) were relatively drought-resistant (SSI values < 1).

SSI values are not enough to determine the drought-tolerant genotypes; this could be done with the help of relative yield under water stress estimate. The mean relative yields values under imposed water stress was 0.63 (Table 6). The cultivar Ideal was relatively high yielding under water stress (RY_s > mean RY_s), comparing with cv. Veleta (RY_s < mean RY_s). These results are in agreement with those obtained by Ibrahim (2011) who found that melon cv. Albasosi was relatively high yielding under water stress (RY > mean RY), while Shahd El-Dokki and Ananas El-Dokki were relatively low yielding (RY < mean RY). Regarding the test of rootstocks, Cobalt rootstock was relatively high yielding under water stress (RY_s > mean RY_s), while non-grafted plants of the two cultivars were relatively low yielding (RY_s < mean RY_s). Furthermore, grafted plants as Ideal/Strong-Tosa, Veleta/Cobalt, and Ideal/Cobalt were relatively high yielding under water stress (RY_s > mean RY_s), while non-grafted plants either cv. Veleta or cv. Ideal and graft combination Veleta/Strong-Tosa were relatively low yielding (RY_s < mean RY_s).

Finally, when cantaloupe plants have to be irrigated with high deficit irrigation, it is recommended to graft the preferred cultivar on Cobalt rootstock, which is a more tolerant rootstocks among the studied rootstocks included non-grafted plants, and could be further tested for their other drought conferring characteristics. Such results coincide with those found by Hussien (2016), who noticed that rootstock Giada obtained relative tolerance to irrigation deficit, followed by Ferro rootstock.

Calculation of costs and benefits of applied treatments

Costs and benefits of grafted and non-grafted plants grown under deficit irrigation water were calculated as average between both seasons as shown in Table 7. The same results in Table 7 show no significant differences among the irrigation water treatments on the costs (1) (L.E). Whereas the highest benefit (3) (9.77 and 9.80 L.E./plant) and income (4) (7.40 and 7.46 L.E./plant) were obtained with irrigation rate of 100 and 75% ETc, respectively. While, the lowest benefit (3) (5.14 L.E./plant) and income (4) (2.82 L.E./plant) were obtained with cantaloupe plants irrigated by 50% ETc of irrigation water. It is due to yield increasing of the plants irrigated with 75% ETc (3.920 kg/plant) and 100% ETc (3.910 kg/plant), compared to 50% ETc (2.050 kg/plant). Although the plants of cv. Ideal recorded the higher costs (1) (2.45 L.E./plant), compared to those of Veleta plants (2.25 L.E./plant), cv. Ideal recorded the highest benefit (3) (9.53 L.E./plant) and income (4) (7.08 L.E./plant), compared to those of Veleta plants which recorded the lowest benefit (3) (6.95L.E./plant) and income (4) (4.70 L.E./plant). It is due to increasing the yield of Ideal cv. (3.81 kg/plant), compared to those of Veleta plants (2.78 kg/plant).

Table 7 Effect of deficit irrigation rates, cultivars and rootstocks on costs and benefits of cantaloupe plants as the average between seasons 2015 and 2016

The highest benefit (3) (9.61 L.E./plant) and income (4) (7.16 L.E./plant) were represented when both cantaloupe cultivars were grafted on rootstock Cobalt, although the grafted plants recorded the higher costs (1) (2.46 L.E./plant), comparing with non-grafted plants (2.13 L.E./plant). It is due to increasing the yield of grafted plants on Cobalt rootstock (3.84 kg/plant), compared to those of non-grafted plants (2.89 kg/plant).

The plants of cv. Ideal recorded the highest yield (2) (4.41 and 4.58 kg/plant) when irrigated with 100% and 75% ETc, respectively, compared to Veleta plants (3.406 and 3.265 kg/plant) at the same level of irrigation water. Accordingly, the Ideal plants recorded the highest benefit (3) (11.03 and 11.45 L.E./plant) and income (4) (8.55 and 9.00 L.E./plant), whereas the lower benefit (3) (4.167 L.E./plant) and income (4) (1.95 L.E./plant) resulted when Veleta cv. plants were irrigated with 50% ETc of irrigation levels. Regarding the interactions between rootstocks and deficit irrigation, the highest benefit (3) (11.20 and 11.41 L.E./plant) and income (4) (8.72 and 8.96 L.E./plant) were represented in rootstock Cobalt and irrigated with 100% and 75% ETc of irrigation levels. Meanwhile, the lowest benefit (3) (4.21 L.E./plant) and income (4) (2.11 L.E./plant) were obtained with non-grafted plants and irrigated with 50% ETc level. This is due to increasing the yield (2) (4.48 or4.56 kg/plant) of grafting plants on Cobalt rootstock and irrigated with 100% or 75% ETc of irrigation levels as well as lower the yield (2) (1.68 kg/plant) of non-grafted plants. However, the grafted plants recorded the highest costs (1) (L.E./plant) compared to non-grafted plants at all irrigation levels.

Concerning the interactions of cultivars X rootstocks, the grafted combinations of Ideal/Strong-Tosa, followed by Veleta/Cobalt, then Ideal/Cobalt obtained the highest benefit (3) (12.71, 10.51, and 8.63 L.E./plant) and income (4) (10.13, 8.26, and 6.05 L.E./plant), respectively. The lowest benefit (3) (7.18 and 7.24 L.E./plant) and income (4) (5.1 and 5.06 L.E./plant) were obtained by Veleta and Ideal plants on its own roots, respectively. Whereas, this is due to increase the yield (2) of these graft combinations, compared to non-grafted plants.

Discussion

According to the aforementioned results, it could be concluded that increasing deficit irrigation levels had deleterious effects on vegetative growth characteristics and then yield and its components of cantaloupe plants. Consequently, both levels (100 and 75% ETc) showed significant positive effects on total yield, compared to deficit irrigation level (50% ETc). This might be due to the increase in vegetative growth characteristics, which reflected a significant increase in dry matter contents, and consequently total fruit yield. Increasing deficit level up to 50% ETc decreased water absorption, so that decreasing essential nutrients. Also, water stress (by the deficit of irrigation) had an opposite influence on many aspects of plant physiology, especially photosynthetic capacity. Consequently, if the drought stress is prolonged, plant growth and production are severely decreased, plants dehydrate and finally will die (Lisar et al. 2012). Restricted water supply is a major problem that might affect plant growth, then fruit yield and quality. This assumption is emphasized by more reduction in plant growth under the high deficit irrigation level (50% ETc) and can interpret the obtained results.

Generally, when cantaloupe plants have to be irrigated with moderate (75% ETc) or high (50% ETc) deficit irrigation water, it is recommended to graft the preferred cultivar on Cobalt rootstock, which is compatible with many cultivars and it was the most superior rootstock in its effect on cantaloupe production parameters without any negative effect on fruit quality. Whereas, the grafting technique led to sustaining total yield under the high deficit irrigation level (50% ETc), compared to non-grafted plants, due to the grafting technique improved vegetative growth characters, i.e., stem length, leaves numbers, fresh and dry weights of shoots under the deficit irrigation level (50% ETc). This clarified that the positive effect of grafting on cantaloupe yield got its highest level with the combination of Ideal/Strong-Tosa, Veleta/Cobalt, and Ideal/Cobalt at all investigated irrigation levels. Because, the graft combination of Ideal/Strong-Tosa, Veleta/Cobalt, and Ideal/Cobalt resulted in the highest values of vegetative growth characters under all irrigation levels. This could be attributed to compatibility between Ideal cv. and Cobalt or Strong-Tosa rootstock as well as between Veleta cv. and Cobalt rootstock and confirms this variance of seedling survival during grafting phase, as shown in Fig. 1. This finding might be due to the strength of these rootstock, compared to non-grafted plants (Zaki et al. 2015; Zaki et al. 2018). Also, this finding might be due to the improvement of some physiological and biochemical acclimation in grafted plants to be adapted to a variety of environmental stresses (Osakabe et al. 2014; Zaki et al. 2015; Zaki et al. 2018). The highest improvement resulted from grafting was detected with medium and highest deficit levels (75 and 50% ETc) of irrigation water.

Fig. 1

% survival of cantaloupe seedling during 2015 and 2016 seasons

Economically also, the graft combination Ideal/Strong-Tosa resulted in the highest benefit (3) (15.34 and 14.62 L.E./plant) and income (4) (12.76 and 12.01 L.E./plant) at 75and 100% ETc, respectively. Also under both 75 and 100% ETc of irrigation levels, the graft combination of Veleta/Cobalt showed the highest benefit (3) (12.67 and 12.67 L.E./plant) and income (4) (10.31 and 10.24 L.E./plant), as shown in Table 7.

Conclusion

It could be concluded that we have to use grafted seedlings of commercial cantaloupe cultivars under deficit irrigation water. It is recommended to use the grafted combinations of Veleta/Cobalt and Ideal/Strong-Tosa, where these combinations increased the WUE with 97.3 and 83.4, respectively at 75% Etc, compared to the control treatment (non-grafted plants of the same cv. at 100% ETc) and improved the average fruit weight, flesh percentage, flesh thickness, TSS, and firmness.