Cotton:
Jassid populations remain low, with only a few adults being observed; however, false jassids are becoming much more common. Silverleaf whitefly (SLWF) numbers are beginning to increase; you should stay ahead of infestations. Once whitefly populations build, control becomes much more difficult and costly. Late-planted cotton is at greater risk than early-planted cotton. This is largely due to the steady increase in regional SLWF populations as the season progresses. Environmental conditions also play a significant role. Hot, dry weather favors rapid SLWF population growth, while intense rainfall associated with thunderstorms can reduce adult numbers. Extended periods of rainfall may further slow population development, but these effects are often temporary. Areolate mildew is present at low levels across much of the South, with ample time remaining before cotton defoliation. Once established, this disease can cause substantial yield losses if left unmanaged. Current fungicide options of choice include Priaxor and Miravis Top, which have provided effective control under favorable application conditions.
Peanuts:
With this weather, I expect we will begin to see spider mite outbreaks in drought-stressed fields, and it has already started in some. On the other hand, consistent rainfall should help keep these problems in check. Regardless of the weather, I expect to see increasing numbers of three-cornered alfalfa hoppers and velvetbean caterpillars in August. While I am not overly concerned about three-cornered alfalfa hoppers, I encourage you to remain vigilant when scouting for caterpillars. Velvetbean caterpillars are our most common worm pest, and they can completely defoliate peanut fields if left untreated. Many of you apply diflubenzuron (Dimilin) as a preventative treatment for velvetbean caterpillars. This product provides excellent control of velvetbean caterpillars, but it offers little activity against soybean loopers and other caterpillar species that may also be present this time of year. I have heard of beet armyworm infestations in peanut fields around. Due to insecticide resistance, this pest can no longer be effectively controlled with products containing the active ingredient chlorantraniliprole (Coragen Evo, Besiege, and similar products). If you have a history of rootworm, especially if you have not applied Vertento at planting or through irrigation in high-risk fields, I recommend considering a chemigation treatment soon. The first generation of adult beetles has already emerged from corn.