Effect of water supply regimes on physiological parameters and productivity in eggplant grown under mediterranean climate conditions

Drought has affected agriculture and intensified water scarcity. The effect of two irrigation regimes was evaluated on 13 eggplant genotypes selected as diverging for several fruit/plant qualitative traits, yield and drought tolerance. Two commercial varieties commonly used by growers in Morocco were tested. The irrigation treatments consisted of two different conditions: (i) control irrigation (Tr-C) adopted by the grower; (ii) water shortage of 50% of the amount of this irrigation (Tr-50%). Results showed that reduced water supply significantly impacted growth and quality parameters of each genotype/variety (p < 0.001) between treatments, particularly, traits such as plant height, number of flowers and leaves. Non-significant differences between treatments were observed Fv/Fm, DI0/CS0 and ABS/CS0 ratios. In terms of relative water content (RWC), genotype C10 showed remarkable drought resilience, with only a 4.12% reduction. Water stress resulted in significant reductions in the number of fruits for C8 by 49.58% and yield per plant for the genotype B1 by 39.19%. Notably, genotypes C10 and C13 demonstrated significantly better performance compared to the other genotypes, yielding 1.48 and 1.53 kg/plant, respectively, while commercial varieties A and V produced 1.98 kg/plant and 1.86 kg/plant. These results provide valuable information for the selecting and breeding of tolerant eggplant genotypes under drought-prone environments.