EVALUATION OF RAINFALL ONSET PREDICTION AND FARMERS SOWING WINDOW ON IRRIGATION STRATEGY AND MAIZE PERFORMANCE AT SAMARU, NIGERIA

Abstract

Crop production in Nigeria is essentially rain fed and the uncertainty of rainfall establishment due to its inter-annual variability is the most crucial problem. Predicted onset dates of rainfall and farmers’ sowing window on irrigation strategy and maize performance at Samaru Nigeria was evaluated in this study. The study also investigated responses of maize varieties to sowing dates, determine yield components and water use efficiency (WUE). The Agricultural Production System Simulator (APSIM-Maize) simulation model was also validated. Three experiments were conducted at the Institute for Agricultural Research, Samaru Zaria (70 38’N, 110 11’E 686M) Research Farm. Three maize cultivars; extra early, early and medium maturing varieties (Sammaz 33, 37 and 26 respectively) were planted on three sowing dates (SD1, SD2, SD3). The 2015 wet season trial was based on rainfall onset predictions by the Nigerian Meteorological Agency (NIMET0, 2015, Omotosho’s model and farmers’ conventional sowing dates Plantings were done on the 29th May, 10th of June and 27th of June respectively. The 2015 and 2016 dry season trial planting dates were at 10days interval starting from March and February respectively. Three levels of irrigation were imposed based on levels of cumulative pan evaporation (Epan) values of 1.0, (EI1), 0.70 (EI2) and 0.40 (EI3). All the experiments were laid out in a split – plot design with planting dates and supplementary irrigation levels as the main plots while maize varieties formed the sub-plot treatment. Results of the wet season experiment showed that SD1 performed significantly better (P < 0.01) followed by SD2 (P < 0.05) and SD3 respectively. The result of the leaf area index (LAI) showed that highest LAI was obtained under D1 (3.83) followed by D2 (3.31) and D3 (3.18) respectively. Analysis of the observed yield parameters under planting dates and varieties indicated significant differences among the parameters with exception of stover weight and seed per cob.