Weekly Field Update – 1/18/22

We hope everyone had a great holiday season and that 2022 is off to a good start! Remember to keep an eye on the Upcoming Events tab over the next couple of months. We have lots of fruit and vegetable-related meetings coming up. This week we have a couple in-person meetings and a virtual tomato and pepper meeting.

Coastal Region

Rob Last reports, “In our area, crops are developing well with few pest or disease issues currently. Some brassicas are displaying a reddening to the older leaves associated with reduced phosphorous uptake. Phosphorous uptake can be reduced in cold temperatures and will recover when we see some warm temperatures. There is no response to an additional application. Where strawberries are flowering or have fruit, it is advisable to remove those to minimize sources of Botrytis gray mold for later in the year.”

Zack Snipes reports, “Strawberry questions have begun rolling this week with the threat of lower temperatures at the end of the week. For growers in the coastal plains, I would not cover my berries. Temperatures are predicted to get into the low to mid-20s. At the stage of development we are in right now, it would take lower temperatures and extended periods of time to do crown damage. Will you lose berries and blossoms? Yes, but right now we shouldn’t be trying to save those anyway. After the weather passes, make sure to clean/sanitize your fields. I am seeing a good bit of botrytis (gray mold) on early fruit. Some growers are trying to save fruit but we have to keep in mind that it is mid-January and the plants need to size up and experience a few cold events. We have a long season ahead of us.”

Gray mold on a previously frozen berry. This berry has thousands of spores that are looking to infect your blossoms Photo from Zack Snipes
2-3 crown stage where most of our plants are right now. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “The weather has been strange over the last couple of weeks. The week after Christmas was very warm and caused strawberries to push out a lot of blooms that were then killed by the cold. We have a ton of dead blooms and fruit on the plants right now. Eventually, these will need to be removed from the plants, as they will become a significant source of Botrytis inoculum if allowed to remain. I’ve had some questions about whether we should cover the plants to protect them from the cold we’ll be experiencing over the next week. This shouldn’t be necessary, as the plants are hardy to the mid-teens (F) in the crown development stage. Plants are still a little behind due to late planting.”

Strawberry plants are a little bit behind right now, but otherwise, look healthy. Photo from Justin Ballew.
Some of the fruit on the plants look ok, but cold damage can be seen easily when sliced open. These fruit will become a major source of Botrytis inoculum as temperatures warm up. Photo from Justin Ballew.

Phillip Carnley reports, “We are thankful to have some rain in Orangeburg and Calhoun counties. There has been little insect pressure on greens in my area, and the harvest was average. Now is the time to start pruning muscadine vines as well as managing soil fertility. Strawberries have started flowering earlier than expected due to the warmer weather we had in December with some light fruiting being seen as well. I recommend if you have the ability, remove any early blooms and fruit to promote crown and root development. In my areas with the cooler temps being called for this weekend strawberries should be fine without being covered.”

Sarah Scott reports, “We have had some chilly temperatures in our area over the last few days but luckily no ice to speak of. The cold weather is helping with the accrual of chilling hours that are needed for a good peach crop this year. Crews are getting busy in the peach orchards, pruning and putting out dormant oil applications.

A worker applying an oil spray to peach trees. Photo from Sarah Scott.

Pee Dee

Bruce McLean reports, “A lot of strawberry growers are looking at a strawberry crop that is well behind where it should be. There are a number of reasons that can be pointed to, but really the main contributor is the cool spell that we had back in the fall, right after planting. Seems like the plants that were planted in the first week of October just look much better than the plants planted a little later – much better sizing, crown count, and vegetative development. Some other problems that have been seen include root rot, j-rooting, and just generally a few weak plants from the nursery. So far, spider mites have not been an issue. Many of the growers (with plants that are really behind) have asked how they can “make up ground” with the crop. Unfortunately, there is not a tremendous amount that can be done to “make up ground”. The plant has to have that period of fall growth to be able to set sufficient crown count and thereby make a crop come spring. Unfortunately, yield will be off. From here on out, manage the crop the best you can to maximize what harvest you will have coming in the spring.”

Upstate

Kerrie Roach reports, “Cold temperatures, ice, and snow have been the name of the game in the Upstate the last few days, and that same theme seems like it’s going to continue into this weekend. Growers with high tunnels and greenhouses should be removing the snow load to prevent collapse. Young fruit trees may need to be shaken to remove ice and snow loads to prevent breakage. Now is a great time to make sure all your equipment is ready and in great shape for the season; tune-up, sharpen blades, check fluid levels, etc.”

Won’t be playing basketball for a few days after 6 inches of snow fell in Oconee County over the weekend. Photo from Kerrie Roach.

Weekly Field Update – 12/6/21

Coming up this Thursday (12/9) will be Part 2 of the Organic and Sustainable Vegetable Grower Meeting. Speakers will be discussing bed formation and alternative fertilizers. This virtual meeting will start at 9 am. Click here to register.

Coastal Region

Rob Last reports, “Pest and disease activity in the area remain low with overall good development of crops. Strawberries continue to develop well with very few issues. Given the misty mornings we are seeing, disease pressures may begin to pick up. Remember to keep scouting regularly.

Midlands

Justin Ballew reports, “The weather last week was beautiful and we had our first real chance to accumulate some growing degree days in our strawberries. This is much needed as I’ve been getting several complaints of plants being small and slow-growing. Late planting and cool weather definitely have held us back so far this season. We have seen a little downy mildew in brassicas that may worsen with the heavy dew we’ve had the last few mornings. Other than that, brassica crops are looking great.”

We have some beautiful, healthy collards in the midlands right now. Photo from Justin Ballew
Downy mildew symptoms on the upper side of a collard leaf. Photo from Justin Ballew

Phillip Carnley reports, “Everything is fairly quiet in Orangeburg and Calhoun counties. With the lack of rain, disease pressure has been borderline nonexistent. The strawberries here are still a little behind due to the later planting but seem to be growing out well with no spider mites currently present. I have seen a decrease in the population of diamondback moth caterpillars in my area, but that does not mean stop scouting.”

Weekly Field Update – 11/22/21

We are currently evaluating the SC Grower site to determine any updates or upgrades that are necessary to better serve our viewers. To help with this, we would love to have your feedback. This quick survey should take about 5 minutes to complete and is completely anonymous. Please take a minute to share some of your likes, dislikes, or suggestions for the SC Grower.

Coastal Region

Rob Last reports, “Crops are continuing to develop well with few insect or disease problems to press. The disease pressure may increase given the welcome rainfall forecast today. Please remember to scout regularly and thoroughly. Problems caught early are easier to manage.”

Midlands

Justin Ballew reports, “We enjoyed the beautiful fall weather last week. Growers are harvesting lots of brassicas right now. Thanksgiving is a big time for collard sales, so folks are going to be busy over the next few days. Most brassicas look great. We haven’t had much rain this fall, so disease is very low. Caterpillar pressure is high in some places. Just a reminder, diamondback moths can develop insecticide resistance very quickly. Monitor population levels closely and always base treatment decisions on thresholds. Do not spray just because it’s been 7 days since the last application. Make sure the population level justifies the application. Also, avoid spraying the same material twice within a 30 day period and NEVER use a pyrethroid or organophosphate when caterpillars are the only pests present.”

Insecticide resistance to multiple modes of action has allowed the diamondback moth population in this field to cause severe damage. Multiple pyrethroid and organophosphate applications have also wiped out beneficial insects. It is unlikely a field like this can recover. Photo from Justin Ballew.

Phillip Carnley reports, “Just like much, if not all the state, it has been exceptionally dry in Orangeburg and Calhoun counties. Despite that, crops are looking good and growing well. Strawberries here are a little behind like much of the state due to late planting, but thanks to being dry, we are not seeing any fungal problems yet. I have seen some death/decline of crowns due to J rooting, but that has not been significant. There have been some flaring populations of diamondback caterpillars in collards exacerbated by the use of broad-spectrum insecticides, which left few to no beneficials in the field. When dealing with diamondback caterpillars, make sure to scout early and often and use more targeted MOA’s to give your beneficial insects a helping hand. One or two applications of the various broad-spectrum insecticides can be detrimental and cause a boom in DBM populations.

J-rooting kept this strawberry plug from getting established. J-rooting is one of the most common reasons plants fail or are slow to get established. Photo from Phillip Carnley.
Severe damage from diamondback moth in collards. Photo from Phillip Carnley.

Timely Diagnosis

From Clemson Plant Pathologist Tony Keinath.

Plants are a rich source of food for microorganisms—for aggressive plant pathogens, for weak pathogens, and for common saprophytes (the 90% of microorganisms that feed only on dead plant parts). Once a pathogen kills parts of leaves or side roots and we see dark brown spots, things change. The normal ways plants defend themselves from pathogens shut down, and it’s a “free for all” for any microorganisms on the leaf, fruit, or root. These weak pathogens and saprophytes suddenly can grow on parts of the plant that weren’t accessible to them when the plant was healthy. It’s part of the natural succession of the phytobiome, the community of microorganisms that live in, on, and around plants.

Although Alternaria leaf spot can still be recognized by the round, brown spots with concentric rings, saprophytic Alternaria growing on the yellowed areas makes diagnosis more difficult.

For a diagnostician, it’s infinitely easier to find a pathogen at the early stages of disease, when suspicious yellow spots appear on a leaf, rather than on a dead leaf, because you’re not “looking for a needle in a haystack,” or more accurately, a pathogen in a forest of microorganisms. Cucurbit leaves, for example, tend to have the same three saprophytes on them, Alternaria, Epicoccum, and even Fusarium. An experienced diagnostician knows to ignore them or use them as forensic clues that the tissue has been dead for some time. I tend to suspect spray burn when I see these fungi growing in distinct spots on leaves.

Every diseased plant sample collected for diagnosis, whether it is for in-person delivery or mailing, should be carefully selected and handled by following these guidelines. Samples collected during the summer or on sunny days at any time of the year should be placed in a cooler with an ice pack after collection. This usually means taking the cooler into the field. Proper handling of samples will help the diagnostician provide an accurate answer or avoid asking for another (better) sample.

As another saying goes, “early is on time.” An early diagnosis is a timely diagnosis.

Weekly Field Update – 11/8/21

Over the next few weeks, we will be evaluating the SC Grower site to determine any updates or upgrades that are necessary to better serve our viewers. To help with this, we would love to have your feedback. This quick survey should take about 5 minutes to complete and is completely anonymous. Please take a minute to share some of your likes, dislikes, or suggestions for the SC Grower.

Coastal Region

Zack Snipes reports, “It feels like winter showed up this past week with cold, windy, gloomy days. Most, if not all of our strawberries have been planted. With the cool weather showing up and our later planting dates this year, some growers are opting to use lightweight row covers to push their plants along a little bit. A few things to remember if you opt to do this: use lightweight row covers, make sure all disease and insect issues are taken care of before putting the row covers on, and only leave them on for a few weeks. We want to encourage some growth of our plants but we don’t want our plants getting too big and succulent going into the winter. I visited several farms this week with poor quality fruit trees. A common thread between these plantings is planting depth. In our sandy soils, plants will sink over time so as Phillip Carnley says, “plant them proud,” which means plant them higher than you think they should be planted. Over time, the plants will settle into the correct depth. Pecans, blueberries, and other crops will not grow roots from their trunks, so over time the plant will rot and pathogens will get into the plant when they are buried too deep.”

A pecan tree that was planted 8 inches too deep. Photo from Zack Snipes.
A blueberry plant that has sunk over the past few years. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “It got pretty chilly towards the end of last week and we saw a light frost in a number of places this morning (11/8). Brassica crops are looking great right now. Diamondback moths are still out there, but they seem to be manageable at the moment. There is a little black rot here and there, though we haven’t had enough rain for it to really be a serious problem. Strawberries are getting established. We didn’t accumulate many growing degree days (GDD) last week since it got so cool. Again, I would think about using row covers for a week or two this month to help accumulate GDDs. Here’s a good Strawberry Grower Checklist from the Small Fruit Consortium that has some great tips for the fall season.”

Collards are looking great in the midlands right now. Soon, we’ll be picking a lot for the Thanksgiving market. Photo from Justin Ballew.

Pee Dee

Bruce McLean reports, “Vegetable crops are looking good around the Pee Dee. Some of the aphid and spider mite pressure that was seen earlier last week has subsided a bit. But, be sure not to drop your guard. Their populations can easily bounce back in dry conditions. Stink bugs are still present in pretty high numbers. Stink bugs (in high enough numbers) can cause damage to brassicas. So, be sure to scout and treat, accordingly. Strawberries are looking good for the most part. Unfortunately, I have seen a good bit of j-rooting in bareroot strawberries. J-rooting is a condition where the roots of the bareroot plant are improperly planted. Instead of the roots of the plant being planted vertically in the soil (where the planting hole is dug to an adequate depth for the length of roots of the transplant), the roots are buried horizontally just below the surface of the soil, often with the root tips exposed. This will severely impact the yield of your plant and if done repeatedly across the field, the yield for the entire planting. And, yield is money. It’s a lot easier to take a few minutes prior to planting to show your workers the proper way to plant bareroot plants. Providing them with a (bareroot) planting bar/tool and showing them how to properly use it helps to eliminate these problems. Checking behind your workers is important to ensure that they are continuing those planting techniques. Coming back and trying to fix a problem (if it is severe) is not realistic and cost prohibitive, because it would mean that every plant might need to be inspected and possibly replanted. Research out of California has shown that j-rooting can reduce yields 18.5%. That’s a pretty big bite of the apple (… or in this case, the strawberry) that the grower can likely lose right off the top. I don’t know too many growers that can handle that much of a loss on such a high value crop.”

Severe j-rooting on bareroot strawberry plant. Photo from Bruce McLean.

Weekly Field Update – 10/25/21

Join us this Thursday (10/28/21) at 12:30pm for the next installment of our CUltivating SC Growers Series. This month Zack Snipes will be discussing the ins and outs of cover cropping. To register, click here.

Coastal Region

Zack Snipes reports, “We had a nice week of weather last week and are getting some rain this morning (10/25). Strawberry plants are arriving and growers will be busy putting in plants this week. I’ve gotten several calls about doing plant dips to prevent disease for the upcoming season. Most growers are using Zivion but it has been somewhat hard to come by so others are using Switch. We are dipping plants so crown rot diseases don’t wipe out our crop. Speaking of wiping out our crop…DEER. Get your fences up now BEFORE you plant. We see black rot on brassicas every season but it seems particularly bad this season.  Cultural practices such as crop rotation, using clean seed and transplants, and spacing plants out can help with the disease. There are no products that will help with this disease.  We had a great fall watermelon crop that will be wrapping up here shortly.

A deer fence was installed for a high deer pressure brassica field.  This fence will provide an incredible return on investment. Photo from Zack Snipes.
A nice spread of cut flowers on Johns Island which reminds me that we have a cut flower production workshop next Wednesday, November 3rd. Register here. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “We finally got our strawberry transplants in and most are now in the ground. We still have a few to finish up and we should be done this week. Even though it is cooling off this week, don’t forget to overhead water newly planted transplants for the first several days. Drip irrigation is often not enough in our sandy soil while the plants are trying to get established. Now is also a good time to go back through the field and check for plants that settled too much after transplanting. Gently pull them up to the correct depth and refirm the soil around them. If you are in an area with deer pressure, now is the time to put up deer fencing. Don’t wait until feeding has already begun or it will be even harder to keep the deer out of the field.”

We finally have strawberry plants in the ground in the midlands. Photo from Justin Ballew.

Upstate

Andy Rollins reports, “We are still in process of planting our 2022 strawberry crop. Growers are looking closely for root diseases of plants as well as leaf disease. Many are concerned about the new disease Neopestalotiopsis (see this article). Growers need to be careful with cutoffs and bare-root planting. J rooting is a common problem. The L-shaped planting tool should be used to hold tips of roots, push plants to the proper depth, hold the crown above ground with the other hand, and push down. This last step was commonly being neglected on several farms. Roots should be straightened or cut off in the last step. We had a case of herbicide damage on turnips. Sulfentrazone (Spartan) is believed to be the culprit. This product builds in the soil, especially when used multiple years in a row.  So, please be careful not to cause your own problem.”

This strawberry planting is looking good so far. Photo from Andy Rollins.
Sulfentrazone can build up in the soil over time and cause some plant damage. Be careful about using it in the same fields in successive seasons. Photo from Andy Rollins.

Fog and Downy Mildew on Collards

From Clemson Plant Pathologist Tony Keinath.

Foggy fall mornings are nature’s warning that conditions are favorable for brassica downy mildew to get started on collard and kale.

Downy mildew sporulation (white masses) on the underside of a collard leaf. Photo from Dr. Tony Keinath.

Remember that because downy mildew affects the harvested, edible portion of the crop, control practices must be very effective to increase yields. Use the following practices to maximize control:

1. Rotate crops to new fields every year. Brassica downy mildew is believed to survive in soil.

2. Check lower, older leaves for angular yellow downy mildew spots on the top of the leaves and black lesions with white downy mildew growth on the bottom of the leaves. Even lesions 1/8-inch in diameter can produce spores.

Yellow downy mildew lesions on the top side of a collard leaf. Photo from Dr. Tony Keinath.

3. Make the first fungicide spray when the first foggy morning is predicted. Fog means the leaves will stay wet all night and a good part of the morning. The lack of sunshine on foggy mornings also allows downy mildew spores to stay alive longer than on sunny mornings, when UV light will kill them in about 24 hours.

4. Potassium phosphite is a very effective, economical alternative fungicide against brassica downy mildew. It is probably “good enough” by itself during sunny periods without rain. Note that it is not labeled for certified organic production.

5. During rainy periods, rotate effective conventional fungicides, like Zampro or Presidio, with potassium phosphite. Fungicide rotation is critical for leafy brassica greens left in the field for more than 2 months when leaves are cropped repeatedly. Zampro may be applied only 3 times per crop. Presidio may be applied 3 times at the 4-ounce rate or 4 times at the 3-ounce rate.

For more info on brassica downy mildew, see Dr. Keinath and Tim Bryant’s article in the latest issue of the Clemson IPM Newsletter.

Weekly Field Update – 10/11/21

Statewide

There are some reports that anthracnose may be issue in strawberries this year. In addition, we are continuing to look out for the new disease, Neopestalotiopsis. Clemson Plant Pathologist Guido Schnabel has recommended applying Zivion S (natamycin) via preplant dip to help prevent these diseases. Dr. Schnabel provided the following instructions:

Mixing Instructions. Add Zivion S while stirring to the volume of water to be applied, or to a smaller volume that is then added to more water to make the expected final volume. Continuously stir the treatment solution unless it is to be applied immediately.
Application Time. Apply prior to plant as a preplant transplant root or whole plant dip treatment. Do not apply after or to harvestable commodities.
Application Rate. Root or whole plant dip: mix 6-12 fl. oz. (0.04 – 0.08 lbs a.i.) of Zivion S per 10 gallons of water. Dip plants for a minimum of 2 minutes, but no more than 5 minutes. Plant treated plants after dip application.

To find Zivion contact Nelson Jameson at 800-826-8302.

Coastal Region

Rob Last reports, “We are progressing well with preparations for strawberry planting. Some Plants are due to be delivered this week. Remember, if fumigants have been used, check to ensure the products have dissipated to prevent damage to the transplants. The same is true to make sure planting restrictions on any pre-emergence herbicides applications are observed. Always refer to the label. Finally, remember to check your plants carefully for pest and disease inoculum from the nursery. Planting any disease or pest-infected plants will lead to a more challenging. If you require any help, please reach to Extension Agents.”

Zack Snipes reports, “I thought I had moved to Seattle last week with all the rain and dreary weather. We have a good week of weather coming up and I expect that everyone will be busy in the fields transplanting greens, finishing laying plastic, and continuing the harvest of fall crops. Watermelons, squash, and winter squash are being harvested this week. Downy mildew is loving this weather and is on basil, squash, cucumbers, winter squash, and cantaloupe. I have seen many freshly transplanted fields with black rot in brassica. This disease shows up every time we plant brassica. It is essential to transplant quality transplants. If your transplant supplier is sending you diseased plants, then visit our Seed and Transplant Supplier list to find a new supplier. You might be surprised how big of a difference it makes. Carolina Farm Stewardship Association is having a webinar this week on Tuesday, October 12 at 12pm on Ginger and Tumeric production in a high tunnel. Please email zbsnipe@clemson.edu for link and passcode.

Black rot with its characteristic yellow “V” shaped lesion. Photo from Zack Snipes.
Transplants that are yellow and have black rot symptoms will not yield like healthy plants. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “We finally saw some sunshine this past weekend after a pretty rainy week. Caterpillar pressure has been high and lots of treatments have been going out. I’ve been seeing a decent amount of pathogenic fungi developing on diamondback moth caterpillars due to the wet conditions creating the perfect conditions for development. We’ve had a couple acres of strawberries planted and ordinarily we would be planting full steam ahead now, but strawberry plants are late coming in this year. Lots of folks are being told it will be next week before their plants come in. I’m also hearing reports that anthracnose may be a problem from nurseries this year. As a result, we are strongly recommending a fungicide dip on transplants before planting to combat this and any potential infections from the new disease Neopestalotiopsis. See Dr. Schnabel’s comments about Zivion above.”

This diamondback moth caterpillar’s corpse is covered in white fungal growth. The recent wet conditions have provided the perfect environment for entomopathogenic fungi development. Photo from Justin Ballew.

Phillip Carnley reports, “Cucumbers are finished in Orangeburg and Calhoun counties. Fall greens are in full swing with some pressure from DBM with the occasional looper. Growers are bedding strawberry fields and applying their pre’s. We have seen heavy infestations of gummy stem blight in fall watermelons, as well as spider mite damage in blackberries.”

Gummy stem blight has been bad in watermelons this fall. Photo from Phillip Carnley.
Yellowing from spider mite feeding in blackberry. Photo from Phillip Carnley.

Sarah Scott reports, “Tree removal and field prep for new peach installations are happening around the ridge. Strawberry plants are being planted now and got a good watering in with last weeks rain. Fall vegetables are looking good, growers should keep up with scouting for disease issues in the field following the week of wet and humid weather.

Tree removal and preparations for new planting are going on now along the Ridge. Photo from Sarah Scott.
Fall tomatoes are looking great. Photo from Sarah Scott.

Upstate

Andy Rollins reports, “I am busy scouting new strawberry plantings this past week. Be on the look out for leaf diseases of plants but also check roots thoroughly for discoloration. When planting make sure crowns are still visible after planting. We are also preparing ground for new peach production going in. We are still picking a few muscadines, but that will be finishing pretty soon.”

Fungal infection on a newly planted strawberry leaf. All plantings need to be looked after carefully for the new disease Neopestalotiopsis. Photo from Andy Rollins.

Weekly Field Update – 9/20/21

Coastal Region

Rob Last reports, “Fall cucurbit crops, including cantaloupes, and watermelons are ripening and approaching harvest. Disease pressure from powdery mildew and gummy stem blight have really increased significantly over the last week. Maintaining a tight spray program will be key to managing disease. As we look forward to strawberry planting land is being prepared. If you are planning to fumigate, make sure the plant back interval between fumigation application and planting is maintained. A good test can be to plant some lettuce seed in the treated area. When lettuce germinates, the risk of damage from fumigation is reduced. Finally, on any remaining fall plantings, consider using a labeled pre-emergent herbicide to help with weed management. Once the crop and weeds emerge, options are drastically reduced.

Zack Snipes reports, “Land is being prepared and fall crops are going in around the Lowcountry. Early fall crops look better with the slightly cooler temperatures and periodic rain. We are wet in some parts. I am seeing lots of bacterial spot in the fall tomato crop. We have good herbicide management plans for greens, but folks will need to take advantage of pre-emergents now.”

Bacterial spot is bad this fall due to the consistent rain. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “This past week was fairly rainy. There are several fields that are pretty soft, even some sandy fields. Folks are still planting brassicas for the fall and they are looking really nice right now. Strawberry growers are also getting prepped to fumigate and lay plastic. We’ve been seeing a lot of damping off (Pythium) in young cucurbits and some brassicas lately. The wet weather is definitely creating the perfect conditions for this. A few things that can be done to help minimize damping off include planting on plastic beds, planting at the proper depth (just deep enough to cover the plug with native soil), rotating fields wisely (tomatoes are a host for Pythium), and using a fungicide at planting may also make sense when environmental conditions are right for Pythium development.”

When transplants are set deep like the one pictured here, the moisture in the soil creates favorable conditions for Pythium to develop all the way up the stem. Instead, set transplants just deep enough to cover the plug with native soil. Photo from Justin Ballew.

Phillip Carnley reports, “Cucumber production is in its final stages here in Orangeburg and Calhoun counties with most growers close to or in the process of harvesting. There is still a noticeable amount of cucurbit downy mildew, but due to the dryer weather it has been easier to keep in check. Sweetpotatoes are currently being dug with yields looking to be fairly good. There have been a few issues with wireworm damage in sweet potato fields with the majority of damage being seen on the lighter colored tubers. Diamondback caterpillar is ramping up in brassica crops, especially in collards. Make sure to scout early and treat in a timely fashion, if your insecticide program is not showing the desired level of control talk with your local agent about scheduling a bioassay to screen your population’s resistance to different insecticides. Also be on the look out for black rot and other fungal problems in early transplants.”

Holes bored into sweetpotato tubers by wireworms. Photo from Phillip Carnley.

Sarah Scott reports, “We received some heavy rain in areas throughout Edgefield and Aiken Counties last week, up to 2 inches in spots. In preparation for October planting, plastic has been laid in strawberry fields. Brassica crops are being planted as field conditions allow. Late summer plantings of broccoli are starting to get some good size on them. Pepper plants that were put out in August are setting fruit that is starting to size up nicely.”

Strawberry plastic laid and ready to go. Photo from Sarah Scott.
These broccoli plants were put out on September 2. Photo from Sarah Scott.
Fall peppers are sizing up nicely. Photo from Sarah Scott.

Weekly Field Update – 9/13/21

Coastal Region

Zack Snipes reports, “We had a heavy downpour of rain last week surpassing 2.5 inches in some spots. I am seeing downy mildew in cucumbers and lots of gummy stem blight in winter squash and pumpkins. The worm pressure has lessened in the past few weeks. I am seeing lots and lots of black rot in transplanted brassicas. Inspect your plants before planting them to make sure the disease is not coming from the nursery. Once a brassica is planted in the field, there is not much we can do to slow the spread except hope that environmental conditions (rain, humidity) are not conducive to spread the disease. I am also seeing lots of early weed pressure in fall planted crops on both bare-ground and plastic. We have some very good herbicide options to apply preplant. Once you plant the crop, we have very few herbicides that can be used over the top of the crop. Right now is the time to get down strawberry herbicides before the season starts. As the old proverb goes: an ounce of prevention is worth a pound of cure.”

Black rot on collard transplant (V-shaped lesion on the margin) just waiting for the right environmental conditions to decimate your yields. Photo from Zack Snipes.
A healthy stand of sunnhemp shades out most, if not all, summer weeds reducing the weed seed bank. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “We received about an inch of rain (at my house), which we really needed. The temperatures over the last week have been very mild and it has started to feel like fall. Fall crops are doing well. We’re still planting brassicas and keeping an eye on caterpillars. Muscadines are being harvested now. Growers are reporting good fruit quality, but lower yields than last year. This is most likely due to the late cold weather that affected muscadine growers across the state. On pecans, black aphid populations and scab incidence are both high. It appears both of these pests are going to significantly reduce yield on sensitive varieties if growers didn’t stay on top of sprays.”

Pecan scab is severe this year. This disease can cause the tree to abort infected nuts. Photo from Justin Ballew
Black aphids are very small, but their damage is easy to see on the leaves. Photo from Justin Ballew