Behavioural pattern of upland rice agronomic parameters to variable water supply in Nigeria

摘要

The response of rice crop to water application is of paramount importance to researchers as it helps in determining its agronomic development. The study was aimed at establishing the agronomic responses of rice crop to differential water supply. A two-year dry season experiment was conducted at the research farm of International Institute of Tropical Agriculture, IITA Ibadan, Nigeria. Two upland rice varieties (NERICA 2 and NERICA 4) were planted on a 5 × 5 m plot in a randomized complete block design with four treatments based on different water application. Agronomic parameters such as plant height, root depth, canopy shading, leaf area index, panicle and tiller configuration, biomass and grain yield in relation to crop water use were obtained and the results were subjected to statistical analysis. Maximum plant height (89.0 and 100.3 cm), maximum root depth (22.1 and 23.8 cm), panicle diameter (3.9 and 4.5 cm), panicle length (26.1 and 25.7 cm), leaf area index (LAI) 3.27 and 3.95, canopy shading (CS) 0.22 and 0.99 were obtained for both NERICA 2 and NERICA 4, respectively. Leaf width (1.3 and 1.4 cm), total tillers (14 and 12) and leaf length (36.9 and 38 cm) were also observed for the two varieties respectively. The highest total grain and biomass yields of 1.94 and 1.95 t/ha were observed in treatment A for NERICA 2 while the least values of 0.29 and 1.09 t/ha were observed in treatment D. As for NERICA 4, the highest values (1.90 and 2.27 t/ha) were from A and the least (0.38 and 2.29 t/ha) in D. The result of ANOVA showed significant differences in biomass and grain yield, LAI, CS, plant height and root depth among treatments (P > 0.05). Specific behavioural pattern to differential water application was observed in the development of agronomic parameters monitored during the experiment. This was indicative that water is a major yield - influencing factor in rice production.