Developing a better understanding of the growth dynamics of different varieties and quantifying resource use efficiency of grown-on cotton in Central Queensland

Climate change in Central Queensland bringing warmer conditions, constraints of limited irrigation water over the last number of years, along with reduced restrictions on the planting time windows for Bollgard cotton varieties has meant significant changes in production systems in this region. Some key aspects of these changes in CQ are planting times (as early as August) which results in crops maturing early the following season (Jan/Feb). Consequently, the grower and consultant have the choice to harvest the crop or allow the crop to ‘grow-on’. Interest to growers is the potential for high yields (>18 bales/ha) of these ‘grown- on’ crops which are harvested in May/June (depending on climate and water availability). Pending changes to the RMP to manage the risk (Bollgard technology) will also enable growers to utilise these management systems. The ‘grown-on’ system adopted by Central Queensland’s cotton growers is most likely to continue even more so when there is full water allocation. Growers and consultants recognise risks associated with these systems, as there are risks with cotton been picked at either time. More research is needed to understand the opportunities, challenges and risk mitigation associated with these systems. This investment will support more detail monitoring of crop growth and associated resource use efficiencies such to inform current practice or identify the need for further research.