Determination of Site-Specific Crop Coefficients of Corn (Zea mays)

Abstract

Knowledge of crop water requirement is important in the operation and management of irrigation systems. Its computation requires crop coefficient (Kc) values corresponding to crop growth stages. Locally determined Kc information is very limited and not available for many important crops in the Philippines. This study was conducted to determine growth stage specific Kc for IPB Var13 corn variety. Drainage-type lysimeter was used to determine crop evapotranspiration (ETc) while local weather data were used to determine the reference crop evapotranspiration (ETo) in CROPWAT 8.0. The growth stages of the crop were assessed in terms of plant height, leaf area and leaf area index (LAI). The computed average Kc values were 0.43, 0.69, 0.92 and 0.70 during the initial, development, mid-season and late season stages, respectively. These values were different from Food and Agriculture Organization-recommended values especially during developmental and mid-season stage that could be a result of soil, climate and crop genetic differences. On the other hand, the computed Kc values were only slightly different to values from local studies with the same climate and soil type, with the discrepancy attributed to varietal difference and method of computing ETo. The generated results are more applicable to local conditions and should be used in the computation of crop water requirement of corn in the Philippines.

Citation:

GONZALES, J., LUYUN, R., JR., DE LOS REYES, R., & GALOSO, R. (2019). Determination of Site-Specific Crop Coefficients of Corn (Zea mays). Philippine Journal of Agricultural and Biosystems Engineering, 15(2), 31–42. https://doi.org/10.48196/015.02.2019.04