Winter sowing for more reliable boll filling in Central Queensland

Abstract

Central Queensland has a unique climate that presents both challenges and farming systems opportunities for cotton production. We have re-examined the Emerald climate to identify opportunities that might enable the production of more consistent cotton yields and quality in what can be a highly variable climate.
This climatic analysis identified that spring and early summer is the most optimal period for boll growth and maturation. However, to unlock this potential requires unseasonal winter sowing that is 4 to 6 weeks earlier than the traditional mid-September planting time. Our experiments have sort answers to two questions: i) how much earlier can cotton be sown whilst maintaining reliable crop establishment and, ii) how should agronomic management be varied to optimise crop performance when sown early.
Data collected over 4 years has demonstrated that August sowing offers the potential to grow reliably higher yields compared to the traditional spring planting window with an average improvement of 2.2b/ha per annum(23%) over 4 years. Sowing cotton during August still presents wet weather related picking risks however the period of crop exposure is reduced compared to the traditional planting window and the increased yield potential offers a significant buffer against seasons when weather related lint quality downgrades may occur. An aspect of this research is that it has been conducted in partnership with growers and consultants at a commercial scale without forsaking scientific rigour. The experiments have also been fully utilised for extension purposes so that growers could experience research outcomes in real time. The outcome has been rapid adoption by some growers during the 2016/17 who have successfully grown early sown cotton for the first time with excellent results. This talk will present an overview of the key agronomic findings that have been consolidated over this 4 year project.