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

Weekly Field Update – 9/7/21

If you haven’t already done so, please take a few minutes to fill out a survey to share your thoughts with us on Extension meetings. We’ll be using the information collected to help plan meetings over the next year. It will take less than 10 minutes and is anonymous. Click here to get started. Thanks!

Midlands

Justin Ballew reports, “We’re getting a little dry here in the midlands and folks have been running irrigation a lot. We got a shower last night (9/6) at my house, but it didn’t amount to much. Our fall crops are looking really good right now. The dry weather is holding down disease though we are still seeing some insects, mainly caterpillars. Squash, zucchini, cucumbers, peppers, tomatoes, turnips, and other brassicas are all growing pretty well.”

Fall zucchini ready to be picked. Photo from Justin Ballew.

Phillip Carnley reports, “Muscadine production is in its final stages here in Orangeburg and Calhoun counties with most growers preparing to harvest or in the process of harvesting. There is still a noticeable amount of angular leaf spot on many vines, but this late in the season, it is not much of an issue. Continue to keep an eye on the population of grape vine borer with the use of traps. Also keep an eye on water, as it is needed for nice plump fruit.

Small amounts of foliar diseases are present in muscadines. Photo from Philip Carnley.
Growers are preparing to harvest muscadines in Orangeburg and Calhoun counties. Photo from Philip Carnley.

Pee Dee

Bruce McLean reports, “Soils are getting pretty dry in many locations. Even though dry weather would greatly benefit the muscadine growers, we could use a little rain. Vegetable crops are looking pretty good. Spider mite activity has increased over the last couple of weeks, especially on tomatoes. Bedding and fumigation (for strawberries) is getting ready to begin. Wine and juice muscadine harvest is upon us. Muscadine harvest is going to be a bit tricky this year. In many locations, half the crop is ready to pick and half the crop needs a little additional time, especially Carlos and Doreen cultivars. This is likely due to the late spring freeze that we experienced this year. Primary growth (that recovered from the freeze) is giving us a timely crop. Secondary growth (growth from secondary buds) is a little delayed. Watch harvesting too much under-ripe fruit. Under-ripe fruit does not contain the sugars or the juice, and will reduce your overall juice yield and total sugars.”

“Skirting the vines” is a common practice where the grower removes (by shearing) the excessive vegetative growth to allow the fruit to be more easily shaken from the vines during harvest. Photo from Bruce McLean.

Upstate

Kerrie Roach reports, “Things have significantly slowed down in the Upstate with the Labor day weekend signaling the true end of summer. The growers who are doing fall vegetable production are in the thick of things with insect and disease monitoring of utmost importance. I would typically be posting about apples and the harvest for this season, but the late cold event from April 22, 2021 has put a significant damper on local orchards. Growers have apples available, but u-pick operations are very limited, if not cancelled for this season. Orchard management is imperative even when the trees are not producing, and can be a good opportunity to get weed control and pest management under control.”

Weekly Field Update – 8/30/21

Don’t forget to sign up for the Virtual Strawberry Production Meeting we will have this Thursday (9/2) at 6 PM. We will have speakers from Clemson, UGA, and NC State and we expect it to be a great program. Visit the Upcoming Events page to see a list of topics and click here to register.

Also, if you haven’t already done so, please take a few minutes to fill out a survey to share your thoughts with us on Extension meetings. We’ll be using the information collected to help plan meetings over the next year. It will take less than 10 minutes and is anonymous. Click here to get started. Thanks!

Midlands

Justin Ballew reports, “We had a chance to dry out some this past week, though it really doesn’t take long with our sandy soil. Fields are still being prepped and planted for fall crops and what has been planted is doing well. We’ve been getting reports of high armyworm counts in pastures and row crops and we’ve been seeing some in vegetables also. Stay vigilant.”

Fall tomatoes are doing well in the midlands. Photo from Justin Ballew.
Armyworms, like this Southern Armyworm, have been showing up in pastures, row crops, and vegetable crops. Stay on top of scouting! Photo from Justin Ballew.

Pee Dee

Bruce McLean reports, “It’s getting into a transitional period for vegetable production. Cool season crops are starting to be planted (in volume), and warm season crops, like squash, zucchini, okra and peas, are still being harvested in some good volume. Fumigation for strawberries is getting ready to get started. Blueberry propagation (green-tip, semi-hardwood cuttings) is going on. Fresh market muscadines are busy being harvested. Wine and juice varieties of muscadines are getting close to harvest. Carlos and Noble are really coloring quickly. Doreen is just starting to color. Testing for sugar content (Brix) will begin this week to identify the correct harvest date for wine and juice muscadines.”

Nobel muscadines are coloring well.
Grape Root Borer on Carlos muscadine.

Upstate

Kerrie Roach reports, “Dry weather this last week was much needed after the significant rains from the week before. As many other areas across the state, armyworms reports and calls are coming in more and more each day. Stay vigilant with your scouting. As with many of our tree fruit and nut crops, the pecan harvest is looking to be pretty slim after the April 22nd cold event that affected many areas of the Upstate. Continue to monitor and treat for disease and insect populations so that next year the are not even more problematic. For bearing trees, now is the time to be monitoring and treating pecan weevil populations. Several specialists have also recommended monitoring and potentially treating non-bearing trees as well, if populations detected are high. While ideally, no pecans means the life-cycle for the pecan weevils would be incomplete, there are most likely enough pecans present in the tree to support some of the population. Check out the Pecan Management Guide for more information.”

Now is the time to monitor and tree pecan weevil populations.

Andy Rollins reports, “Bigred peaches are in the upstate and quality is amazing.  Use of pheremone ties Isomate OFM to exclude males from being able to find mates has been a huge success for late season peach.  Insecticides alone previous years even with adequate rotation did not prove successful. We have fall collard, broccoli and other brassicas being planted. Both hot and other peppers are being harvested in quantity despite excessive rains earlier in the year.  Squash and zucchini production is slowing with only limited late season plantings.  Nematode survey work is being done this week.”

Herbicide injury to peach trees.  Look out for your investments.  In this case a local cable company had spread a granular herbicide on the ground directly onto the rootzone of several peach trees adjacent to a power pole and a above ground cable box.  Check all of your borders of your plants regularly, especially where they meet up with a right-of-way or a neighbor.  This is normally not done intensionally but it does cause an economic impact larger than what you probably realize.  Clemson’s Department of Pesticide Regulation can help with these cases.

Weekly Field Update – 8/23/21

If you haven’t already done so, please take a few minutes to fill out a survey share your thoughts with us on Extension meetings. We’ll be using the information collected to help plan meetings over the next year. It will take less than 10 minutes and is anonymous. Click here to get started. Thanks!

Midlands

Justin Ballew reports, “Last week was warm and humid again. Some of our sandier fields got dry enough early in the week that crops were wilting in between waterings. We got a bunch of rain over the weekend, though (a little over 2 and a half inches at my house). Overall, fall planted crops are coming along nicely. Some of the earliest planted fall squash and zucchini is being picked now. We’re still seeing the same disease problems that have plagued us all summer, though growers seem to be managing them fairly well. As far as caterpillars go, I’m seeing mostly diamondback moth and armyworms with a few loopers here and there. Get ready. This could be a high pressure fall for caterpillars.”

Even though we’ve had lots of recent rain, it doesn’t take long for the sandy soil in Lexington to dry out and let the plants wilt. Photo from Justin Ballew.

Phillip Carnley reports, “Not much has changed here in Orangeburg or Calhoun Counties. Its been hot and humid and we’ve had a few untimely showers delaying cucumber harvests. There is still plenty of downy mildew to go around. We are seeing loopers on pickling cucumbers that are ready for harvest. At that stage the loopers should be treated prior to harvest with Coragen, Harvanta, or Radiant. Fall brassica, peas, and tomatoes are just now being planted.  We are seeing increased amounts of scab in pecans this year, due to the rain and humid weather. For insect and disease management in pecans, have a look at the UGA Commercial Pecan Spray Guide.”

Caterpillar damage to fall cucumbers. Photo from Phillip Carnley
Loopers are causing some damage to fall cucumbers in the Orangeburg area. Photo from Phillip Carnley.

Upstate

Andy Rollins reports, “Excessive rains have caused cracking of fruit at several upstate muscadine farms. Powdery mildew is also present but I’m not sure how much of a role it is playing on the cracking part. The powdery is damaging the skin of the fruit. Topsin M is labeled and recommended with Captan but have to wait 7 days to pick so have to watch your PHIs. Also finding some insect pests in peach. Oriental fruit moth and sap beetles have been found last week but only a small amount of affected production. Herbicide control has been difficult this year because all the rain has caused excessive grass growth, especially in new orchards.”

Seeing some cracking of the skins in muscadines in the upstate. Photo from Andy Rollins.
This new grower has done a good job of keeping his understory clean. This will pay off for him in the spring of next year if he can keep up the diligent work. Photo from Andy Rollins.

Weekly Field Update – 8/16/21

Coastal Region

Zack Snipes reports, “Its hot and humid in the Lowcountry. Fall tomato and watermelons are in the ground and enjoyed a week of mostly dry weather. Okra and sunchokes, aka Jerusalem artichokes, are loving this heat. With the exception of those crops, there aren’t too many crops in the ground right now.  I am seeing lots of summer cover crops. I love the idea of using a mixed species of cover crop. One reason is, it spreads out the risk that one of the species in the mix won’t germinate or will be eaten by deer. So by using multiple species, you can almost guarantee that something will be there covering the soil. Multi-species mixes also provide different benefits to the farm. Cowpeas may fix nitrogen while sorghum X Sudan hybrids may be a deer deterrent and shade out weeds.”

A beautiful mixed-species stand of cowpeas and sorghum X Sudan hybrid (sudex). Photo form Zack Snipes.
Buckweat is one of my personal favorites because of its ability to attract beneficial insects and mine potassium from the soil. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “Not much has changed here in the midlands over the last week. Its been warm and humid and we got a little rain a couple times throughout the week. Recently planted fall brassica and cucurbit crops have gotten off to a good start. We are seeing some caterpillar activity already. We are seeing increased amounts of scab in pecans this year, thanks to the rain and humid weather. I’m seeing some black pecan aphids causing damage as well. For insect and disease management in pecans, take a look at the UGA Commercial Pecan Spray Guide.”

Pecan scab is really showing up this year. If growing cultivars with poor scab resistance (Desireable, Pawnee, Kiowa, Oconee), stay on top of fungicide applications. Photo from Justin Ballew.
Black aphid damage on pecan foliage. Photo from Justin Ballew.

Phillip Carnley reports, “It’s that time of year to be on the look out for Southern stem blight (Athelia rolfsii) in hemp. To avoid possible infections of this pathogen, avoid planting in fields that have previously had tomatoes, peppers, eggplant, or peanuts. Crop rotation is your best avenue for mitigation as there are no fungicides labeled for control of Southern blight in hemp at this time. Also be on the lookout for plant stunting from girdling roots. For information on chemicals labeled for hemp checkout the EPA website.”

Southern blight mycelium (white fuzzy looking growth) and sclerotia (small, tan bb-shaped structures) developing around the base of a hemp plant. Photo from Phillip Carnley.
This hemp plant has wilted due to Southern blight cutting off its ability to transport water from the roots to the shoots. Photo from Phillip Carnley.

Upstate

Kerrie Roach reports, “Late summer season crops are still producing in the upstate, but many market producers are starting to lose the disease battle. When something is finished for the season, make sure to remove all parts of the crop. Do not leave diseased plant material in the field. Dispose of the diseased crop in an area far away from your fields or garden. Do not use diseased plant material for compost. Most home compost piles do not reach consistent and uniform temperatures at which pathogens will be killed. Dead plant material harbors insects and pathogens that can and will cause issues for fall season crops as well as next year’s crop.”

Weekly Field Update – 8/9/21

Coastal Region

Rob Last reports, “Generally speaking, we are in the change over period from spring to fall crops, with some fumigants being applied to next year’s strawberry plantings. If fumigants are to be used, make sure soil moisture is good and beds are firm to gain maximum efficacy. One thing we have observed in blackberries and blueberries in the area is the emergence of bark scale. Bark scale is a new pest to South Carolina and has previously been noted in ornamentals. However reports for Asia, where the pest is native, indicate the bark scales can survive on Rubus species.

Bark scale egg sacks and adults. Photo from Rob Last.

The images show the egg sacks and adults of the bark scale. The insects appear white and are very waxy, similar in appearance to mealybugs. The wax coatings can make management complex, preventing insecticides from penetrating the layer to be effective against the insects. The addition of crop oils to the pesticide solution may enhance efficacy by helping to strip off the waxy coatings. In blueberries, adults can be found underneath the exfoliating bark, again making contact with the insecticides more difficult. When crawlers emerge, they will be pink and barely visible to the naked eye, and monitoring will be easier with the aid of a hand lens. We will find crawlers hatching in April or May, with a second flush emerging in late summer. An excellent way to detect crawler movement is to wrap the branches in double-sided sticky tape to help to catch the crawlers. Contact insecticides can be very effective against the crawlers. Insect growth regulators may also be effective for management. Unfortunately, systemic materials such as imidacloprid appear to have little effect. Please get in touch with an Extension Agent to help with identification and management options.”

Bark scales have a waxy coating that helps protect them from insecticides. Photo from Rob Last.

Zack Snipes reports, “It’s wet in the Lowcountry. We are getting heavy rain showers what seems like everyday. This is making it hard to get equipment in fields to spray or prepare for fall plantings. I have seen some watermelon and tomato fields and they look ok considering the rain and soggy conditions. I saw some bacterial spot on pepper and expect to see the same on fall tomato with the rain and humidity we’ve had. Get out your preventative fungicides, if you can. I also saw some leafminer damage on these crops which is unusual in my tenure. It seems plants were impacted a few weeks ago but the new growth looks to be unaffected. Melonworms were found in cucumbers, so get ahead of them.”

Leafminers are showing up on tomatoes on the coast. Photo from Zack Snipes.
Melonworms were found in cucumbers this week. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “This past week was a relatively nice, mild week compared to the week before. We had some rain to start the week and more to finish it out. Planting of fall crops continues and what’s been planted seems to be growing well. I looked at a few fields this week of seedling brassicas and I’m already seeing diamondback moth caterpillars and armyworms feeding. Remember to start scouting as soon as plants go into the ground. It doesn’t take many caterpillars to eat up seedlings and small transplants. Don’t forget we can run field bioassays to screen for insecticide resistance, so call us when you start seeing worms.

Diamondback moth caterpillars are already showing up on fall brassicas. Photo from Justin Ballew
It doesn’t take many caterpillars to eat up these small plants. Photo from Justin Ballew.

Pee Dee

Bruce McLean reports, “Vegetable crops are still harvesting well, for the most part. Other than cucurbit downy mildew affecting cucumbers and some powdery mildew affecting squash, there are no widespread vegetable diseases seen in the fields. Cowpea curculio is still widespread on peas and must be intensively managed (starting prior to bloom) to minimize damage. Spotted Wing Drosophila is still very active in late-season blueberries, with trap counts showing very high capture numbers. Grape root borers (GRB) emergence is starting to increase in muscadines. Trap captures for GRB is on the rise. Much of the state is outside the window of Chlopyrifos application for GRB… except on late harvesting cultivars (more than 35 from application to harvest) and maybe some wine grape cultivars in the Upstate. Pecan weevil emergence is just getting started (in pecans). Ground and lower canopy application of Carbaryl and/or a trunk application of Tanglefoot are effective methods of control. Monitor traps and weevil movement through September (especially after rains). Re-treatment of Carbaryl will be necessary and can be reapplied at (up to) 7 day intervals. Pecan scab is becoming more evident in pecan orchards. Also, fall armyworm numbers have exploded over the last two weeks. This is a pest that can affect a wide variety of crops.

Who is spitting in my muscadine vines? That is not actual spit. It is a sticky, frothy substance produced by the spittlebug for protection from predation. Photo from Bruce McLean.
This tiny insect is the spittlebug (what is inside the frothy spittle on muscadines and other plants). They feed upon the foliage of the muscadine vine and do not cause any noticeable damage to the plant. Photo from Bruce McLean.
Grapevine aphids populations on muscadines can be quite significant in late summer. They feed primarily on the foliage and late flower clusters. They seldom require chemical management except when present during spring bloom. Heavy rains and natural predation usually keep them in check. If extended periods of dry weather occur and their feeding does lead to noticeable problems (or if honeydew and sooty mold become evident on fruit and leaves) an insecticide application may be necessary. Photo from Bruce McLean.

Weekly Field Update – 8/2/21

Coastal Region

Zack Snipes reports, “Summer crops like okra are still coming in and looking good. We’ve had a lot of rain and some fields are soggy. More rain is coming. Some growers have started planting peppers and tomatoes. Remember to get out in the fields and destroy spring crop residue. Nematodes and other pests can really thrive on that old residue.”

Root knot nematode infestation on tomato roots. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “Last week was by far the hottest week we’ve seen so far this summer. It’s been a very mild summer, so last week was actually a reminder of what “normal” is here. Tomatoes, squash, zucchini, cucumbers, and sweet corn are still being harvested. More fall brassicas, cucurbits, and some tomatoes were planted this past week. I haven’t heard of any reports of serious caterpillar activity yet, but remember to start scouting as soon as you plant. It doesn’t take long for caterpillars to significantly damage brassica seedlings.”

We’re still picking some good looking sweet corn in the midlands. Photo from Justin Ballew.

Upstate

Kerrie Roach reports, “Things in the Upstate, like much of the rest of the state, have been particularly hot and dry this last week. Irrigation has been of utmost importance as well as mitigation of disease and insects. As we move later in the season, things are starting to slow down, but now is the time to start prepping and planning for any of those fall plantings. For our smaller market growers, season extension by utilizing fall crops can be a great addition. Many farmers markets are looking for growers to sell in the early fall, and competition is slim, often making sales easier. Do your homework BEFORE plating and start looking now at local markets ending dates, vendor loads, customer preferences, and plan accordingly. Check out the SE Veg Crop Handbook for fall planting dates from many of your favorite crops. 

Weekly Field Update – 7/26/21

Statewide

The SC Specialty Crop Association is offering a new grant opportunity, the Enhancing Crop Packaging Cost-share Program. With this new cost-share program, growers can receive reimbursement up to $1,800 per grower for packaging needs. All that is required in addition to the application are copies of receipts used for purchasing packaging materials. You will also be required to fill out two surveys, one initially and one 12 months after submitting the application. All information is confidential. For more information, contact LauraKate McAllister. The application can be downloaded below.

Coastal

Zack Snipes reports, “We are in a summer weather pattern with warm, muggy days and occasional thunderstorms. Most crops have finished up or are in the process. Now is a great time to sit down and do some crop planning and field rotation planning. I collected many soil and root tissue samples lately and had them analyzed for nematodes. I was surprised at how many nematodes were present in the fields. Nematodes can interfere with growth, cause stunting, and lower overall yields. Sometimes the symptoms of nematodes can be very discrete so sampling right now is the best way to get a baseline of your populations and how to properly manage and rotate fields. If left unchecked, thousands of dollars are wasted before the first seed is planted into a field.”

Significant galling from root knot nematodes on a cucumber seedling. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “It was another fairly mild week with high humidity and some pretty decent rain. Not much has changed on the disease front. We’re still seeing plenty. Growers are still prepping fields for planting fall crops. Some fall cucurbits and brassicas have been planted already. More are on the way. As soon as brassicas go in the ground, start scouting for worms. Remember, we can perform bioassays to screen for insecticide resistance in diamondback moths populations. Reach out to your local fruit and vegetable agent when you start seeing worms to schedule one.”

Bacterial spot is common on tomatoes right now. Photo from Justin Ballew.
Recently planted kale is growing well. Start scouting for worms as soon as you plant brassica crops. Photo from Justin Ballew.

Pee Dee

Bruce McLean reports, “Vegetable crops are harvesting well, with good volumes of squash, zucchini, cantaloupe, watermelon, cucumber, butterbeans, peas, tomatoes and okra. Sweet corn is beginning to wrap up. Late season blueberries are still being harvested in some volume, but will be finishing soon. Muscadines are sizing well. Vineyards that were only slightly affected by the Easter freeze are looking good and should have a good crop. Vineyards that were more significantly affected by the freeze are very short on crop this year. Grape root borer traps in muscadine vineyards are starting to catch moths in all locations. Spotted wing drosophila (SWD) trap captures (in blueberries) have dramatically increased over the past few weeks, showing that even in late season when fruit is becoming less and less plentiful, the fly is still very active and must be managed.”

Bucket trap baited with the Grape root borer (GRB) pheromone lure in muscadines. Photo from Bruce McLean.
Where we did not see significant damage from the Easter freeze, there is a good looking crop of muscadines. Photo from Bruce McLean.

Upstate

Andy Rollins reports, “I identified a major scale problem on peaches. A grower from middle part of state called about red spots on peaches. Earlier in the year across the whole state we had red spots on leaves. We found prunus necrotic ring spot on all of those samples last year but we are still unsure of the origin. In this case, it is something much different. This is an insect that feeds on the fruit and the tree itself. The adult stage of this insect doesn’t move but the crawlers do. After consulting with Dr. Brett Blaauw, regional entomologist for Clemson, the grower decided to go ahead and treat now. On Friday, he sprayed Movento at the label rate. There is great concern because with this high of a population, the life of the entire trees at risk. The plan is to follow that application with chlorpyrifos and oil at low rates after the leaves drop. You have to be careful when doing this as the oil can damage the next years bud crop if temperatures are too hot. We will be trapping using black electrical tape wrapped around the limbs then double sided scotch tape around that. We will then look for the crawlers on the scotch tape. This ensures money isn’t wasted killing a pest that has already been controlled.”

Red spots have been common on peaches this year. Photo from Andy Rollins.
In this close up of the bark on a peach tree, you can see the tiny, black and grey colored scales. Photo from Andy Rollins.

Weekly Field Update – 7/19/21

Statewide

Dr. Tony Keinath’s remarks on fungicide stewardship:

Growers who are applying newer fungicides that are pre-mixes of two active ingredients do not need to add another fungicide to the tank mix. Pre-mixes can easily be identified by the two FRAC Codes on the label in the top right corner. Please consider the following points:

Quadris Top contains two fungicides: a group 11 and a group 3.
  • Many newer fungicides are sold as pre-mixes to reduce the risks of fungicide resistance in fungal and water mold pathogens. Mixing two active ingredients often is a way to prevent or slow resistance development, as long as both active ingredients work against the same disease.
  • Sometimes two active ingredients are mixed to expand the range of diseases controlled. For example, Quadris Top controls both anthracnose (the Quadris part) and gummy stem blight (the “Top” part, which is Inspire).
  • Mixing more than 2 pesticides, whether they are 3 fungicides or 2 fungicides plus an insecticide, increases the risk of pesticide injury (burn). Risks may be greater if a spreader-sticker is added, or when air temperatures are above 90 F.
  • Adding another fungicide to a pre-mix fungicide increases fungicide costs, often without increasing disease control.

Growers should contact their Extension agent before adding another fungicide, even a protectant, to a pre-mix fungicide to be sure it’s really necessary.

Midlands

Justin Ballew reports, “Not much has changed in the midlands over the last week. We’ve received some scattered rain and it has been warm and humid. As a result, we are still seeing disease issues. We’re still picking tomatoes, squash, zucchini, cucumbers, sweet corn, and a few greens. We’re at an in-between stage in several fields where the spring crops have been finished and folks are preparing to plant fall crops. Some have already started fall cucurbit plantings. For anyone planting strawberries this fall, if you are still deciding which varieties to try, take a look at the NCSU’s 2020/2021 variety comparison data (pages 9 and 10).

Disease development like this anthracnose of watermelon is still being favored by the weather. Photo from Justin Ballew

Pee Dee

Bruce McLean reports, “Vegetable crops are looking pretty good across the Pee Dee. Fields that have received rain or are irrigated look very good. Fields that have missed the rain are a bit drought-stressed. Sweet corn, peas, butterbeans, tomatoes, squash, watermelons, cantaloupes, and cucumbers are all being harvested in good volume. Okra is just beginning to be harvested well. Growers are still fighting cucurbit downy mildew (CDM) on cucumbers. Fields that have been sprayed with fungicides for CDM (Orondis Opti, Gavel, Ranman, and Omega) are relatively clean and producing well. Fields that have not received those products are in severe decline. Cowpea curculio is still being a challenge. Some growers have asked about adding PBO8 (Piperonyl Butoxide) synergist to their insecticide application. Research has shown some efficacy, so it does help. But, it is not the silver bullet that everyone is looking for. There really is no alternative to having a robust spray program, spraying every three to five days starting prior to bloom.

Many varieties of blueberries have already finished up, with only mid-late and late rabbiteye blueberries going now. Blackberries have finished up, as well. Summer primocane tipping and floricane removal has begun. Be sure to apply a broad-based fungicide to all open wounds/pruning cuts to prevent disease development (I.e. cane blight, etc). Muscadines are sizing up pretty well. Grape root borer traps have been placed in vineyards, but no moths captured yet.

Upstate

Kerrie Roach reports, “Things in the Upstate were a little wet the last few days and it looks like showers will continue into the middle part of the week at least. Continue preventative measures for disease control and if/when a plant seems too far involved, remove and dispose of the entire plant to prevent further spread. Squash vine borer has been one of the continued problems in market garden production in the last 2 weeks. At this late point in the season and lifecycle, monitor plants closely and as soon as frass is seen, carefully cut the stem longitudinally and remove/kill the larval stage of the borer. You can mound soil on the cut part of the stem to help encourage new root growth. If done early enough, plants can continue to thrive despite the slice in the stem. New plantings of cucurbits set out in the last week or so should mature after the adults have finished laying eggs, but monitor closely for any wilting. Crop rotation, row covers, traps (yellow bowl of water), and pesticide applications can also be used as a part of a good IPM program. Check out the crop handbook for more specifics. 

Organic Upstate vegetable production. Photo from Kerrie Roach.

Andy Rollins reports, “We are having thrips issues on 3 crops peaches, pepper and cucumber. Thrips as seen in the picture cause surface damage to the outside make it aesthetically less appealing and marketable. On pepper they damage the leaves and can transmit viruses to the plant (on cucumber also). They are much worse in greenhouse and high-tunnel settings.  I have been recently concerned about presence of chili thrips and I am waiting on definite identification. This is a good website about this new pest. I also found a rare disease called foot rot of squash in the upstate. It was identified by Dr. Tony Keinath. Rotation is very important with all of our vegetable crops. We are picking some excellent quality peaches in the upstate. Cold damage has limited our wholesale picking.”

Thrips injury to peaches. Photo from Andy Rollins.
Fusarium foot rot of squash. Photo from Andy Rollins.

Weekly Field Update – 7/12/21

Coastal

Rob Last reports, “Crops are generally coming to market with good quality from cucurbits through corn, tomatoes and peppers. Be on your guard for foliar diseases, given the temperatures and humidity there are a large number of diseases present from anthracnose, powdery and downy mildew, and alternaria. Fungicide applications will help.to manage diseases applied in a timely manner.”

Zack Snipes reports, “The tropical storm brought some wind and heavy rain in some parts of the Lowcountry. We received 3.86 inches at the CREC in Charleston. Most fields have dried out and things are back to normal. I have seen an increase in bacterial spot on tomato and a rise in the spider mite population. Remember that using pyrethroids (group 3 insecticides) (Brigade, Bifen, Karate, Warrior, Tombstone, Mustang Maxx, etc.) will kill spider mites but will also kill all beneficial insects. In most cases, spider mite numbers are higher 5-7 days after a pyrethroid spray than they were before. There is also resistance to some pyrethroids in spider mite populations. Bottom line…don’t use pyrethroids to control spider mites. We have plenty of registered, spider mite specific products in our tool box.

A spike in spider mite numbers can be seen when pyrethroids are used. Choose wisely. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “Tropical Storm Elsa came through the midlands in the early morning hours Thursday and brought 1.3 inches of rain (at my house) with it. Disease is still the big story here in the midlands. It’s been very warm and humid and we’re still seeing plenty of downy mildew, powdery mildew, anthracnose, and bacterial spot. For anyone planting strawberries this fall, now is the time to start soil sampling. Some folks held onto their strawberries well into June this year. If that was you and you plan to replant the same fields this fall, start removing plastic and discing ASAP to destroy the crop residue.”

Plenty of disease such as powdery mildew of cucurbits here in the midlands. Photo from Justin Ballew.