Reduction of Almond Hull Rot Disease Caused by Rhizopus stolonifer by Early Termination of Preharvest Irrigation. B. L. TEVIOTDALE, Department of Plant Pathology, University of California, Davis/Kearney Agricultural Center, Parlier 93648, and M. VIVEROS, University of California Cooperative Extension, Bakersficld 93370. T. J. MICHAILIDES, Department of Plant Pathology, and D. A. GOLDHAMER, Department of Land, Air and Water Resources, University of California, Davis/Kearney Agricultural Center, Parlier 93648, and M. VIVEROS, University of California Cooperative Extension, Bakersficld 93370. Plant Dis. 79:402-405. Accepted for publication 29 December 1994. Copyright 1995 The American Phytopathological Society. DOI: 10.1094/PD-79-0402.

Preharvest termination of weekly irrigation prior to harvest from late June to mid-August 1990 and 1991 was studied for control of almond hull rot disease caused by Rhizopus stolonifer. When trees were irrigated within 2 wk of harvest, there was more infection of hulls by R. stolonifer, more leaf strikes per tree, and in 1991, more shoot and branch death per tree than when irrigation was discontinued earlier. Percent hull split incidence and hull moisture content increased as irrigation continued through the season, but these criteria did not explain differences in disease incidence among trees in the first six compared with the last two irrigation termination dates

Keyword(s): cultural practices, Primus dulcis