Grafting compatibility and performance of Brinjal scions on wild solanum rootstocks

Abstract:

Can wild Solanum species serve as reliable rootstocks for commercial brinjal production in subtropical regions? This research aimed to answer that question by evaluating grafting compatibility and agronomic performance of brinjal (Solanum melongena L. cv. Pusa Purple Long) scions grafted onto four wild rootstock species: Solanum torvum, Solanum sisymbriifolium, Solanum khasianum, and Solanum incanum. The experiment was carried out from June 2023 to February 2024 at the Escola Superior de Ciências Agrárias do Sul, Porto Alegre, Brazil, using a randomized complete block design with four replications and ten plants per treatment. Cleft grafting was the chosen technique, and graft success rate, vascular connection quality, plant height, number of branches, days to first flowering, fruit yield per plant, and fruit quality traits were measured across all treatments. Solanum torvum showed the highest graft take (87.3%) and produced a strong vascular union confirmed through histological cross-sections. Plants on S. torvum rootstock recorded a mean yield of 3.47 kg per plant, which was 28.6% higher than the non-grafted control. Solanum incanum also performed well, with an 81.5% graft take and 3.21 kg yield per plant. Both S. sisymbriifolium and S. khasianum gave acceptable but lower compatibility. Fruit quality parameters including total soluble solids, firmness, and skin color didn't differ markedly between grafted and non-grafted plants. These results point to S. torvum and S. incanum as practical rootstock options for brinjal growers in subtropical Brazil.