Effects of nutrient and water stress on vegetative and reproductive growth in Vitis vinifera L.

Abstract

Two watering and two nutrient regimes were applied to small vines established in pots and grown under greenhouse conditions. With water, a comparison was made between water adequacy (WH) and intermittent water stress (WL); with nutrition, between nutrient sufficiency (NH) using fertiliser‐enhanced potting medium and insufficiency (NL) with one‐fifth fertiliser application. NL reduced major growth parameters ‐ shoot length, stem weight and leaf weight ‐ more than did WL. Both NL and WL reduced node and leaf number, but only NL reduced internode length, leaf area and weight. WL had bigger effects when combined with NH than with NL. WL, especially when combined with NH, advanced maturity by ten days. Effects of W and N on pH, malic acid, tartaric acid and total soluble solids (°Brix) were different. The °Brix values were similar in WH and WL, but were less in NH than in NL. The treatments interacted in pH, malate and tartrate: pH was highest in WL/NH and lowest in WH/NH; malate tended to be less at both WL and NL, while tartrate concentration tended to become smaller from WH to WN but greater from NL to NH. No significant changes in the levels of citric acid, anthocyanin or reducing sugars were observed as a consequence of any treatment. Thus, although levels of stress due to WL or NL may have been different, the differences in the effects on several variables indicate that there is no general response to stress but that responses vary according to the factor inducing the stress. The level of reduction in variables measuring vegetative growth was 2– to 3‐fold greater than induced changes in juice composition. Advancement of maturity would suggest a potential value of intermittent water stress combined with adequate nutrition in areas with short seasons. Low‐nutrient soils might be desirable in areas where other factors are likely to induce strong growth.