Verticillium Wilt Management: Elucidating Mechanisms of Resistance and Integration of Sustainable Alternatives in Tomato Production Systems

View the project final report

• 2012 annual report

Commodities

• Vegetables: tomatoes

Practices

• Education and Training: participatory research
• Pest Management: genetic resistance, integrated pest management

Verticillium Wilt (VW) caused by the organism Verticillium dahliae, is the most important soilborne pathogen that limits tomato production in Western North Carolina (WNC) and surrounding mountain production regions. This organism colonizes the tomato plant’s vascular tissue causing the plant to wilt resulting in yield loss. Currently, fumigation is the only tool used to manage the disease. However, with the phase-out of methyl bromide and the increased production of organic systems, alternative sustainable solutions must be found. In preliminary research, specific rootstocks have reduced VW incidence and increased yield in organic systems and in comparison to fumigation in conventional systems. There is a need to advance our understanding of the mechanisms of resistance to inform future recommendations to growers and to advance our scientific understanding of the role of tolerant or resistant rootstocks as a component of sustainable tomato production systems. We will design field experiments combined with advanced molecular methods to examine diverse rootstocks and their efficacy to limit Verticillium infection and/or colonization. Pathogen colonization data will be complemented with the collection of disease incidence, plant growth parameters, and yield. We will evaluate 5 rootstocks, some that appear to be tolerant and a novel rootstock we just secured from Japan that is reported to offer resistance to race 2 of the pathogen which is the major problem in WNC. New knowledge gained and advanced integration of grafting technologies will provide sustainable alternatives to manage VW in organic and conventional production systems.

1) Evaluate the utility of rootstocks as a viable mechanism for growers to manage Verticillium wilt in fumigated and non-fumigated soils.
2) Advance our knowledge about mechanisms of host resistance through intensive field sampling, PCR analysis and greenhouse assays;
3) Communicate results to growers and other clientele with recommendations of designing integrated and sustainable tomato production systems.