The 2012 ASHS Annual Conference

Eggplant, a high value crop in Washington State, sustains significant losses from Verticillium wilt (caused by V. dahliae). Producers need tools other than soil fumigation for disease management. Grafting has been used to manage soilborne diseases in solanaceous crops throughout the world. Vigor, yield, and Verticillium wilt severity were evaluated for ‘Epic’ eggplant grafted on Solanum aethiopicum and ‘Beaufort’ rootstocks as well as non-grafted and self-grafted ‘Epic’ eggplant in two fields (eastern and western Washington) in 2010 and 2011. S. aethiopicum–grafted plants were less vigorous and had lower yields and more severe disease than the other treatments at both locations. Beaufort-grafted plants had greater stem diameter and plant height than the other treatments at both locations, but there was no consistent difference in plant dry weight among treatments. Beaufort-grafted eggplant total marketable weight was 45% greater than the other treatments in 2010 (P = 0.0093) and 28% greater than the other treatments in 2011 (P = 0.0567) at the eastern Washington location. Beaufort-grafted eggplant had significantly less disease severity at eastern and western Washington locations in 2010 (P = 0.0062 and P = 0.0030) and 2011 (P = 0.0010 and P = 0.0002), respectively. However, interveinal chlorosis, v-shaped necrosis, and wilting were observed in Beaufort-grafted plants and V. dahliae was isolated from stem tissue. The reduced disease severity and increased yields of Beaufort-grafted eggplant suggests that Beaufort rootstock has partial resistance to Verticillium wilt. Grafting eggplant onto vigorous disease tolerant rootstocks reduced Verticillium wilt severity without compromising yield or vigor and may be an effective alternative to soil fumigation.