With current rainfall from Idalia and cooler temperatures over the next three days, peanut fields with a history of SB (Sclerotinia blight) should be sprayed soon with a fungicide that can reduce losses to that disease.

SB is favored by rainfall and periods of high relative humidity, but what really triggers it is cooler temperatures. The current forecast is for daily highs to be in the upper 70s and 55 to 60° lows over the next three days. Those lows will really get SB cranked up! I have already seen SB slowly moving in my trials and I’ve heard reports that peanut growers are seeing it in some of their fields. According to Dr. David Jordan, peanuts are likely 1 week behind in maturity compared to last year due to the record cool temperatures observed in May, so there’s plenty of time for SB to do some damage.

This late in the game the second spray of Miravis tank-mixed with Elatus surely has been applied, or is about to based on when the first spray was applied. I do not recommend the first application of the Miravis/Elatus tank-mix be used this late, mainly due to it’s having no curative activity on either LLS (late leaf spot) or SB and for reducing risk of fungicide resistance to those chemistries. I’m quite hesitant even to recommend the second application at this time.

The safe bet is applying Omega 500 for SB tank-mixed with an effective fungicide for LLS. If you sprayed Miravis/Elatus the first week of August, I’d prefer to use Omega 500 at 1.0 pt/acre in the next few days to protect against SB. If you have a field that’s notorious for severe losses to SB, you can go to 1.5 pt/acre, but I haven’t seen a big difference in control between the two rates. I consider Omega 500 to have 3 weeks of activity against SB. So if it’s been 3 weeks or more since you applied Omega 500, I’d be thinking about that 2nd application right about now. Remember, Omega 500 has a 30 day PHI (preharvest interval). That’s 30 days prior to harvesting with a peanut picker, not 30 days until digging.

One saving grace is that temperatures go up again next Monday and maintain daily lows in the upper 60s/low 70s and highs in the upper 80s/low 90s until about September 11th according to the current forecast. Most peanuts in the region have fairly dense canopies now, so while the higher temperatures may slow SB development, the disease will continue to progress and potentially explode again if favorable conditions present themselves.

There are several corn earworm pheromone traps being monitored around Virginia. Many of the Eastern Shore locations have reported relatively low numbers this week, except for one humongous exception, the Eastern Shore AREC in Painter, VA, where Helene Doughty counted nearly 800 CEW moths in just two nights in one of the traps. That’s the highest density that I’ve ever seen in 20 years. It’s really quite striking because the other traps around Northampton County, VA didn’t catch very many.

In Halifax County, Virginia, Mr. Bill Tiver, is still reporting relatively high trap catch at his farm. Catch has ranged from 100 to 250 moths per week. Those numbers would likely suggest that CEW control on susceptible crops like sweet corn, tomato, and beans is a must. Sweet corn spray rotations should probably be 3 times a week under that trap catch level. Meanwhile, in Blacksburg, VA, trap catch has been relatively low so far.

Another pest of sweet corn and some other crops is fall armyworm. According to VCE agent, Stephanie Romelczyk, a sweet corn farm in the Northern Neck of Virginia had a fall armyworm outbreak in the whorls, which required a spray of Coragen. We’re all hoping that it did the trick. So in short, it’s definitely time to monitor for the “worm” pests in your late summer crops.

INSECT MONITORING PROGRAM – 2023

We are monitoring for corn earworm in multiple Virginia locations this year using the Heliothis (mesh) trap baited with the Hercon pheromone lure.  These moths can damage numerous crops including sweet corn, tomatoes, cotton, soybeans and green beans. Traps of 7 or more moths per week indicate the need for intensive scouting of crops for the pest.

Thank you to all of our trap monitors. 

Northampton County and Eastern Shore AREC – Led by Helene Doughty, Research Specialist Sr. | Entomology, Eastern Shore Agricultural Research and Extension Center

Bill Tiver monitoring in Clover, VA (Halifax County)

Brian Currin (Montgomery County, VA)

Week July 20^th – July 27^th 2023   Helitothis traps have been set up in 4 locations in Northampton County as well as one location each in Accomack County, Montgomery County, and Halifax County to monitor the activity of the corn earworm moths.  Pheromone bucket traps have also been set up in Northhampton County to monitor the flight activity of the fall armyworm. 

Fall armyworm trap catch has been low so far, although it’s a little early for that tropical moth. 

Within the past week two outbreaks of FLS (frogeye leaf spot) have been reported in southeastern Virginia. Southeastern Virginia has experienced warm, humid conditions and frequent rain events which favor FLS development. Both outbreaks were found on soybean varieties susceptible to FLS in the R1 stage. This creates an issue as the recommendation for fungicide timing on soybeans is R3-R5. Having disease already in the field is also less than ideal as fungicides perform better if applied prior to symptom development. To deal with this situation I recommend:

Scout fields for FLS and Target…

• fields planted to FLS-susceptible varieties and with a history of frogeye leaf spot
• fields in continuous soybean production
• fields in short rotations between soybean crops
• fields with conservation tillage
• low-lying areas of fields

If you have fields that meet the above risk factors you should use a preventive fungicide application no sooner than R1. If you find FLS in R1 soybeans spray immediately with a FRAC Group 3 (DMI, triazole) fungicide as these fungicides have some curative activity. University pathologists in the U.S. have had the best results with Domark, Topguard, Lucento, Revytek, and Miravis Top when spraying after FLS is detected. Follow-up sprays may be needed if FLS continues to progress.

Written by Brian Currin (Entomology Graduate Student at Virginia Tech). Brian is working on sweet corn IPM for his research. Corn earworm monitoring is continuing in Virginia. As we grow nearer to the time corn begins to silk, and when corn earworm moths lay their eggs, monitoring is important for integrated pest management strategies.

Trap catch for this week ending July 20 at two locations was as follows:

Clover, VA (Data collected by Bill Tiver) 77 moths per wk (high pressure)
Blacksburg, VA (Data collected by Brian Currin) only 2 moths (very low pressure)

The farm in Blacksburg has yet to reach its reproductive stage but during trap monitoring more adults were seen flying in the corn.

Mid-July is that time of year when we begin to see corn earworm moth activity really pick up in Virginia.  As most of us know, corn earworm moths deposit their eggs on flowering plants of many important agricultural crops including sweet corn, cotton, soybean, and hemp, to name a few.  Eggs hatch in a couple days into larvae that feed on buds, flowers, fruit, and leaves.  Pheromone trap counts of 7 or more CEW moths per week indicates that this pest is active on the farm and could potentially become a pest threat.   

Trap catch for this week ending July 14 at several locations is as follows:

In summary, CEW moth activity has subsided on the Eastern Shore for the time being as the pest is likely mostly in the larval stage right now.  In Chatham (southside VA) CEW moth activity has remained high >50 moths per week.  Blacksburg, VA has experienced only low moth numbers so far. 

Thank you to Helene Doughty who is monitoring the traps on the Eastern Shore, Bill Tiver who is monitoring a trap in Clover, VA, and Brian Currin who is monitoring traps around Blacksburg.