While research on cover cropping and compost application have surged in the past decade, organic growers are still struggling to maintain sufficient levels of available nitrogen (N) in vegetable cropping systems. Especially in semiarid regions like California, relying on N mineralization from banked reserves in soil organic matter has not provided enough N to support high crop yields competitive with conventional systems; an additional source of labile N may be needed during the season.
The object is to breed disease-resistant heirloom-quality tomatoes, especially those resistant to late blight and a number of other diseases. I have already crossed ten premiere heirloom tomato varieties—full-size red, pink, black, orange, and paste types—to the hybrid ‘Iron Lady’, which is resistant to late blight and a number of other relevant diseases. And I have developed the second-generation (F2) populations from each of these ten crosses.
This project aims at developing integrated irrigation practices that capitalize on soil health to improve the efficiency of irrigation water and decrease pest pressure and potential N losses of California organic processing tomato production. The current drought has dramatically decreased irrigation water allocated to organic tomato growers and there is an urgent need to test new irrigation strategies that reduce water inputs while maintaining product quality, nutrient supply and high productivity levels.
The objectives of this research were to: 1) Evaluate susceptibility to early blight in 16 heirloom and modern hybrid cultivars. 2) Evaluate whether disease incidence and severity are reduced on a susceptible tomato variety intercropped with a resistant variety, compared to a monoculture of the susceptible variety.
Seven materials approved for organic production were tested for foliar disease control on tomatoes on a certified organic farm in western New York. Four were commercial products registered for disease management on tomatoes (Plantshield, Mycostop, Trilogy, Champion WP). Three were materials thought to strengthen plant health and disease resistance through either soil or foliar application (CaCO3, SW-3, Humega). Plantshield is a formulation of the beneficial fungus Trichoderma harzianum labeled for foliar and soil drench applications.
Late blight of tomato and potato, caused by the fungal pathogen Phytophthera infestans, is currently the most destructive disease of tomato (Lycopersicon esculentum) in the Pacific Northwest. Geographically this includes regions stretching from the San Francisco Bay in California to the coastal islands of British Columbia.
This project examined whether targeted mowing of winter rye cover crop (Secale cereale L.) would increase its weed suppression ability by increasing levels of rye’s major allelochemicals, Hydroaxamic acids (Hx), and subsequently increase crop yield in an organic tomato production system. The project was conducted on organic farms in Upper Marlboro (2003), and Beltsville (2004), Maryland, using a rye cover crop that was grown as a monoculture and as a mixture with crimson clover, and black mulch.
The purpose of the present study was to simplify the previous experiments by utilizing the same substrate (peat:perlite), the same additions (low rates of limestone), the same greenhouse, and the same pest management practice (biological control with Encarsia) for all treatments. We also wanted to try several recently-OMRI certified materials which would potentially be easier to formulate, less expensive, and easier to apply with the drip system.
This experiment is a long term study comparing continuous tomatoes with vegetable rotation under five possible production systems to determine which system is most viable for each vegetable commodity produced. Some vegetables in the southeast can be grown easily with organic production methods (sweet corn, cabbage, broccoli, peppers, etc.) but others have numerous problems (foliar diseases in tomatoes) that will require changes in production strategies. By rotating vegetable crops we are able to see which crops also can be grown under conservation tillage.