Deficit irrigation reduced the accumulated evapotranspiration (ETc), relative water content (RWC), leaf water potential (蠄l), osmotic potential (蠄蟺) and turgor (蠄p) in both cultivars. Stomatal conductance (gs) was reduced due to deficit irrigation, but more so in 鈥楤en Hope鈥?than in 鈥楾itania鈥? indicating that 鈥楤en Hope鈥?is more affected by drought stress than 鈥楾itania鈥? In both cultivars, deficit irrigation led to a significant decrease in the area of developing leaves, implying that leaf development of blackcurrant is sensitive to drought stress. Following deficit irrigation the speed of recovery of gs was faster in 鈥楾itania鈥?than in 鈥楤en Hope鈥? whereas root growth remained more inhibited in 鈥楾itania鈥?than 鈥楤en Hope鈥?during recovery. This supports the proposition that 鈥楤en Hope鈥?is more affected by drought stress than 鈥楾itania鈥? In the long term, deficit irrigation reduced the number of strigs and flowers per node in 鈥楤en Hope鈥? whereas in 鈥楾itania鈥?high temperature during flower initiation seemed more important for the formation of flower initials than water availability.
Overall, the results of this study stress the importance of postharvest irrigation and breeding for cultivars that are tolerant to drought stress and high temperatures during flower initiation in order to meet future climate changes.