Paraquat (most commonly used as Gramoxone) will have a new label beginning as early as August 2019. The new label requires applicators to take a training every three years. Currently, the training is only available online. The link below is a PDF of a step-by-step tutorial made to guide someone through the online training. Paraquat Training Instructions. The training and assessment should take around 45 minutes to complete.
Also, under this new label, every applicator applying paraquat must have a pesticide applicator’s license. Applicators may no longer apply paraquat under the supervision of another certified applicator. Contact your local Clemson Extension office about opportunities to get a pesticide applicator’s license.
Zack Snipes reports, “Everyone is busy in the Low country harvesting summer crops. This should be a big week for us in the field and at local markets and roadside stands as July 4 approaches. The tomato crop is either finished or finishing up this week.”
A variety of tomatoes from the coast. Photo from Zack Snipes.
Midlands
Justin Ballew reports, “It’s getting hot here in the midlands and it’s getting dry too. Harvest is still going strong on a number of crops. We have a reduced blueberry crop because of the hot, dry weather back in May, but picking is going on now. Lots of hemp has been planted in the last two weeks and is growing well.”
Hemp going in the ground in the midlands. Photo from Justin Ballew
Sarah Scott reports, “We are picking several summer varieties of peaches along the Ridge, many varieties coming in early. Freestone peaches are beginning to ripen and become available. A second population of Brown Marmorated Stink Bugs is near its peak based on high numbers found in traps across the Ridge. Be on the lookout for egg masses, generally in groups of 28 eggs. (picture) BMSB damage from earlier populations causes distortion as fruit ripens. Damage goes beyond skin into flesh.
Brown marmorated stink bug (BMSB) eggs. Photos from Sarah Scott.
BMSB damage within the peach flesh. Photo Sarah Scott
Pee Dee Region
Bruce McLean reports, “Harvest for many vegetable crops are rolling right along. Watermelons and cantaloupes are starting to see some volume. Early season rabbiteye blueberries are starting to wrap up. Mid and late season rabbiteyes are looking good. Heat and dry weather is starting to have an impact on crops, even those with irrigation. Growers are adjusting irrigation schedules to compensate for the increased heat and the lack of rain.”
Rabbiteye blueberries looking good. Photo from Bruce McLean
Zucchini wilting in the heat. Photo from Bruce McLean
Tony Melton reports, “Downy Mildew is showing up in later planted cantaloupes, cucumbers, and squash. First planting of cantaloupes and watermelons are winding down. Processing peas are drying and will be terminated soon for harvest. Butterbeans that reset pods after heat at the beginning of June will begin harvest this week. Sweet potato planting is winding down many of the first planted are laid-by. Pepper and eggplant harvest has begun.”
Yesterday (6/27/19) Clemson’s Department of Pesticide Regulation (DPR) released a list of pesticides they are now allowing for use in hemp production. A PDF including a letter from DPR and the list of approved products can be accessed here: Approved Hemp Pesticides.Please read the letter from DPR before using any chemicals on the list. Additionally, it is recommended that growers speak with their processors to ensure using these chemicals will not result in any unacceptable residues.
Growers will now have some chemical options for treating insect and disease pests in hemp crops.
Previously, growers were only allowed 25(b) products, which the EPA deems “minimum risk products”. These are products that do not have EPA registration numbers (mostly plant extract oils).
Zack Snipes reports, “Summer crops are looking good and we are continuing with harvests. It seems like every crop is coming in right now from basil to zucchini. We have had mild temperatures and just the right amount of rain.
Freshly harvested melons in the Coastal region. Photo from Zack SnipesShishito peppers. Photo from Zack Snipes
Midlands
Justin Ballew reports, “We had a few storms last week that brought rain to most of the midlands. Everything is growing well and we are really benefiting from the timely rain and mild temperatures. Growers are harvesting collards, kale, cucumbers, squash, zucchini, herbs, tomatoes, peppers, and sweet corn.”
Bacterial soft rot on a collard stalk that was severely stressed by the hot, dry weather back in May. The inner stalk has turned to mush and has a strong odor. Photo from Justin Ballew
Sarah Scott reports, “Potatoes are being dug around Aiken. Conditions have been favorable for blackberry leaf rust. Plants that are affected will show small orange colored spots, or pustules on the undersides of leaves and on shoots. Pustules can appear on undersides of leaves as well. In severe cases defoliation can occur and a lack of vigor in canes. Refer the Small Fruit Consortium website for information on control and management.”
Leaf rust pustules on the upper side of a blackberry leaf. Photo from Sarah Scott Freshly dug potatoes. Photo from Sarah Scott
Pee Dee Region
Tony Melton reports, “Tomatoes are ripening. Sweet potatoes are mostly planted and lay-by has begun. Some peas are ready for harvest and the last of the collards are being harvested.”
Upstate
Andy Rollins reports, “Orange isn’t a good color to be seeing in your blackberry plants! Be on the look-out for leaf rust in Blackberry and get it properly identified. Over the last 2 weeks I have found this on 3 farms in the upstate and one in the midlands with another agent. This light orange colored leaf rust isn’t as destructive as the orange rust that can be found in the early spring on the ‘Navaho’ variety especially but it does deserve your attention. Spores can be found on the top and bottom of leaves so look closely sometimes it’s hard to see. There is a another leaf rust that has yellow colored spores. If you are still picking fruit, Rally or a generic product containing the same active ingredient ‘myclobutanil’ can be used but as always read and follow the label. Tilt (propiconazole) is labeled also but has a 30 day PHI. So, I would use Rally then follow with Tilt when I was finished picking. Hopefully this will help keep your blackberry patches clean. There maybe other options for organic growers also but I am not sure how effective they would be. NARBA (North American Raspberry and Blackberry Association) has a good article on this here https://www.raspberryblackberry.com/is-it-blackberry-leaf-rust-or-orange-rust/ .
Leaf rust pustules on underside of blackberry leaf. Photo from Andy Rollins
Zack Snipes reports, “We received a good amount of rain last week. Some farms got just the right amount while others received 15 inches or more. I am seeing disease now that the rain has passed in all crops, especially the tomato and cucurbit crops. Keep on top of your spray programs to finish the season out. I am also seeing some cracking in heirloom, cherry, and grape tomatoes because of the rain. Stink bugs are increasing in number and tomato growers should scout their crops for them and make adjustments to insecticide programs. On Friday I visited a farm that had buckwheat strips beside the cash crop. They had, by far, the least amount of insect pressure on their cash crops as a result of providing a beneficial insect refuge.
Stink bugs nymphs on a tomato. Photo from Zack SnipesThis buckwheat strip planted in the row middle provides refuge for beneficial insects. Photo from Zack Snipes.
Midlands
Justin Ballew reports, “The first half of the week was rainy, but by the end of the week, irrigation systems were running again in places. The temperatures have been pretty mild for mid June. Vegetables are growing fast since the rain and we’re picking sweet corn, green onions, tomatoes, peppers, squash, cucumbers, and zucchini now. We’re continuing to scout for downy mildew as it’s been found in several places on the coast now. It’s only a matter of time before it shows up here, so stay on top of spray programs. Hemp is also going in the ground.
Squash is growing fast. Photo from Justin BallewHemp transplants ready to go to the field. Photo from Justin Ballew
Sarah Scott reports, “After a long period of dry weather, the recent rains have stirred up some cases of anthracnose in peaches and plums. Orchard floor and perimeter management of leguminous hosts and wild Prunus species can help prevent spread of this disease. Refer to the Southeastern Peach, Nectarine, and Plum Pest Management and Culture Guide for chemical recommendations to use pre-harvest. Peaches harvested in the Ridge are starting to get some size on them and are looking good.
Anthracnose on a peach. Photo from Sarah ScottPeaches harvested on the Ridge are looking good. Photo from Sarah Scott.
Pee Dee Region
Tony Melton reports, “Only 1 farmer had butter beans to harvest. They were planted on March 23 and sneaked-by those last frosts. After these the next harvests will be in July because of the heat causing flower drop and reset during the cool week of June 10. It is drying out quickly and we will need another rain this week to keep crops going. Collards are really doing well since the cool spell gave them relief from the heat. Southern peas are flowering and need to be sprayed for cowpea cucurlio. Snapbeans took a real hit from the heat and there will be poor yields except for later planted ones the flowered during the cool spell.
Dr. Tony Keinath reported downy mildew being found on cucumbers in Bamberg County this past week. He cautioned all cucumber, cantaloupe, and watermelon growers to begin preventative sprays, if they are not already doing so. Refer back to this post for more info.
Downy mildew on cucumber leaves.
Coastal Region
Zack Snipes reports, “We finally got some much needed rain in the Lowcountry. I expect to see some disease to show up this week. Growers should be scouting all crops and spraying when needed. Downy mildew was found on cucurbits this week so be aware that you may see it in your fields as well. We had a great field day this week at the Coastal Research and Education Center.”
Clemson Plant Pathologist Tony Keinath discussing watermelon diseases at the Coastal REC Field Day. 6/5/19. Photo from Zack Snipes.
Midlands
Justin Ballew reports, “We had thunderstorms come through late in the week and it’s rained every day since. We needed it badly. Sweet corn and tomato picking has begun and they are looking good. We’re seeing a few stink bugs in sweet corn, but nothing severe. Powdery mildew is showing up on some cucurbits now that moisture has returned. Downy mildew could show up at any time here, so keep an eye out for that and stay on a good preventative spray schedule.
Sweetcorn ready for harvest. Photo from Justin BallewThese tomatoes will be harvested soon. Photo from Justin Ballew
Sarah Scott reports, “Rain fall amounts range from 1 inch to over 5 throughout Aiken,Saluda and Edgefield Counties which will give irrigation systems a much needed break. Flea beetles are showing up on peppers.”
– Adult flea beetle and damage to pepper plant. Photos from Sarah Scott
Pee DeeRegion
Tony Melton reports, “Pythium has been awful with all the heat. Bad on snapbeans, cucumbers, etc. Southern stem blight has been awful on tomatoes and peppers with the heat. Black rot has taken over some kale, cabbage, collard fields. Sensation strawberry has had very poor yields this spring but is still bearing in the heat. Pickleworm is hear and is worse in yellow squash, then cucumbers, and then zucchini. The heat caused the flowers to fall on the early planted butterbeans causing all the early plantings to come together with the later planting then with the rain and cooler temperatures all plantings are setting now. It appears we may have butterbeans but all plantings will come in at the same time causing problems with marketing.”
From Clemson Entomology Postdoctoral Fellow Dr. Monica Farfan
Predatory mites, such as this Proprioseiopsis mexicanus,
the most commonly collected predatory mite in watermelon fields in South
Carolina, are first line of defense in the case of an outbreak of pests, such
as spider mites and thrips (shown here). Since these mites supplement their diets
with pollen resources, growers can encourage predatory mites through having a
high diversity of vegetable crops and allowing for contact between the
watermelon plants and other flowering crops or ornamentals, such as Crimson
clover and Sweet Alyssum, and weedy row middles.
This video was taken in a culture of Proprioseiopsis mexicanus. It is awesome because it is the first evidence we have of this species being a particularly vicious predator of thrips.
The first SC report of cucurbit downy mildew this year came on June 6 from a crop consultant, who found it on cucumbers in Bamberg County. Growers should spray all cucumber and cantaloupe crops to prevent or manage downy mildew. The cheapest downy mildew fungicide is Ranman. It can be tank-mixed with chlorothalonil, mancozeb, or tebuconazole to add protection against fungal leaf spots, like gummy stem blight and anthracnose, that will start to spread with the rain. Another option is Orondis Opti, a pre-mix of Orondis and Bravo (chlorothalonil). Watermelon growers should be spraying with protectants, as downy mildew has been spotted on watermelon in south Georgia.
Downy mildew lesions on cucumber leaf. Note how they are delineated by the veins in the leaf. Photo from Dr. Tony Keinath.
For more info on downy mildew management in cucurbit crops, refer to this fact sheet.
Dr. Tony Keinath reports,”Powdery mildew was found on watermelon at the Coastal REC on May 30. Typical symptoms of powdery mildew on watermelon are distinct yellow spots, although the spots may be indistinct yellow blotches rather than round spots. The symptoms seen this week included more browning than is typical for the size of the spots, perhaps due to unusually hot weather. To manage powdery mildew on watermelon and other cucurbits, click here. Powdery mildew-resistant cultivars of cucumber and cantaloupe are holding up well, but squashes with partial resistance to powdery mildew should be sprayed.”
Yellow spots include more browning than usual for powdery mildew. The hot weather probably contributed to this. Photo from Dr. Tony Keinath.
Coastal Region
Zack Snipes reports, “Another week without rain for most of the Lowcountry. The irrigated crops that have gotten enough water and look great including tomato, watermelon, cantaloupe, cucumbers, and squash. We are at the beginning of tomato, melon, rabbiteye blueberry, and blackberry harvest. Blueberry growers will want to look out for anthracnose fruit rot in harvested berries. There is nothing that can be done this year but we can work on spray programs for next year. The tomato crop looks great except for the usual bacterial wilt and southern blight. I heard of a few hot spots of spider mites last week so scout regularly especially during this hot and dry period.”
Cantaloupe looking good in the Coastal region. Photo from Zack Snipes.
Anthracnose in blueberries. The photo on the right shows berries that were just picked. The berries on the left were picked 3 days prior to the photo being taken and stored at room temperature. You can see the orange spore masses on some of the berries. Photos from Zack Snipes.
Midlands
Justin Ballew reports,”Last week was another hot, dry week. It’s been 23 days now since we’ve had rain that amounted to anything more than a brief sprinkle. Irrigation systems are not getting much rest. Squash and zucchini yields have suffered some, most likely because bee activity decreases when it is extremely hot and dry. We have some blueberries that are suffering because the drip system is not able to keep up with the water demand. Other irrigated crops like sweet corn, tomatoes, peppers, and eggplant are looking fine. We need rain pretty badly, though.
Collards just outside of the reach of the end gun are wilting and the bottom leaves are drying out. Photo from Justin BallewBlueberries are showing signs of drought stress in the Midlands. Photo from Justin Ballew
Sarah Scott reports, “Things are busy and man has it been HOT! I’ve been speaking with Brett Blauuw, entomologist from UGA, about what to expect when the temps dip back down to “normal” as far as the pest outlook is concerned and here are some notes from our conversation:
Scale insects tend to become inactive at temperatures greater than 90, but they will continue to develop at night when the temperatures dip back down. The activity should decrease compared to a ’normal’ spring where it’s in the 80s. We still have a couple of weeks before we see another peak abundance of scale crawlers.
Stink bugs don’t mind the heat much. The adults that emerged from overwintering are dying right now, so the numbers are declining but, they have laid eggs and the nymphs will be developing. In a couple of weeks we should expect another large number of BMSB adults.
Plum curculio is also more abundant and active this year. Still catching adults down in Fort Valley, so that is another concern.
Thrips, unfortunately love hot, dry climates, so right now is the perfect weather for them. For organic producers, Entrust is an affective product.”
Squash bugs showing up on cucurbits in the Midlands. Photo from Sarah Scott.
Dr. Tony Keinath reports, “Downy mildew has moved into south Georgia on cucumber and watermelon. Growers should have downy mildew fungicides on hand and be ready to spray cucumber, cantaloupe, and watermelon when rain starts in the lower half of the state. A preventative spray of mancozeb or chlorothalonil would be a good idea in the meantime. You can keep track of the spread of downy mildew here.
Despite the dry weather, anthracnose was found on watermelon in the Bamberg/Barnwell County area last week. All watermelons in the state should be sprayed with mancozeb as a preventative.”
Anthracnose lesions on watermelon leaf. Photo from Dr. Tony Keinath
Coastal Region
Zack Snipes reports, “It has been unusually hot for the month of May. The current heat wave coupled with the lack of rain is really starting to have an impact on crops, even irrigated crops. The tomato and melon crops look good but are starting to feel the intense heat and lack of rain. I have seen very little disease and insect pressure on all crops.
Irrigated watermelons are looking great on the Coast. Photo from Zack Snipes.Irrigated peppers wilting in the heat of the day. Photo from Zack Snipes
Midlands
Justin Ballew reports, “This past week was hot and dry. It felt more like July than May. It’s been over two weeks now since we’ve had any rain and irrigation systems are running a lot. In larger fields with overhead irrigation, we are seeing some wilting where the pivots aren’t getting around fast enough. Drip irrigated crops are looking good. Silks are starting to brown on the earliest planted sweet corn. Blackberry picking will begin soon and muscadines have begun blooming.
Collards wilting in between watering. Photo from Justin BallewSilks are turning brown on earliest planted sweet corn. Photo from Justin Ballew
