Spray and Seed Tuber Treatments for Late Blight Control in Potatoes. W. F. T. Hartill, Plant Diseases Division, Department of Scientific and Industrial Research, Mt. Albert Research Center, Auckland, New Zealand. Plant Dis. 64:764-766. Copyright 1980 American Phytopathological Society. DOI: 10.1094/PD-64-764.

Potato late blight was controlled by applications of metalaxyl, milfuram, and 2-methoxy-N-(2,6-dimethylphenyl)-N-(tetrahydro-2-oxo-3-furanyl) acetamide. These acylalanine analogs were applied as scheduled sprays, as sprays only when conditions favorable to disease spread had prevailed, or as seed tuber treatments before planting, with fungicides suspended in 2% methyl cellulose. Curative sprays of a mixture of mancozeb or of mancozeb plus Curzate were less effective than metalaxyl in controlling late blight but were equally effective when used as preventive sprays. Yields of salable potatoes were similar from plants treated with these three fungicides in preventive or curative spray programs or by seed tuber dressing.