In the last few years, the management of foliar diseases in cotton has been a big topic. Areolate mildew has been a growing concern for Colquitt County cotton growers. In order to answer questions about managing this issue, a cotton fungicide trial was established in a field with a history of areolate mildew in 2021.
The treatments included: untreated check, Miravis Top 13.7 oz/A, Priaxor 6 oz/A and Abound 6 oz/A. The treatments were applied with a 18 row self propelled sprayer and each treatment was replicated 3 times. The grower planted DG 3615 at this site.
Dr. Bob Kemerait, UGA Plant Pathologist, rated this test for canopy defoliation three times: 37 days after treatment (DAT), 51 DAT, and 76 DAT. At 37 DAT, Priaxor and Miravis Top significantly reduced canopy defoliation as compared to the untreated check. At 51 DAT, the Abound (45%) significantly reduced canopy defoliation compared to the untreated check (74%). The Priaxor (10%) and Miravus Top (16%) significantly reduced defoliation compared to the Abound. At 76 DAT, no significant differences were noted among the treatments.
No significant differences in lint yield were noted at harvest. However, Priaxor and Miravis Top increased lint yield by 105 and 81 lbs per acre, respectively. At current cotton prices, the increase in yield from the fungicide application will result in a profit.
In conclusion, areolate mildew has become an important disease affecting cotton production in Georgia. Over the last four years, numerous cotton fungicide trials have been conducted in Colquitt County to investigate this topic. This data was presented at the 2022 Beltwide Cotton Conference and is available below. In the 4 out of 5 trials where areolate mildew was the predominant disease, lint yields increased by at least 100 lb/A when Priaxor or Miravis Top was applied.
This research could not have been possible without the help Perryman Farms, Buckner Farms, BASF, Syngenta, and Funston Gin.
If you have any questions please contact your local county Extension agent .