Growth, yield and nutrient-use responses of drought-tolerant maize varieties to sowing date and fertilizer microdosing in northern Benin

Changing sowing dates has been a farming low-cost strategy to mitigate climate induced water stress during the juvenile stage of crops. This study evaluates the potential of drought-tolerant maize varieties and fertilizer microdosing to enhance maize productivity under different sowing dates in rainfed conditions. We conducted a two-year strip split-plot trial with three sowing dates (early, normal, and late), five maize varieties (DMR, TZEE, TZE, 2008Syn, and 2000Syn) and five fertilizer treatments (control: no fertilizer, three microdosed rates MD1: 25 kg N + 4 kg P ha-1, MD2: 25 kg N + 8 kg P ha-1, MD3: 35 kg N + 8 kg P ha-1, and the recommended rate RR: 76 kg N + 13 kg P ha-1). DMR is a drought-susceptible variety; and TZEE, TZE, 2008Syn, and 2000Syn are drought-tolerant. Results show that grain yield was 9.9% higher and 10.2% lower under early and late sowing, respectively, compared to normal sowing. Grain yield was 29.9, 37.8, 26.5 and 12.5% higher under TZEE, TZE, 2008Syn, and 2000Syn, respectively compared to DMR; and 153.3, 200.9, 247.2 and 220.8% under MD1, MD2, MD3 and RR, respectively compared to control. DMR achieved its highest mean grain yield under the recommended fertilizer rate, whereas the drought-tolerant varieties achieved their highest mean yields under MD3. The findings confirm that late sowing reduced maize performance, while drought-tolerant varieties and fertilizer microdosing independently improved average productivity.