Characterizations of Growth, Yield and Water Use Efficiency of Adzuki Bean as Affected by Drought Stress

Abstract

Accurate and optimal water supply to crop is critical in growing stalks and producing maximum yields. Adzuki bean is one of the representative legume crops and known as a vulnerable crop to water stress. This study investigated drought effect on adzuki bean at various growth stages and water use efficiency (WUE) with different soil moisture contents in order to evaluate response of adzuki bean to drought. The experiment was performed at National Institute of Crop Science in Miryang. Adzuki beans were planted in a Wagner pot filled with 50% of silt loam soil and 50% of bed soil. Drought treatment was applied at six growth stages: V1, V3, V5, R1, R3, R5. Another pot experiment was performed in a stainless steel pot with an automated irrigation system in order to maintain targeted soil moisture content (40, 60 and 80% of field capacity). Growth and yield characteristics of adzuki bean were measured from all pots. Crop susceptibility (CS) was calculated from the Wagner pots to quantify drought effect at each growth stage and WUE was measured from the stainless pots to determine the least water requirement to prevent drought damage. Drought effect was the greatest in growth reduction at V1 and yield reduction at R3. CS value was the smallest value at V3 and the greatest at R3. Growth, yield and WUE data of adzuki bean were not different between soil moisture 60% of field capacity and 80%, while ones from 40% soil moisture content were smaller than others. Adzuki bean exhibited great vulnerability to drought stress at reproductive stage and it required at least soil moisture 60% of field capacity to prevent drought damage. These results will be useful to water management of adzuki bean and prevent drought damage in adzuki bean cultivation. Results of daily water used from adzuki bean cultivated with different soil moisture content (40, 60, 80% of filed capacity). DAP represents days after planting.