Effects of Different Rates of Nitrogen Application on Phenology of Maize (Zea Mays L.) in Berekum Municipality of Ghana

Abstract

Judicious usage of fertilizers could boost crop productivity and reduce negative effects on the environment. Farmers in Berekum have insufficient information on the specific rate of nitrogen application for hybrid (Pannar 12) and open pollinated (Omankwa) maize varieties. Field studies (March – November, 2019) were, therefore, carried out in Berekum Municipality of Ghana to determine the effect of different rates of N fertilizer on time of flowering and physiological maturity of hybrid and open-pollinated maize varieties. Pannar 12 and Omankwa maize varieties were treated with no nitrogen (control), 90, 120 and 150 kgN/ha in a 2×4 factorial, arranged in a Randomized Complete Block Design with three replicates. The parameters measured were days to 50% tasselling and silking, anthesis-silking interval and days to physiological maturity. The results of the present study showed that fertilizer application had significant (P<0.05) effects on tasselling, silking, anthesis-silking interval and physiological maturity in both test crops. Generally, Omankwa flowered and matured earlier than Pannar 12. Omankwa grown with 150 kgN/ha took 50-51 days to tassel, 52-54 days to silk and had a short anthesis-silking interval. However, it was observed that physiological maturity was delayed in Omankwa by 2-4 days and reduced by 2-5 days in Pannar 12 due to application of nitrogen. The studies indicated that increasing levels of nitrogen application (150 kg/ha), promoted early flowering, and hastened physiological maturity in Pannar 12, resulting in the highest grain yield of 6146 kg/ha in the major rainy season and 6095 kg/ha in the minor season of 2019. However, high nitrogen levels (150 kg/ha) delayed physiological maturity in Omankwa, culminating in its relatively low grain yield of 4401 kg/ha in the major rainy season and 4688 kg/ha in the minor rainy season of 2019.

Keywords: Maize, Variety, Phenology, nitrogen