Efficacy of Anaerobic Soil Disinfestation for Control of Prunus Replant Disease

Prunus replant disease (PRD) is an important soilborne complex that suppresses growth and productivity of replanted stone fruit and nut orchards. It is effectively managed with preplant soil fumigation but, due to regulatory challenges, nonfumigant-based control strategies for PRD and other soilborne disease problems may become increasingly important, especially in California. We examined the potential of preplant anaerobic soil disinfestation (ASD) for control of PRD in four repeated orchard replant trials on sandy loam soil near Parlier, CA. After removal of the old orchard trees, alternative ASD treatments, all using rice bran as the main carbon source, were implemented, starting in late September. The alternative treatments incorporated rice bran at (i) 20 t ha−1, alone, in 3.0-m-wide row strips; (ii) 20 t ha−1, preceded by incorporation of a sudangrass cover crop and followed by drip application of molasses (10 t ha−1), in 3.0-m-wide row strips; (iii) 20 t ha−1, alone, in 1.8-m-wide strips; or (iv) 1...