With as hot as it’s been in July, it’s hard to imagine Sclerotinia blight showing up in peanuts. I have been searching for it in my trials but haven’t seen it yet. However, highs in the low 80s and lows around 70 today through next week means conditions will be favorable for disease development. Plus, adequate soil moisture is present due to recent rains and peanut canopies are dense enough to favor Sclerotinia blight. I recommend monitoring the Virginia Sclerotinia Blight Advisory on the Peanut Cotton InfoNet to check the risk of this disease in your area and scout for disease, especially in fields with a history of Sclerotinia blight. Access the Peanut Cotton InfoNet using this link https://infonet.ext.vt.edu/. You can also call the VA Peanut Hotline at 1-800-795-0700 for up-to-date disease advisories.

At this point in the season I recommend fungicides Omega or Vantana tank-mixed with a leaf spot fungicide if you haven’t already applied Miravis + Elatus. I hesitate to recommend the first application of Miravis + Elatus this late in the season due to concerns about late leaf spot escapes as these products have no curative activity against leaf spot. You’re okay if it’s the second application. Fontelis at 1.5 pt/acre can provide some disease suppression if sprayed preventively.

Please contact me if you have questions.

David Langston. (757) 870-0498 cell email: dblangston@vt.edu

We hit the tarnished plant bug threshold for the first time this season on July 15 at the Tidewater AREC, in Suffolk. Reports of threshold numbers are rolling in from collaborators as well. Here are a few key reminders for successful plant bug management this year;

1. Use economic thresholds

These economic thresholds are the point at which you will see a return on investment from spraying for plant bugs.

Pre-bloom threshold;

8 plant bugs/100 sweeps AND less than 80% square retention

Many of our cotton fields here on the research farm and in on-farm trials are beginning to flower this week. Once you reach 50% of plants in a field with flowers, switch to using a drop cloth to sample plant bugs. The drop cloth should be placed on the ground between two rows and the plants on either side vigorously beaten over top of the sheet. Take a sample in 6-8 spots throughout a field and average to determine the number of bugs per drop cloth sample. Making the switch from sweep net samples to drop cloth samples during bloom is critical for making informed management decisions on plant bugs.

Threshold from the 1^st week of bloom on;

3 plant bugs/5 row feet

Even if you are using a Thryvon cotton variety, it still needs to be scouted and treated for plant bugs at the recommended thresholds. Weekly scouting will provide the best insight on when and where insecticide applications are needed.

2. Insecticide rotation

Hold off on using strong broad-spectrum insecticides until late in the season. These include pyrethroids and organophosphates;

Organophosphates: Bidrin, Orthene

Pyrethroids: Warrior II, Bifenthrin, countless generics (look for insecticide MOA 3A on the label). Many premixed products, including Endigo or Brigadier include a pyrethroid.

Plant bugs have developed resistance to pyrethroids, and these products eliminate beneficial insects, which may keep other pests in check later in the season. An early pyrethroid spray can often flare spider mites, aphids, and bollworms later in the year.

A good option for your first spray for plant bugs is Transform @ 2 oz/ac. Diamond @ 4-6 oz/ac can be included as well, where there are nymphs present. This product is an insect growth regulator and will not have activity for adult plant bugs. If timed correctly, it has been shown to increase the time before another plant bug spray is needed. Neonicotinoids (Centric, Admire) can also be effective early in the season, but need to be combined with other products to get good control as the year progresses. Be sure to check the label for restrictions on use patterns during bloom (e.g., application restrictions because of risk to bees and other insect pollinators).

David Langston 07/09/2025

Peanuts are growing fast and that first leaf spot spray has been applied or should be soon.  Typically folks go with Bravo (1.5 pt), Alto + 1.0 pt Bravo, or Aproach Prima + 1.0 pt Bravo with or without tebuconazole.  With the weekly rain and high humidity, conditions for leaf spot are favorable.  Some folks are thinking about their second spray pretty soon.  Fungicides I like for the second spray are Provysol + tebuconazole, Lucento, Fontelis (1.0 pt) or Miravis.  If you have fields with a history of southern stem rot (white mold) you may need to tank mix the leaf spot fungicide with Convoy, Elatus or Excalia or bump the Fontelis rate up to 1.5 pts.  I’d plan on the third spray being Bravo at 1.5 pt + tebuconazole or substitute tebuconazole with one of the so. stem rot fungicides above.  The fourth spray I like Provost Silver because of it’s “kick-back”/curative activity.  The last spray or last two sprays can be either Provost Silver again or Bravo at 1.5 pt + tebuconazole.  If you think there may be issues with Sclerotinia blight, Omega/Vantana can be used, preferably at disease onset or before, or a second spray of Miravis + Elatus.  Don’t be afraid to use Bravo a couple of times as it doesn’t increase Sclerotinia blight unless it’s sprayed 4-5 times.  However, if it turns hot and dry you should avoid Bravo as it can flare spider mites.