Influence of Rootstock on the Response of Seyval Grapevines to Flooding Stress

Abstract

St. George, Couderc 3309, Riparia Gloire, Kober 5BB, Seyval, and Cynthiana vines were subjected to soil flooding under greenhouse conditions. The rate of shoot elongation (RSE), net CO₂ assimilation rate (A), stomatal conductance (g_s), transpiration (E), and water use efficiency (WUE) were measured at one to four day intervals as an estimate of sensitivity to flooded conditions. In general, RSE was the most sensitive and WUE the least sensitive parameter to flooding. St. George, Couderc 3309, and Riparia Gloire were the most tolerant cultivars, while Kober 5BB, Seyval, and Cynthiana were the most susceptible cultivars to flooding. Symptoms of flooding were desiccation of the shoot apex, flagging of leaves, necrotic areas on leaves, senescence of basal leaves and regeneration of roots near the water surface. The effect of rootstock on flooding tolerance of a susceptible scion was measured during an eight-day flooding period. Treatments were own-rooted Seyval and Seyval grafted on Seyval, Couderc 3309, and St. George. Flooding tolerance of Seyval was increased slightly by grafting onto Couderc 3309.