Foggy fall mornings are nature’s warning that conditions are favorable for brassica downy mildew to get started on collard and kale.
Remember that because downy mildew affects the harvested, edible portion of the crop, control practices must be very effective to increase yields. Use the following practices to maximize control:
1. Rotate crops to new fields every year. Brassica downy mildew is believed to survive in soil.
2. Check lower, older leaves for angular yellow downy mildew spots on the top of the leaves and black lesions with white downy mildew growth on the bottom of the leaves. Even lesions 1/8-inch in diameter can produce spores.
3. Make the first fungicide spray when the first foggy morning is predicted. Fog means the leaves will stay wet all night and a good part of the morning. The lack of sunshine on foggy mornings also allows downy mildew spores to stay alive longer than on sunny mornings, when UV light will kill them in about 24 hours.
4. Potassium phosphite is a very effective, economical alternative fungicide against brassica downy mildew. It is probably “good enough” by itself during sunny periods without rain. Note that it is not labeled for certified organic production.
5. During rainy periods, rotate effective conventional fungicides, like Zampro or Presidio, with potassium phosphite. Fungicide rotation is critical for leafy brassica greens left in the field for more than 2 months when leaves are cropped repeatedly. Zampro may be applied only 3 times per crop. Presidio may be applied 3 times at the 4-ounce rate or 4 times at the 3-ounce rate.
For more info on brassica downy mildew, see Dr. Keinath and Tim Bryant’s article in the latest issue of the Clemson IPM Newsletter.
There are some reports that anthracnose may be issue in strawberries this year. In addition, we are continuing to look out for the new disease, Neopestalotiopsis. Clemson Plant Pathologist Guido Schnabel has recommended applying Zivion S (natamycin) via preplant dip to help prevent these diseases. Dr. Schnabel provided the following instructions:
Mixing Instructions. Add Zivion S while stirring to the volume of water to be applied, or to a smaller volume that is then added to more water to make the expected final volume. Continuously stir the treatment solution unless it is to be applied immediately. Application Time. Apply prior to plant as a preplant transplant root or whole plant dip treatment. Do not apply after or to harvestable commodities. Application Rate. Root or whole plant dip: mix 6-12 fl. oz. (0.04 – 0.08 lbs a.i.) of Zivion S per 10 gallons of water. Dip plants for a minimum of 2 minutes, but no more than 5 minutes. Plant treated plants after dip application.
To find Zivion contact Nelson Jameson at 800-826-8302.
Rob Last reports, “We are progressing well with preparations for strawberry planting. Some Plants are due to be delivered this week. Remember, if fumigants have been used, check to ensure the products have dissipated to prevent damage to the transplants. The same is true to make sure planting restrictions on any pre-emergence herbicides applications are observed. Always refer to the label. Finally, remember to check your plants carefully for pest and disease inoculum from the nursery. Planting any disease or pest-infected plants will lead to a more challenging. If you require any help, please reach to Extension Agents.”
Zack Snipes reports, “I thought I had moved to Seattle last week with all the rain and dreary weather. We have a good week of weather coming up and I expect that everyone will be busy in the fields transplanting greens, finishing laying plastic, and continuing the harvest of fall crops. Watermelons, squash, and winter squash are being harvested this week. Downy mildew is loving this weather and is on basil, squash, cucumbers, winter squash, and cantaloupe. I have seen many freshly transplanted fields with black rot in brassica. This disease shows up every time we plant brassica. It is essential to transplant quality transplants. If your transplant supplier is sending you diseased plants, then visit our Seed and Transplant Supplier list to find a new supplier. You might be surprised how big of a difference it makes. Carolina Farm Stewardship Association is having a webinar this week on Tuesday, October 12 at 12pm on Ginger and Tumeric production in a high tunnel. Please email email@example.com for link and passcode.
Justin Ballew reports, “We finally saw some sunshine this past weekend after a pretty rainy week. Caterpillar pressure has been high and lots of treatments have been going out. I’ve been seeing a decent amount of pathogenic fungi developing on diamondback moth caterpillars due to the wet conditions creating the perfect conditions for development. We’ve had a couple acres of strawberries planted and ordinarily we would be planting full steam ahead now, but strawberry plants are late coming in this year. Lots of folks are being told it will be next week before their plants come in. I’m also hearing reports that anthracnose may be a problem from nurseries this year. As a result, we are strongly recommending a fungicide dip on transplants before planting to combat this and any potential infections from the new disease Neopestalotiopsis. See Dr. Schnabel’s comments about Zivion above.”
Phillip Carnley reports, “Cucumbers are finished in Orangeburg and Calhoun counties. Fall greens are in full swing with some pressure from DBM with the occasional looper. Growers are bedding strawberry fields and applying their pre’s. We have seen heavy infestations of gummy stem blight in fall watermelons, as well as spider mite damage in blackberries.”
Sarah Scott reports, “Tree removal and field prep for new peach installations are happening around the ridge. Strawberry plants are being planted now and got a good watering in with last weeks rain. Fall vegetables are looking good, growers should keep up with scouting for disease issues in the field following the week of wet and humid weather.
Andy Rollins reports, “I am busy scouting new strawberry plantings this past week. Be on the look out for leaf diseases of plants but also check roots thoroughly for discoloration. When planting make sure crowns are still visible after planting. We are also preparing ground for new peach production going in. We are still picking a few muscadines, but that will be finishing pretty soon.”
During the ceremony, Tony was repeatedly described as a role model, hard-working, and, most of all, humble. “This [award] is one deserved. This is not given. This is earned the old-fashioned way.” said Sen. Williams.
Coming up this Thursday (10/7/21) is the Farm Safety Day for Women hosted by the SC Women’s Ag Network (SCWAgN). Topics will include chainsaw, electrical/fire, pesticide, tractor, and trailer safety. Click here to register.
Zack Snipes reports, “We had near perfect conditions for working in the fields this week compared to past weeks. Muscadine harvest is near complete and watermelons are beginning to be harvested. I sampled a good many blueberry fields this week with red foliage and weak plants. We have identified some bacterial leaf scorch in a few orchards and are hoping other farms don’t have this pathogen as well. There are currently no management options once this disease is found in blueberry. I also saw some herbicide injury on plants this week as well.”
Rob Last reports, “As planting season is well underway for fall crops, I am getting calls about suspected herbicide damage to sensitive crops. Symptoms include stunting of the plants; discoloration, be that yellowing or bleaching. There are several steps to preventing issues associate with herbicide damage. Firstly make sure your spray application equipment is cleaned carefully according to the product’s label to be applied. The process could be as simple as a triple wash or may need to wash out using a tank cleaner, again following directions on the label. Secondly, be sure of the plant back restrictions for herbicides applied to the previous crops. Many residual (soil acting) herbicides can have significant effects on sensitive crops. Remember always follow the label and if you are in doubt, ask an Extension Agent for help.”
Justin Ballew reports, “It was a little warmer this past week and it has gotten dry. Lots of irrigation has been running lately. Caterpillar populations remain high in brassica crops and growers are making treatments. Remember, it is important to use a surfactant with caterpillar insecticides when spraying brassica crops like collards, kale, cabbage, broccoli, etc. The waxy leaf coating makes water bead up and roll right off the leaves. A surfactant helps the spray droplets spread out and stick to the leaves. Forgetting a surfactant can make insecticides appear to have poor efficacy even when the insect population is in fact sensitive.”
Andy Rollins reports, “Fall blackberry production on Primeark 45 has been exceptional this year. Spring crop was killed out and seemed to force better than normal fall production. Muscadine picking is also in full force still and quality is excellent. We are finished bedding for strawberry and some growers already have their plants in the ground. Close inspection of plug plants for blackened roots is extremely important. Also please make sure plants are properly planted. This is especially true for cutoff and bareroot plantings. We are also getting new ground ready for peach plantings in 2022. Incorporation of lime and phosphorus at this time is critical for longterm success in this instance. Many times lime recommendations need to be doubled to achieve the desired pH.”
Kerrie Roach reports, “With a significant loss in the apple crop from the late April cold event in the Upstate, growers have had to work together to keep things available for customers. The reduction in spray applications throughout the season has shown through on the crop that remained on the trees. This tends to be a pay for it now, or pay for it later kind of situation. End of season and dormant applications are going to be that much more important for the 2022 growing season. Muscadines are really starting to come in strong, and figs are just about to finish in the next week or so. Last week was beautiful, but this week looks to be filled with rain and cooler temperatures. Keep an eye on fall planted crops and monitor closely for disease activity.”
Coming up this Saturday (10/2/21) is a Waste Pesticide Collection Event held by the SCDA in York. Take a look at their news release here and take advantage of this event if you have any pesticides sitting around that you don’t expect to use.
Zack Snipes reports, “We have had plenty of rain as of late in the Lowcountry. Many growers could not get in the fields due to fields being soggy. We have some beautiful weather coming this week so I expect a good bit of ground to be prepped and planted. We have plenty of moisture in the soil so those preemergent herbicides should have great efficacy if put down properly. I am seeing some odd yellowing symptoms of watermelon vines that lead to a collapse in the plant. We sent off samples to the Plant Diagnostic Lab. If you are suspicious of a plant disease, we can identify the disease for you. I also received a few calls this week about greenhouses. Before buying a greenhouse, consider retrofitting a shipping container. Thousands of transplants can be grown in a very small space which saves you money on your heating and cooling bill.”
Justin Ballew reports, “We’ve really been enjoying the fall weather here in the midlands. We got some rain and the high temperatures have been in the upper 70s/low 80s. The majority of folks got their beds formed and plastic laid for strawberries last week. I’m getting some reports that strawberry nurseries are facing a tight supply this year. Hopefully, everyone got their orders in early. On brassicas, we’ve seen a significant increase in caterpillar population levels over the last week. That makes now a great time to run a field bioassay to screen for insecticide resistance in diamondback moth populations. Contact your local agent to schedule one.”
Phillip Carnley reports, “Brassica production is ramping up in Orangeburg and Calhoun and Clarendon counties. Diamondback caterpillar is making itself known in brassica crops, especially in collards. Make sure to scout early and treat in a timely fashion. If your insecticide program is not showing the desired level of control, talk with your local agent about scheduling a bioassay to assess your population’s resistance to different insecticides. Also, be on the lookout for black rot and other fungal problems in early transplants. Loopers seem to be a non-issue currently but stay vigilant in monitoring. I am still getting plenty of calls for pecans and the majority of the issues are pecan scab and yellow aphid damage, causing nut drop and premature defoliation. Also be mindful to monitor/ test for nematodes, in my area I am seeing population loading due to lack of cultural and chemical control. On blackberries, make sure to harvest in a timely manner and maintain a high level of sanitation, as there is plenty of spotted wing drosophila to go around.”
Bruce McLean reports, “Last week’s rainfall really helped to moisten dry soils around the Pee Dee. Fall vegetable crops are coming along. Disease activity is low and insect activity is light to moderate. Surprisingly, diamondback moths have not been observed yet. Looper activity has been light to moderate on brassicas and cabbageworms have been observed in some fields. Aphids have been seen, as well. Stink bug activity has been moderate on okra. Okra harvest has begun to slow down, but decent volumes are still being harvested. Wine and juice muscadine harvest is complete, but some fresh market muscadines are still being picked in limited volumes. Most folks have bedded and fumigated for strawberries (… or will be this week). Talking to growers, it sounds like strawberry plants (plug and bare root) are getting a bit scarce… more so than normal for this time of the year. If you’re looking for some plants, you may have to go with varieties that you might not familiar with. Be sure to order early next year to get the varieties and volumes you need.”
Rob Last reports, “Fall cucurbit crops, including cantaloupes, and watermelons are ripening and approaching harvest. Disease pressure from powdery mildew and gummy stem blight have really increased significantly over the last week. Maintaining a tight spray program will be key to managing disease. As we look forward to strawberry planting land is being prepared. If you are planning to fumigate, make sure the plant back interval between fumigation application and planting is maintained. A good test can be to plant some lettuce seed in the treated area. When lettuce germinates, the risk of damage from fumigation is reduced. Finally, on any remaining fall plantings, consider using a labeled pre-emergent herbicide to help with weed management. Once the crop and weeds emerge, options are drastically reduced.
Zack Snipes reports, “Land is being prepared and fall crops are going in around the Lowcountry. Early fall crops look better with the slightly cooler temperatures and periodic rain. We are wet in some parts. I am seeing lots of bacterial spot in the fall tomato crop. We have good herbicide management plans for greens, but folks will need to take advantage of pre-emergents now.”
Justin Ballew reports, “This past week was fairly rainy. There are several fields that are pretty soft, even some sandy fields. Folks are still planting brassicas for the fall and they are looking really nice right now. Strawberry growers are also getting prepped to fumigate and lay plastic. We’ve been seeing a lot of damping off (Pythium) in young cucurbits and some brassicas lately. The wet weather is definitely creating the perfect conditions for this. A few things that can be done to help minimize damping off include planting on plastic beds, planting at the proper depth (just deep enough to cover the plug with native soil), rotating fields wisely (tomatoes are a host for Pythium), and using a fungicide at planting may also make sense when environmental conditions are right for Pythium development.”
Phillip Carnley reports, “Cucumber production is in its final stages here in Orangeburg and Calhoun counties with most growers close to or in the process of harvesting. There is still a noticeable amount of cucurbit downy mildew, but due to the dryer weather it has been easier to keep in check. Sweetpotatoes are currently being dug with yields looking to be fairly good. There have been a few issues with wireworm damage in sweet potato fields with the majority of damage being seen on the lighter colored tubers. Diamondback caterpillar is ramping up in brassica crops, especially in collards. Make sure to scout early and treat in a timely fashion, if your insecticide program is not showing the desired level of control talk with your local agent about scheduling a bioassay to screen your population’s resistance to different insecticides. Also be on the look out for black rot and other fungal problems in early transplants.”
Sarah Scott reports, “We received some heavy rain in areas throughout Edgefield and Aiken Counties last week, up to 2 inches in spots. In preparation for October planting, plastic has been laid in strawberry fields. Brassica crops are being planted as field conditions allow. Late summer plantings of broccoli are starting to get some good size on them. Pepper plants that were put out in August are setting fruit that is starting to size up nicely.”
Zack Snipes reports, “We had a heavy downpour of rain last week surpassing 2.5 inches in some spots. I am seeing downy mildew in cucumbers and lots of gummy stem blight in winter squash and pumpkins. The worm pressure has lessened in the past few weeks. I am seeing lots and lots of black rot in transplanted brassicas. Inspect your plants before planting them to make sure the disease is not coming from the nursery. Once a brassica is planted in the field, there is not much we can do to slow the spread except hope that environmental conditions (rain, humidity) are not conducive to spread the disease. I am also seeing lots of early weed pressure in fall planted crops on both bare-ground and plastic. We have some very good herbicide options to apply preplant. Once you plant the crop, we have very few herbicides that can be used over the top of the crop. Right now is the time to get down strawberry herbicides before the season starts. As the old proverb goes: an ounce of prevention is worth a pound of cure.”
Justin Ballew reports, “We received about an inch of rain (at my house), which we really needed. The temperatures over the last week have been very mild and it has started to feel like fall. Fall crops are doing well. We’re still planting brassicas and keeping an eye on caterpillars. Muscadines are being harvested now. Growers are reporting good fruit quality, but lower yields than last year. This is most likely due to the late cold weather that affected muscadine growers across the state. On pecans, black aphid populations and scab incidence are both high. It appears both of these pests are going to significantly reduce yield on sensitive varieties if growers didn’t stay on top of sprays.”
The Environmental Protection Agency (EPA) issued a ruling in August to revoke all tolerances for chlorpyrifos, the active ingredient in Lorsban, following a lengthy review and legal battle.
The summary of the ruling states, “On April 29, 2021, the United States Court of Appeals for the Ninth Circuit ordered EPA to issue a final rule concerning the chlorpyrifos tolerances by August 20, 2021. Based on the currently available data and taking into consideration the currently registered uses for chlorpyrifos, EPA is unable to conclude that the risk from aggregate exposure from the use of chlorpyrifos meets the safety standard of the Federal Food, Drug, and Cosmetic Act (FFDCA). Accordingly, EPA is revoking all tolerances for chlorpyrifos.”
Chloripyrifos has been used to manage insect pests in fruit and vegetable crops since the 1960s. This ruling is bringing its use to an end. According to the ruling, “This final rule is effective October 29, 2021. The tolerances for all commodities expire on February 28, 2022.”
We are still learning how this will affect the fruit and vegetable industry, but as of right now it appears growers will be able to use existing stock through the 2021 season.
If you haven’t already done so, please take a few minutes to fill out a survey to share your thoughts with us on Extension meetings. We’ll be using the information collected to help plan meetings over the next year. It will take less than 10 minutes and is anonymous. Click here to get started. Thanks!
Justin Ballew reports, “We’re getting a little dry here in the midlands and folks have been running irrigation a lot. We got a shower last night (9/6) at my house, but it didn’t amount to much. Our fall crops are looking really good right now. The dry weather is holding down disease though we are still seeing some insects, mainly caterpillars. Squash, zucchini, cucumbers, peppers, tomatoes, turnips, and other brassicas are all growing pretty well.”
Phillip Carnley reports, “Muscadine production is in its final stages here in Orangeburg and Calhoun counties with most growers preparing to harvest or in the process of harvesting. There is still a noticeable amount of angular leaf spot on many vines, but this late in the season, it is not much of an issue. Continue to keep an eye on the population of grape vine borer with the use of traps. Also keep an eye on water, as it is needed for nice plump fruit.
Bruce McLean reports, “Soils are getting pretty dry in many locations. Even though dry weather would greatly benefit the muscadine growers, we could use a little rain. Vegetable crops are looking pretty good. Spider mite activity has increased over the last couple of weeks, especially on tomatoes. Bedding and fumigation (for strawberries) is getting ready to begin. Wine and juice muscadine harvest is upon us. Muscadine harvest is going to be a bit tricky this year. In many locations, half the crop is ready to pick and half the crop needs a little additional time, especially Carlos and Doreen cultivars. This is likely due to the late spring freeze that we experienced this year. Primary growth (that recovered from the freeze) is giving us a timely crop. Secondary growth (growth from secondary buds) is a little delayed. Watch harvesting too much under-ripe fruit. Under-ripe fruit does not contain the sugars or the juice, and will reduce your overall juice yield and total sugars.”
Kerrie Roach reports, “Things have significantly slowed down in the Upstate with the Labor day weekend signaling the true end of summer. The growers who are doing fall vegetable production are in the thick of things with insect and disease monitoring of utmost importance. I would typically be posting about apples and the harvest for this season, but the late cold event from April 22, 2021 has put a significant damper on local orchards. Growers have apples available, but u-pick operations are very limited, if not cancelled for this season. Orchard management is imperative even when the trees are not producing, and can be a good opportunity to get weed control and pest management under control.”
Don’t forget to sign up for the Virtual Strawberry Production Meeting we will have this Thursday (9/2) at 6 PM. We will have speakers from Clemson, UGA, and NC State and we expect it to be a great program. Visit the Upcoming Events page to see a list of topics and click here to register.
Also, if you haven’t already done so, please take a few minutes to fill out a survey to share your thoughts with us on Extension meetings. We’ll be using the information collected to help plan meetings over the next year. It will take less than 10 minutes and is anonymous. Click here to get started. Thanks!
Justin Ballew reports, “We had a chance to dry out some this past week, though it really doesn’t take long with our sandy soil. Fields are still being prepped and planted for fall crops and what has been planted is doing well. We’ve been getting reports of high armyworm counts in pastures and row crops and we’ve been seeing some in vegetables also. Stay vigilant.”
Bruce McLean reports, “It’s getting into a transitional period for vegetable production. Cool season crops are starting to be planted (in volume), and warm season crops, like squash, zucchini, okra and peas, are still being harvested in some good volume. Fumigation for strawberries is getting ready to get started. Blueberry propagation (green-tip, semi-hardwood cuttings) is going on. Fresh market muscadines are busy being harvested. Wine and juice varieties of muscadines are getting close to harvest. Carlos and Noble are really coloring quickly. Doreen is just starting to color. Testing for sugar content (Brix) will begin this week to identify the correct harvest date for wine and juice muscadines.”
Kerrie Roach reports, “Dry weather this last week was much needed after the significant rains from the week before. As many other areas across the state, armyworms reports and calls are coming in more and more each day. Stay vigilant with your scouting. As with many of our tree fruit and nut crops, the pecan harvest is looking to be pretty slim after the April 22nd cold event that affected many areas of the Upstate. Continue to monitor and treat for disease and insect populations so that next year the are not even more problematic. For bearing trees, now is the time to be monitoring and treating pecan weevil populations. Several specialists have also recommended monitoring and potentially treating non-bearing trees as well, if populations detected are high. While ideally, no pecans means the life-cycle for the pecan weevils would be incomplete, there are most likely enough pecans present in the tree to support some of the population. Check out the Pecan Management Guide for more information.”
Andy Rollins reports, “Bigred peaches are in the upstate and quality is amazing. Use of pheremone ties Isomate OFM to exclude males from being able to find mates has been a huge success for late season peach. Insecticides alone previous years even with adequate rotation did not prove successful. We have fall collard, broccoli and other brassicas being planted. Both hot and other peppers are being harvested in quantity despite excessive rains earlier in the year. Squash and zucchini production is slowing with only limited late season plantings. Nematode survey work is being done this week.”