Project overview

Every cotton grower knows that a good start leads to a good finish — but what exactly does a ‘good start’ look like when assessing plant stands? Is it the number of plants? The gaps? The doubles? Or the overall pattern they form down the row? This initiative helps answer these questions by analysing how plant population and spacing uniformity work together to determine yield potential. 

Using seven seasons of data from 35 sites across Australia, CSD analysed over 880 trial plots to understand how plant numbers and stand evenness interact. This work combined controlled trials with real-world field variability to reflect the conditions growers face every season. The goal was not simply to describe plant stand effects, but to provide growers with a practical, in-season way to judge stands and protect yield. 

The key message is simple: plant population sets the ceiling for yield, and spacing uniformity determines how much of that ceiling is captured. This project provided the most comprehensive, Australian-grown dataset on how plant stands influence yield — and forms the basis for a decision-support tool to guide replant decisions and planter optimisation. 

Outcomes and achievements

• Analysed 883 individual plots across 35 trial sites from Emerald to the Murrumbidgee to quantify plant stand–yield relationships
• Identified the importance of effective plants per metre (plants <3 cm apart counted as one productive unit) for accurately predicting yield
• Demonstrated that uniform spacing (low standard deviation) significantly increases yield at all population levels
• Defined the “sweet spot” for high yield as 8–10 effective plants/m, with spacing variability (SD) below ~10 cm
• Developed an algorithm and decision-support tool that predicts yield risk from in-season stand assessments
• Produced practical grower guidelines for interpreting clumps, gaps, planter performance, and replant decisions. 

Project status

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