Investigation different amounts of irrigation water on some vegetative and reproductive parameters of grafted and ungrafted iranian melon [Cucumis melo (L.)] Souski-e-Sabz accessions under drip irrigation system

Due to lack of water resources in the country, adopting deficit irrigation techniques and efficient use of limited water resources is necessary and inevitable. Appropriate strategies to deal with water shortage, use the grafting technique. Hybrid rootstocks have strong and extensive root system to absorb water and nutrients to the plant (scion). So, the use grafting technique of fruit vegetable, can be used as an approach to increase plant resistance to deficit irrigation is raised. Numerous studies in the world, on the basis of specific features of vine crops rootstocks, such as resistance to pathogens, low temperatures and soil salinity have been conducted. As well as various mass vine crops, mixed reaction to the deficit irrigation conditions. But information about the composition of the Various rootstock and scion (indigenous) in response to deficit irrigation have been reported rarely. A field experiment was performed to determine grafting and deficit irrigation effects on the some quantitative and qualitative traits of Souski-e-Sabz melon (Landrace). Experimental design was conducted as split plots based on randomized complete block design with three irrigation levels of 60 (5417.63 cubic meters per hectare), 80 (6853.64 cubic meters per hectare) and 100 (8289.65 cubic meters per hectare) % in, and (consumed water) respectively, based on total available water depletion in the research field of higher education institution Imam Khomeini (RA) under the Ministry of Agriculture in Karaj in 2014 and four grafting combinations include grafting onto Shintozwa and Ferro-RZ, self grafted and non grafted (as control) on three replicates with drip irrigation system were evaluated. Water requirement of melon at different stages of growth and development was measured by a profile probe set. The results were demonstrated that grafted plants onto cucurbit rootstocks had significantly higher values for vegetative growth, yield and water use efficiency in comparison with un-grafted plants. The highest (4.45 kg/m-3) biomass water use efficiency (WUEb) was recorded in 60% irrigation level and also no significant differences between irrigation levels of 60 and 80 % were observed. The highest (7.06 kg/m-3) and lowest (5.59 kg/m-3) fruit yield water use efficiency (WUEy) was recorded in grafting combinations of Souski-e-Sabz onto Shintozwa and Souski-e-Sabz onto Souski-e-Sabz respectively. The maximum (194.12 ml/24ha) and minimum (92.01 ml/24ha) volume of xylem sap was recorded in plants grafted onto Shintozwa and Souski-e-Sabz onto Souski-e-Sabz respectively. The maximum (39.23 tons per hectare) and minimum (27.16 tons per hectare) marketable yield were related to 100 and 60 % irrigation levels respectively. The concentration of N, P and K, in leaves was improved significantly in grafted than in ungrafted and self grafted plants. The highest (12.56°Brix) total soluble solids of fruits were obtained from grafted melon plants under deficit irrigation 80 %. The total acidity was no significantly influenced by the irrigation levels and grafting combinations. The findings of this study showed that the grafting combinations of Souski-e-Sabz onto shintozwa and Ferro-RZ rootstocks, in most of the quantitative and qualitative traits, with no negative effects on the quality of fruit, were more effective than non-grafted and own-rooted plants.