Dr. G.C. WakchaureDHARMENDRA KUMART-108642024-06-182024-06-182022https://krishikosh.egranth.ac.in/handle/1/5810210591Grafting with viable rootstocks have strategic role for sustaining productivity of fruiting vegetables and mitigating water stress in drought prone areas. However, its impacts is yet be quantified for eggplant (Solanum melongena L.), a popular moderately tolerant vegetable crop cultivated in water stressed regions of Deccan Plateau of India. Therefore, field study was conducted during year 2021-22 to evaluate the interactive effects of grafting of wild rootstocks viz., Solanum macrocarpon (SM), Solanum gilo (SG), and Solanum torvum (ST) and commercial cultivar (cv. Ajay, AJ) and varied levels of water deficit irrigations (100, 75, 50 and 25% ET) applied based on crop evapotranspiration using line source sprinkler system. The maximum total fruit yields (TFY) of 40.6 Mg ha-1 was obtained at 100% ET and declined to 31.6, 20.1 and 9.2 Mg ha-1 at low (75% ET), medium (50% ET) and severe (25% ET) stress conditions, respectively. Marketable fruit yields (MFY) and water productivity (WP) were improved by 15.4-43.9% and 5.8-11.1 kg m-3 in grafted treatments under medium and severe water deficits owing to its better growth, canopy and physiological traits. Fruit yield 1. Title of the Thesis : Water Production Functions for Stress Tolerant Rootstocks of Eggplant (Solanum melongena L.) 2. Full name of the candidate : Dharmendra Kumar 3. Full name of the Research Guide : Dr. G.C. Wakchaure 4. Discipline : Agricultural Engineering 5. University : ICAR-IARI, New Delhi 6. Degree to be awarded : M. Tech (Soil and Water Conservation Engineering) 65 losses reduced by 27.5-65% in grafting of wild rootstocks over non-grafted eggplant. Further, this study specified that selection of appropriate grafting combinations viz., AJ/SM and AJ/SG reduces water usage by 26.1-42.2 per cent. The linear functions (R2=0.97-0.99) best defined the relationship between TFY and AW, whereas the quadratic functions fitted (R2 = 0.93-0.99) best define the relationship between WP and AW, indicating that efficient utilization of water stored in the root zone by grafted plants in water deficit conditions due to deeper root systems of wild rootstocks. The lower values of yield response factors viz., KAJ/SM and KAJ/SG i.e. ≤ 1 with AJ/SM and AJ/SG grafting combinations indicates their higher tolerance to water stress. The physiochemical fruit quality traits such as harvest index, mean fruit diameter, mean weight, protein and TSS declined with water deficit stress while these were markedly rectified with grafting of wild rootstocks. Similarly, higher accumulation of dry matter, rehydration quality, phenolic and flavonoids compounds in fruits of grafted eggplants under medium water deficits indicating their suitability for transportation, storage and processing purpose. Overall, among the different grafting combinations, AJ/SM was found super for enhancing crop growth, productivity and fruit quality owing to its better compatibility and higher capacity of water and nutrients absorption under water deficits. It is concluded that shifting towards grafting of wild rootstocks Solanum macrocarpon and Solanum gilo along with medium deficits could help in rational utilization of water resources and thus enhanced fruit yield and quality of eggplant fruits under drought prone regions of Deccan Plateau, India.EnglishThesis