cold | The South Carolina Grower

Statewide

Dr. Matt Cutulle reports, “Love is in the air, and your crabgrass (Digitaria spp.) PRE herbicides should be on the ground if you are in the Low Country. When soil temperatures reach 55 F for 2 to 3 days, which will usually occur before March 1^st in the Low Country, March 15^th in the Midlands and March 30^th for the upstate crabgrass germination is possible and can continue throughout the spring and summer. No matter how well crabgrass has been controlled in previous years, there is still a tremendous seed bank in the soil and open spots in crop canopy will allow this fast-growing summer annual to invade. Crabgrass’ rapid emergence and extremely fast growth rate make it a problematic weed in early spring to summer. One study by NC State showed that for every week large crabgrass emergence was delayed an increase in 373 watermelon fruit was observed. This relatively small grassy weed can cause a big problem in early season cucurbit crop plantings.”

Crabgrass seedlings. Photo from Virginia Tech

Coastal

Zack Snipes reports, “A wet week is coming to the Lowcountry. Most farms are discing up land and pressing beds in preparation for the season. I saw some potatoes going in last week on a farm or two. If you have strawberries and have started spraying, then keep spraying. Protectant fungicides applied before a weather event are the best measure at preventing disease. The weather coming is perfect for gray mold and Anthracnose to develop. If you have a smartphone download the MYIPM app (make sure to use WiFi) to key you in on diseases and preventative measures for small fruits.

Land being prepped for spring vegetables. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “More rain on the horizon. Lots of collards are bolting and fall brassicas, in general, are wrapping up. Some spring brassicas have already been planted. Black rot is showing up in some fields following the storms and warm weather, so if, you’re done with a field, get rid of it! It never got cold enough Friday to kill strawberry blooms, but lots of growers had their row covers on just in case. Growers are protecting blooms from now on. This will have us picking around mid-March. Make sure to sanitize the fields as soon as it stops raining and it’s safe to pull off the row covers and start your fungicide programs and fertigation now.

Black rot showing up in collards after the recent storms. Photo from Justin Ballew.

Workers busy putting row covers on strawberries. Photo from Justin Ballew.

Pee Dee

Bruce McClean reports, “We have been on a bit of a roller coaster for the last couple of weeks… warm temps separated by brief periods of cool, windy conditions. The cool weather has not been that severe or persistent, and the warmer weather has been much more dominant. This has caused crops like blueberries and strawberries to really start to push. Heavy flowering in both crops is very evident now. With strawberries, we’re not too worried about losing early blooms… the plant will make more. But with blueberries, persistent early warm temps can ruin the upcoming season’s crop quickly. Some growers have asked about frost protecting this early. The challenge is “do you have enough water to protect until all risk of frost is gone”… likely not. The only thing worse than losing a crop because you didn’t frost protect is frost protecting all winter only to run out of water on the last night of freezing temps. Try to assess how much water supply you have and try to make decisions based on that. If you need help, please reach out to Clemson Extension for assistance.

Some chores to be doing now – finish up pruning your vineyards and orchards over the next week, or so. Look closely for dead wood in your vineyard, especially on the cordons. Now is the best time to identify it and remove it. Also, if you are planning to do some hardwood propagation on blueberries, now is the time to select one-year-old canes for cuttings. Be sure to keep them bagged (with moist peat moss or pine bark) and refrigerated until you are ready to sprig in the spring.

Unhealthy muscadine condon that needs to be pruned out. Photo from Bruce McLean

Hardwood blueberry cutting. Photo from Bruce McLean.

Tony Melton reports, “Farmers wish the rain would stop so they can get greens planted. One way to keep plants from growing too tall in the greenhouse is blowing with a leaf blower every day it will harden them off and cause them to be shorter. Time to bed sweet potatoes for slips if not to wet. If you’ve started to save/protect strawberries, blueberries, peaches, etc. (some already in full bloom) get ready for Friday night.

Remember to keep an eye on the “Upcoming Events” tab for new meeting and workshop announcements from around the state.

Statewide

Dr. Tony Keinath with more on white mold. “Growers who grow sweet alyssum (Lobularia maritima, syn. Alyssum maritimum) as a nectar source for beneficial insects should be aware that sweet alyssum is susceptible to white mold. Diseased alyssum could increase the level of the pathogen in soil if the white mold fungus forms sclerotia on diseased plants. Growers who have alyssum in or along their fields in winter or early spring should check for symptoms of white mold. Symptoms include collapse of part or all of the plant and yellowing or blackening of tissue.”

Sweet alysum is increasingly being grown in or around vegetable fields as a nectar source for beneficial insects, but is also susceptible to Sclerotinia white mold.

Coastal

Zack Snipes reports, “The cold weather (at least a few days of it) has showed up. This cold weather might slow our strawberries down which wouldn’t be a bad thing. I have seen ripe berries on some farms. The question I keep getting is should we start fertilizing to push our berries and cover them. Most farms I have been on do not have a plant that is large enough to support bearing fruit. Most farms have 3-4 crowns right now per plant and I would personally like to see that 4-5 before we really start pushing them. Keep in mind that if we begin to fertilize and cover this time of year we will be picking in about 35 days. Here are a few questions you might want to ask yourself. Do you plan on opening the last week in February? Do you plan on covering each night the temperature dips into the low 30’s? Are you ready to apply protective fungicide sprays starting now? Another question I have gotten recently is when to cover and when to not cover. The chart taken from Strawberry Plasticulture: A Grower’s Guide shows the critical temperatures for each of the bloom and fruiting stages.”

Midlands

Justin Ballew reports, “Last week was fairly mild, but it turned cold over the weekend. Lows have been in the upper 20’s the last couple of mornings. We’ve seen a lot of blooms developing on strawberries over the last two weeks and this cold is going to take them out. I’ve been getting a lot of questions about covering, but it’s still too early to start protecting blooms. Letting them die right now is the best thing to do and it won’t hurt yields. More blooms will develop when the weather begins to warm up. Just be sure to sanitize the plants well in the early spring to remove all the dead blooms that can become inoculum for Botrytis.

Lots of blooms developed over the last two weeks, but will die in the cold this week. Photo from Justin Ballew

Pee Dee

Bruce McLean reports, “The weather has returned to a more seasonal pattern… for at least a little while. Collards and cabbage are still looking very good (for the most part). Sclerotinia is being found (localized) in fields – effecting cabbage more than other brassica crops. Strawberries are looking good. Other than some early flowering (due to the recent heat), no problems are being seen in the field. Muscadines are currently being pruned, as well as blueberries and blackberries. The recent warm weather has begun to push some early bud break and flowering on some blueberries, on both highbush and rabbiteyes. Hopefully, the return of colder temps will delay any further growth until a little later into the season… because it is still a bit early for them to wake up.

Sclerotinia showing up in some brassica fields. Photo from Bruce McLean.

Collards are still looking good in the upper Pee Dee. Photo from Bruce McLean.

Tony Melton reports, “Greens including collards are damaged severely by cold. Demand for greens has dropped drastically but some small growers have covered to maintain supply. Most strawberry growers are not protecting from cold and allowing cold to kill flowers and fruit.”

Upstate

Kerrie Roach reports, “With almost 16.8 inches of rain recorded for January so far at the Oconee Airport, the Upstate is soggy to say the least. Cold temperatures have finally arrived, and pruning has commenced in full force for tree fruit growers. Apples are just about finished with most growers waiting a few more weeks to start any peach pruning. We are finally significantly adding to chilling hours.”

Before (left) and after (right) pruning of semi-dwarf variety apple.

The South Carolina Grower

Fruit and Vegetable News for Growers and Agribusinesses in South Carolina

Tag Archives: cold

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