Weekly Field Update – 9/21/20

Coastal

Zack Snipes reports, “Cooler temperatures have finally arrived in the Lowcountry!  We had a good bit of rain in certain areas last week and some fields are soggy.  I saw lots and lots of silverleaf disorder in squash this past week.  Silverleaf disorder is caused by whiteflies.  The nymphs of the whitefly feed on the newly developing tissue which causes the upper epidermis of the leaf to separate thus giving the plant a silver appearance.  I am still seeing heavy whitefly pressure in most crops throughout the Lowcountry so keep up with spray programs and remember to ROTATE chemistries. For more information on the whitefly, click here.

Silverleaf of squash is a symptom of whitefly feeding. Photo from Zack Snipes.
Whitefly feeding damage on collards. Photo from Justin Ballew.

Midlands

Justin Ballew reports, “These cooler temperatures that have arrived following the rain feel great, but they are going to slow crop development some. Folks are already picking fall brassicas, though some may be a little small. Just trying to keep up with demand. There are plenty of caterpillars out there. I’m seeing diamondback moths (of course) as well as cabbage loopers and a few corn earworms. Be sure to rotate your insecticides when spraying for caterpillars. Folks are continuing to prep fields for the rapidly approaching strawberry season.”

Cabbage loopers are showing up. Loopers frequently rear up like a cobra when disturbed. Photo from Justin Ballew

Sarah Scott reports, “Heavy rains, in some areas totaling near 6 inches, fell around Aiken and Edgefield Counties last week. Rain was definitely welcome, however, the downpours led to some erosion issues as well as waterlogged soils in low spots. Brassica crops are benefitting from the cooler temperatures. Peach season has ended and post-season cleanup has begun. Plastic has been laid for fall plantings of strawberries.”

Eggplant is looking good. Photo from Sarah Scott.

Pee Dee

Tony Melton reports, “Rain, rain, rain. It came quickly, so most drained off quickly, if drainage was adequate.  Need to dig sweet potatoes as quickly as possible to keep down the amount of rot.  Greens, pickles, and peas are struggling to survive the rain – some are drowned.  Ponds are back in the fields.  Some strawberry plastic is already down but the rest of the folks are just beginning this week.  Transplants are scarce and most likely will be late getting here this year. 

Upstate

Kerrie Roach reports, “There has been a significant rise in wine grape production interest over the last month or two in the Upstate. Each week seems to bring another caller asking for recommendations. While climates here are relatively good for grape production overall, high humidity and heat make disease control difficult. Pierce’s Disease is one of the deadliest to deal with; prevention requires intense insect vector control and control means the complete removal of the affected plant. Recent studies have brought new cultivars to the forefront which are helping southern growers become more successful in this niche industry.

‘Traminette’ with leaf scorch symptom of Pierce’s Disease. Photo from Kerrie Roach.
‘Traminette’ with a dead leaf petiole still attached to the vine. Another symptom of Pierce’s Disease. Photo from Kerrie Roach.
‘Traminette” with Pierce’s disease showing islands of green tissue surrounded by brown. This specific grower has already disposed of the affected vines, and will be replacing with newer more resistant cultivars. Photo from Kerrie Roach.

Field Update – 4/20/20

Coastal

Zack Snipes reports, “We had severe storms roll through the Lowcountry at the beginning of last week.  Fortunately, we had very little damage to most of our crops.  We had some damage to older squash and zucchini and some damage to untied tomatoes.  For the most part, we escaped with little to moderate damage and should still make some good crops. Strawberries are coming in strong but it seems like this could be our last push of the season.  I do not see many blooms coming on and our overall plant size and number of crowns per plant seem low for this time of year.

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Ants and mole crickets have become more of a problem for produce growers in the past few years. Photo from Zack Snipes.

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Burn on leaf margins caused by overapplication of boron. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “We didn’t see any damage from the storms last Monday morning other than some water damaged strawberries. We’re sure to have more damaged berries once the rain clears out today. Be sure to carry damaged and rotting berries out of the fields so they won’t become a source of inoculum for Botrytis and anthracnose. Growers selling locally are still seeing good demand for their produce. To try to keep everyone safe, some strawberry growers are opting to sell only pre-pick berries. Brassicas are growing rapidly and looking great, though diamondback moth caterpillar pressure has become pretty high. Be sure to rotate modes of action when selecting DBM insecticides. Everything else (tomatoes, peppers, sweet corn, squash) is growing well also.

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Water damaged strawberries. Photo from Justin Ballew.

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The first plantings of tomatoes are growing really well.  Photo from Justin Ballew.

Sarah Scott reports, “Peach trees continue to be thinned. This week we will likely begin to see scale crawlers present and should take action with a spray of Esteem. Bacterial canker has been noted across the state this year as seasonal conditions warranted a good year for inoculation.  Peach fruit is progressing nicely with some of the earliest varieties potentially beginning to ripe in just a few weeks.”

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Peaches that have been thinned with fruit distanced about 6 inches apart. Photo from Sarah Scott.

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Early variety peach progressing nicely in Edgefield County. Photo from Sarah Scott.

Pee Dee

Bruce McLean reports, “Planting of vegetables is wide open, right now. Cucurbits (cucumbers, squash, melons), beans and peas, sweet corn, tomatoes, eggplant, and peppers are all going in. Greens are looking good. Potatoes are coming along nicely, despite having to be planted late. Starting to see Colorado potato beetles in potatoes. Frequent scouting and timely insecticide applications are key to their control. Strawberries yields are really starting to pick up. A lot of nice-sized, sweet strawberries are available now. Blueberry fields are starting to get that tinge of blue on the earliest berries. We should start seeing some fruit being harvested in the next few days.

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Colorado potato beetle on a potato leaf. Photo from Bruce McLean.

Tony Melton reports, “It was getting dry, thank goodness for the rain.  Most of our butterbeans and peas are grown with irrigation.  Most of our first crop cucumbers are starting to hit the rapid growth stage – get out and sharpen the plows.  Greens are loving this weather.  Watch out for yellow margined beetle- you will most likely see the brown ugly small grubs – they like sandier soils.

Upstate

Kerrie Roach reports, “With beautiful skies over the last week since the outbreak of tornadoes across the state, growers have been able to get back into the fields. Last night and this morning’s heavy rains caused some minor runoff and ponding, but nothing we haven’t seen before. A few scattered nights/mornings with cold temperatures do not seem to have caused any significant damage to the peach or apple crops. The biggest news in the Upstate has been cleanup… cleanup of the Seneca area and further up near Pumpkintown. So far, there has been a very limited reported effect from the tornados on the fruit & vegetable growers. We’ve had many livestock producers with downed fences and shelter roof damages, but nothing too severe. Residential areas were the hardest hit, and the community has really shown out in its response.

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EF3 tornado damage from Seneca, SC. Photo from Kerrie Roach.

Andy Rollins reports, “This is damage seen on multiple farms is believed to have been caused by self-inflicted miticide application with a surfactant, or possibly damaged from the sun. What allowed us to learn this is that almost all of the damage is located on the top side of the fruit but when flipped over the portion of the shaded berries remained undamaged.  Please be careful with all fungicide/pesticide applications and make sure you are following all of them.  If the label doesn’t call for a surfactant to be used…..please do NOT use one.

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Damage possibly from using a surfactant with a miticide or from the sun. Photo from Andy Rollins.

Common Predatory Mites Found to Prey on Thrips

From Clemson Entomology Postdoctoral Fellow Dr. Monica Farfan

Predatory mites, such as this Proprioseiopsis mexicanus, the most commonly collected predatory mite in watermelon fields in South Carolina, are first line of defense in the case of an outbreak of pests, such as spider mites and thrips (shown here). Since these mites supplement their diets with pollen resources, growers can encourage predatory mites through having a high diversity of vegetable crops and allowing for contact between the watermelon plants and other flowering crops or ornamentals, such as Crimson clover and Sweet Alyssum, and weedy row middles.

This video was taken in a culture of Proprioseiopsis mexicanus. It is awesome because it is the first evidence we have of this species being a particularly vicious predator of thrips.