With the wet spring we’ve had thus far, it’s easy to see the potential for Pythium and Phytophthora problems to develop once transplanting begins.
Unlike in the past, there currently are a number of good options for early season control of these pathogens, it just takes a little bit more planning ahead of time.
Options for pre-transplant applications include a Ranman (cyazofamid, 21) drench one week before transplanting for Pythium in tomatoes; as well as Previcur Flex (propamocarb HCL, 28) for the suppression of Pythium and Phytopthora in tomatoes and peppers. Phosphite fungicides, such as ProPhyt, Rampart, and K-Phite (FRAC code 33) can also be applied as a pre-transplant drench in the greenhouse on many crops.
Additionally, there are a number of biologicals such as Trichoderma, Streptomyces, and Bacillus products which can also be used in the greenhouse to help suppress soil-borne pathogens that organic growers can take advantage of. Remember, biological’s need to be applied without conventional fungicides.
At-transplanting applications now include Ranman (cyazofamid, 21) in the transplant water or through drip irrigation for Pythium control. There is a section 2ee for the use of Previcur Flex (propamocarb HCL, 28) + Admire Pro (imidacloprid) in transplanting water for Pythium control in lettuce, cucurbits, peppers and tomatoes (see section 2ee for details). Presidio (fluopicolide, 43) now has a label for drip application for Phytophthora control when conditions are favorable for disease development. Additionally, phosphite fungicides (FRAC group 33) can also be used in pre-plant root dips or applied through drip irrigation at transplanting to help suppress Phytophthora blight.
For further details on use and crop labeled please refer to the specific fungicide label. Remember the label is the law.