The impact of the irrigation regimes on the Ravaz index in vineyard plavinci under climate change

Abstract

With increasing aridity and the frequency of extreme events predicted in the near future according to global climate models, soil water availability may become a more important limiting factor in wine production and quality. Wine quality and yield are strongly influenced by climatic conditions and depend on a complex interaction between temperature, water availability, plant material, and viticultural techniques. The aim of this research is to determine the differences between different watering regimes on yield components, with a focus on the value of the Ravaz index. The experiment was conducted during the growing season of 2022 in an organic vineyard called Plavinci (Serbia). The grapevine variety is Panonia and the vines are trained using Smart-Dyson system. The drip irrigation method was applied in three regimes as a percentage of crop evapotranspiration (ETc): full irrigation, F (100% ETc); deficit irrigation, D (50% ETc); and rainfed, R (0% ETc), treatment without irrigation. The watering turn was 7 days, and the watering norm was 15 mm for D and 30 mm for F treatment. The obtained results show that the average weight of bunches are 2.92 kg∙plant−1, 3.18 kg∙plant−1, and 2.83 kg∙plant−1 for F, D, and R, respectively. The Ravaz Index (RI) was calculated by expressing the ratio between the yield and pruning weight. The values of the RI by treatment are 8.3, 7.5, and 6.3 for F, D, and R, respectively. These results confirm the influence of irrigation on yield and severity of pruning, which caused differences in RI between treatments as it increased with the amount of irrigation water applied. Since the RI values in our experiment range from 5 to 10, it indicates a good balance between vegetative growth and productivity in the Panonia grapevine.