Modelling heat stress effect on two maize varieties in Northern Region of Ghana
Agriculture in Ghana accounts for more than 30% of GDP and three-quarters of export earnings. In Sub-Saharan Africa, climate change is predicted to affect the agricultural sector most. The objectives of this study were: to use the SIMPLACE (Scientific Impact assessment and Modelling Platform for Advanced Crop and Ecosystem management) to simulate maize yield under heat stress. To compare SIMPLACE model output with heat stress, and without heat stress. Finally simulate the effect of heat stress on maize yield depending on the sowing date. The study collected and analysed data from field experiments during the 2012/2013 dry season and repeated in 2014 at Botanga irrigation site and the 2014 rainy season at Gbulahagu farming community based on three (3) sowing dates (SD). Comparing the SIMPLACE model output to the observed field data, the duration of development phases were predicted with acceptable accuracy among the three sowing dates. Simulated and observed showed good agreement for maize biomass at several growth stages of the maize. The heat stress component of SIMPLACE gave a good prediction for yield under heat stress when no other stress (water, nutrients) occurred. The estimations of the final yield showed an over estimation when the model was run with no heat stress condition in the rainy season experiment in particular under nutrient stress. The model was successfully parameterized and evaluated for simulating the effect of heat stress on maize yield under no nutrient and drought stress and can therefore be used as a research tool in the study area.