Wet conditions in October accelerated the spread of late-season disease, specifically alternaria leaf spot, in Texas cotton. The disease causes browning or bronzing of the leaves and can lead to premature defoliation. While cotton fields in the High Plains and Rolling Plains may appear to be in bad shape due to these symptoms, Texas A&M AgriLife Extension Service experts say that the mature state of the crop in affected areas should help limit affect to yield. However, if the epidemic would have occurred earlier in the season, growers may have observed greater yield loss. Therefore, growers are encouraged to monitor and keep record of the problem areas within fields so preventive measures can be put into place next season.
Preventive measures include:
- Incorporate cotton residue and/or rotate to alternate crops
- Ensure proper soil fertility, especially potassium
- Reduce plant stress through adequate drainage and other cultural practices
- Minimize rank vine growth to help prevent excessive humidity in the crop canopy
- Implement a preventive disease management program
To complete your arsenal, we suggest Quadris® fungicide, which offers broad-spectrum control of foliar cotton diseases, including alternaria leaf spot.
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