The film-forming antitranspirant, di-1-p-menthene, is able to reduce transpiration in a number of crops, potentially resulting in water savings and improved productivity. The success of the response is, however, dependent on genotype and environmental factors. We aimed to assess the efficacy of this natural terpene polymer on red raspberry (Rubus idaeus, L.) cv. Tulameen leaf water-use efficiency across a 25–40 °C temperature range under controlled conditions. The film reduced transpiration (E) and was most effective when applied to the lower leaf surface. Leaf net assimilation (A) and stomatal conductance (g) were also curtailed after the application of di-1-p-menthene, and as a consequence intrinsic transpiration efficiency (A/g) and instantaneous transpiration efficiency (ratio of net carbon fixation to water loss, A/E) did not improve. At 40 °C, gas exchange of both treated and untreated leaves was minimal due to stomatal closure. The antitranspirant was effective at reducing water loss from berries, but only at the immature stages when transpiration rates were naturally high. Further studies are required to determine if the antitranspirant, di-1-p-menthene, will offer protection against dehydration across a range of temperatures and if productivity and berry composition will benefit.

Background and Aims Tissue nutrient concentration is useful for determining vine nutritional status and managing vineyard nutrition. Current Australian guidelines are based on the analysis of petioles at flowering and leaf blades at veraison, sampled adjacent to the basal inflorescence and bunch. The comparative value of these two tissue types and that of the bunchstem for assessing plant nutrient status at the two phenological stages is required. Moreover, the impact of node position and cultivar is unclear. Methods and Results We characterised the macro and micronutrients at flowering and veraison of three segments of the petiole, the entire leaf blade and the bunchstem at two node positions of cvs Cabernet Sauvignon, Shiraz and Chardonnay grown under identical conditions. Nutrient concentration was non‐uniform along the length of the petiole. The middle segment had the lowest concentration of most macronutrients, while Mn was generally highest in the middle segment. When averaged across petioles, blades and bunchstems the lower node had a higher nutrient concentration than the upper node, except for K. The concentration of some nutrients within the leaf blade was correlated with those of the petiole but this was dependent on the cultivar and the time of sampling. The nutrient concentration of the bunchstem was more closely correlated to the petiole than to the blade. Cultivar differences were also apparent, but this depended on the individual nutrient and the sampling time. Conclusions Nutrient concentration was inconsistent along the length of the petiole. The nutrient concentration of petioles, blades and bunchstems was node, cultivar and time specific. Therefore, tissue nutrient analysis will be meaningful only if sampling is consistent across these variables. Significance of the Study These results will aid in the formation of better sampling protocols for accurate grapevine nutrient diagnosis.