Physiological and ethylene accumulation responses of cassava under drought stress

Abstract Drought is a major production constraint of cassava worldwide. The objective of this study was to evaluate the chemo-physiological and phytohormone responses of cassava under water stress conditions. Five cassava (Manihot esculenta) varieties were grown in greenhouse conditions under different water regimes (field capacity (FC), 2/3 and 1/3 available water (AW)). The physiological responses to drought were monitored. Plant height, relative water content (RWC) and SPAD Chlorophyll meter reading (SCMR) were recorded at 3, 4 and 5 months after planting. Ethylene accumulate were recorded at 1, 2 and 3 weeks after withholding water at 2 months after planting. The result revealed that plant height and RWC decreased significant difference under water deficit. Plant height and RWC under 1/3 AW had lowest followed by 2/3 AW and FC conditions. Under 1/3 AW, ethylene and SCMR increased significant difference followed by 2/3 AW and FC conditions. Thus, plant height, RWC, SCMR and ethylene accumulation could be used as a criterion in breeding programs to improve drought tolerance in cassava.