The season began with a hot, dry spell that put early pressure on cotton establishment. Relief arrived in early November as storms and cooler weather helped crops regain momentum. Most fields are now ranging from establishment to first flower or peak flower, while some planting is still underway. Across the region so far, approximately 7,500ha of irrigated cotton and 300ha of dryland cotton has been planted, with more to go in. More than 30% of the area features varieties containing XtendFlex®, giving growers a chance to evaluate performance in their conditions and management. 

Despite improved temperatures, heavy rainfall and waterlogging during November slowed progress, and early mirid damage has remained a challenge, causing tipping-out in early crops. While many plants are compensating, frequent rain and cloudy conditions have pushed some crops to flower or cut out earlier than preferred. All irrigated and dryland trials planted, have reached first flower and are looking promising. There isn’t much in the timing of flowering between the varieties but are all progressing well.  In my January update I hope to have some progression graphs comparing the varieties in their growth, boll numbers etc., following flowering.   

Image: 2025 XtendFlex® dryland trial

ThryvOn ® 

You may have heard people talking about ThryvOn® technology. While there is not a trial in the Dawson Valley this season, there is a trial in Emerald. As information comes to hand about the trial and how it is progressing, I will pass it on in these updates.   

So, what is it? The ThryvOn® trait is built on the integration of Mpp51Aa2.834_16, a single pore-forming insecticidal protein produced by the bacterium Bacillus thuringiensis (Bt), into the cotton genome.  Simply, it is a single protein trait that aims to protect the crop throughout the season from egg-laying and as a feeding deterrent for thrips. It does NOT provide complete control of thrips species and has little impact on adult thrips. It is only registered for thrip suppression, with no on label use for mirids. It has no known activity on caterpillars, stink bugs, aphids, or whiteflies.  

Trials have been ongoing with Bayer since 2017, with 2025 marking the first year that the CSD Extension Team have been involved. These ThryvOn® trials use a pair of cotton lines developed by CSIRO. These lines are genetically identical, and both contain Bollgard® 3 XtendFlex® (B3XF) technology—but only one has the ThryvOn® trait. This setup allows us to directly compare the impact of ThryvOn® without other genetic differences influencing results. These lines are strictly for research and demonstration. They will not be commercialised. 

The aim is to have a limited release of varieties containing this technology from the 2028 season, but that will be dependent on performance. 

November Weather Snapshot 

November brought hot days and stormy nights across Central Queensland.  

• Temperatures: Daytime highs averaged 32–33°C, with warm nights around 18–19°C.  

• Rainfall: After a dry start, mid to late month storms delivered around 90–95 mm across the region. Some local gauges recorded even higher totals due to intense thunderstorms.  

• Conditions: Mostly sunny early in the month, shifting to humid and unsettled as summer approached.  

• UV Index: Extreme   

Overall, November was warmer than average and wetter than expected, setting the stage for a typical Queensland summer.  

Agronomy Trials Update

CQ P & K disease trial  

Early tissue samples from the CQ P & K disease trial show strong nitrogen levels across all treatments. Phosphorus responded the most, with the double rate giving the highest leaf P. Potassium is still even across treatments at this early stage, which is normal as K responses typically show up later as crop demand increases. Higher fertiliser rates also lifted sulphur and some micros like zinc and manganese. No deficiencies or toxicities detected so far. We’ll keep tracking how this nutrition profile relates to plant vigour and leaf disease (Alternaria, leaf spot, grey mildew) as the season progresses. Disease related K effects may appear closer to rapid growth → flowering → boll fill, when K demand spikes. 

We should start seeing clearer nutritional–disease relationships from:  

• December (disease pressure peaks in humid conditions and high fruit loads) 

• January (similar to December but hot and humid nights can increase risk of plant health)  

eNpower Trial Update

Early November tissue tests confirm that all nitrogen treatments (eNpower and white urea) are performing strongly, with petiole nitrate levels right in the ideal range for that stage. Leaf samples also show balanced nutrition with no deficiencies, while the NIL treatment is clearly N-limited. At this point, there’s no difference of concern between eNpower and white urea — both are feeding the crop well as it moves into flowering. 

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