Water potential in cape gooseberry (Physalis peruviana L.) plants subjected to different irrigation treatments and doses of calcium

To determine whether the management of irrigation and nutrition in cape gooseberry crops with calcium to reduce the cracking of fruits affects the water potential of the plants, the present study was carried out using a randomized block design with 12 treatments in a 4×3 factorial arrangement. The blocks were the irrigation frequencies (4, 9 and 14 days apart). The first factor was the irrigation coefficient (0.7, 0.9, 1.1 and 1.3 of the evaporation tank of class A), and the second factor was the calcium dose (0, 50 and 100 kg ha-1), representing 36 experimental units. Seed propagated cape gooseberries were transplanted in 20 L pots using peat moss as substrate. The water potential in the leaves (ψ leaf ) and stems (ψ stem ) was measured as well as the water consumption and irrigation water-use efficiency (WUEi) of the plants. The ψleaf and ψstem of the cape gooseberry plants presented a sinusoidal trend throughout the day. The water frequency of 4 days with an irrigation coefficient of 1.1 showed the highest values of ψ leaf and ψstem. The ψ stem and ψ leaf reached the highest values at predawn (4 am) as a result of the low vapor pressure deficit (VPD) levels that occurred at that time and reached their lowest point in the midday hours. The irrigation coefficient of 1.1 had the second largest WUEi and, thus, represented the water level most suitable for growing cape gooseberry since it generated the largest number of big fruits and the smallest percentage of cracked fruits.