Weekly Field Update
Clemson Extension agents provide updates in The South Carolina Grower this week about the status of various crops being produced throughout the state.
Statewide
Tom Bilbo – Vegetable Entomologist
- Keep an eye out for armyworms in sweet corn, especially later plantings. As the season carries on, the risk of Fall armyworm, in particular, will increase significantly. This insect feeds primarily in the corn whorl and plants are relatively tolerant of foliar feeding, but significant feeding pressure can reduce plant stand and yields. Look for live larvae in addition to feeding damage.
- Strict economic thresholds for fall armyworm in sweet corn in our region have not been worked out, but consider insecticide applications when infestations are greater than 15 or 20% of the field. One study has indicated it is most important to protect plants from fall armyworm damage during the late whorl stage (V9-R1) compared to earlier stages. Learn more about the fall armyworm here.
Midlands
Phillip Carnley
- Squash are being harvested. Yield looks great, as is quality, with little to no issues in plant health. Make sure that when spraying row middles to choose chemicals and chemical mixtures carefully, as I have seen leaf damage.
- Depending on planting date, sweet corn is starting to come in, though in some areas it is just starting to tassel.
- Cucumbers are still faring well with the cooler nights. Downy mildew is definitely a concern. Cucumber beetles have reared their ugly heads, and damage has been reported on the fruit. There has also been some paraquat speckling on leaves from row middle weed control.
- Cowpeas and butterbeans are doing great. Both of which are starting to flower. For cowpeas, this marks the start of spraying for the cowpea curculio. Butterbeans are starting to load up nicely with the cooler weather. There is plenty of deer damage to go around.
- Okra seems to be a little stunted for my area due to the cooler-than-usual night temperatures but is overall healthy.
- Leafy greens are doing well, with increased presence of imported cabbageworm and diamondback caterpillar in older plantings. Your course of action should be determined by your harvest window and whether the economic threshold is met. In newer plantings, grasshoppers have been a bigger pest issue than caterpillars.
- Bell peppers and tomatoes are moving into full production. As with all solanaceous crops, keep a close eye out for bacterial spot/speck, early blight and Southern blight. Insect pressure for these crops hasn’t been too outlandish, but hornworm has been of note.
- Snap beans are looking great right now, with potential yields looking very promising. Pest pressure has been variable with the biggest issues being stinkbugs and grasshoppers.
- Watermelons are not as far along in the Midlands or lower Pee Dee as in the coastal regions, but fruits are sizing up nicely with vines lapping the rows. Deer feeding on the shoot tips is a constant problem.
Rob Last
- Strawberries are producing well, though anthracnose and gray mold are apparent in many fields. Sanitation and regular fungicide applications are necessary to retain control. As we enter June, we must begin ordering plants for next season to ensure timely deliveries. Insect activity is also increasing, with sap beetles making the most of water-soaked and over-ripe fruit.
- Blackberries are coming to harvest with good quality and volumes. Pest and disease activity remains low.
- Cucurbit crops are developing well. Remember to keep up fungicide applications to prevent gummy stem blight, downy and powdery mildew. Cucumber beetle activity remains low. However, this year, squash bugs are very active and apparent in many fields.
- Tomatoes, peppers, and eggplant are flowering well with a good fruit set. Some bacterial spot is present in places following cool, wet weather over the last weekend. Manzate and fixed copper applications may help to hold the disease at bay. Keep monitoring for thrips. We are also entering the season for tomato hornworms.
Pee Dee
Bruce McLean
- These unseasonably mild temperatures are allowing strawberry growers to continue to pick some really good fruit. The forecast for the next couple of weeks looks favorable for a continued harvest. But after that, it looks like the long-range outlook is calling for a return to seasonable (or slightly warmer) temperatures, and summer will finally make an appearance. Usually, when we get into summertime heat, the strawberry season comes to a close.
- Blueberries are looking good. Looks like we have gotten past the cold injured fruit. Late Southern highbush blueberries are picking very well, and early Rabbiteyes are starting to come into harvest.
- Blackberries and peaches are harvesting well.
- Some vegetables are still being planted. Most are growing well.
- There still seems to be some lingering nutrient deficiencies with some tomatoes (contributed to cooler, cloudy conditions). Potatoes, tomatoes and onions are coming into harvest and are looking very good.
- Peas and butterbeans are coming along pretty well. Harvest will be here before you know it.
Upstate
Andy Rollins
- We’re finding powdery mildew on multiple Upstate farms on cucumber, cantaloupe, squash and zucchini. There are many products labeled for controlling this disease. Rather than going with a broad-spectrum, dual-action 7+11 group fungicide like Pagaent or Pristine, one grower used a more specific DMI group 3 fungicide, Procure, which was wise in her case. For others with multiple diseases, they needed a broader-spectrum material. Manzate was being used as a protectant and preventative fungicide prior to powdery showing up, but conditions for the disease must have overwhelmed its effectiveness.
- Strawberry production is continuing much later than normal. Some growers are seeing their highest yields of the year now, while others are slowing down. Some plants are producing runners, indicating stress and nearing the end of the season.
- We are picking a very few peaches in the Upstate on some farms, although, there isn’t widespread volume of any particular variety.