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.

Weekly Field Update – 11/15/21

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 in the area are developing well, with few disease problems. In brassica crops, we are still seeing increased insect pressure from diamondback moths and whiteflies. Please remember to rotate insecticides with different modes of action. Following cooler weather, some brassicas are displaying some reddening to the leaves. This phenomenon often concerns the plant closing down phosphorous uptake. It is not necessarily indicative of a phosphorous deficiency in the soil. Generally speaking, the plants will ‘green up” as the temperatures increase.”

Midlands

Justin Ballew reports, “It was a little warmer last week, though we had some cool nights. We got a little rain (.3” at my house) and we could use more. Strawberries are continuing to get established and are looking decent so far. Some folks have opted to cover their plants for a couple weeks to accumulate more growing degree days. I’m glad to see that since we planted late and it’s been cool. I’ve already seen some deer feeding damage. It doesn’t take them long to find the plants once new leaves start growing. Get fencing in place before deer feeding begins. I don’t know of any repellants that work as well as a fence.”

This plant just barely had enough time to push out a couple new leaves before the deer found it. Photo from Justin Ballew.

Sarah Scott reports, “We’ve had some areas of patchy frost just as some of the crops like eggplant and bell peppers are starting to wind down. Broccoli harvest is wrapping up and this season turned out to be a good one. Fumigation has been done on fields where new peach trees will be planted and growers are plowing and preparing for planting. “

Broccoli that is ready for harvest. Photo from Sarah Scott.
Peach trees with fall color. Photo from Sarah Scott.
Cover crops in between rows to be hilled for new peach plantings. Photo from Sarah Scott.

Upstate

Kerrie Roach reports, “With the first real cold nights over the weekend, things have officially begun to crawl as far as production is concerned. However, soil sampling, land preparation, and winter chores have started off with a bang. This is a great time to get things going with soil sampling. Results are typically available within 2 weeks and adjustments can be started and made in time for planting. Check out the Clemson site for information, or contact your agent for help!”

Andy Rollins reports, “I am still in process of inspecting all upstate strawberry plantings for this new year of production. Plants should have leaves with three leaflets (like clover). Occasionally, you may find one plant here or there with four leaflets, this is within reason. You should not be finding nearly every plant with this abnormal growth. There can be several issues that can cause this. The use of runner stimulating hormones by plant producers and phytoplasmas (a type of bacteria) can also cause this effect. I have only found this problem on ‘Camino Real’ on one farm this year, but I am looking everywhere.  In a previous year when this was found, we later had deformed berries that looked more like a mangled up leaf than a strawberry. We have had some more root rot issues in fall crops and we are preparing new ground for peach plantings now.”

Strawberry leaves with 4 leaflets are ok if seen occasionally, but it is not normal to see this on every plant. Photo from Andy Rollins.

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.

Updated Paraquat Safety Measures

In 2016, the Environmental Protection Agency (EPA) released a number of new safety measures to reduce the risks of paraquat exposures to applicators. This includes:

  • Changing labels and other supplemental warning materials to emphasize paraquat toxicity.
  • Requiring training (every three years) for paraquat users.
  • Restricting the use of all paraquat products to certified applicators only.
  • Requiring closed system packaging for all non-bulk (less than 120 gallons) end use product containers of paraquat.

Earlier this year, additional changes to the paraquat label were released, including:

  • Requiring limitations on aerial applications, including a residential buffer.
  • Prohibiting pressurized handgun and backpack sprayer applications.
  • Requiring enclosed cabs or respirators for groundboom applications.
  • Increasing the Restricted Entry Interval (REI) for several crops.

The following document from the Association of American Pesticide Control Officials (AAPCO) provides an excellent summary of the new rules (including the bullets above) and answers frequently asked questions about the rules.

Just as a reminder, applicators must complete an online training every three years if they plan to apply paraquat. In addition, every applicator applying paraquat must have a pesticide applicator’s license.  Applicators may no longer apply paraquat under the supervision of another certified applicator.  Use this guide for step-by-step instructions on how to complete the training.

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 – 11/1/21

For anyone looking to diversify their operation, check out this week’s virtual program on cut flower production. The program will be this Wednesday (11/3) from 12-1pm. Click here to register.

Coastal Region

Rob Last reports, “Following the welcome rainfall last week, crops are looking good. The precipitation will help establish strawberry plants in the area because a lot have only recently been transplanted. Fall brassica crops are developing well, with pressure from diamondback moths being moderate. There are also isolated incidences of whitefly in brassica plantings. The best policy is to scout thoroughly and regularly allow decisions on applications to be made quickly.”

Zack Snipes reports, “Cooler temperatures showed up this past week along with some rain. Everyone is busy planting strawberries. We are a few weeks behind this year but overall the plant quality looks good. Many growers dipped plants prior to planting to prevent crown rot pathogens. One common issue that I have seen this year, and every year, is planting crews planting plants too deep. Although it may not seem like a big deal, planting too deep will cause plants to be small and have reduced yields. You still have time to walk the fields and lift plants up a bit. Bananas and citrus are just about ready to pick in the Lowcountry.”

A Meyer Lemon just before harvest. Photo from Zack Snipes.
A nice cluster of SC bananas. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “Temperatures were a little cooler last week and we got some much-needed rain. Strawberry planting has finished now and plants are starting to push out some new leaves. We have seen some plants that were planted a little deep and some that settled too much after transplanting, so be sure to go through the fields and gently pull these plants up to the correct height and reform the soil around them. The best time to do this is before the plants have produced tons of new roots. It’s going to be cooler this week and plants are already a little behind from being planted late. Therefore, growers may want to consider using row covers this month for 2-3 weeks to increase growing degree days and promote growth. There is a great article in the latest NC Strawberry Association Newsletter (pages 6-8) about using row covers in the fall.”

Strawberry plants are starting to push out new leaves. Photo from Justin Ballew
New roots seem to be developing pretty well so far. Photo from Justin Ballew.

Pee Dee

Bruce McLean reports, “Last week’s rain helped to moisten up the soil a bit, but we are still pretty dry across the Pee Dee. Fall vegetable crops are looking good for the most part. Spider mites, aphids, and stink bugs have been very active. Last week’s showers likely knocked back the aphid and spider mite population some, but they will come back. Be sure to actively scout for them. Strawberries are finishing up being planted, and are looking good. Much of the strawberry crop is a little late this year. Be sure to monitor soil moisture (…since it is rather dry), making sure it doesn’t get too dry underneath the plastic. Also since spider mite activity has been up, it would be a good idea to scout for spider mites on strawberries and treat accordingly if mite pressure becomes high enough.”

Bob Hall Named 2021 Southeastern Farmer of the Year

Bob Hall of Bush-N-Vine Farm in York, South Carolina has been named the 2021 Swisher Sunbelt Expo Southeastern Farmer of the Year. The Farmer of the Year was announced at this past week’s Sunbelt Ag Expo in Moultrie, GA.

Bob and Susan Hall with representatives from Clemson Extension, SC Farm Bureau, and the Sunbelt Ag Expo. Photo from Millie Davenport.

Hall was previously named South Carolina’s Farmer of the Year back in July and competed against 9 other farmers from around the Southeast. Hall was nominated by Clemson Extension Agent Andy Rollins.

Check out this great article about Hall and Bush-N-Vine Farm from the Sunbelt Ag Expo.

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.

Weekly Update – 10/18/21

Coastal Region

Rob Last reports, “As we begin to see strawberry plants delivered into the area, don’t forget to examine the plants for pests and disease closely.  With regards to disease, check the leaves for foliar disease and the roots for discoloration.  A root dip fungicide application is very practical for managing crown rots.  Also, don’t forget your deer fences.”

Midlands

Sarah Scott reports, “Broccoli is starting to head and looking pretty good. Some growers have already received strawberry plants and have them in the ground while the rest are still awaiting plant arrival. Late summer/fall harvest of tomatoes, eggplant, and summer squash continues and peppers are still coming on. The peppers pictured have a large population of whiteflies and some aphids causing sooty mold. The new growth is slightly deformed due to heavy feeding. A foliar treatment with a product having low PHI may be necessary on these developing plants.  Refer to the vegetable crop handbook for treatment options.”

Justin Ballew reports, “We had beautiful sunny weather last week that really helped dry things out. Strawberry transplants are due in this week and growers will start getting them in the ground as soon as they can. We have heard some reports of anthracnose coming from nurseries, so be sure to closely examine your plants and do not plant any that look weak. Since we are planting a little late, proper planting is all the more important. Be sure crews are planting transplants at the proper depth. Supervise them closely. Using row covers to push growing degree days may also be helpful this fall since most folks are planting a week or more late. There is a good article in this month’s NC Strawberry Association newsletter (pages 6-8) about using row covers in the fall.”

Supervise planting crews carefully to make sure plants are going into the ground at the proper depth. The crown should be just above the soil line. The plant pictured here is planted too deep and the crown is not visible. As a result, this plant is always going to be behind. Photo from Justin Ballew.

Phillip Carnley reports, “Nothing much has changed in Orangeburg or Calhoun counties. Like most of the state, shipments of strawberry plugs and crowns have been delayed upon arrival; make sure to inspect plants with care to ensure that they are healthy. Brassica crops are loving the cooler night temperatures we’ve gotten recently, and I have noticed higher armyworm and looper pressure. With these caterpillar pests, make sure you have a targeted spray program and rotate MOA’s. Try to not use the same MOA within a 30-day time span.”

Imported cabbageworm. Photo from Phillip Carnley.
Armyworm. Photo from Phillip Carnley.

Upstate

Kerrie Roach reports, “The temperatures have taken a significant turn with mornings in the 30s and 40s. Like many other areas, strawberry plugs seem to be running well behind schedule, which in our area has made for some tough decisions. Planting in the upstate (Oconee/Pickens/Anderson) should typically be done around the end of September give or take 1-2 weeks. With the cool weather that has quickly moved in and plugs still not here (many not expected until the end of Oct), some growers have decided against planting for the 2022 season.”

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.