Yield Loss of Cotton Cultivars Due to Rotylenchulus reniformis and the Added Benefit of a Nematicide

The objective was to determine cotton yield loss due to Rotylenchulus reniformis and document any yield benefit from the addition of a nematicide. Field trials were established in two adjacent fields: one infested with R. reniformis and one where R. reniformis was not detected. In both fields, seven cotton cultivars were planted with and without Velum Total (1.02 liters/ha). In 2017, R. reniformis reduced cultivar yields by an average of 59% between the noninfested and the R. reniformis-infested field. The nematicide application increased seed cotton yields in the R. reniformis field by 55%, and no yield increase was observed in the noninfested field. In 2018, R. reniformis reduced seed cotton yields by an average of 42% between the noninfested field and the R. reniformis-infested field. Across the cultivars, addition of the nematicide increased seed cotton yields by an average of 6% in the R. reniformis-infested field and an average of 8% in the noninfested field. The nematicide reduced R. reniformis eggs per gram of root by an average of 92% in 2017 and 78% in 2018 across all cotton cultivars. Overall, R. reniformis reduced seed cotton yields by 50%, which was equivalent to 2,225 kg/ha.