Growth and mineral composition of the sultana grapevine as influenced by salinity and rootstock

Abstract

Sultana grapevine growing on its own root system, or else grafted to Dogridge, 1613, Harmony and Ramsey rootstocks, was irrigated with 0, 12.5, 25, 50 or 75 mM solutions of chloride salts under glasshouse conditions for three consecutive growing seasons. Cations accompanying chloride were sodium, magnesium and calcium in the ratio of 0.6:0.2:0.2 m.e./l. Growth was progressively suppressed by salinity in all vines, but scions on stocks of Vitis champini (Dogridge and Ramsey) showed linear decreases in growth, whereas self-rooted vines and scions on Harmony and 1613 stocks gave curvilinear responses in which the rate of decline in growth was greater at lower salinities than at higher salinities. Scions on 1613 rootstocks performed poorest, particularly when salt treatments were applied before budburst. With the exception of Dogridge, rootstocks growing under glasshouse conditions generally lowered the chloride concentration in leaves of scions below that of self-rooted vines. Canes on 1613 stock accumulated much higher concentrations of chloride than did the other vines. Rootstocks lowered sodium, particularly in petioles and raised potassium concentrations in all plant parts. Dogridge and Harmony stocks led to very high concentrations of potassium in petioles even in the absence of salt treatment. Salt treatment resulted in greatly elevated phosphorus concentrations within scions. Magnesium showed increases in leaves and canes with increasing external salinity, whereas calcium did not. Nitrogen concentrations did not change with rootstock or salt treatment. The results have relevance for irrigated horticultural areas along the River Murray, for which the ionic composition of the watering medium was formulated, and for situations where saline wastewater is to be reutilized.