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 – 3/15/21

If you haven’t already filled out the Clemson Agribusiness Team’s COVID-19 Ag Impacts Survey, please take a minute to do so now. Click the graphic below or scan the QR code with your iPhone to access the survey. If you have any questions about the survey or the results, please reach out to Kevin Burkett, Kburke5@clemson.edu, 540-239-4602.

Coastal

Rob Last reports, “Strawberry crops in the area are developing well with good fruit set. I am seeing a little gray mold around, so sanitation is going to be key as well as fungicide applications. There are also a few thrips in some crops, so scouting for these pests will be very important. Peaches and blueberries are blooming with little evidence of any chill injury from last weeks overnight lows in the upper 20’s. Asparagus crops are beginning to come to market with some chill affected spears early last week. With the dry weather conditions, field work and land prep is going well with plastic being laid for melon crops.”

Zack Snipes reports, “Great week of weather in the Lowcountry which has really improved the way things are looking. Greens, lettuces, root crops, and strawberries are looking good. The strawberries are absolutely loaded up with blossoms right now and are still putting on crowns. Fall planted cover crops are finishing up and being turned under. A bit of sad news this week as Author “Ikee” Freeman passed away. Ikee was a huge supporter of Clemson Extension and the farming traditions in the Lowcountry of South Carolina. His friendship, mentorship, leadership, and sense of humor will be missed by many.”

A fall planted daikon radish cover crop is flowering which provides early season nectar, pollen, and habitat for beneficial insects and bees. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “We had another beautiful week of weather last week that really pushed plants along. Strawberries have a ton of blooms on them now. The weather has been pretty dry the last two weeks, but with a few days of rain in the forecast for this week, now would be a good time to throw one of the site specific fungicides into your fungicide rotation. Temperatures are still in the perfect range for Botrytis spore development (60-70 degrees F) and with moisture returning, we could see a lot of Botrytis in the next week or two.

Lots of blooms present now that we need to protect from Botrytis. Photo from Justin Ballew.
These are the site specific fungicides listed on the MyIPM app with the best efficacy for Botrytis control on strawberries. It would be a good idea to apply one of these ahead of the rain this week.

Sarah Scott reports, “Last week’s warm temperatures have pushed peaches into bloom. There was a significant increase in open buds from the beginning to end of the week. Early varieties are near 90% bloom. Temperatures look like they will level out in the next 7 days which is good as temperatures that are way above normal can lead to developmental damage for fruit set. Some pruning is still underway, as well as bloom sprays for blossom blight using products like Captan or chlorothalonil.”

Upstate

Andy Rollins reports, “So far peach season is off to great start. We got all of our chill hours in and are between pink and 5% blooms on all large scale varieties, with a few oddballs further along. Plum growers are even further along and many are preparing for bloom fungicide applications with primarily Bravo (Chlorothalonil). I will be repeating last years testing of new biological, Ecoswing, in bloom this week compared with Bravo. Strawberry production is progressing nicely. This week looks good as far as frost but things change quickly, so all growers will be intimately aware of every weather change at this point. I was very happy to help with a new 10 acre pecan orchard planted last week. It encouraged me because several local growers, University of Georgia specialist, a retired NRCS conservationist, and myself all worked together to help a widow in need. Her planning and execution was impeccable and diligent.”

10 acres of new pecan trees planted last week. Photo from Andy Rollins.

Weekly Field Update – 2/8/21

Don’t forget to check out the Upcoming Meetings page for all the meetings coming up over the next couple months. There are 3 coming up this week: Small Fruits this evening (2/8), Peaches on Thursday afternoon (2/11), and Brassicas Thursday evening (2/11).  We hope to see you there!

Statewide

Dr. Matt Cutulle reports, “With the cold temperatures we have been consistently having, it might be good to use Prefar or Dacthal for PRE herbicides instead of Treflan in new collard plantings to avoid injury.”

Midlands

Justin Ballew reports, “Last week was pretty cool and it looks like this week will be about the same. Things are a little slow in the fields, but folks are preparing land for spring plantings and harvesting a little mustard, collards, and herbs. Strawberry growers are still working on sanitizing. Now is also a good time to make sure drip systems are hooked up and ready to go when it’s time to start fertigating. Deer are still wearing out the plants in some fields. Temporary deer fences aren’t that expensive and they can pay for themselves by preventing the degree of damage seen in the photo below.”

This picture was taken last Thursday (2/4). After 3 and a half months in the ground, these plants should be significantly larger, but the deer are wearing them out. A fence should have been used here. Photo from Justin Ballew.
Busted feeding on strawberry leaves. Photo from Justin Ballew.

Upstate

Andy Rollins reports, “We are still in the middle of establishing new peach orchards and inspecting strawberry plantings. I met with new and experienced growers and want to point out most common mistake made. Strawberry wise, I found mites on only one farm growing chandler plugs. Some of the mites were still in diapause (hibernation) and will be orangish in color but there were plenty of active adults and eggs out as well on that farm. Expensive miticides are not effective if mites are not present. The most common mistake made in planting peaches is planting them too deep. To look at the picture below, you wouldn’t think anything was wrong, but the first main root is actually about 4 inches too deep. Please make sure when you are finished planting that the first main root is within the top inch of the soil. An easy way to tell they are too deep is if they have created a hole around the stem from wind movement. Anywhere you are growing in heavier clay soil this becomes even more important. We are still spraying oil and copper on peaches and probably will continue till bloom.

This peach tree was planted about 4 inches too deep. Photo from Andy Rollins.
If trees are planted too deep they will create a hole in the soil around them as they move in the wind. Photo from Andy Rollins.

Weekly Field Update – 9/8/20

Statewide

Dr. Matt Cutulle reports, “With all the rain we had in August the weed seed bank is starting to pop. Nutsedge pressure can be really tough in September.  For fall cole crop plantings, it is important to initiate the stale seed bed technique (allow weeds to come up and burn them down multiple times before planting). In some cole crops, such as broccoli, Dual Magnum may be used, which provides some pre-emergent suppression of yellow nutsedge (Max 60% probably). Following with an in-row cultivation several weeks after planting will strain the photosynthate reserves of nutsedge, which could be lethal to the nutsedge if we get a  cold snap in late October.”

Coastal

Zack Snipes reports, “I saw whiteflies everywhere last week.  I saw them on just about every crop in the field: squash, zucchini, tomato, peas, eggplant, okra.  We have very good options to manage whiteflies, so consult with your local agent or look up the specific products for the crop you are growing in the Southeast Crop Handbook. Be careful not to use pyrethroids for whiteflies as resistance will develop very quickly.  Longer lasting, more specific options are available that are better options.  I also saw a good many worms last week such as the melonworm in cucurbits and the beet armyworm in other crops.  If you have whiteflies and worms in a crop then the group 28 insecticides (Coragen, Verimark/Exirel, Harvanta) are excellent options to take care of both pests at the same time with good residual.”

Whitefly infestations are severe in some places on the Coast. Photo from Zack Snipes.
Whiteflies on tomato leaves. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “Last week was extremely hot and dry, though we finally got some relief from the heat over the weekend. Crops are progressing well, though we are seeing caterpillar activity increase. We’re seeing diamondback moth and cabbage loopers in brassica crops and armyworms in tomatoes. Be sure to rotate insecticide MOA’s when treating for caterpillars. I’m also seeing a few whiteflies around, but nothing severe yet. Black rot is starting to show up on some brassicas. Strawberry growers are starting to apply their preplant fertilizers in preparation for shaping the beds.”

Black rot getting started on a young collard plant. Photo from Justin Ballew

Pee Dee

Bruce McLean reports, “Muscadine harvest is starting to wind down. Harvest looked good and had very good yields. Brix averaged out at 13.5 to 14.5%, depending upon the cultivar and the vineyard. Now is a good time to evaluate successes and problems from this season and write them down while they’re fresh on your mind. Also, look at the overall amount of foliage on the vines. Is it too much? Not quite enough? Start planning how you need to adjust fertility for next year. A post-harvest potassium fertilizer application has proven to be beneficial to the crop (in on-farm settings), especially in wet years. Overall plant health, spring emergence and vigor, and next year’s yields should be well improved.”

A bin of Carlos muscadines ready to be loaded and delivered for processing. Photo from Bruce McLean.

Tony Melton reports, “Getting dry and need some rain. Busy planting turnips, mustard, and collards. Harvesting processing sweet potatoes as quickly as they can process them (problems in the plant). Picking pickles and yielding much better with dryer conditions. Also, pickling plants having trouble with getting enough labor so very few peppers harvested. Still spraying processing peas for cowpea curculio. Watch out for southern stem blight it is still raging havoc.”

Upstate

Kerrie Roach reports, “The last few peaches are making their way to stands and markets. Things are continuing to look good as the Apple crop progresses in the upstate. Growers to the north in Hendersonville, NC suffered multiple hail events causing a large amount of damage, but SC growers seem to have escaped the worst of it. Vegetable production has slowed significantly with many small growers finishing for the season over the next few weeks. Muscadines are coming into their prime, and look to be highly productive this year.”

Golden Delicious apples that still have a little ways to ripen for optimum sugar content, but work great for baking. Notice the green tint. As they continue to ripen, a yellow cast & even a blush may appear. Photo from Kerrie Roach.

Andy Rollins reports, “These plants were found positive for Phytopthora root rot last week in an early upstate strawberry planting.  Inspection of plants when they arrive can accurately diagnose this problem.  Brown to blackish colored roots are characteristic.  A small portion of this material is taken from 5-10 plants then placed into a pouch that accurately identifies the presence of Phytopthora within a few min.  As in picture, 1 line tells you the test worked properly 2 lines indicates presence of the fungus.  Early treatment with Ridomil and or any of the phosphite (Rampart/Prophyt) is very helpful but must begin quickly if plants are widely infected for the best results.”

Dark colored roots are a characteristic symptom of Phytophthora root rot. Photo from Any Rollins.
An immunostrip test can be used to diagnose phytophthora. Two horizontal red lines on the strip (right side of the bag) means the sample is positive for phytophthora. Photo from Andy Rollins.

Field Update – 7/27/20

Coastal

Zack Snipes reports, “It has been a hot week in the Lowcountry. Most spring and summer crops have finished up. Ground is being prepared and planted for fall crops. I have received a few texts from growers that have yellow dots on their zucchini plants, which is downy mildew. Even in this heat downy can still be an issue. I have also had some reports of green-colored squash in fields which is an indication of a viral pathogen. The crop handbook has recommendations for cultivars that are resistant to these viruses that cause this discoloring. Fall is notoriously bad for cucurbit viruses so plan accordingly.  I have also seen some flea beetle damage on crops as of late.”

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Downy mildew looks a little different on zucchini and pumpkin than it does on cukes. Photo from Zack Snipes.

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Flea beetle feeding damage on blackberry foliage. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “It’s been hot in the midlands and we’ve gotten to the point where there isn’t much relief at night. We had some scattered rain throughout the week, but overall we’re still quite dry. Lots of land is still being prepped for fall crops. We’ve had some fall brassicas and cucurbits planted already and they’re looking good so far. Last week I got to watch a pecan grower in Lexington thin some pecan trees. Without thinning, he would have seen a massive yield this year, which would result in a significantly diminished yield next year. Pecan growers aim for nuts on just 70% of the terminal buds.”

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Fall squash seedlings just beginning to emerge. Photo from Justin Ballew

Thinning pecans with a mechanical shaker. You can see the nuts fall as the tree vibrates.

Pee Dee

Tony Melton reports, “Pickles are still being harvested and planted. We still have hundreds of thousands of bushels in contract to be planted and harvested.  Peas for processing are being rapidly harvested and replanted, some seed is short.  Sweet potatoes are starting to swell and size.  Processing peppers are being harvested but we have a shortage of labor and multi-millions of lbs. left to harvest.  Processing tomatoes will be finished harvest this coming week.  Spring planted fresh market butterbeans and peas are mostly harvested but seed is short to plant the fall crop. Still have some flooded fields and drowned crop.”

Upstate

Kerrie Roach reports, “Spotty rain across the county again last week has led to continued issues for growers without irrigation. Fall planting for vegetables is in full force. Peaches are looking good, and apples are coming along. Most growers will be putting on a fungicide cover spray this week before significant rains are forecasted.”

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Reverted apple rootstock (believed to be M7) volunteer tree with aborted fruitlet. Photo from Kerrie Roach.

Andy Rollins reports, “Bacterial speck and bacterial spot of tomato are major problems in plum tomato varieties in the upstate right now.  They were not able to control this disease even with a vigorous spray program using mancozeb + copper on several farms.  In nearby plantings of large fruit varieties, the disease is present but not a problem.  Samples have been sent to researchers at Auburn University where the have confirmed the presence of copper resistant isolates from other farms.  Call on your extension agent for assistance with identifying and controlling this problem.”

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Bacterial speck on a tomato leaf from the upstate. Photo from Andy Rollins.

Field Update – 7/13/20

Coastal

Zack Snipes reports, “Summer crops are all but about done. The afternoon thunderstorms, humidity, and heat have just about finished off the tomato and watermelon crops. Growers are getting fields ready for the fall season now. Consider putting up deer fencing now before crops are planted.

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A field of squash on Johns Island protected with a two-tiered poly fence. Photo from Zack Snipes.

Midlands

Justin Ballew reports, “We got some more rain early in the week and the sky was overcast most of the week. Downy mildew finally showed up here in cucumbers. Even though it’s been found all over the coast, it took a while to make it this far inland this year. The dry weather we had most of the month of June may have had something to do with that. Anyone growing cucurbits from now through the fall definitely needs to be applying preventative fungicides. Lots of fields are transitioning from spring crops to fall crops right now. We’re still picking sweet corn, tomatoes, peppers, eggplant, squash, zucchini, cucumbers, etc.”

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Dark-colored downy mildew spores on the underside of a cucumber leaf. Photo from Justin Ballew

Lalo Toledo reports, “Sweet potatoes are in the ground and thriving. Please be aware of any pest activity and disease activity. Weeds are becoming a problem, especially in organic operations. However, there are several options to suppress weeds. Please contact your extension agent for information on chemical and cultural practices. Hemp is having trouble taking off with so much heat and weeds are gaining ground on it. Peppers are doing great with some minor bacterial lesions.”

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Hemp field with nutgrass (organic operation). Photo from Lalo Toledo.

Pee Dee

Tony Melton reports, “Poured rain every day last week – awful.  Processing peas are ready to harvest but cannot get a dry period to burn down to harvest.  Need to get second crop processing peas planted before August if fields will ever dry out – don’t forget to control thrips early and do your best to keep deer out of fields.  Processing tomatoes & peppers are being harvested.  Pickling cucumbers are continually being harvested and replanted.  Sweet potatoes are planted, most have been laid-by, many have vines covering beds, and some are starting to size potatoes.  We may have some insect damage on roots since it is difficult to get bifenthrin applied and plowed-in.  Hopefully, the Lorsban will control insects, and since it is too wet to plow until the rain can wash the bifenthrin into the soil to keep the sun from degrading it.  Don’t forget the boron on sweet potatoes.”

Upstate

Kerrie Roach reports, “Peaches are the showstopper this week in the Upstate! Even with what appears to be late cold damage causing split pits and some varieties not to ripen, the peach crop is still booming. Apples are maturing on schedule and growers should begin harvesting early varieties over the next few weeks. With limited and spotty rain events over the last seven days, irrigation has been vital for vegetable producers…. but heat and humidity (despite the overall lack of rain) has increased the need for fungicide cover sprays, as we’ve seen various fungal activity picking up across the board.”

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Peaches are coming in and are looking great in the upstate. Photo from Kerrie Roach.