Growth-stage-specific crop coefficient and consumptive use of Capsicum chinense using hydraulic weighing lysimeter

This research was conducted to determine growth stage-specific crop coefficient (Kc) and Consumptive Use (CU), for Capsicum chinense (Ata rodo) grown under irrigation in Omu-Aran, North central Nigeria. Daily CU and growth stage-specific crop coefficient Kc for Capsicum chinense was measured using a developed and calibrated hydraulic weighing lysimeter over 2 consecutive dry seasons (2015/16 and 2016/17). The values of CU and growth stage-specific Kc obtained were compared to that estimated using CROPWAT 8.0 and with existing Food and Agricultural Organization (FAO) Kc values for bell pepper. The Kc values determined over the growing seasons varied from 0.32 to 0.7, 1.02 to 1.45 and 0.76 to 0.9 representing Kc initial, Kc mid-season and Kc late season (Kcini, Kcmid and Kcend), respectively. These Kc varied significantly (P < 0.05) from FAO established Kc values. The observed Kc was validated using relevant statistical methods. The seasonal CU of Capsicum chinense was 580.01 ± 54 mm, while the reference evapotranspiration increased from 3.26 mm day−1 in October to 4.19 mm day−1 in February. The crop factor increased from 0.7 in October to attain its peak of 1.45 in January, but decreased to 0.9 during crop senescence in February. Likewise, the daily crop water need was 2.28 mm day−1 in October but reached its peak of 5.82 mm day−1 in January and thereafter decreased to 3.77 mm day−1 in February. Mean monthly water need of Capsicum chinense pepper was 68.36 mm month−1 in October. The water need of crop rose to its peak of 166.32 mm month−1 in December, and thereafter declined to 113.13 mm month−1 in February It is inferred that the application of growth stage-specific Kc will assist in irrigation management and would serve as useful guide for precise water applications for areas around Omu-Aran as it differs from region to region.