Weekly Field Update – 7/19/21

Statewide

Dr. Tony Keinath’s remarks on fungicide stewardship:

Growers who are applying newer fungicides that are pre-mixes of two active ingredients do not need to add another fungicide to the tank mix. Pre-mixes can easily be identified by the two FRAC Codes on the label in the top right corner. Please consider the following points:

Quadris Top contains two fungicides: a group 11 and a group 3.
  • Many newer fungicides are sold as pre-mixes to reduce the risks of fungicide resistance in fungal and water mold pathogens. Mixing two active ingredients often is a way to prevent or slow resistance development, as long as both active ingredients work against the same disease.
  • Sometimes two active ingredients are mixed to expand the range of diseases controlled. For example, Quadris Top controls both anthracnose (the Quadris part) and gummy stem blight (the “Top” part, which is Inspire).
  • Mixing more than 2 pesticides, whether they are 3 fungicides or 2 fungicides plus an insecticide, increases the risk of pesticide injury (burn). Risks may be greater if a spreader-sticker is added, or when air temperatures are above 90 F.
  • Adding another fungicide to a pre-mix fungicide increases fungicide costs, often without increasing disease control.

Growers should contact their Extension agent before adding another fungicide, even a protectant, to a pre-mix fungicide to be sure it’s really necessary.

Midlands

Justin Ballew reports, “Not much has changed in the midlands over the last week. We’ve received some scattered rain and it has been warm and humid. As a result, we are still seeing disease issues. We’re still picking tomatoes, squash, zucchini, cucumbers, sweet corn, and a few greens. We’re at an in-between stage in several fields where the spring crops have been finished and folks are preparing to plant fall crops. Some have already started fall cucurbit plantings. For anyone planting strawberries this fall, if you are still deciding which varieties to try, take a look at the NCSU’s 2020/2021 variety comparison data (pages 9 and 10).

Disease development like this anthracnose of watermelon is still being favored by the weather. Photo from Justin Ballew

Pee Dee

Bruce McLean reports, “Vegetable crops are looking pretty good across the Pee Dee. Fields that have received rain or are irrigated look very good. Fields that have missed the rain are a bit drought-stressed. Sweet corn, peas, butterbeans, tomatoes, squash, watermelons, cantaloupes, and cucumbers are all being harvested in good volume. Okra is just beginning to be harvested well. Growers are still fighting cucurbit downy mildew (CDM) on cucumbers. Fields that have been sprayed with fungicides for CDM (Orondis Opti, Gavel, Ranman, and Omega) are relatively clean and producing well. Fields that have not received those products are in severe decline. Cowpea curculio is still being a challenge. Some growers have asked about adding PBO8 (Piperonyl Butoxide) synergist to their insecticide application. Research has shown some efficacy, so it does help. But, it is not the silver bullet that everyone is looking for. There really is no alternative to having a robust spray program, spraying every three to five days starting prior to bloom.

Many varieties of blueberries have already finished up, with only mid-late and late rabbiteye blueberries going now. Blackberries have finished up, as well. Summer primocane tipping and floricane removal has begun. Be sure to apply a broad-based fungicide to all open wounds/pruning cuts to prevent disease development (I.e. cane blight, etc). Muscadines are sizing up pretty well. Grape root borer traps have been placed in vineyards, but no moths captured yet.

Upstate

Kerrie Roach reports, “Things in the Upstate were a little wet the last few days and it looks like showers will continue into the middle part of the week at least. Continue preventative measures for disease control and if/when a plant seems too far involved, remove and dispose of the entire plant to prevent further spread. Squash vine borer has been one of the continued problems in market garden production in the last 2 weeks. At this late point in the season and lifecycle, monitor plants closely and as soon as frass is seen, carefully cut the stem longitudinally and remove/kill the larval stage of the borer. You can mound soil on the cut part of the stem to help encourage new root growth. If done early enough, plants can continue to thrive despite the slice in the stem. New plantings of cucurbits set out in the last week or so should mature after the adults have finished laying eggs, but monitor closely for any wilting. Crop rotation, row covers, traps (yellow bowl of water), and pesticide applications can also be used as a part of a good IPM program. Check out the crop handbook for more specifics. 

Organic Upstate vegetable production. Photo from Kerrie Roach.

Andy Rollins reports, “We are having thrips issues on 3 crops peaches, pepper and cucumber. Thrips as seen in the picture cause surface damage to the outside make it aesthetically less appealing and marketable. On pepper they damage the leaves and can transmit viruses to the plant (on cucumber also). They are much worse in greenhouse and high-tunnel settings.  I have been recently concerned about presence of chili thrips and I am waiting on definite identification. This is a good website about this new pest. I also found a rare disease called foot rot of squash in the upstate. It was identified by Dr. Tony Keinath. Rotation is very important with all of our vegetable crops. We are picking some excellent quality peaches in the upstate. Cold damage has limited our wholesale picking.”

Thrips injury to peaches. Photo from Andy Rollins.
Fusarium foot rot of squash. Photo from Andy Rollins.

Weekly Field Update 11/30/20

Coastal

Zack Snipes reports, “After a long Thanksgiving nap, I was able to waddle out in the fields and look at some strawberries.  We have had some really good strawberry growing weather especially considering most folks got their plants out somewhat late this year.  We need some cold weather to slow them down a bit in places.  I am seeing a tiny bit of plant collapse and death in some spots within the fields.  It is very important to send these plants into our lab to get a positive identification of the pathogen.  Phytophthora crown rot and anthracnose crown rot can cause similar symptoms but are managed completely different. For information on how to submit a sample during COVID times, click here. I am also keeping my eye on a good bit of leaf spotting in some fields to make sure its not the new disease, Neopestalotiopsis. I don’t think we have it yet, but being proactive is better than being reactive.  More information on that disease can be found here.”   

A healthy and a diseased plant side-by-side.  Perhaps a positive identification of the pathogen can help with management to protect the healthy plant. Photo from Zack Snipes.
Determining the pathogen responsible for plant collapse can be tricky in the field.  Send in a plant pathology sample to our lab.  Is this anthracnose, phytophthora, or another pathogen? Photo from Zack Snipes.

Midlands

Justin Ballew reports, “The mornings were nice and cool last week and we saw light frosts in a few more areas. We’ve been getting a fair amount of rain also. This has the brassica crops looking great. Caterpillar populations are still fairly high. Don’t give up on scouting as it gets cooler this week. Diamondback moth caterpillars and adults can survive for several hours at temperatures well below freezing, so a few nights in the upper 20’s is unlikely to affect them, other than slowing down their life cycle a bit. Don’t give up on scouting for mites in strawberries either. Even though we’ve had some wet weather lately, they’re still out there.”

Lacinato kale is growing well and looking good. Cropping has already started in this field. Photo from Justin Ballew
Keep up with scouting for caterpillars as the weather gets cooler. Winters in SC don’t get cold enough to wipe out diamondback moth populations. Photo from Justin Ballew.

Pee Dee

Tony Melton reports, “We still have some sweet potatoes in the ground. Greens are growing well except for bacterial diseases. Some diamondback are hard to kill. We are trying everything.”

Upstate

Kerrie Roach reports, “With a low of 30 degrees Fahrenheit predicted tonight, and 26 degrees F predicted tomorrow night(Tuesday), growers in the Upstate should be making preparations for a hard freeze event. Wind speeds from 10-25 miles per hour have begun, and are expected to continue through Tuesday. So make sure any protective measures are held down tightly!”

Field Update – 4/6/20

At this point, only a few cities (Columbia, Charleston, and Myrtle Beach) have issued shelter-in-place orders.  The Commissioner of Agriculture, Hugh Weathers, has drafted a Notice of Essential Food and Agriculture Employee form that farms in these areas may fill out for each employee certifying them as an essential employee.  They should keep this letter with them while commuting to and from work.  Commissioner Weathers also sent this letter to the law enforcement community in regards to his notice.

Coastal

Zack Snipes reports, “A beautiful week of weather for working outside this past week.  Our spring crops look great as well as our early summer planted crops. Tomatoes look great and have really jumped.  I found some cranberry fruit worm in highbush blueberries last week that all blueberry growers will want to keep an eye out for.  Local produce sales are in great demand right now with lots of growers finding new ways to sell to new clientele.  Strawberry season is in full swing with U-pick operations having trouble keeping up with demand.  I’ve seen lots of makeshift handwashing stations at U-Pick farms, which I applaud growers for.  Had a few calls about thrips in strawberry this past week so keep an eye out for damage.  In every strawberry field that I was in this past week, I saw hot spots of spider mites.  Scout your fields, the entire field, daily and treat the hot spots before you have to treat the entire field.  It will save you money on both treatment and potential yield loss.”

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Handwashing stations at U-Picks are protecting both growers and customers. This one was set up for around $70. Photo from Zack Snipes.

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Thrips damage on strawberry will leave the berry with a bronzed look and the outside of the berry will be hard resembling a plastic coating. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “The weather was a little cooler this past week than the week before.  We also had a little rain early in the week and dew several mornings. These were perfect conditions for Botrytis and anthracnose to develop in strawberries and both showed up in a number of places.  We have a lot of blooms and green fruit out there right now, so make sure to stay on a good spray schedule and rotate MOA’s.  Spider mite pressure remains high in some places. Strawberry yields have not picked up yet and growers are easily selling everything they pick. Brassicas are growing fast in this beautiful weather. Caterpillar pressure is still up requiring widespread sprays. Keep scouting.”

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Botrytis developing on a strawberry.  Weather conditions have been perfect for Botrytis and anthracnose recently. Photo from Justin Ballew.

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Strawberry yields have not picked up yet, but we have lots of blooms and green fruit coming on. Photo from Justin Ballew.

Sarah Scott reports, “Peach trees continue to progress,  thinning of fruit is happening for some varieties now. Strawberry crop is beginning to pick up. Cooler night temperatures last week slowed ripening some. Vegetable crops continue to be planted including eggplant and peppers.”

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Broccoli plants growing well in Saluda County. Photo from Sarah Scott.

Pee Dee

Tony Melton reports, “Full speed planting processing vegetables.  Pickles, green beans, Butterbeans, peas, peppers, tomatoes are being planted.  Having trouble getting all the strawberries picked.  2nd Butterbean planting going in. 3rd sweet corn planting going in.”

Upstate

Kerrie Roach reports, “With beautiful skies and warm weather this past week, our upstate market gardeners are beginning to put things in the ground. While a little early for some, others are hedging their bets with multiple plantings over the next few weeks. Apples and peaches are continuing to progress with most apple varieties now in or near full bloom.”

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Tomato transplants for sale at a local garden supplier. Photo from Kerrie Roach.

 

Field Update – 6/3/19

Statewide

Dr. Tony Keinath reports,”Powdery mildew was found on watermelon at the Coastal REC on May 30. Typical symptoms of powdery mildew on watermelon are distinct yellow spots, although the spots may be indistinct yellow blotches rather than round spots. The symptoms seen this week included more browning than is typical for the size of the spots, perhaps due to unusually hot weather.  To manage powdery mildew on watermelon and other cucurbits, click here. Powdery mildew-resistant cultivars of cucumber and cantaloupe are holding up well, but squashes with partial resistance to powdery mildew should be sprayed.”

Yellow spots include more browning than usual for powdery mildew. The hot weather probably contributed to this. Photo from Dr. Tony Keinath.

Coastal Region

Zack Snipes reports, “Another week without rain for most of the Lowcountry.  The irrigated crops that have gotten enough water and look great including tomato, watermelon, cantaloupe, cucumbers, and squash. We are at the beginning of tomato, melon, rabbiteye blueberry, and blackberry harvest.  Blueberry growers will want to look out for anthracnose fruit rot in harvested berries.  There is nothing that can be done this year but we can work on spray programs for next year.  The tomato crop looks great except for the usual bacterial wilt and southern blight.  I heard of a few hot spots of spider mites last week so scout regularly especially during this hot and dry period.”

Cantaloupe looking good in the Coastal region. Photo from Zack Snipes.

Anthracnose in blueberries. The photo on the right shows berries that were just picked. The berries on the left were picked 3 days prior to the photo being taken and stored at room temperature. You can see the orange spore masses on some of the berries. Photos from Zack Snipes.

Midlands

Justin Ballew reports,”Last week was another hot, dry week. It’s been 23 days now since we’ve had rain that amounted to anything more than a brief sprinkle. Irrigation systems are not getting much rest. Squash and zucchini yields have suffered some, most likely because bee activity decreases when it is extremely hot and dry. We have some blueberries that are suffering because the drip system is not able to keep up with the water demand. Other irrigated crops like sweet corn, tomatoes, peppers, and eggplant are looking fine. We need rain pretty badly, though.

Collards just outside of the reach of the end gun are wilting and the bottom leaves are drying out. Photo from Justin Ballew
Blueberries are showing signs of drought stress in the Midlands. Photo from Justin Ballew

Sarah Scott reports, “Things are busy and man has it been HOT! I’ve been speaking with Brett Blauuw, entomologist from UGA,  about what to expect when the temps dip back down to “normal” as far as the pest outlook is concerned and here are some notes from our conversation:

  • Scale insects tend to become inactive at temperatures greater than 90, but they will continue to develop at night when the temperatures dip back down. The activity should decrease compared to a ’normal’ spring where it’s in the 80s. We still have a couple of weeks before we see another peak abundance of scale crawlers.
  • Stink bugs don’t mind the heat much. The adults that emerged from overwintering are dying right now, so the numbers are declining but, they have laid eggs and the nymphs will be developing. In a couple of weeks we should expect another large number of BMSB adults. 
  • Plum curculio is also more abundant and active this year. Still catching adults down in Fort Valley, so that is another concern.
  • Thrips, unfortunately love hot, dry climates, so right now is the perfect weather for them. For organic producers, Entrust is an affective product.”
Squash bugs showing up on cucurbits in the Midlands. Photo from Sarah Scott.