Pathogens such as Fusarium, Pythium, Phytophthora, Thielaviopsis and Rhizoctonia that cause pre- and post-emergent damping-off can cause serious problems in organic (and conventional) transplant production.
The key to controlling and/or suppressing damping-off pathogens with biological controls is keeping the biological populations high and continually present on root surfaces of the host, and by following good cultural practices. [Read more…]
Organic Production: Suppressing Soil-borne Pathogens
Bacterial Leaf Spot Update
Last summer a pepper differential trial was done near Vineland, NJ to help determine if new races of bacterial leaf spot (BLS) were present in the area. At least 11 races of BLS have been identified to date.
…look at ways to detect the presence of BLS susceptibility on your farm. Run your own internal “tests”: plant a few cultivars with known BLS resistance and take note which ones develop symptoms. Be ready to adopt cultivars with a larger BLS resistance package.
Understanding Damping-off Pathogens
Damping-off is caused by a number of important vegetable pathogens and is very common during transplant production and early-spring. Damping-off can kill seedlings before they break the soil line (pre-emergent damping-off) or kill seedlings soon after they emerge (post-emergent damping-off). Common pathogens that cause damping-off include Pythium, Phytophthora, Rhizoctonia and Fusarium spp.
It is extremely important to know which pathogen is causing the damping-off problem and which fungicide to properly apply.
Vegetable Production Recommendations and Organic Practices
Growers who chose to farm under organic conditions can find valuable information on cultural practices, variety recommendations, alternative pest management methods, and NOP approved products in the 2014 Commercial Vegetable Production Recommendations Guide.
Note that people who apply pesticides for the purpose of raising an agricultural commodity, including organic farmers, need to be licensed as a Private Pesticide Applicator. Small/Organic Farms Private Pesticide Applicator Training is being held April 9, 2014 in Mercer County.
The 2014 Commercial Vegetable Production Recommendations Guide is published annually and is now available for free download. Between publications, updates to the guide can be found here on the Plant & Pest Advisory.
Greenhouse Seed Treatment, Selected Fungicides, and Bactericides Updates
Seed Treatment
Important diseases such as Bacterial leaf spot of tomato and pepper can cause major problems in transplant production if introduced into the greenhouse. Bacterial leaf spot of tomato and pepper can be seed-borne and infested seed can be a major source of inoculum in the greenhouse and cause problems in the field later in the growing season. As a rule for any crop, any non-certified or untreated seed should be treated, if applicable, with a Clorox treatment, or hot-water seed treatment, or dusted to help minimize bacterial or damping-off diseases. For more information on seed treatments for specific crops please see Table E-14 on page E45 in Section E of the 2014 New Jersey Commercial Vegetable Production Recommendations Guide.
Selected Organic and Conventional Fungicides, Bactericides
An updated table for selected organic and conventional fungicides and bactericides labeled for greenhouse use is available in Section E of the 2014 New Jersey Commercial Vegetable Production Recommendations Guide. The table includes a comprehensive list of fungicides and biological agents approved for greenhouse use. Table E-15 can be found on pages E46-48.
Greenhouse Sanitation Important for Disease Management
Proper greenhouse sanitation is important for healthy, disease-free vegetable transplant production.
Efforts need to be made to keep transplant production greenhouses free of unnecessary plant debris and weeds which may harbor insect pests and disease. Efforts need to be taken throughout the transplant production season to minimize potential problems.
- All equipment, benches, flats, plug trays and floors should be properly cleaned and then disinfested prior to use.
- Any weeds in or around the greenhouse structure should be removed prior to any production.
- Any transplant brought into the greenhouse from an outside source needs to be certified ‘clean’, as well as, visually inspected for potential insects and diseases once it reaches your location.
Remember, disinfestants, such as Clorox, Green-Shield, or hydrogen dioxide products (Zerotol – for commercial greenhouses, garden centers and Oxidate – commercial greenhouse and field), kill only what they come into direct contact with so thorough coverage and/or soaking is necessary. The labels do not specify time intervals for specific uses, only to state that surfaces be ‘thoroughly wetted’. Therefore, labels need to be followed precisely for different use patterns (i.e., disinfesting flats vs. floors or benches) to ensure proper dilution ratios. Hydrogen dioxide products work best when diluted with water containing little or no organic matter and in water with a neutral pH.