A yellow squash plant is infected with whitefly-transmitted cucurbit leaf crumple virus. Discolored fruits are typical following infection with this virus.
One of the best management tactics for vegetable growers when dealing with whitefly infestations is to get rid of any plants left in the field once harvest season is done. University of Georgia Cooperative Extension vegetable entomologist Stormy Sparks continues to preach proper sanitation to producers amid the worst whitefly outbreak in Georgia since 2017.
“This is really for all pests but definitely for whiteflies, when you get done with a crop and if you’re not managing that crop for whiteflies and it’s a crop that hosts whiteflies, you need to get rid of it as soon as possible,” Sparks said. “It needs to be destroyed so it cannot harbor or produce any more pests. That really should become a priority. In vegetables, getting a crop in on time is just paramount, nothing stops that. We really need to move towards that as far as getting crops out as well.”
Huge Problem This Year
Whiteflies are a greater problem this year due in large part to the mild winter. While colder temperatures do not eliminate whiteflies, they do kill off many of their wild hosts and slow population development in cultivated hosts. Warmer temperatures allowed for larger whitefly populations to overwinter and become mobile earlier this summer.
Whiteflies migrate from winter vegetables to spring vegetables to agronomic crops, like cotton, to fall vegetables and back to winter vegetables. Whiteflies cause feeding injury issues in vegetables and transmit two new viruses: cucurbit leaf crumple virus and cucurbit yellow stunting disorder virus.
Washington, DC — The Office of the U.S. Trade Representative, the Department of Agriculture, and the Department of Commerce released a report today outlining the Trump Administration’s plan to address the threat posed by increased foreign imports to American producers of seasonal and perishable fruits and vegetables.
Robert Lighthizer (Official White House Photo by Stephanie Chasez)
The plan follows public hearings held in August where more than 60 witnesses testified, in addition to over 300 written submissions.
“President Trump recognizes the challenges faced by American farmers and is committed to promoting and securing fair trade and a level playing field for all American producers. Secretary Perdue, Secretary Ross, and I are fully engaged in this effort. We would like to thank all of the elected officials, agricultural leaders, and dozens of farmers who participated in these hearings and helped make this plan a priority,” said U.S. Trade Representative Robert Lighthizer.
Based on information collected from these hearings, the agencies commit to the following actions to support America’s seasonal and perishable fruit and vegetable producers:
Plan to Support American Producers of Seasonal and Perishable Fruits and Vegetables
1. USTR will request the International Trade Commission to initiate a Section 201 global safeguard investigation into the extent to which increased imports of blueberries have caused serious injury to domestic blueberry growers.
2. USTR will pursue senior-level government-to-government discussions with Mexico over the next 90 days to address U.S. industry concerns regarding U.S. imports of Mexican strawberries, bell peppers, and other seasonal and perishable products.
3. USTR will work with domestic producers to commence an investigation by the International Trade Commission to monitor and investigate imports of strawberries and bell peppers, which could enable an expedited Section 201 global safeguard investigation later this year.
4. The Department of Commerce will
(a) establish an outreach program to connect with Southeastern and other growers of seasonal and perishable fruits and vegetables, to enhance understanding of applicable trade remedy laws and processes; and
(b) establish a formal channel for stakeholders to provide information related to unfair subsidies for foreign producers and exporters of seasonal and perishable fruits and vegetables, including those in Mexico – building on ongoing efforts to partner with U.S. industry to identify such subsidies.
5. The Department of Agriculture will
(a) increase targeted outreach to producers of seasonal and perishable fruits and vegetables to maximize the use of existing Department of Agriculture programs; and
(b) develop a market promotion strategy for domestically produced produce; and
(c) initiate conversations with relevant federal partners to better understand the extent to which imports of seasonal and perishable products are utilized to enable criminal activity.
6. USTR, the Department of Commerce, and the Department of Agriculture will establish an interagency working group to monitor seasonal and perishable fruit and vegetable products, coordinate as appropriate regarding future investigations and trade actions, and provide technical assistance to Members of Congress in developing legislation on this issue.
This plan does not foreclose additional actions and investigations by the Trump Administration to support producers of seasonal and perishable fruits and vegetables. The Administration is dedicated to supporting America’s hardworking farmers across the country and recognizes the importance of preserving and enhancing a diverse and homegrown food supply.
Clemson Extension will host a virtual strawberry production meeting on Wednesday, Sept. 2 at 6 p.m. The Strawberry Grower 101 meeting will be geared towards new or beginning growers.
Topics to be covered included cost and economics, timeline, plant selection and varieties available and fertility.
Though Mexican exports of tomatoes have not reached the ‘peak’ season, inspections appear to be running smoothly and efficiently, says Michael Schadler, executive vice president of the Florida Tomato Exchange.
The inspection provision, which was part of the Tomato Suspension Agreement established in September, 2019 between the U.S. Department of Commerce and Mexican tomato exporters, allows for the United States Department of Agriculture to inspect certain kinds of tomatoes being transported from Mexico to the United States. It started in early April but will be tested when higher volumes of tomatoes ramp up during the winter months.
“The heaviest times of the season as far as imports from Mexico are January, February and March. The inspections haven’t been tested with the biggest volumes of the season,” Schadler said. “We’re bringing in Mexican tomatoes year-round. There’s very significant volumes every week of the year, every month of the year. But in those three months, that’s really the peak for the big production out of Mexico. That will be more of a test. By the time it’s January, they will have had a good eight months of practice, I think it’ll be fine.”
Cause for Concern?
Schadler believes there should not be cause for concern that inspections of tomatoes could create a bottleneck of shipments, especially during those months when more of the crop will cross the border.
“Frankly, I don’t think it should be a worry for anyone. First of all, USDA (Agricultural Marketing Service) AMS, that’s what they do; they’re in the business of offering inspections services. They’ve ramped up employment and staff to the level they can handle the situation,” Schadler said. “I think people would have been a little nervous if their start had been Jan. 1 of 2020, right as the big volume was coming in. That would have been a little much.
“I don’t think there is any worry. If you hear about importing companies expressing concern, I personally don’t think that’s justified. But I can understand it if I was an importer, how it’s an adjustment that they have to make. As far as we understand it, the process has been going fairly smoothly. Both sides have been working together well.”
Purpose of Inspections
According to the International Trade Administration, the purpose of the Suspension Agreement inspections is to prevent low-quality and poor-condition tomatoes from entering the U.S. market and injuring the U.S. domestic tomato industry through price suppression or undercutting.
The tomatoes that are being inspected include Round tomatoes, Round meaning fresh tomatoes; Roma tomatoes, Roma meaning Roma or Plum fresh tomatoes; stem on tomatoes, stem meaning any type of fresh tomato, except specialty and tomatoes on the vine; and Grape tomatoes in bulk.
“It’s a quality grade inspection. It makes it so that if you’ve got tomatoes that grade below U.S. No. 2, you can’t bring them into the country. You either have to cull them there on the spot or you have to return the shipment back to Mexico,” Schadler said. “It’s really good for the overall market. It’s good for the downstream market because you’re getting higher quality, but it’s good for the trade as well because you get some of that rough quality out of the system and prices will be helped for everyone.”
Exempt Tomatoes
Those tomatoes that are exempt from inspections include tomatoes on the vine, meaning any type of fresh tomatoes, except specialty, in which there are two or more tomatoes, normally in a cluster, with the vine attached; specialty tomatoes, meaning Grape, Cherry, Heirloom, Cocktail fresh tomatoes or any other tomato varietal, other than Round and Roma tomatoes, with or without the stem; and Grape tomatoes in retail packages of 2 pounds or less.
The September issue of VSCNews magazine is packed with information about breeding updates and new varieties. Readers can see what’s new in strawberries, blueberries, blackberries and cucurbits.
Breeding new varieties is a vital component to push agriculture forward. The University of Florida (UF) is a leader in the breeding industry. Recently, blackberries have emerged as an alternative crop in Florida. Zhanao Deng, a professor at the UF Institute of Food and Agricultural Sciences (UF/IFAS) shares the work that UF has done trialing and developing cultivars for the Sunshine State. According to Deng, UF plans to produce the first blackberry production and spray guide by early 2022.
Seonghee Lee, a research assistant professor and Vance Whitaker, an associate professor, both at the UF/IFAS Gulf Coast Research and Education Center in Wimauma, discuss a new strawberry variety that UF will soon commercialize. These white strawberries, actually found in nature, are expected to be the first white strawberries on the market in the U.S.
Patricio Munoz, an assistant professor and Doug Phillips, UF/IFAS blueberry Extension coordinator, discusses the UF/IFAS blueberry breeding program. Get the latest details on the program in his article.
The September issue also offers something for cucurbit growers. Cucurbit crops are some of the most widely grown vegetable crops in the Southeast. However, the hot and humid climate can present a number of challenges to growers when it comes to pests and diseases. Cecilia McGregor, an associate professor and George Boyhan, a professor and Extension specialist, both at the University of Georgia (UGA), share the work being done by the UGA cucurbit breeding programs, developing cultivars that are well adapted to the Southeast.
Finally, the September issue includes a wrap-up of the recent virtual Vegetable & Specialty Crop (VSC) Expo. Readers can get some of the highlights from the Expo educational program inside the September issue. Also, be sure to mark your calendars for the 2021 VSC Expo, returning Aug. 18-19, 2021, to the Lee Civic Center in North Fort Myers, Florida.
If you would like to receive future issues of VSCNews magazine, click here.
Clemson Extension agents provided updates in The South Carolina Grower this week about the status of various crops being produced throughout the state.
Coastal
Zack Snipes reports, “We had between 4-6 inches of rain last week with daily thunderstorms. Growers are working the fields, getting ready for the fall crops to go in. If it happens to rain on Wednesday night, then you should tune in to our Strawberry 101 class from 6 p.m. to 8 p.m. We will be discussing economics, seasonal timeline, varieties and common mistakes, and fertility. This is an excellent opportunity to learn about growing strawberries. You must register ahead of time to participate.“
Midlands
Justin Ballew reports, “After some rain early in the week, the weather turned dry and the temperatures and humidity reminded us that summer isn’t over yet. Fall crops are continuing to progress well, though we are continuing to see a fair amount of disease like anthracnose, downy mildew, and bacterial spot due to the recent wet conditions. Caterpillar populations are climbing on fall brassicas as well. In scouting a field trial, I observed diamondback moths, cabbage loopers, and armyworms. Keep a close eye out and be sure to rotate chemistries when you start spraying.”
Anthracnose spots on a cantaloupe leaf. Photo from Justin Ballew.Cabbage looper on a collard leaf. Photo from Justin Ballew.
Sarah Scott reports, “Peach season has wrapped up in the Ridge and post- harvest fertilizer applications are being applied. Fall vegetable crops are looking good as we received some decent rain fall over the past week. Hot temperatures have had some effect on lower seed germination of some brassicas.”
Pee Dee
Bruce McLean reports, “Harvest time is finally upon us. Sunshine and warm temperatures are doing the trick for giving growers that final push for ripening the muscadine crop. Crop is looking good, but some bitter rot and ripe rot is starting to show. Brix for Carlos and Noble is averaging around 13.5%. Doreen is still a little ways from being ready to harvest, but it won’t be long.”
Grape harvester picking muscadines. Photo from Bruce McLean.
Tony Melton reports, “So wet in areas it is hard to spray peas for curculio. Some are having to use airplanes. Harvesting sweet potatoes for processing and yield is good. Planting greens for processing. Harvesting pickles but stopped planting this week. Still harvesting processing peppers but harvesters are getting real tired.”
Upstate
Kerrie Roach reports, “Heavy rains, humidity and continued high temperatures over the last week have continued an increased trend in disease incidence across the board in both vegetables and fruits. Growers need to be proactive to stay ahead of diseases (and insects) by scouting often and well. We are finishing out the peach season with late varieties like ‘Big Red’. Apples are gaining steam and early varieties are looking and tasting great. Overall the production seems to be on target for a significant increase over last season.”
By G.E. Vallad, J. Desaeger, J. Noling and N. Boyd
Vegetable and strawberry growers have long relied on soil fumigants to contend with various soilborne pathogen and pest complexes, as part of an integrated management strategy that includes crop resistance, cultural control and pesticides. However, with the loss of methyl bromide (MBr), many growers have struggled to maintain consistent soilborne pathogen and pest control with the available fumigants.
Much of this relates to the inability of available fumigants to disperse throughout the soil in the same manner as MBr. This is due to the physical differences in volatility, as revealed by comparing the vapor pressure and boiling points (see Table 1) of currently available fumigants to MBr and water. Volatility is the tendency of any substance to convert to a gas at a given temperature and is directly related to the substance’s specific vapor pressure, which is inversely related to boiling point.
Figure 1. The Yetter Avenger Coulter system has a pair of coulters straddling the raised bed. Final application depth is greater than 8 inches below the soil.
By comparing vapor pressure and boiling point values of fumigants to water, it is easier to understand why the current fumigants are referred to as volatile liquids. Vapor pressure values for Pic and 1,3-D are on average 70-fold less than MBr at 20° C (68° F), and the ITC generators are even less volatile with physical characteristics more similar to water. MBr, as a true gas, would rapidly volatilize from a liquid once applied to the soil and quickly fill available airspace within the soil profile. In comparison, all the current alternatives remain liquid following application and then slowly volatilize. These physical characteristics limit fumigant movement within the soil of the prepared, raised bed.
Figure 2. Roots are emerging below the plastic tuck from the side of the bed.
Unfortunately, threats from soilborne pathogens and pests are not always limited to the immediate raised bed. For example, research previously demonstrated that supplemental applications of chloropicrin along bed edges below the tuck (Figure 1) protected tomato roots emerging from the fumigated bed into non-fumigated soils (Figure 2), which subsequently reduced the incidence of fusarium wilt (Figure 3). Similarly, research demonstrated that deep-shank soil applications of 1,3-dichloropropene (Telone) (Figure 4) were necessary to manage nematode populations deeper in the soil, below raised beds, that were beyond standard in-bed fumigant applications (Figure 5).
Figure 3. A field trial demonstrates the supplemental application of Pic 100 to bed edges compared to the grower standard of Pic-Clor 60 alone.
FIELD TRIALS Many operations have problematic fields with a complex of soilborne pests and pathogens. Large replicated field trials were recently conducted to address such situations, combining both supplemental approaches in tomato fields affected by root-knot nematodes and fusarium wilt. Combinations of deep-shank Telone II, with in-bed fumigation, supplemental chloropicrin and plastic mulch [virtually impermeable film (VIF) vs. totally impermeable film (TIF)] were evaluated.
Figure 4. A broadcast, deep-shank application of Telone II (inset shows applicator). The tractor at top is making a 16 to 18-inch application at 12 gallons per acre, followed by a disk to disrupt chisel traces (center pass) and then packed with a roller to seal the fumigant (bottom pass).
Two fields received deep-shank applications of Telone II (12 gallons per acre) in 600-foot by 50-foot strips alternated with 50-foot non-fumigated strips across the entire field. A month later, raised beds prepared over the Telone II strips received in-bed applications of either Pic-Clor 60 (300 pounds per acre), Pic-Clor 80 (225 pounds per acre) and Pic 100 (180 pounds per acre) with supplemental application of Pic 100 along the bed edge (150 pounds per acre).
Raised beds prepared over the non-Telone II strips received Pic-Clor 60 (300 pounds per acre) either with or without the supplemental Pic 100 along the bed edge as additional controls. Each of the described combinations were covered with both TIF and VIF plastic mulch (for a total of 10 treatments) and then planted accordingly. Each treatment plot consisted of three beds (approximately ¼ acre) and was replicated five times in each field.
RESEARCH RESULTS Two weeks after deep-shank applications of Telone II, deep soil cores pulled across fumigated and non-fumigated portions of the field found total nematode levels (including parasitic Meloidogyne species) were reduced by 82 percent, from an average of 8.3 nematodes per 100 cubic centimeters of soil to 1.1 nematodes. The reduced nematode counts were further reflected at the end of the season with a 97 percent reduction in root-knot galling between deep-shank Telone II and non-deep-shank fumigated plots.
Figure 5. A demonstration of deep-shank applied Telone II on root-knot nematodes in cucumber. Telone was applied perpendicular to raised-bed preparation. The image shows a strip where the deep-shank applicator was turned off.
Supplemental Pic applications reduced average root gall ratings 24 percent and reduced average fusarium wilt incidence by 47 percent. Unexpectedly, deep-shank Telone II applications had the greatest statistical effect on fusarium wilt, reducing disease incidence by 66 percent, from 19.4 to 7.5 percent average incidence across all treatments. In-bed fumigants also had a significant but minor effect on average root gall ratings and fusarium wilt, with in-bed Pic-Clor 60 and Pic-Clor 80 performing better than Pic 100.
Statistically, mulch had no effect on nematode gall ratings, fusarium wilt or yields. In-bed fumigation had numerical but no statistical effect on tomato yields. A replicated lab study further demonstrated the fungicidal activity of 1,3 dichloropropene (Telone II) against Fusarium oxysporum f. sp. lycopersici. Several other studies have reported similar findings for 1,3 dichloropropene against soilborne pathogens and for chloropicrin against nematodes.
CONCLUSION These findings further support the notion of developing supplemental fumigation strategies that target soilborne pests and pathogens at their source. These supplementary approaches are meant to be prescriptive in nature, based on the specific soilborne pest or pathogen problems observed in fields.
Current and future research will address the frequency of supplemental fumigation and the use of other fumigants, as well as reducing in-bed application rates to help offset the cost of supplemental fumigation. Improvements in available post-plant fungicides and nematicides may also change fumigation strategies, as well as the availability of crop varieties with improved tolerance to soilborne pathogens and pests. Parties interested in participating in such studies are welcome to contact Gary Vallad at gvallad@ufl.edu or 813-419-6577.
Vidalia onion plants will soon be going in the ground across Southeast Georgia. Chris Tyson, University of Georgia Extension Area Onion Agent at the Vidalia Onion & Vegetable Research Center in Lyons, Georgia, pinpoints the week of Sept. 7 that some growers will start planting this year’s crop with most planting the week after.
“After Labor Day, definitely there will be some going in. Then there will be a lot that will go in around…I’ll just use the (Sept.) 15th as an arbitrary date. A lot of people will plant at the 15th; a big bulk of the onions. But there are some that are planted before then, definitely,” Tyson said.
Vidalia onion acreage the past two years has hovered around 9,300 acres, which is down from what it had been for several years prior. Tyson said this year’s acres could fluctuate some either way, but he doesn’t anticipate any huge changes in acreage.
“The acreage has been about the same the past two seasons. But you never know, it could go up some or it could stay the same,” Tyson said. “A lot of times we really don’t know until after planting, really what everybody does and what it’s going to actually look like.”
Seedbeds will be planted in September through the first of October.
Tomato planting is currently underway across the Southeast. It is never too early to start thinking about insect pests that could hinder fall production in Alabama.
According to the Tomato Insect Pests 101 video, Ayanava Majumdar, Auburn Extension Professor in Entomology and Plant Pathology, cautions growers to scout their tomato fields every week for pests and look for insects over and under the leaves and also at the plant base.
Tomato plants have five growth stages during the production season: seedling, vegetative, flowering, fruit formation and mature fruiting.
“Seedling and fruiting stages are most vulnerable to insect attack,” Majumdar said. “They must be protected.”
What to Watch for?
Early season insect pests include flea beetles, thrips and aphids. Flea beetles’ ability to chew small round holes across the leaves can lead to death for small tomato plants. Thrips have piercing-sucking mouthparts and can transmit viruses when feeding. Aphids suck plant sap and produce honeydew resulting in sooty-mold fungus.
Specific insects, such as the brown stink bug and leaffooted bug, can cause quality losses. Stink bugs have piercing-sucking mouth parts. Its feeding causes extensive fruit discoloration. These are often unmarketable and can rot fast in storage. Leaffooted bugs have leaf-like expansion on their hind legs. They aggregate in large numbers on fruits.
Caterpillars can cause holes on tomatoes. Beet armyworms, fall armyworms, yellowstriped armyworms, southern armyworms, fruitworms, hornworms and loopers are pests to watch out for. Fruitworms make round holes with the head tucked inside the fruit. Hornworms feed on the leaves, stems or entire fruit. Loopers are often late-season pests in Alabama.
Majumdar implores farmers to apply pest management tactics. This includes: plant and harvest your crop in a timely fashion; use pest exclusion fabric or netting early to stop moths and stink bugs; and use conventional or organic insecticides if needed.
Holly Bell, director of cannabis for the Florida Department of Agriculture and Consumer Services (FDACS), gave an update on Florida’s hemp program as part of the Citrus Expo virtual general session.
“Florida is becoming the leader in the country — if not the world —on how we’re getting our hemp program rolled out and the standards that we’re setting,” she said.
On April 27, FDACS began issuing hemp cultivation permits. As of mid-August, 550 permits were issued and another 400 were being processed. The 550 permits encompass 18,000 acres of indoor- and outdoor-grown hemp. Bell said applying for a permit is a quick and easy process that can be done online. She noted that there is no fee for a hemp cultivation permit in 2020. Questions about the permit process can be sent to DPIhemp@FDACS.gov.
Bell reported that FDACS has been inspecting hemp products for consumer safety and checking to ensure that what is listed on the labels is what is found in the products.
“We found some alarming trends in samples that we pulled,” Bell said. “We have found high levels of lead in a lot of the tinctures that are in bottles (CBD oil) and sold across the state.”
FDACS is working with the Food and Drug Administration to remove tainted CBD oil from Florida shelves and in other states where the products are sold.
“We really are setting the bar in the United States for testing and quality control,” Bell said. “Several people with hemp businesses in other states now want to come to Florida to do business here. Florida is setting an example.” She added that several states have reached out to FDACS to help them get their hemp programs up and running.
For help, questions or concerns regarding Florida’s hemp program, Bell encouraged reaching out to cannabis@FDACS.gov or directly to her at holly.bell@FDACS.gov. “We are eager and here to help you, and we’re looking forward to building this industry up,” she concluded.
