Weekly Field Update – 6/7/21

Posted on June 7, 2021 by Justin Ballew

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.”

Weekly Field Update – 9/21/20

Posted on September 21, 2020 by Justin Ballew

Coastal

Zack Snipes reports, “Cooler temperatures have finally arrived in the Lowcountry! We had a good bit of rain in certain areas last week and some fields are soggy. I saw lots and lots of silverleaf disorder in squash this past week. Silverleaf disorder is caused by whiteflies. The nymphs of the whitefly feed on the newly developing tissue which causes the upper epidermis of the leaf to separate thus giving the plant a silver appearance. I am still seeing heavy whitefly pressure in most crops throughout the Lowcountry so keep up with spray programs and remember to ROTATE chemistries. For more information on the whitefly, click here.

Silverleaf of squash is a symptom of whitefly feeding. Photo from Zack Snipes.

Whitefly feeding damage on collards. Photo from Justin Ballew.

Midlands

Justin Ballew reports, “These cooler temperatures that have arrived following the rain feel great, but they are going to slow crop development some. Folks are already picking fall brassicas, though some may be a little small. Just trying to keep up with demand. There are plenty of caterpillars out there. I’m seeing diamondback moths (of course) as well as cabbage loopers and a few corn earworms. Be sure to rotate your insecticides when spraying for caterpillars. Folks are continuing to prep fields for the rapidly approaching strawberry season.”

Cabbage loopers are showing up. Loopers frequently rear up like a cobra when disturbed. Photo from Justin Ballew

Sarah Scott reports, “Heavy rains, in some areas totaling near 6 inches, fell around Aiken and Edgefield Counties last week. Rain was definitely welcome, however, the downpours led to some erosion issues as well as waterlogged soils in low spots. Brassica crops are benefitting from the cooler temperatures. Peach season has ended and post-season cleanup has begun. Plastic has been laid for fall plantings of strawberries.”

Eggplant is looking good. Photo from Sarah Scott.

Pee Dee

Tony Melton reports, “Rain, rain, rain. It came quickly, so most drained off quickly, if drainage was adequate. Need to dig sweet potatoes as quickly as possible to keep down the amount of rot. Greens, pickles, and peas are struggling to survive the rain – some are drowned. Ponds are back in the fields. Some strawberry plastic is already down but the rest of the folks are just beginning this week. Transplants are scarce and most likely will be late getting here this year.

Upstate

Kerrie Roach reports, “There has been a significant rise in wine grape production interest over the last month or two in the Upstate. Each week seems to bring another caller asking for recommendations. While climates here are relatively good for grape production overall, high humidity and heat make disease control difficult. Pierce’s Disease is one of the deadliest to deal with; prevention requires intense insect vector control and control means the complete removal of the affected plant. Recent studies have brought new cultivars to the forefront which are helping southern growers become more successful in this niche industry.

‘Traminette’ with leaf scorch symptom of Pierce’s Disease. Photo from Kerrie Roach.

‘Traminette’ with a dead leaf petiole still attached to the vine. Another symptom of Pierce’s Disease. Photo from Kerrie Roach.

‘Traminette” with Pierce’s disease showing islands of green tissue surrounded by brown. This specific grower has already disposed of the affected vines, and will be replacing with newer more resistant cultivars. Photo from Kerrie Roach.

Field Update – 5/20/19

Posted on May 20, 2019 by Justin Ballew

Statewide: Dr. Guido Schnabel reports, “Green fruit rot is starting to show up in commercial peach orchards. This disease is caused by the fungus Monilinia fructicola. In spring we had an extended period of bloom with lots of rain. That led to blossom blight caused by the same fungal pathogen. Growers must take this disease very seriously as it can cause significant preharvest and postharvest fruit rot. Many take advantage of our lab service to determine potential weaknesses in fungicide spray programs. For more information contact your local county agent or Dr. Schnabel directly at schnabe@clemson.edu.”

Green fruit(*Monolinia fructicola*) rot on a peach. Photo from Dr. Guido Schnabel.

Coast: Zack Snipes reports, “We have had nice warm weather that is helping the development of irrigated crops. We are starting to get dry and could use some rain for dry land crops and to settle dust. We are in the middle of squash and cucumber harvest. We are starting to see powdery mildew show up on cucurbit crops. The tomato crop looks promising this year despite the usual bacterial wilt common in fields. To test for bacterial wilt, select a wilting plant, cut it through the stem, and put into a jar of water. If the pathogen responsible for bacterial wilt is present (Ralstonia solanacearum), you will get what’s known as bacterial streaming which is a milky white stream coming from the cut end of the plant.

Bacterial wilt ( *Ralstonia solanacearum*) on tomato. Photo from Zack Snipes

Powdery mildew on squash leaf. Photo from Zack Snipes.

Midlands: Justin Ballew reports, “The weather this past week was pretty mild, but dry. Thrips have become a problem in strawberries in some areas, but we are so close to the end of picking that most growers would not benefit from a treatment. Production has really decreased and some growers have already begun redirecting picking labor to other crops. Spring planted squash and peppers are starting to come into production and everything is looking pretty good. Keep an eye out for spider mites on tomatoes as it gets hot and stays dry this week.

Peppers are developing well in the midlands. Photo from Justin Ballew

Sarah Scott reports, “We have begun picking early varieties of peaches across the Ridge. Things are looking good for a nice crop this year. Green fruit rot (Monilinia fructicola), also known as brown rot, has shown up in a few spots around the Ridge. We are continuing to monitor stink bug populations in orchards. Traps have shown high numbers of insects but damage has been scattered in this area.