Weekly Field Update – 10/5/20

Coastal

Zack Snipes reports, “The cooler weather and lots of rain have brought out the diseases. I saw some watermelon diseases last week including gummy stem blight. We need to protect our foliage just a few more weeks to finish off those melons so keep at the spray programs if you can.  Whiteflies continue to hammer us in all crops this fall. Strawberry planting is just about upon us. Rains and wet ground have slowed some farms from laying plastic. Remember that preplant fertility and herbicides are critical to spring success. Spartan and Devrinol  are the only two preplant herbicide options this late in the season. Other products require a 30-day wait period. Let me know if you want me to come check your strawberry plugs before you plant them.”

Gummy stem blight on watermelon foliage. Photo from Zack Snipes.

Rob Last reports, “Fall crops are looking good in this area with good development in brassicas and beets.  Insect and disease activity remain moderate however with cooler weathers and rainfall scouting will be critical to success for these crops.  Adult moths are very active at present so be on the lookout for eggs and caterpillars. Plastic is down and awaiting strawberry planting in the next week.”

Growers are ready for strawberry planting. Photo from Rob Last.

Midlands

Justin Ballew reports, “The weather has been pretty fall-like and enjoyable over the last week. The cooler temperatures and high amounts of recent moisture have diseases like powdery mildew, downy mildew, and anthracnose increasing. Caterpillar activity has increased in the last week as well. Be sure to rotate modes of action when spraying for caterpillars. Strawberry growers are ready to plant and will probably start within the next week.”

Powdery mildew has been picking up on fall cucurbit crops. Photo from Justin Ballew.
Adult diamondback moth that just finished pupating on a collard leaf. Photo from Justin Ballew.

Sarah Scott reports, “Daytime temperatures have been mild with cooler night temps. Early last week areas saw anywhere from trace amounts to 2 inches of rain. Low spots in fields may remain wet and this could lead to potential problems.  Peppers are looking good as well as eggplant and late squash. Brassica crops are having some issues with aphids causing leaf curling.  Pecans are beginning to fall as well. Scab seems to be particularly bad this year,  most likely because of wet weather during critical spray times for fungal management in late June and July. 

Pecan scab has been rough this season. Photo from Sarah Scott.

Pee Dee

Tony Melton reports, “Greens are growing fast with cool temperatures; however, beans, peas, pickles, and sweet potatoes have slowed down with these temperatures.  Most sweet potatoes need to find a home.  We are using a lot of potassium phosphide to keep down root rot especially on greens.  Most growers also use it as a dip for strawberries transplants or put through drip system as soon as they plant.  Getting ready to plant strawberries as soon as the transplants get here.”

Upstate

Kerrie Roach reports, “Clear skies since Tuesday with cool fall temperatures at night and warm days has consumers looking for all things fall. Growers with pumpkins, gourds, mums, corns stalks, and/or anything fall related have been busy keeping up with demand. Agritourism demand/opportunities has picked up significantly in the last few weeks. Apples are in peak season with Stayman being one of the current varieties available.”

Andy Rollins reports, “Upstate peaches are finished up for the year but muscadines are still being harvested although slowing some and strawberry planting is in full swing. I was called to examine poorly growing peach trees at an upstate farm. The majority of trees were dying from the most devastating disease of peach ‘Oak Root Rot.’  There was gumming at the base and I was fully expecting a greater peach tree borer problem but closer examination and cutting of the below ground bark revealed the Oak Root Rot fungus growing at the base of the trees.  When pushing your older peach trees up be sure to examine the main roots for the sign of this disease which is the white to yellowish fungal growth deep inside of the bark below the soil level.  There are a few other fungi that can have a similar symptom but they tend to grow just on dead tissue and don’t grow as deep into the wood of the tree.  There are some things you can do about it, but proper identification comes first.”

Gumming and yellowish white fungal growth at the base of a peach tree from oak root rot. Photo from Andy Rollins.
Poor tree growth as the result of oak root rot. Photo from Andy Rollins.

Weekly Field Update – 9/28/20

Coastal

Zack Snipes reports, “Cooler temperatures have really helped out the direct seeded fall crops.  Carrots, beets, and arugula are looking great around the Lowcountry.  We had about 2 inches of rain so many fields are soggy.  I am still seeing high numbers of whiteflies on just about every crop.  Whitefly feeding will lower yields so make sure to scout the underside of leaves. I expect to see an increase of disease, particularly downy mildew on cucurbits and black rot on brassicas with the cooler temperatures and abundance of moisture.”

Arugula is looking great in this cooler weather. Photo from Zack Snipes.
Whitefiles on the underside of a cucumber leaf which will cause yield drags. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “It’s been cooler this week and we got a little rain from the remnants of Beta. Its been several days since we’ve seen the sun, also. Lots of brassicas are being harvested now and more are being planted. There is a little black rot out there and plenty of caterpillars still. Strawberry plastic has been laid in a number of places and planting is just right around the corner.”

Strawberry plastic being laid in the Midlands. Photo from Justin Ballew.

Pee Dee

Tony Melton reports, “Too wet to plant greens or harvest sweet potatoes & peas.  Peas are falling down reducing yield due to the inability to combine harvest.  Sweet potatoes are beginning to rot due to the wet soils reducing yields and quality.  Farmers are having to mud through fields to harvest pickles.  Downy Mildew, Pythium leak, and belly rot are bad!”

Upstate

Kerrie Roach reports, “With the end of September, most all the local farmers markets are finishing up for the season. Online markets and specialty/holiday markets will continue, but many produce growers have finished production until spring. Apples are continuing to be about 2 weeks ahead of schedule with decent crops across the board. Some growers have experienced high rates of fungal pathogens just because of the high rain incidence.” 

‘Brooks Spot’ preliminarily identified on Granny Smith apples. Photo from Kerrie Roach.

Weekly Field Update – 9/8/20

Statewide

Dr. Matt Cutulle reports, “With all the rain we had in August the weed seed bank is starting to pop. Nutsedge pressure can be really tough in September.  For fall cole crop plantings, it is important to initiate the stale seed bed technique (allow weeds to come up and burn them down multiple times before planting). In some cole crops, such as broccoli, Dual Magnum may be used, which provides some pre-emergent suppression of yellow nutsedge (Max 60% probably). Following with an in-row cultivation several weeks after planting will strain the photosynthate reserves of nutsedge, which could be lethal to the nutsedge if we get a  cold snap in late October.”

Coastal

Zack Snipes reports, “I saw whiteflies everywhere last week.  I saw them on just about every crop in the field: squash, zucchini, tomato, peas, eggplant, okra.  We have very good options to manage whiteflies, so consult with your local agent or look up the specific products for the crop you are growing in the Southeast Crop Handbook. Be careful not to use pyrethroids for whiteflies as resistance will develop very quickly.  Longer lasting, more specific options are available that are better options.  I also saw a good many worms last week such as the melonworm in cucurbits and the beet armyworm in other crops.  If you have whiteflies and worms in a crop then the group 28 insecticides (Coragen, Verimark/Exirel, Harvanta) are excellent options to take care of both pests at the same time with good residual.”

Whitefly infestations are severe in some places on the Coast. Photo from Zack Snipes.
Whiteflies on tomato leaves. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “Last week was extremely hot and dry, though we finally got some relief from the heat over the weekend. Crops are progressing well, though we are seeing caterpillar activity increase. We’re seeing diamondback moth and cabbage loopers in brassica crops and armyworms in tomatoes. Be sure to rotate insecticide MOA’s when treating for caterpillars. I’m also seeing a few whiteflies around, but nothing severe yet. Black rot is starting to show up on some brassicas. Strawberry growers are starting to apply their preplant fertilizers in preparation for shaping the beds.”

Black rot getting started on a young collard plant. Photo from Justin Ballew

Pee Dee

Bruce McLean reports, “Muscadine harvest is starting to wind down. Harvest looked good and had very good yields. Brix averaged out at 13.5 to 14.5%, depending upon the cultivar and the vineyard. Now is a good time to evaluate successes and problems from this season and write them down while they’re fresh on your mind. Also, look at the overall amount of foliage on the vines. Is it too much? Not quite enough? Start planning how you need to adjust fertility for next year. A post-harvest potassium fertilizer application has proven to be beneficial to the crop (in on-farm settings), especially in wet years. Overall plant health, spring emergence and vigor, and next year’s yields should be well improved.”

A bin of Carlos muscadines ready to be loaded and delivered for processing. Photo from Bruce McLean.

Tony Melton reports, “Getting dry and need some rain. Busy planting turnips, mustard, and collards. Harvesting processing sweet potatoes as quickly as they can process them (problems in the plant). Picking pickles and yielding much better with dryer conditions. Also, pickling plants having trouble with getting enough labor so very few peppers harvested. Still spraying processing peas for cowpea curculio. Watch out for southern stem blight it is still raging havoc.”

Upstate

Kerrie Roach reports, “The last few peaches are making their way to stands and markets. Things are continuing to look good as the Apple crop progresses in the upstate. Growers to the north in Hendersonville, NC suffered multiple hail events causing a large amount of damage, but SC growers seem to have escaped the worst of it. Vegetable production has slowed significantly with many small growers finishing for the season over the next few weeks. Muscadines are coming into their prime, and look to be highly productive this year.”

Golden Delicious apples that still have a little ways to ripen for optimum sugar content, but work great for baking. Notice the green tint. As they continue to ripen, a yellow cast & even a blush may appear. Photo from Kerrie Roach.

Andy Rollins reports, “These plants were found positive for Phytopthora root rot last week in an early upstate strawberry planting.  Inspection of plants when they arrive can accurately diagnose this problem.  Brown to blackish colored roots are characteristic.  A small portion of this material is taken from 5-10 plants then placed into a pouch that accurately identifies the presence of Phytopthora within a few min.  As in picture, 1 line tells you the test worked properly 2 lines indicates presence of the fungus.  Early treatment with Ridomil and or any of the phosphite (Rampart/Prophyt) is very helpful but must begin quickly if plants are widely infected for the best results.”

Dark colored roots are a characteristic symptom of Phytophthora root rot. Photo from Any Rollins.
An immunostrip test can be used to diagnose phytophthora. Two horizontal red lines on the strip (right side of the bag) means the sample is positive for phytophthora. Photo from Andy Rollins.

Field Update – 7/20/20

Statewide

Dr. Matt Cutulle reports, “It is always good to control goosegrass even if it is past the critical period for competition with the crop. Lack of late-season control made hand-harvesting tomatoes difficult in the field pictured below. Also, there will be a huge deposit of goosegrass seeds into the soil seed bank for next year unless the seeds are destroyed after the harvest.”

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Late season goosegrass growth can make harvest difficult and contribute lots of seed to the seed bank, which will have to be dealt with in future crops. Photo from Dr. Matt Cutulle.

Coastal

Zack Snipes reports, “We experienced a nice hot week of weather in the Lowcountry.  Most crops are finishing up with the heat and recent rains.  On later season tomato I have seen bacterial leaf spot on the fruit which makes fruit unmarketable.  I am seeing this on the second cluster of fruit set and not on the first or third clusters.  Hemp seems to be off to the races and looking pretty good so far.  There are within every hemp field occasional wilted, stunted, and yellowed plants.  These plants always have a weak root system and most of the time have girdling and interveinal discoloration.  Peppers and eggplants are loving this heat and are producing in high volumes.”

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Bacterial leaf spot showing up on the second set of fruit on the tomato plant. Photo from Zack Snipes. 

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Wilting of hemp is very common and often sporadic throughout fields. Photo from Zack Snipes

Midlands

Justin Ballew reports, “Last week was hot and mostly dry, though we did have some scattered thunderstorms come through over the weekend. Field prep for fall crops continues. We’ve had some fall tomatoes, peppers, and brassicas transplanted already and more to come this week. Everything is growing pretty fast right now and we’re still picking spring crops. Keep an eye out for spider mites, as they love the hot, dry weather we’ve had lately.”

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Fall tomatoes transplanted in Lexington this past week. Photo from Justin Ballew

Sarah Scott reports, “We are still ahead of schedule on peach varieties being harvested.  Early August Prince and August Prince are being picked now which is over a week earlier than usual. The fruit quality is still good with slightly smaller than ideal fruit.  With the extreme heat and lack of rain in the past week, summer crops like tomatoes and cucumbers are looking rough. Bell peppers are doing well.”

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An Edgefield County grower assessing his Early August Prince orchard. Photo from Sarah Scott.

Pee Dee

Bruce McLean reports, “Sweet potatoes are looking good. Establishment seems to be very good for the most part. Long green cucumbers, yellow squash, zucchini, cantaloupe, peas, okra, and sweet corn are harvesting well. Condition is good to very good. Sweet corn will be wrapping up shortly. Blueberries are pretty much finished, with only a few remaining fruit on Powderblue. Fruit condtion is fair to good. Muscadines are coming along nicely and appear to have an excellent crop. Fresh muscadines should be beginning harvest soon, with wine/juice grapes still a few weeks from harvest. Be on the lookout for Grape root borer moths. They are starting to emerge. They were being caught in traps placed in vineyards in Marion and Horry counties.

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Grape root borer moths being caught in a bucket-style trap. Photo from Bruce McLean.

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No, this is not a paper wasp. It is a grape root borer moth. Photo from Bruce McLean.

Tony Melton reports, “Harvested first crop of processing peppers. Continuing to pick and plant pickles. Processing greens are over for the spring crop. Harvesting the first crop of processing and seed peas and planting fall crop.  Getting processing tomatoes out of the field as quickly as the plant can take them.  Things are drying out, hope we don’t go into drought with the heat.”

Upstate

Kerrie Roach reports, “Spotty rain and high temperatures have left many small growers scrambling for irrigation options throughout the Upstate. Peaches and nectarines are still being harvested. Blueberries are just about finished, and farmers’ market produce is starting to wind down with the heat. Apples should begin next week with early varieties like ‘Ginger Gold’  and ‘Golden Supreme’.”

Andy Rollins reports, “Plenty of early blight, bacterial spot/speck on tomatoes this season, but some of the more troublesome problems have been various tomato virus problems. When diagnosing virus problems it is important to get lab verification because herbicide injury can look very similar when just going by visual symptoms. If you suspect herbicide drift from a neighboring farm. Look for damage to other broadleaf plants in the area in between the suspected source and the damaged plants. Follow the wind direction.  You should have more severe damage on the leading edge. Also, herbicide residual from a previous crop like sunflowers can also give you herbicide damage that you did to yourself. Read and follow all pesticide label directions. There are plant back restrictions on some herbicides so be careful. If this is the case the damage should be fairly consistent/uniform throughout the area that was planted in the other crop.

Unlike both of these other situations, virus problems may come from your seed source, the greenhouse where plants were grown, or from weeds in the field. Pokeweed is commonly a source, as are many other broadleaf weeds. Thrips, aphids, and whiteflies are all known to vector viruses into plants. Symptoms are what you see below with “shoestring” looking leaves, leaves with distorted veins, and mosaic yellow and green coloration. There are many viruses that infect plants. Each of them can show different symptoms and also they can each look different on other plants as well. It’s even possible for a healthy-looking plant with no symptoms to be infected with several viruses.”

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“Shoestring” type leaf distortion may be a symptom of a virus or herbicide damage. Get confirmation from the plant disease lab. Photo from Andy Rollins.