Water requirement and crop coefficient of three chickpea cultivars for the edaphoclimatic conditions of the Brazilian savannah biome

Chickpea ( Cicer arietinum L.) is a very important legume crop mainly due to its nutritional properties, being cultivated in several countries. However, parameters on water consumption and crop coefficient (Kc) are limited by cultivar for irrigation management. Thus, this study aimed to determine the water requirements and Kc for three chickpea cultivars. The crop reference evapotranspiration (ETo) was estimated using the Penman–Monteith method with meteorological data recorded inside the greenhouse. Crop evapotranspiration (ETc) was obtained by weighing minilysimeters and soil moisture sensors. The Kc was determined by the ETc/ETo ratio. The chickpea cultivars evaluated were Cícero, BRS Aleppo, and BRS Cristalino. The average ETc throughout the cycle was 4.5, 4.1, and 4.5 mm days −1 for cultivars Cícero, BRS Aleppo, and BRS Cristalino, respectively. The average ETc for the respective cultivars was 2.3, 2.5, and 2.4 mm days −1 in the initial phase, reaching 5.6, 4.5, and 5.4 mm days −1 in the crop phase of growth. The Kc values ranged from 0.38 to 1.00 for Cícero, 0.39 to 0.80 for BRS Aleppo, and 0.38 to 0.95 for BRS Cristalino. The cultivar Cícero showed higher Kc and higher water demand. The cultivar BRS Aleppo was the one with the lowest Kc and water demand, but longer duration of maximum value due to indeterminate growth habit. The variation in Kc correlated positively with the leaf number and crop phases patterns. This demonstrates the importance of determining Kc to increase efficiency in irrigation management by cultivar instead of adopting generalized Kc values.