Project overview

Cotton crops in Northern Australia grow rapidly due to warmer temperatures, longer daylight hours, and higher humidity. Managing this vigorous growth is essential to avoid rank crops, delayed maturity, and poor fibre quality. The Mepiquat Chloride (MC) Management in Northern Australia project was developed to help identify how plant growth regulators can be used most effectively under these unique conditions. 

The project trialled different MC rates and application timings under commercial conditions at Kununurra in Western Australia. By comparing multiple treatment combinations, the research team examined how MC influences crop height, fruit retention, yield, and fibre quality. 

The results are helping build management strategies tailored to northern environments — supporting growers to optimise canopy structure, harvest timing, and profitability in new cotton-growing regions. 

Outcomes and achievements

• Have conducted one replicated trial to date in Kununurra testing different rates and timings of MC applications
• Identified that earlier, at-flowering applications were most effective in controlling growth and maintaining yield
• Demonstrated that late or high-rate MC use provided little additional benefit under mild seasonal conditions
• Provided key learnings on how planting date, crop stress, and temperature influence MC response
• Findings have been used to design additional experiments to be undertaken in 2026
• Established groundwork for refining regional PGR management guidelines for northern systems. 

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Project status

Trials are planned for the Ord region in 2026.

Resources

Report – Crop Canopy Management for Northern Australian Environments using Mepiquat Chloride

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