Effect of soil fertility and maturity stages at harvest on maize yield under rain-fed conditions

Understanding critical management practices during seed development would help to improved crop production as climate patterns change. This study focused on the interactive effect of soil fertility with harvesting stages, on hybrid maize yield under two different agro-ecological locations during the 2014/2015 and 2015/2016 summer seasons in KwaZulu-Natal, South Africa. The 2015/2016 season was drier than that of 2014/2015. The field trials were split plots design, where varying fertility levels (main plot) and harvesting stages (sub plots) were replicated four times. The interaction was determined by variables of plant growth, physiology and yield parameters. The plant growth and physiological parameters measured were significantly influenced (P<0.001) by the interaction of fertility levels across days after planting and silking. The interactions of soil fertility levels with harvesting stages had significant effects (P<0.05) on all yield components during the wetter 2014/2015 season, as well as on seed yield, harvest index, thousand seed weight and total biomass in the drier 2015/2016 season. Optimal fertilization improved maize yield at each stage of harvesting. This study showed that harvesting stress-free optimally-fertilized maize at dent stage maximized yield potential than allowing it to reach physiological maturity under stressful conditions.