Integrated pest management with fumigation to control Fusarium wilt and Macrophomina

Authors: Henry, Peter

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/2/2022
Publication Date: 2/2/2022
Citation: Henry, P.M. 2022. Integrated pest management with fumigation to control Fusarium wilt and Macrophomina. Annual Strawberry Production Research Meeting, February 2, 2022 (virtual).

Interpretive Summary:

Technical Abstract: Fusarium wilt and Macrophomina charcoal rot are diseases that cause significant yield loss in strawberry every year. These diseases are caused by soilborne pathogens that were historically controlled by fumigation with methyl bromide and chloropicrin. An international treaty regulating the use of ozone depleting chemicals made methyl bromide unavailable for strawberry production. It has been replaced by increased use of 1,3-dichloropropene (1,3-D) in combination with increased rates of chloropicrin. However, there is little information from California production systems on the contribution of 1,3-D, which historically has only been recommended as a nematicide, to control of the pathogens causing Fusarium wilt and Macrophomina charcoal rot. Data from the first two years of a three-year study show that the addition of 1,3-D to chloropicrin fumigation greatly improves control of Macrophomina charcoal rot, but not Fusarium wilt. Over a shorter growing season (only until the beginning of August) bed fumigation with 1,3-D and chloropicrin provided protection against Macrophomina that was comparable to flat fumigation. Bed fumigation can reduce costs and total fumigants applied by ~30%. Maximum rate flat fumigation with 1,3-D and chloropicrin was not enough to prevent Fusarium wilt disease. Growing Fusarium wilt-resistant cultivars could provide much better protection and be supplemented with lower fumigation rates to reduce costs. Fragmenting infested crowns only somewhat improves disinfestation efficacy during fumigation and is not a cost-effective way to improve disease control by fumigation.