Effect of Anaerobic Soil Disinfestation and Mustard Seed Meal for Control of Charcoal Rot in California Strawberries

Anaerobic soil disinfestation (ASD) and mustard seed meal (MSM) appear to be promising non-fumigant alternatives for soilborne pathogens control. However, studies of their effect on charcoal rot caused by Macrophomina phaseolina in California strawberry are limited. A demonstration field trial with ASD with rice bran 20 t ha(-1) (ASD-RB), MSM 4.5 t ha(-1) (MSM), and ASD with rice bran 6.7 t ha(-1) + MSM 4.5 t ha(-1) (ASD-RB+MSM) treatments was conducted in a M. phaseolina-infested organic field in Oxnard, CA. A doubling of fruit yields relative to the grower standard, and a reduction in plant mortality by M. phaseolina, was achieved by ASD-RB. MSM failed to control M. phaseolina and resulted in fruit yields that were more than 20% below the ASD-RB yield. Fruit yield in the ASD-RB+MSM plot was intermediate between ASD-RB and MSM. Treatment effects on soil pH, EC, inorganic N dynamics, and soil microbial communities were also examined.