Speakers
Description
Maize is a key staple crop in Ghana, yet changing climate conditions are making traditional planting decisions increasingly unreliable threatening maize yield and food security. Though the climate of Ghana has changed little is known about how these changes has disrupted the Growing Degree Days (GDD) of maize in the country. In this work, we used a climate-based model to determine the GDD requirement of maize under Ghana’s changing climate. We applied the Baskerville–Emin method to calculate the GDD for maize in two contrasting locations: Kumasi in the south and Navrongo in the north. Using ERA5 reanalysis temperature data over a 12-week growing period, crop development and seasonal variability were analyzed across three farm sites. Our results revealed that maximum temperature directly influenced GDD, while minimum temperature had little effect. The farms in Kumasi accumulated GDD more steadily, which supported better growth and in turn resulted in high yield potential whereas the farm in Navrongo recorded faster but more variable accumulation due to consistently high temperatures which resulted in lower yield potential. Threshold GDD values were observed at 1,948 (KNUST), 1,953 (Oforikrom), and 1,313 (Navrongo), marking physiological maturity of maize in these areas. These result highlight the north–south differences in maize growth, and calls for GDD based climate-smart farming to improve productivity and food security in Ghana.
Keywords: Growing Degree Days, Maize, Climate, Ghana