PSIS Scientists Collaborate on Multistate USDA Research Grant to Study Disease Contol Strategies for Sweet Basil Production

Sweet basil (Ocimum basilicum L.), a frequent visitor to our dining tables, is the most important commercial culinary herb in the United States. However, 100% of the US production (~11,000 acres) is at risk to two economically important diseases; downy mildew and Fusarium wilt. Since 2007, entire fields and greenhouse crops have been lost due to inadequate control options for these two diseases. Dr. Robert Wick and Dr. Li-Jun Ma from the Department of Plant, Soil & Insect Sciences, University of Massachusetts at Amherst have joined a multistate research team that includes Rutgers University, University of Florida and Cornell University to tackle this specific problem. The research project proposed by this collaborative effort: “Strategies for Improving the U.S. Responses to Fusarium, Downy Mildew and Chilling Injury in Production of Sweet Basil (Ocimum basilicum L.)” was recently awarded $1.8 million from the USDA. The project runs over a four year period, with the objectives to i) develop improved varieties of sweet basil with tolerance to downy mildew, Fusarium wilt and chilling-injury, ii) develop standard laboratory techniques for detection of Fusarium wilt and downy mildew infested seed before distribution, iii) develop improved management strategies to effectively control downy mildew based on a disease forecasting and monitoring system and through the identification of effective organic and conventional fungicides, and (iv) develop cost/benefit considerations for each strategy.

The UMass team will combine the strengths of plant pathology (Wick) and genomics (Ma) to survey basil seed for pathogens and investigate the population structure of the downy mildew organism, Peronospora belbahrii. The UMass team will also study the relationship of a yeast Pseudozyma which can colonize P. belbaharii, and evaluate its potential as a biological control agent for downy mildew.

Pictures shown downy mildew infection on sweet basil plant leaves