Light Interception and Radiation Use Efficiency of Cassava under Irrigated and Rainfed Conditions and Seasonal Variations

Determining the effect of irrigated and rainfed conditions on light interception, light extinction coefficient (k), radiation use efficiency (RUE), biomass, and storage root accumulation of cassava was the objective of this study. The field experiment was arranged in a randomized complete block design (RCBD) with four replications. The effect of irrigated and rainfed water conditions in cassava were evaluated under two planting dates for two years. Light interception depended on k and LAI which affected solar radiation accumulation and thus biomass production for cassava. The k values ranged from 0.49 to 0.93 a nd 0.46 to 0.86 for irrigated and rainfed crops, respectively. The RUEbi and RUEsr depended on water conditions and crop growth stages and seasons, whereas rainfed crops in the May planting were slightly lower in RUEbi than irrigated crops. RUEbi of the crop planted in November was not significantly different for irrigated and rainfed crops. Irrigation at the late growth stage could maintain higher LAI, light interception, and RUE for the crop planted in May, whereas those in November planting were not significantly different.