Field Response of Vitis vinifera Cultivars to Methanol

¹ Department of Horticulture, Colorado State University, Fort Collins, CO 80523
² Viticulture Laboratory, Colorado State University Orchard Mesa Research Center, 3168, B.5 Road, Grand Junction, CO 81503.

The response of Vitis vinifera cultivars to methanol was investigated at the Orchard Mesa Research Center in Grand Junction, Colorado. Sublethal methanol doses, based on visual observations, were 90% for leaves and 100% for trunks. The accumulation of total soluble solids (TSS) in berries was also monitored weekly until harvest. There was no significant difference between the treated and control vines during the period of study, with the exception of Muscat blanc, which showed a slightly higher TSS content in methanol-sprayed vines than in controls. This difference, however, disappeared during ripening. There was no significant effect of methanol on photosynthesis, transpiration, nor stomatal resistance. At harvest, data on yields estimated by cluster weight, berry weight and berry size indicated no differences between the two treatments. Methanol did not alter cold hardiness of dormant buds, measured by differential thermal analysis. It was concluded that in this study methanol had little or no physiological, nor practical effect on grapes.

Key words: cold hardiness, photosynthesis, total soluble solids, yield components

Submitted on September 14, 1995