The effect of water deficit at the flowering time The plant water potential have played important rule in rice, in term of water deficit its reduced the proportion of panicle exertion and effects to the percent fertile grain on panicle,
thus plant water potential may have a direct effect on the fertile grain and indirect effect via the exertion of the panicle. It also appears that pant water potential influence the delay in flowering (Pantuwan et al., 2002a).
At flowering time if no standing water and soil become dry it cause spikelet sterility and the sterility are higher according to the severity of drought (Fischer and Fukai, 2003).