Weekly Field Update – 6/21/21

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Coastal

Rob Last reports, “Given the rainfall and humidity levels, we are seeing increases in foliar and fruit diseases on a range of crops. This includes cottony leak in cucumbers, anthracnose in pepper, tomatoes, and cucurbits. Also, please be aware cucurbit downy mildew is very active now. As a result, it is going to be really important to maintain fungicide programs in both a timely manner and to be robust. That being said, we have some great quality melons, both cantaloupe and watermelons, coming to harvest, as well as good volumes of quality peaches, blackberries, and a host of other vegetable crops.”

Zack Snipes reports, “We had some heavy downpours this past week which has beat some crops up. Hopefully everyone got their fungicides out ahead of the rain. The CREC hosted their annual Field Day last week. A special thanks to all that attended. I learned a good bit about herbicide carryover damage and direct herbicide damage from Dr. Matt Cutulle. I think the cool weather this spring made our plants and herbicides have some unusual reactions.”

Plant specimens showing herbicide carryover damage at the CREC Field Day. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “After a pretty dry week, Tropical Depression Claudette came through over the weekend and dropped a lot of rain (a little over 3 inches at my house). More rain is forecast for this week, so again, be sure to stay on top of fungicide sprays. This past week we started seeing bacterial spot on tomatoes, anthracnose fruit rot on peppers, and Southern blight remains active on several crops. We’re getting close to the end for the spring brassica crops. Tomatoes, squash, zucchini are being harvested and sweet corn will be coming soon.”

Anthracnose fruit rot on bell pepper. Photo from Justin Ballew

Pee Dee

Tony Melton reports, “Thank goodness the rain was not as heavy as predicted for the tropical storm. We are fighting belly rot and downy mildew on pickles with all the possible controls. Hard to get sweet potatoes laid-by and fertilized with the wet conditions. Snap beans are doing and yielding well but processors are having trouble keeping up because of labor problems. Bad thrips problems on peaches losing 1/3 of #1 yield.”

Upstate

Kerrie Roach reports, “Things are looking pretty good in the ‘golden corner’ area. Heavy rains over the weekend have caused some ponding and erosion, but nothing major. Disease pressure continues to be high with the perfect conditions (humid and warm), so growers should continue to practice preventative control methods. Insect pressure has still been considerably low for this time of year, but we’ve seen a subtle increase in populations in the last 2 weeks. Monitoring is extremely important for management strategies to be successful, in general nymphs or the juvenile form of most insects are much easier to manage than adults. Strawberries are just about done, with most growers doing some final pickings this week.”

Grapes are coming along nicely this season. Photo from Kerrie Roach.

Andy Rollins reports, “Phytophthora can be a devastating disease of Pepper. We have suffered extreme losses on one farm. The worst fields had been planted for 2nd year in pepper which is not recommended. Rotation is highly encouraged. Grower had treated with Ridomil twice and used phosphite repeatedly. It is believed there is resistance in this field to Ridomil, but testing hasn’t been completed yet. Dr. Tony Keinath has a complete description of this disease and control options in this article. We are mostly finished with strawberries at this point and preparing for next year. We are picking some peaches in the upstate although picking is very light do to extreme cold damage from April 3rd.  We are picking some tomatoes in high tunnels. Early blueberry crop was observed last week but picking is very light there also.”

Wilted pepper plants due to phytophthora. Photo from Andy Rollins.
Discolored vascular tissue in pepper stem from phytophthora. Photo from Andy Rollins

Weekly Field Update – 6/14/21

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The Coastal Research and Education Center Field Day is coming up this Thursday, June 17 beginning at 8:30. You must have registered to attend this year.

Coastal

Zack Snipes reports, “We received some welcomed rain but 5+ inches in a day or so was a bit much. Conditions this week will dry things out. I cannot stress enough how important it is to get out fungicides once you can get in the fields. I saw a few squash fields going downhill last week. Upon closer examination, I found thousands of squash bugs. They tend to congregate on the crown of the plant and will hide under the plastic when you look for them. 

Squash bugs can quickly take down a healthy squash crop. Photo from Zack Snipes.
Multiple life stages of the squash bug seen on this plant. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “More rain fell in the midlands this past week. We’re up to a little over 4 inches of rain at my house for the month of June, more than March and April combined. Some places have received much more. Crops have been loving the rain, but it does come with a cost. As expected, we’ve seen diseases pop up here and there. We’ve seen some Southern blight and bacterial wilt in tomato fields, fusarium in watermelons, and more black rot in brassicas. Weeds are loving the moisture as well. Keep up with fungicide applications, as diseases can get out of hand in a hurry in these conditions.

Southern blight developing at the base of a tomato plant. Photo from Justin Ballew.

Pee Dee

Bruce McLean reports, “Vegetable crops are growing well. Sweet corn, squash, cucumbers are being harvested in good volumes. Downy mildew was observed in a smaller planting of cucumbers. Powdery mildew was seen on a smaller planting of squash. Tomato harvest is just beginning. Blossom end rot has been an issue on some early tomatoes. This can be contributed to environmental stresses to the plants (high UV, extremely low humidity, high air temps) from a couple of weeks ago. Blueberries are being harvested in good volumes. The quality of the blueberries is good (for the most part), but a bit undersized. Blackberries are looking good, but botrytis (gray mold) is likely right around the corner. Muscadines are looking good in most locations. Even with the frequent rains, calyptra release has been good. Thrips activity has been low so far. Some early-season ALS (Angular leaf spot) is starting to show. Rally is a good product to control ALS. Some fields are getting a bit wet, limiting equipment and harvest activity in the field.

Placing a sheet of paper underneath the cordon of your muscadine vine and bumping the vine with your fist gives you a good opportunity to look at calyptra release, early fruit drop and thrips activity. Photo from Bruce McLean.
Japanese beetle activity in muscadines looks worse than it actually is. Japanese beetles are foliage feeders… and muscadines have more than enough foliage to spare. Japanese beetle typically are only a concern on newly planted vines. Photo from Bruce McLean.

Tony Melton reports, “Peppers and tomatoes are rotting at bottom of the plants from too much rain. Belly rot and Pythium leak is bad on cucumbers. Pickleworm is here and needs to be controlled. Southern stem blight is getting bad on tomatoes. Peas that are flowering need to be sprayed for cowpea curculio. Lots of potassium phosphide, metalaxyl, and mefenoxam are being used to keep down rots. Started side dressing, laying by, applying bifenthrin, and boron to sweet potatoes.”

Upstate

Andy Rollins reports, “Bacterial canker of peach is much worse this year in the upstate. This disease is caused by a Pseudomonas sp. that is different than the bacteria that causes bacterial spot (Xanthomonas sp.). It is common in younger plantings, 3 to 6 years old. A common tell is dead blooms that remain on the tree. This is one of many sites where the bacteria will invade the plant. Fall pruning is a huge mistake as it creates even larger openings for bacteria to enter. This disease can be part of a disease complex (Peach tree short life) or can act independently. The presence of ring nematode would contribute in this case. Cold damage from southwest injury to the trunks is very common and also provides entry. Unfortunately, there is very little that can be done to remedy this problem after being found. Trying to limit the above mistakes is helpful and some research has shown positive results from painting pruning wounds. Other Rutgers research recommended early winter copper applications for bacterial canker in cherry.

A young peach tree suffering from bacterial canker. Photo from Andy Rollins.
Bacterial canker can significantly reduce the life of peach trees. Photo from Andy Rollins.

Weekly Field Update – 6/7/21

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The Coastal Research and Education Center Field Day is coming up on June 17 beginning at 8:30. You must register to attend this year. Registration may be found here.

Statewide

Dr. Matt Cutulle reports, “The coastal rain events of  the past week resulted in a lot of weeds popping up. For fields not planted yet this is a perfect opportunity to burn down  the flush of weeds to reduce the weed seed bank in the field.”

Coastal

Rob Last reports, “After some welcome rain in the area over the weekend, crops are looking good. However, given the humidity and rainfall, we are likely to find disease pressure increasing. Strawberries are all over. The wet humid conditions have spiked infections of botrytis and water soaked berries. Blueberries, blackberries and peaches are all coming to market with good quality and volumes with few insect or disease pressures being seen currently. Watermelons and cantaloupes are developing well with some early planted crops coming to harvest. In response to rainfall and increased humidity, keep an eye out for diseases such as bacterial spot in pepper and tomatoes. In addition, some cantaloupe crops are beginning to show Alternaria leaf spot. Make sure fungicide timings are good using a robust program.”

Zack Snipes reports, “We finally got a little bit of rain last week which knocked the dust down some. We could use more and hopefully we will get some this week. Incidence of Southern blight increased last week in tomato. Make note of these fields and avoid planting them in tomato, eggplant, pepper, squash, or melons next season. Overall, the crops look solid. We are in the thick of things when it comes to tomato harvest and rabbiteye blueberry harvest is starting this week as well. We have really humid and wet conditions coming this week so don’t forget to use protectant fungicides. I know everyone is busy, but during the busy season is when most of our insect and disease pressure spiral out of control.”

Classic signs of Southern Blight on tomato. Knowing the difference in Southern Blight and Bacterial Wilt is critical to management. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “We finally got some significant rain in the midlands this past week. I’m up to 1.8 inches at my house and there is a good chance in the forecast for more. It has been warm, overcast, and very humid the last several days, which is the perfect recipe for disease development. Make sure you are using preventative fungicide where necessary. Insects seem to be picking up a bit as well. Caterpillars are going strong, we’re still seeing plenty of mites on various crops, and I’m getting reports of stink bugs here and there. We’re harvesting brassicas, squash, zucchini, cucumbers, and herbs.”

Tobacco hornworm egg on a tomato leaf. Hornworms start out small, but eat significant amounts of foliage as they grow. Photo from Justin Ballew.
Two adult diamondback moths making more diamondback moths. Photo from Justin Ballew.

Sarah Scott reports, “Much needed rain has occurred throughout the area this week with more predicted. With rain may come an increase in disease cases, growers should be aware of brown rot as it has been seen in several orchards this week. Removing fruit mummies and diseased fruit if possible can remove some inoculum from the field and limit future spread. Bacterial spot still isn’t being seen on a widespread basis, but again, after the moisture moving in for the extended forecast, growers should keep an eye out. Strawberries are wrapping up with some harvest still happening. Peppers and eggplants are progressing nicely and will also benefit greatly from some rain.”

Brown Marmorated Stink Bugs can be a problem for peach growers as they are hard to treat especially for organic growers. Entomologist Dr. Brett Blauuw will discuss these pesky pests on an upcoming podcast episode. November2019Newsletter.pdf (uga.edu). Photo from Sarah Scott.
Brown Rot on peach. The diseased fruit, most likely infected during blossom, did not fully develop and size and is now an inoculum source for disease in the field. Samples of diseased fruit can be sent in for fungicide resistance profiling to help growers better manage for this disease in the future. Contact your extension agent for details. Photo from Sarah Scott.

Pee Dee

Tony Melton reports, “1 pickle worm was found in a local squash. Processing and fresh market peppers will be ready to harvest on the week of June 13. Early tomatoes are just beginning to ripen. The rains have been mostly very beneficial but some spots have had excessive. Mudding through to pick pickles in spots. Very difficult to apply timely application of chemicals and some have to be reapplied after rains.”

Upstate

Kerrie Roach, “Things are looking good in the Upstate with warm season crops starting to come off. It’s still early for too many disease and insect issues, but high humidity and a couple days of spotty rain will most likely increase pressure significantly.”

Squash are beginning to set fruit in the Upstate. Photo from Kerrie Roach.

Weekly Field Update – 6/1/21

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Coastal

Rob Last reports, “On the whole disease pressure in most crops remains low. The exception is cucurbits where we are finding powdery mildew in cucumbers as well as downy mildew. Cucurbit bacterial wilt has been found in isolated fields. This disease is characterized by wilting of one vine or the whole plant. Once cut the stem will ooze a sticky sap from the wound. It is transmitted by the feeding activities of cucumber beetles. Strawberries are beginning to slow down while tomatoes peppers and peaches are doing very well.”

Midlands

Justin Ballew reports, “We had an unseasonably hot week last week followed by a much cooler weekend. Some places received a little rain early in the week and some places received a little on Saturday. However, the Midlands are very dry overall. Crops responded well to the heat last week. Brassicas and cucurbit crops progressed extremely quickly. Squash and zucchini are setting fruit and some are being picked. Brassica and herbs are still being harvested. Tomatoes are setting fruit, but we still have a little time before picking on a large scale.”

Squash has grown rapidly in the last week in the Midlands. Photo from Justin Ballew
A bumble bee pollinating a squash blossom. Photo from Justin Ballew.

Sarah Scott reports, “Peaches are still going strong in the Ridge. Some varieties are showing more cold damage than anticipated, but there is still a good crop out there. It seems that the very early varieties and then some of the very late varieties are the ones with the most damage. Some bacterial spot is showing up but not near as bad as last season, mainly due to dry conditions. We’ve had some really hot days but this past week we finally got some relief from the temperatures and some cloudy days. Hopefully rain is in the future as growers are irrigating heavily now. Some second croppings of Camarosa strawberries are still being harvested this week. Squash, zucchini, and cucumbers are producing well. Insect pressure is starting to occur more heavily, but disease, for the most part, is still at bay.”

Pee Dee

Bruce McLean reports, “Blueberry harvest, after getting a late start, is starting to provide good quantities. Strawberry harvest is winding down for most. Last week’s heat caused much of the strawberries to become soft and unmarketable. Some varieties are still holding up though, with limited harvest. Some early blackberries are being harvested in good volume, with very good quality. Peach harvest is light and fruit is a bit small. Tomato harvest should begin late this week/early next week. Tomatoes have been experiencing some environmental stress (heat, low humidity, high UV), causing some leaf curl. This should subside with the increased moisture and lower temperatures. Squash are starting to be harvested. Cucumbers harvest isn’t far away. Peas and beans have been affected by thrips, but are growing out of that damage. Sweet corn harvest is getting near. Vegetable planting is starting to resume with the recent moisture and reduced temps.”

Although small and difficult to see, thrips (larva pictured above) can be a limiting factor for yield in muscadines. Thrips feed upon the blooms of the crop, damaging the flowers and early developing fruits. Checking for their presence during bloom is critical for their control. Placing a sheet of white paper underneath the clusters of blooms and forcefully bumping the wire or cordon with your fist should dislodge the insect, allowing it to drop onto the paper for detection. The size of the insect is small – about 0.5 – 1.0 mm in length.

Tony Melton reports, “Peppers and tomatoes are setting fruit. Harvesting pickles consistently. Applying downy mildew and pickleworm materials regularly. Finishing up first cut of collards for processing. Started 2nd cut of processing turnips. Harvesting processing cabbage. Snap beans and butter beans are flowering. Setting sweet potatoes as fast as slips become available.”

Weekly Field Update – 5/24/21

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Coastal

Rob Last reports, “As we mentioned last week, cucurbit downy mildew has been confirmed in cucumber crops locally. All cucurbit growers should be applying downy-mildew specific fungicides such as Ranman tank mixed with either chlorothalonil or mancozeb. Other pests and disease levels in cucurbits remain low. Tomatoes and peppers are developing well with good fruit development and low pest and disease pressure. A little bacterial spot is beginning to show in untreated crops. Applications of mancozeb or copper can help to hold the disease. Note applications are unlikely to “cure” bacterial disease. Fruit crops continue to progress with good quality and low disease. Strawberries are showing a little botrytis and anthracnose, but this is at a low level. Peaches are coming to market along with blueberries and blackberries.

Midlands

Justin Ballew reports, “Dry weather has returned to the midlands. Strawberries have slowed down and while we’re still picking a few, we are seeing very few blooms. The heat we’re expecting this week is likely to cease bloom production. The heat could be a problem for tomato and cucurbit pollination as well, as we may see some blooms die. Brassicas have been growing well. There has been an increase in diamondback moth activity over the last week. If you start seeing large DBM populations on your farms, contact your local agent about doing a bioassay to test for insecticide resistance. This is a great way to figure out which materials may work best on your farm. We don’t charge anything for this service. Don’t forget downy mildew was found this past week in cucumber in multiple places in the coastal plain, so it’s time to start preventative fungicide sprays in cukes if you haven’t already.”

An adult diamondback moth has just finished pupating and has not yet dispersed. Remember, insecticide applications should target the larval form rather than the moths. Photo from Justin Ballew

Sarah Scott reports, “We are in full swing with early variety peach harvest. Some peaches are developing a little smaller in size partly due to previous cold weather events. Something spotted in the field has been some nutrient deficiency. Growers may have been tempted to dial down nitrogen or calcium nitrate applications on peach blocks that suffered cold damage as they thought those blocks would not produce a viable harvest, however this could lead to leaf drop and less reserves for next year’s crop. If you skipped out on some of your fertilization keep in mind yellowing, spotting and leaf drop could occur. A soil application of calcium nitrate at 30lb/acre now and another in late July can help those trees recover some foliage and build up a nutrient supply for next year’s reserve. Be careful if you want a quick result and try foliar applications, as this could burn the leaves and cause more drop that you may not be able to afford.”

Nitrogen deficiency on a mid season peach variety. Photo from Sarah Scott
Discoloration from nitrogen deficiency looks similar to copper burn but has smoother edges and more rounded spots on leaves. A nutrient analysis can be taken around July to determine accurate levels. Photo from Sarah Scott.

Pee Dee

Bruce McLean reports, “Irrigated vegetables are looking good for the most part. Seeing some stress to tomatoes with a heavy fruit load – likely from very low humidity and very high UV. Nonirrigated crops are starting to show some drought stress. Strawberries are starting to wind down. Blueberries are finally starting to be harvested, much later than usual. Blooming on muscadines appears to really stretched out due to the Easter freeze. Early flower clusters on growth from primary buds appears to be somewhat on time. But, flower clusters developing from secondary buds are really behind… possibly 3-4 weeks (easily). Soil is really starting to get dry in many areas.”

Green beans are really coming along. Photo from Bruce McLean
Now is a good time to walk the fields and pull weeds. Over-the-top herbicides are limited for most vegetable crops, and often hand weeding is the only viable option. Vigorous weeds like pigweed can quickly overtake a field. Photo from Bruce McLean.

Tony Melton reports, “The higher temperatures have started to speed-up crops. We will start to harvest pickles this week. Spraying downy mildew fungicides on cucurbits. Some farmers are starting to apply insecticide for pickleworm. They don’t want to put out insecticides this early but they see the gamble of an entire field of pickles being rejected because of 1 pickleworm as too much of a gamble. These farmers think we need a system set-up to detect pickleworm in the southern part of the state to give them a better indication of when pickleworm arrives. Harvesting greens, cabbage, and broccoli as quickly as possible. Started planting sweetpotatoes. Many farmers getting deer depredation permits for peas, beans, and sweetpotatoes. Also, many farmers are applying acephate and dimethoate to control thrips with the added benefits of repelling deer. Peppers and tomatoes are begin to load with fruit. Many farmers still harvesting strawberries.”

Upstate

Kerrie Roach reports, “Things in the ‘Golden Corner’ are looking up for vegetable producers, despite the dismal projection for tree fruit crops because of the cold events in April. For market growers, cool season crops are at their absolute last with 90+ degree temps forecasted for this week. Warm season crops are starting to really get growing, and many growers are starting to see some potential harvests this week. With higher than normal temps projected, make sure irrigation is consistent, scheduled and set for early morning to avoid leaf wetness late in the day and overnight and reduce disease incidence.”

Cucurbit Downy Mildew Found In SC

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Cucurbit downy mildew was found in SC this week in Bamberg, Barnwell, and Calhoun Counties. In each case it was found on cucumbers and for now severity seems low. This is about two weeks earlier than in the past couple years.

Downy mildew symptoms on cucumber. Lesions are often limited by the veins in the leaves.
Dark-colored downy mildew spores developing on the underside of cucumber leaves.

If not already doing so, all cucumber and cantaloupe growers in SC should begin applying protective fungicides to help prevent or manage downy mildew. Ranman tank-mixed with a protectant, such as chlorothalonil or mancozeb, or applications of Zampro are good options for protecting plants prior to symptom development. For more info, see Dr. Tony Keinath’s CDM Management publication.

Weekly Field Update – 5/17/21

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Check out the new podcast, “The SC Grower Exchange” featuring Clemson Extension fruit and vegetable agents. The podcast is moderated by Sarah Scott from Edgefield and covers a more detailed look at what is happening in the fields across the state. New episodes are recorded weekly, so listen weekly and subscribe through Spotify, Google, or Apple.

Coastal

Zack Snipes reports, “Everything is progressing nicely in the Lowcountry.  We got some much needed rain last week.  Temperatures have been cool so things are somewhat slow from a developmental standpoint.  All the crops look great especially the tomato crop.  We have a really nice fruit set and very little disease.  I am expecting to see bacterial spot to show up sometime soon and have been getting a few calls about bacterial wilt taking down plants. I’ve also gotten a few calls about blossom end rot. That is typical on the first fruit set and will usually correct itself provided there is ample calcium in the soil AND the soil moisture is consistent.  In our sandy soils the main cause of blossom end rot is allowing the soil to dry out during the fruiting stage. Folks might want to consider multiple 30 minute to 1 hour irrigation cycles on tomatoes per day.”

A beautiful field of tomatoes on one of the Sea Islands. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “We got right at an inch of rain at my house this past Wednesday. While the rain was much needed, the moisture and cool temperatures has allowed plant diseases to get a foothold in numerous crops. Over the last week, I’ve seen bacterial blight in mustard, downy mildew in collards, Septoria leaf spot in Italian parsley, and of course botrytis and a little bit of anthracnose fruit rot in strawberries. Growers have been sanitizing, applying fungicides, and/or terminating old crops to manage disease. When selecting fungicides, be sure to rotate MOA groups (referred to as “FRAC Codes” in the SE Vegetable Crop Handbook) to avoid developing fungicide resistance in your fields.”

Bacterial blight showed up in mustard following the recent heavy rain. Photo from Justin Ballew.

Pee Dee

Tony Melton reports, “A major pickle company found cucurbit downy mildew on pickles in Calhoun County. I have seen 100 acres of pickles damaged by hail and another 100 acres damaged by Reflex carry over. Next year, please make sure you are planting the right variety of strawberry for the intended market. When markets get full like this year, buyers are picky of the variety they will buy and many acres were not harvested to their full potential. Remember to control thrips on small peas, cucumbers, and beans. Also, control thrips in the flowers of tomatoes and beans. 

Fusarium Wilt in Watermelon

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From Clemson Plant Pathologist Tony Keinath.

Fusarium wilt is showing up in watermelon fields and in research plots at Coastal REC in Charleston. The most telltale symptoms are wilting of a few leaves at the crown of the plant, wilting of one vine on a plant, or wilting without yellowing of a small plant.

One vine of this watermelon plant has wilted. This is a telltale sign of fusarium wilt.

A good field diagnostic trick is to cut a wilted vine close to the crown, split it open lengthwise, and look for reddish brown spots on the crosswise cut or streaks in the lengthwise cut.

Cross section of a watermelon stem showing the discolored, reddish brown spots.

The Fusarium fungus is most active when the soil temperature is below 81 degrees F. Although daytime temperatures were warm in April, the nights were still cool enough to allow infections. At this point, there is nothing that can be done to mange Fusarium wilt. All successful management practices must be done before transplanting. See: Keinath AP. Integrated Management for Fusarium Wilt of Watermelon. Land-Grant Press by Clemson Extension. 2019; LGP 1022.

Field Update – 5/10/21

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Statewide

Dr. Matt Cutulle reports, “I have received calls regarding injury from Curbit in direct seeded cucumbers this year. This can be partly attributed to the colder spring we had this year and potentially seeding to shallow. Seeds germinating in that herbicide layer will have increased stunting in colder soil temperatures.”

Coastal

Rob Last reports, “Following some hail events last week, we find some shredded leaves in cucurbits and some small fruit crops. Strawberries continue to develop well, with isolated incidences of gray mold being seen. Sanitation is one of the critical methods for managing gray mold along with fungicide applications. Thrips are also beginning to be observed. Blueberries in the area are being harvested with good quality fruit. Keep a close eye on scouting for insects. Spider mites are still active in many crops. Cucumber beetles continue to increase as they are migrating from overwintering sites. Many populations are at or very close to the threshold of five adult beetles per plant.”

Zack Snipes reports, “The word in the field right now is…boring. We have had mild temperatures and not much rain so there isn’t a whole lot of disease in the fields right now. I saw the first tomato plant casualties to Bacterial wilt earlier this week. There isn’t anything you can do if you see this disease at this point. Take notes on what varieties and where you see the wilting to help with the issue next year. We have a good fruit set on the tomato crop.  We are seeing heavy volumes of squash and zucchini being picked right now. Melons are blooming in some places and in more coastal areas are sizing up.”

Bacterial wilt causes sudden wilt of tomato plants. Typically it will get a few plants within the same row. Photo from Zack Snipes.
Highbush blueberry variety trial taste test. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “Last week was a tough week for strawberries. We had a couple heavy rain events, one of which brought hail with it. Several crops suffered torn leaves from the hail including strawberries, brassicas, and cucurbits. We had a lot of water damaged berries which have kept growers busy sanitizing. We are seeing higher amounts of disease since the rain including botrytis and a little bit of anthracnose fruit rot. Cyclamen mites were found in strawberries this past week. Infested plants from nurseries are a major source for cyclamen mites. The symptoms are very similar to thrips damage, so if you’re seeing crinkled, dark-colored leaves or bronzing and cracking on the fruit, reach out to your local Extension agent for help distinguishing the cause before making treatments. Also, I’m not seeing a whole lot of blooms on the plants, so we may only have a couple weeks of picking left. Keep that in mind if planning miticide or insecticide applications and plan accordingly.”

Monday afternoon hail left holes and tattered leaves in several crops across a fairly wide swath in Lexington County. Photo from Justin Ballew
Crinkled, dark colored leaves from cyclamen mites. Thrips cause similar symptoms, so be sure to determine what caused the damage before treating. Photo from Justin Ballew
Cyclamen mites on a developing strawberry (45x magnification). The arrow on the right is pointing to a juvenile mite. The arrow on the left is pointing to an egg. Photo from Justin Ballew

Sarah Scott reports, “Peach harvest has slowly started with the earliest of varieties. With the drier weather we have not seen a lot of bacterial spot however we will be on the lookout in the coming days with the forecast showing some moisture coming our way. Cover sprays continue for later varieties and we expect active scale crawlers in the next week or so.”

Pee Dee

Bruce McLean reports, “Much of the northern portion of the Pee Dee received beneficial rains over the last week or so, although it did come by the way of severe storms. Damage to fruit and vegetable crops was (for the most part) minimal, with more significant damage (damaged plastic, broken tomato plants, wind damaged leaves on cucumbers and squash) localized. Vegetable planting has resumed. Thrips activity has been seen on cucurbits and peas. Disease on strawberries (primarily botrytis) has been really heavy, since we have received recent rains. Growers need to step up on old, damaged and disease fruit removal and their fungicide sprays to try to get it back under control. Blueberries are coming along… slowly. First harvest looks to be a bit behind normal timing. Muscadines did take a bit of a hit during the Easter freeze. A lot of primary buds were damaged (on Carlos and Noble muscadines) and were replaced by secondary buds. How it will affect the harvest…we’ll see.”

Lost of primary buds during the Easter freeze event forced the secondary buds to break. Photo from Bruce McLean.

Tony Melton reports, “Seeing 2,4-D damage on tomatoes including a high tunnel plants near harvest, a high tunnel with transplants, and a field with plants setting fruit. Also seeing Roundup damage in a field of tomatoes and a greenhouse with thousands of many types of transplants (sprayed under beds).  We’ve seen hail damage on a strawberry field, and plastic destroyed on a high tunnel. Curbit damage on 50 acres of pickles. Planting too shallow and too much irrigation. Starting to harvest fresh market cabbage and processing collards. Pickle plants starting to run, flower, and get sprayed for belly rot. Spraying peas, beans, and cucumbers for thrips.”

Upstate

Kerrie Roach reports, “Things are starting to pick up speed in the Upstate. With the potential of a late frost finally past, growers have been busy planting warm season vegetable crops in the ground. Strawberries are still doing well, with heavy rains interrupting harvest only a few times early last week. This week’s weather is projected to be unseasonably cool, but not cold with potential rain for a couple days. Insect issues should continue to stay low, but growers should be monitoring closely for disease under these conditions.”

Weekly Field Update – 5/3/21

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Coastal

Rob Last reports, “Botrytis (gray mold) is evident in places following rainfall. Sanitation and removal of the infected berries are critical to reducing inoculum loading. Fungicide applications will also be required to prevent spore germination and further spread of the disease. Where spider mite treatments have been applied, they have effectively reduced the populations but will still require scouting and monitoring.  Yields achieved are very good. Cucurbit crops continue to develop well with a low incidence of chill injury from the cooler temperatures observed on April 21/22. Crops are running well, with some flowering being observed. Cucumber beetles are being monitored, and a few aphids are present in places. Cucumber beetles observed are currently below the threshold of 5 beetles per plant. Squash bugs are also being found on some sites. Careful monitoring will be required because numbers can increase rapidly. Crops are free from disease; however, protectant fungicides are still a critical input. Blueberries are swelling well and beginning to blush.  Blackberries are flowering with excellent fruit set and bud formation. Spider mites have been evident in these crops too; however miticide applications are proving very effective.

Squash bugs are showing up in the coastal region. Photo from Rob Last.

Zack Snipes reports, “We had another nice week of weather in the Lowcountry. We are starting to dry out again so some rain would be nice. All of our crops look really great right now with no huge issues. The biggest issue I see right now is spider mites on all crops which makes sense with the warm dry weather. I’ve gotten a few calls about some strawberry plants putting out runners. We need to get in the fields and pinch those off while we are cleaning up dead berries, blossoms, and tissue. I have been in several vegetable fields lately and seen some inconsistencies in plant growth and vigor. Upon further inspection of some tomato and squash crops, I found galling on the roots which is an indicator of root-knot nematodes. If this is the case on your farm, pull up a few plants and look at the roots. We need to keep good notes on where these areas or fields are and practice good crop rotation for next season or use resistant cultivars. There are some cover crops that help with suppression as well. If you want to pull a soil sample to check for nematodes, give your local agent a call. We are doing a statewide survey looking for the guava root-knot nematode and can assist with sampling. In case you missed the “Update from the Tomato Fields” talk last Wednesday, here is the link.

Smaller squash plants in a large field made me question root-knot nematode damage.  Upon inspection of the roots, I found galling which is an indicator of nematode pressure. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “The weather last week was mild and it is very dry again. The inch of rain we got last weekend didn’t go very far. Strawberries are still yielding well, though in some fields, we’re starting to see berry size decrease, like we frequently see towards the end of picking. Folks had to remove water-damaged berries from their fields following the rain this past weekend. I guess the silver lining in this dry spell is we haven’t had many water-damaged berries yet this year. We’re still seeing some mites here and there, but disease pressure remains low. I found a berry last week with an anthracnose fruit rot lesion for the first time this season. So even though disease pressure is low, we still need to keep up with fungicide programs. There is some rain in the forecast for this week, so now would be a good time to throw in one of the site specific fungicides.”

Fungicides with the best efficacy on gray mold (left) and anthracnose (right) Photo from MyIPM app.
Cabbage with some cold damage from the cold a little over a week ago. Photo from Justin Ballew

Sarah Scott reports, “Along the Ridge, crews are still finishing up thinning in peach orchards to ensure good sizing on fruit. We are well into our summer cover spray programs for the season. During pit hardening it is critical to do preventative treatment for bacterial spot. Growers should be watching for plum circulio activity as well as scale crawlers in the next week as well. Sime powdery mildew has been found on foliage. Refer the the 2021 SE Peach, Nectarine, and Plum Management Guide for specific treatment recommendations. Strawberries are performing well. Some spider mite activity as well as some botrytis in the fields, which could worsen with several days of wet weather in the forecast. Transplanting of summer crops continues, including tomatoes and peppers. Curcurbits are becoming established and harvest will begin soon. 

Peach tree after thinning. Notice all of the green fruit on the ground surrounding it. Photo from Sarah Scott.

Pee Dee

Tony Melton reports, “Tomatoes, peppers, cucumber, and sweet potato slips are really growing since it has warmed up. Getting ready to sidedress and plow cucumbers. Fresh market cabbage will be ready to harvest soon. Processing collards are almost ready to harvest- some downy mildew has been seen. Asparagus suffered from excessive rains last year. Saw some sunscald and chemical burn on strawberries, so watch what products you are applying foliar, especially fertilizers. With the small amount of rain we had last week many acres of peas have been planted; however, it is awfully dry again.”