Efficacy of Thrips Management Options for Reducing Damage and Preserving Cotton Yields, ACC#28
Studies were conducted at the Prattville Agricultural Research Unit (PARU) in Prattville, AL and at the Tennessee Valley Research and Extension Center (TNVREC) in Belle Mina, AL, to evaluate selected seed and in-furrow treatments against thrips infesting seedling cotton.
To evaluate treatments, whole plot thrips injury ratings were made on a 0-5 scale. On this scale, “0” means no injury is observed, “3” is considered the threshold when delays in maturity are likely and yield loss is possible, and “5” means thrips have killed all the plants in the plot. Although initial thrips injury ratings were higher at PARU, both locations had significant pressure at the final rating. Except for Cruiser and Orthene 97S at PARU, all treatments significantly reduced thrips injury ratings compared to the untreated controls (black seed, fungicide only).
As has been consistently reported across the Mid-South and Southeast, Cruiser performed poorly at both locations, while Orthene performance was different at each location (see figure above). Although no significant differences in yield were observed among treatments, using a recommended at-plant insecticide yielded an average of ≈117 lbs of lint per acre compared to the untreated control (see figure below). These data show a consistent return on investment when using an at-plant insecticide to manage thrips in seedling cotton. Results from this study have also led to the removal of Cruiser from the AL Cotton IPM Guide recommendation for thrips management.
Figure below: Impact of seedling thrips control during bloom
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