Excerpt
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 Bontanga 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.