Effect of nitrogen application rate on tarnished plant bug (Lygus lineolaris) in Mid-South cotton

Research was conducted in 2012, and 2013 at the Delta Research and Extension Center located in Stoneville, MS. Plots were 16 40 – inch rows that were 75 ft. in length. All treatments were replicated 4 times. Nitrogen in the form of UAN 32% was applied at pinhead square, banded 9” to one side at 3” deep. Rates used in testing were 0, 40, 80, 120, and 160 lb. /ac. At each rate in testing there were treated plots and untreated plots for tarnished plant bugs. Plots were scouted weekly using appropriate methodology. Insecticides were applied to treated plots based upon thresholds developed by Mississippi State University. Plots receiving ≥ 80 lb. /ac significantly increased final plant height when compared to plots receiving no nitrogen. Regardless of Nitrogen application rate tarnished plant bug populations stayed above threshold for most of the flowering period of cotton in the sprayed plots. Unsprayed plots contained a 4-fold higher population of tarnished plant bugs. Yields and net profit were maximized in plots receiving 80lb/ac of nitrogen. Applications required to control tarnished plant bugs were reduced by ≥ 1 application when comparing plots receiving 80 lb. /ac to plots receiving 120 and 160 lb. /ac.