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  • Author or Editor: James K. Mitchell x
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European Vitis vinifera L. (four cultivars); interspecific hybrid (seven cultivars); and American V. aestivalis Michx. (one cultivar), V. labrusca L. (three cultivars), and V. rotundifolia Michx. (two cultivars) grapevines were tested for susceptibility to Septoria leaf spot disease. V. rotundifolia cultivars Cowart and Fry exhibited hypersensitive-type resistance. All other American, European, and hybrid cultivars tested were susceptible with varying levels of disease severity. Cultivars with little (e.g. interspecific hybrid) or no (e.g. European) V. labrusca L. heritage were more susceptible to Septoria leaf spot than American V. labrusca cultivars.

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European Vitis vinifera L. (four cultivars); interspecific hybrid (seven cultivars); and American V. aestivalis Michx. (one cultivar), V. labrusca L. (three cultivars), and V. rotundifolia Michx. (two cultivars) grapevines were tested for susceptibility to septoria leaf spot disease. V. rotundifolia cultivars Cowart and Fry exhibited hypersensitive-type resistance. All other American, European, and hybrid cultivars tested were susceptible with varying levels of disease severity. Cultivars with little (e.g., interspecific hybrid) or no (e.g., European) V. labrusca L. heritage were more susceptible to septoria leaf spot than American V. labrusca cultivars.

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Previously published research suggests that the yield and water-use efficiency of C-3 plants can be enhanced through foliar-applied methanol. Potatoes (Solanum tuberosum L. cv. Russet Burbank) grown in Oregon at Klamath Falls, Madras, and Ontario were subjected to repeated foliar methanol treatments during the 1993 season. Methanol was applied at 20%, 40%, and 80% concentration with Triton X-100 sticker-spreader at 0.1%, and methanol was applied at 20% and 40% without Triton X-100. Methanol had no effect on tuber yield, size distribution, grade, or specific gravity at any location. Tuber stem-end fry color showed no methanol response at the two locations where it was measured. Soil water potential (measured at Madras and Ontario) showed no difference in water-use efficiency between methanol-treated and nontreated potato plants.

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