Evaluation of eggplant rootstocks for grafting eggplant to improve fruit yield and control bacterial wilt disease

Bacterial wilt caused by Ralstonia solanacearum is a major devastating soil-borne disease impeding eggplant cultivation worldwide. The present investigation was conducted to recognize and assess bacterial wilt resistant rootstocks among Solanum melongena (Haritha, Surya, SM 1, SM 2, SM 3, SM116, and SM 398), Solanum torvum (St TNAU 1 and St KAU 1), and Solanum sisymbrifolium (SS 1) for vigor, yield and qualitative traits of ‘Green Long Hybrid’ scion through grafting. The artificial inoculation method as well as the sick plot method of bacteria wilt screening were adopted. The root dip method of artificial inoculation was found to be the most reliable method as compared to media drenching and stem inoculation methods. All the rootstocks except Solanum sisymbrifolium possessed a high degree of bacterial wilt resistance (in artificial as well as sick plot conditions). Maximum plant spread, stem girth, number of primary branches, yield per plant (6.69 kg), number of fruits per plant (94.80), fruit length (22.22 cm), root length (63.65 cm), and root spread (87.05 cm) were exhibited by Green Long Hybrid scion when grafted onto Solanum melongena cv. Haritha rootstock. Taller plants with high fruit girth (10.97 cm) and average fruit weight (78.00 g) of scion were recorded on SM 116 rootstock. The highest dry matter content (11.12%) and total phenolic content (113.30 mg/100 g) of fruits were observed in scion when SM 398 and SM 3 were used as rootstocks, respectively. Overall, ‘Haritha’ cultivar was found to be the best rootstock for grafting in the current study. Thus, grafting technology can be effectively used for the control of bacterial wilt as well as for acquiring higher yield in eggplant.