Yield Response of Greenhouse Grown Grafted Eggplant to Partial Root Drying and Conventional Deficit Irrigation

Global climate change negatively affects life, thus complicating the production of vegetables. In addition to this, very little is known about eggplant cultivation under different irrigation strategies. For example, although water use efficiency gives better results in some plant species and varieties without any decrease in yield when the partial root drying (PRD) technique is used, the PRD technique has not been adequately examined in eggplant cultivation. The potential reactions of grafted and ungrafted eggplant plants under different irrigation water levels (100%, 80%, 60% and 40%) with the use of the conventional and deficit irrigation and PRD technique were investigated in this study. The research was conducted in a glass greenhouse during two cultivation seasons in 2019 and 2020. Irrigation was applied equally to both grafted and ungrafted eggplant plants using the drip irrigation method. In the study were examined the growth, quality criteria, yield, yield components, WUE, IWUE, and ky of eggplant to determine the reactions of grafted and ungrafted eggplant plants under different irrigation applications. It was found in the study that the method and amount of irrigation water applied had a significant effect on the grafted and ungrafted eggplant plants. Irrigation water was applied in the first and second season respectively between 148.45 and 365.48 mm, 245.61 and 584.84 mm. The statistical differences were found in the level of importance of yield, evapotranspiration, water-use efficiency, LSD classification of irrigation water-use efficiency values p<0.01 and/or p<0.05. Regression analysis values between irrigation water and yield of grafted and ungrafted eggplant in both cultivation seasons were found to be at a fairly good level (0.80<R2). In addition, as an important finding, the regression analysis value of grafting in the second season was found to be at the highest level (R2=91). In general, grafted eggplant plants were found to have had a higher total yield than the ungrafted plants. As the amount of irrigation water applied decreased, the yield also decreased. In the first season, the highest yields were recorded statistically in FPRD100, I100 and FPRD80 (45.26, 44.01 and 39.26 t ha-1, respectively). Similarly, in the second season, the highest yields were obtained in I100 and FPRD100 (50.97 and 48.96 t ha-1, respectively) followed by FPRD80 (48.96 t ha-1). The advantages of the PRD technique over conventional and deficit irrigation have also been revealed. As a result of the research, it could be recommended that the cultivation of grafted eggplant seedlings is more suitable, and irrigation applications could be carried out using the PRD technique.