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.
- Depending on planting date, sweet corn is between V5 to V8 growth stages and looking great. Make sure not to under-fertilize or water.
- Tomatoes are looking good, with evidence of phytotoxicity from high insecticide application rates coupled with a surfactant.
- Cucumbers are growing a little slow with the cool nights but are disease free so far. Look out for early signs of pythium.
- Strawberries are still producing well, with disease pressures hardly showing, other than a little bit of phytophthora.
- Squash and okra are coming on strong, but make sure to manage any grassy weeds in or around the plants, so as not to decrease yields.
- Currently, the biggest insect pests are aphids and spider mites, with scattered diamondback moth caterpillars.
- Following last week’s high winds, many crops display papery lesions to the leaf or the margins. The lesions are dry scars and associated with windburn. Crops will grow out of the damage. Keep monitoring soil moisture. Given last week’s wind and dry conditions, we are seeing rapid drying of the soils.
- Small fruits are developing well, with significant volumes coming to market. Keep monitoring for spider mites and rotating insecticides where required. Gray mold and anthracnose are around; again, keep monitoring and sanitizing plants allied to rotated FRAC group fungicide applications.
- Brassicas display increasing levels of diamondback moth activity and a low population of aphids.
- Squash is flowering with an early fruit set, along with zucchini. Cucumbers, cantaloupes, and watermelons are all developing well with vines running. Keep monitoring for squash bugs and cucumber beetles. Both are very active right now. Disease levels remain low. However, I would recommend making protectant fungicide applications based on either chlorothalonil (before fruit set) or Manzate (after fruit set).
- Solanaceous crops are established well, with early flowers and fruits beginning to set. At present, crops look very good.
- We had a new commercial blackberry field planted last week. Plants coming in were clean and full of clean roots.
- Strawberry production is still slow although improving some from previous weeks.
- In an early planted tomato field, we found white rot or Sclerotinia. It is easily distinguished by black sclerotia that are found inside the stem that look like seeds. The stem turns completely white. Cool, wet weather is believed to have brought this on. Also, a lack of rotation can build this problem up in the soil.
- Muscadine flower buds are now evident but not yet opening, as are persimmons.