Adapting rain-fed sorghum agronomy to breeding progress - cropping system model parameterisation

Abstract

Over the last decades, there has been considerable investment from the private and public sector in genetic improvement of sorghum hybrids, but the high yield potential of these new genotypes is not always achieved in farmers’ fields. Matching these new genotypes to seasonally optimised crop management has the potential to increase productivity. One of the best ways to determine a hybrid’s yield potential in a specific location, but also to identify best hybrid by environment by agronomic management combinations and to demonstrate benefits and trade-offs between productivity, investment and risks, is to use a crop model, such as APSIM (www.apsim.info). To enhance APSIM’s ability to predict grain yield for various sorghum genotypes, growth and development parameters of new hybrids have to be determined. Here we present flowering time data for one previous and eleven newly-released sorghum hybrids that were parameterised in specially-designed experiments with five different sowing times and the fit between model-predicted and observed values. This information, together with other growth parameters, will be used to parameterise the model to improve APSIM’s ability to simulate yield of the new sorghum types.