Different effects of water-saving management on canopy microclimate, spikelet sterility, and rice yield in the dry and wet seasons of the sub-humid tropics in northern Ghana

•Drainage at flowering (DF) reduced dry (DS) but not wet season (WS) rice yield.•DF had small impact on inner-canopy temp (Tc) at flowering time and grain sterility.•DF greatly increased Tc from late afternoon to midnight in DS but not in WS.•Negative effect of DF is ascribed to late-afternoon-to-midnight Tc increase in DS.