Use of the ceres-maize model to evaluate effects of planting dates on the yields of maize in a semi-arid area in Zimbabwe - Addis Ababa (Ethiopia) CIMMYT|EARO : 1999 - p. 296-298 - Printed
Delayed planting in communal areas is mainly caused by lack of draught power and insufficient/late rainfall at the beginning of the cropping season. Information on the effect of late planting and its interactions with inorganic fertilizers on crop yields in the semi-arid areas is scarce. The maize variety CG4141 was grown at Chiredzi Research Station and Chivi under four nitrogen levels during the 1996/7 and 1997/8 seasons. The data collected and historical trial data from Chiredzi Research Station was used to validate the CERES-maize model (v3.1). The model was used to evaluate the effect of planting dates on the yields of maize which was fertilized with four levels of nitrogen (O, 15,30 and 60 kg ha-1) for two seasons in Chivi during the 1995/6 and 1996/7 seasons. The model, which over predicted grain yield by 1.5 % was considered reasonable as indicated by a slope coefficient of 0.82 of the estimated equation and an R2 value of 0.66. Both the 1995/6 and 1996/7 simulated yields from the planting scenarios performed shows that planting can be extended to early December, late December, early January and late January without a significant decrease in yield by adding no nitrogen, 15,30 and 60 kg ha-1 respectively. Yield penalties associated with delayed planting increased with additional fertilizer levels.
633.15 / EAS No. 6