“We surveyed a small sample of fields for plant bugs this season, but they reached threshold in only a small percentage of those fields.
“In soybean, a few soybean loopers are showing up early. We’re coming across velvetbean caterpillars and green cloverworms. We have a combined defoliation threshold for all of those foliage feeders. Prior to mid-bloom we can stand 30% defoliation, but after mid-bloom – when we have pods on the plant – the threshold drops to 15% defoliation.
“When you see that level of defoliation, go in with a drop cloth before deciding on a treatment plan. Determine what is feeding on leaves. If it’s soybean looper, you’ll need to go with a selective insecticide. If it’s anything else, we can apply a pyrethroid.”
Brad Smith, Nutrien Ag Solutions, Selma, Alabama:
“Overall the crops look good, and some corn probably will make it to black layer this week.
“In cotton, we’re treating stink bugs. Aphids are no longer here, either due to treatments or the fungus. We’re treating weed where they haven’t already been addressed. Plant growth regulators are going out. We expect cooler temperatures later this week.
“We recently found areolate mildew in cotton in Elmore County, and that’s the only issue of immediate concern. Hopefully, it won’t spread, but we’re keeping an eye out.
“Fall armyworms are showing up in pastures and in grain sorghum, which we always expect in late July.
“In soybeans, we’re seeing foliage feeders and stink bugs. We’re cleaning up stink bugs and making fungicide sprays in the MG IVs and most of the MG Vs.”
Dominic Reisig, NCSU Extension Specialist, Entomology, Plymouth, North Carolina:
“The insect side is the only good news for our cotton crop right now – it is quieter than usual. It started out as a real buggy year. The stink bugs were earlier and more numerous than usual in corn and cotton, but that’s quieted down.
“In soybeans, stink bugs are getting in the fields at R3 to R4, and I encourage growers to be protective at that stage. We don’t usually see them until R5.”
“In cotton, we’re paying close attention to bollworm. For 3-gene cotton, I encourage growers to stick to the threshold and save their money. We haven’t seen a yield benefit to spraying Bollgard III, Widestrike 3 or TwinLink Plus.
“Bollworm are around but not as many per acre as you might expect.
“We also don’t need to control bollworm to manage for resistance. That idea seems to be floating around this season. A widely accepted Southeast study used the gossypol marker to determine the percentage of moths that come out of cotton. That percentage is really, really low – less than 1% between mid-June and September, with a late-season increase to 19% in September. For me, that was a surprising finding, but that’s the state of knowledge on it right now.
“In 2-gene cotton, we have sprayed for bollworm eggs. A lot of growers are moving to 3-gene cotton because companies are using 3-gene traits in all of their new varieties. Growers who are planting a 2-gene variety that’s yielding well can include the cost of a worm spray in their program.
“We do expect worm pressure to increase after this dry spell ends. The species can survive through what’s known as facultative diapause. That means it’s hot and dry, and the larvae will wait in the soil for better conditions. That’s why we often see a population increase once the weather breaks after an extended stretch of hot, dry weather.
“In late-planted corn, watch for fall armyworms. A fair amount of fall armyworm is around and they can put a hurting on ear-stage corn. I’m not so worried about whorl-stage, but we need to protect our ear-stage corn. For soybean fields, it’s too early to tell, but the species that puts a hurting on corn can infest soybean, as well.”
Bryce Sutherland, Extension Agent, Worth County, Georgia:
“We are managing cotton at a lot of different stages, but the crop is progressing well overall. A blanketing rain last weekend helped. On the older cotton, we’re moving into the critical blooming period.
“We’re scouting closely, following stink bug recommendations and treating threshold populations. In 2-gene cotton, we’re finding corn earworm escapes but nothing at threshold yet.
“Low levels of silverleaf whitefly are showing up in cotton. Nothing has reached treatment level, but we’re monitoring closely. Growers need to evaluate populations and make treatment decisions carefully.
“With watermelons finished up in the county, let’s quickly destroy those fields. We understand the value and purpose of pinhookers, but watermelon fields provide a whitefly haven, and we must break that lifecycle.
“In peanuts, caterpillars are picking up, but we haven’t found any fields at threshold – yet. Conditions are really good for white mold, and we’re seeing that.”
Sally Taylor, Virginia Tech Extension Entomologist, Tidewater:
“Insects are quiet in cotton with the exception of a few problem lygus fields. Moth trap catches have started to climb this week and we are finding eggs in cotton. Scout closely and follow our trait-based threshold recommendations.
“For 2-gene cotton – Bollgard II, Widestrike and TwinLink – I recommend spraying Prevathon or Besiege when you find 25 eggs per 100 terminals or leaves. This strategy is only recommended with these two insecticides. I do not anticipate needing to spray 3-gene cotton for worms. That includes Widestrike 3, Bollgard III, and TwinLink Plus. Spray that cotton only if you find live worms.
“This week we are starting the annual bloom survey for lygus in cotton. Information from that will be provided on Friday, July 26, on the Virginia ag pest advisory website.”
De Broughton, Florida Regional Specialized Agent, Live Oak:
“In peanuts, disease is emerging – low occurrence of early leaf spot and instances of white mold. Also, we are seeing significant amounts of Aspergillus niger – much higher than usual. Plant stress at planting probably gave aspergillus the opportunity, and some of those rot problems have surfaced and continue to grow.