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.
Tom Bilbo reports, “Cyclamen mites are another pest mite of [possible] concern for South Carolina growers and you should know what to look for as I have confirmed their presence on several farms this spring, and several county agents have detected them in previous years. These mites are smaller than spider mites and require a microscope to see them, so you must look for their symptoms — stunted plants, crinkled/deformed leaves, small leaves, shrunken fruit with protruding seeds. If you see these symptoms and cannot attribute them to another cause (e.g. stunted plants from transplanting crowns too deep), contact your local county agent to assist with collecting samples and confirming their presence. My lab has ongoing research this spring to collect and confirm the occurrence of cyclamen mites in S.C. to better determine their pest status.”
Zack Snipes reports, “Things are looking pretty good down this way. Strawberries have very few blooms, so not sure what that means for the rest of the season. We have lots and lots and lots of spider mites on strawberry. If you have tomato, blackberry, melons, or cucumbers and have strawberries as well, take care of the mites now or you will be battling them on your other crops all year long. They will make their way to those crops, and you’ll be reading about spider mites from me until the first frost comes. Highbush blueberries are coming off and looking great. We will have significant yield loss from cold damage in rabbiteye blueberry varieties this year, depending on the farm location and cultivar. It seems the later-season varieties made it out okay, but the early-to-mid-season rabbiteye varieties will have few if any berries.”
Rob Last reports, “Crops in the area are developing well and moving away from the abiotic stress and damage being seen. Strawberries are loading up well with growers doing a great job of sanitation and keeping fungicides up to date, minimizing gray mold and anthracnose. Mites remain present in some fields, and vigilance is required to manage populations. Caterpillars, particularly diamond-back moths, are very active. Remember, rotation of insecticides with different modes of action groups will be crucial. Cucumber beetles are showing up in cucurbit fields. Applications made early can help to protect plants from damage until later in the season. One note of caution about pyrethroids, while controlling cucumber beetles, will cause spikes in two-spotted spider mite populations. Otherwise, fungicide applications, such as Bravo in cucurbits, will be beneficial in managing disease. Transplanted tomatoes, peppers, and eggplant are looking good. Blueberries are coming to harvest with good volume and quality, while blackberries are beginning to set fruit. Keep an eye on the weather forecast. We are forecasting cooler temperatures and rainfall. Fungicides applied preventatively before the rain will be effective.”
Phillip Carnley reports, “Orangeburg and Calhoun vegetable season is in full swing. Early butterbean and field peas are already up and putting on their true leaves. Just like most other parts of the state, we are seeing some odd leaf damage, but plants seem to be growing out of it nicely. Strawberries have been producing well. The rain held off for the first weekend in quite some time. With this drier weather, make sure to scout often and monitor populations of spider mites. If you’re seeing five or more per leaflet, it’s time to treat. With the lack of rain, we have also seen a great slowdown in the amount of fruit loss due to anthracnose and botrytis fruit rots. Even with this drier weather, I still recommend using Captan as a protectant. Neopestalotiopsis is still present and showing symptoms but has been less of an issue than expected, thanks to drier weather and a spray program with Switch, Captan and Thiram in rotation. The first planting of cucumbers is in the ground. If last year is any indication of cucumber issues, be prepared to see pythium, followed by CDM later in the season, probably in the tail-end of the first planting and into the second planting. For pythium control, mefenoxam is recommended pre-plant as either a banned application or broadcast also being incorporated. Spring greens are growing nicely, but in high tunnel production, we are seeing outbreaks of powdery mildew. Make sure that your planting densities are not too high and that you have adequate airflow to help prevent this issue.”
Andy Rollins reports, “Strawberry production quality is excellent, although volume is much lower due to fluctuating temperatures. We have had some nutrient deficiencies of boron, sulfur, magnesium and leaf nitrate nitrogen. In one location, regular rain and high humidity have brought on slug problems. Deadline Bullets (metaldehyde) or Bug-N-Sluggo (iron phosphate) would be the better control options. Alternatives with the same active ingredients listed in parenthesis would act similarly. An organic option would be diatomaceous earth. These can get into the fruit with split centers, so be careful selling these berries if slugs are present. Also, we’re finding plum curculio on peach, but only in unmanaged orchards where there was no management for at least a month. No scale crawlers have been found here yet, but possibly soon, as they were found in Georgia approximately 10 days ago.”