Effective management of irrigation water in citrus orchards under a water scarce hot sub-humid region

• Deficit irrigation (DI) in initial fruit growth period and final fruit growth period enhanced fruit yield by improving the fruit size.
• The effective root zone of the citrus trees was confined in top 0.40 m soil under drip irrigation.
• The internal quality of fruits and water productivity improved under DI.
• The micronutrient contents in leafs was marginally affected by DI.
• Leaf nitrogen concentration, stomatal conductance and canopy volume were found as the best predictors of fruit yield of the trees.

Water scarcity is one of the major causes of low productivity and decline of citrus orchards. Deficit irrigation (DI) is a recently proposed water saving technique in irrigated agriculture. The impact DI versus full irrigation (FI: 100% crop water requirement) was evaluated in citrus orchards under a hot sub-humid climate of central India. Two DI strategies applied to citrus trees were DI1: 20% FI during initial fruit growth period (IFGP) + 40% FI during final fruit growth period (FFGP) + FI during rest of the period, and DI2: 70% FI during entire irrigation season. Fully irrigated trees had the highest vegetative growth. However, DI1 produced 18% higher fruit yield with superior quality fruits, resulting 30% improvement in water productivity under this treatment compared to FI. Fruit yield prediction based on vegetative growth and leaf physiological parameters of the trees using principal component regression analysis technique was found reasonable accurate. These results suggest for adoption of DI1 in citrus orchards of central India and elsewhere having similar agro-climate of this study region.