Effects of water deficit on days to maturity and yield of three NERICA rainfed rice varieties

Abstract

Water deficit is a major problem in rice grown under rainfed conditions. It affects plant growth and development and ultimately leads to a considerable yield reduction or crop failure. Although the rice crop is susceptible to water deficit, there is a marked genotypic variation in response to water deficit. The objective of this research was to investigate the effects of water deficit on days to maturity and yield development of three recently developed rainfed rice varieties that is, New Rice for Africa (NERICA coded as N2, N4 and N11) with a view of establishing the most drought tolerant rice variety that can be grown under rainfed conditions in Kenya. This study was carried out in the University Botanic Garden, Maseno during 2005-2006. Plants were subjected to water deficit treatments in the green house a factorial set up. The seeds of the three NERICA cultivars of rice were planted in 20 Litre PVC pots arranged in a completely randomized block design (CRBD) with four treatments and four replications. The treatments included watering a litre of water once a day (control), Watering every 2, 4 and 6 days. The parameters measured included tiller number, days to 50% heading and flowering, days to harvesting, panicle length and yield. The water stressed plants took the longest to mature and N2 took the least number of days to maturity (109) while N11 took 114 days and N4 took 118 days. The yield component declined with the increase in water deficit, N2 had the highest yield at higher soil moisture deficit (1500 kg/ha) followed by N4 (818 kg/ha) and then N11 (736 kg/ha). Results indicate that under moisture deficit conditions N2 is least affected and had …