For the second straight year, the Using Pesticides Wisely program will be offered in a virtual format amid the ongoing coronavirus pandemic. The training, which is offered by the University of Georgia (UGA) Cooperative Extension and Georgia Department of Agriculture (GDA), will be offered on 11 different dates in March and April.
Culpepper
University of Georgia Extension weed specialist Stanley Culpepper provides insight on what farmers and their applicators can expect when attending this year’s training.
“Like every year, part of our Using Pesticides Wisely Training platform is to bring all of our applicators up to date on our challenges and share information to help them overcome those challenges. This year’s training will focus on a lot of different topics,” Culpepper said. “We’re going to make sure everybody’s really comfortable with the new Dicamba labels. That’s had some significant changes, so we’re going to make everybody comfortable with those new changes. We’re going to focus on topics to help every grower achieve their objective of keeping every pesticides on target.”
He added that additional topics will include the Paraquat training that is now required by the Environmental Protection Agency, herbicide resistance and farmer health.
“Everything that we’re focusing on this year is important to anyone if they think pesticides are a critical tool to their sustainability as they search to feed, produce feed, food and fiber for the world,” Culpepper said.
UGA Extension and the Georgia Department of Agriculture created the UPW trainings in 2015.
Trainings Schedule
The trainings schedule is as follows:
March 8 5:30 p.m.
March 11 9 a.m.
March 15 5:30 p.m.
March 18 9 a.m.
March 22 5:30 p.m.
March 25 9 a.m.
March 29 5:30 p.m.
April 1 9 a.m.
April 5 5:30 p.m.
April 8 9 a.m.
April 12 5:30 p.m.
Each individual applicator must pre-register to attend the training. Registration is permitted up to two hours prior to the training. No trainings will be offered after April 15 for the 2021 season.
Bacterial streak and bulb rot caused by Pseudomonas viridiflava. A: Foliar symptoms include water-soaked lesions and collapsed leaf tissues. The corrugated appearance is due to protruding veins in leaves. B: A blue-green appearance is occasionally observed in post-harvest rots caused by this pathogen.
By Bhabesh Dutta
The climate prevalent in the Vidalia onion zone (southeastern Georgia) is conducive to many diseases. Among the diseases, those that are caused by bacteria and fungi are the prominent ones. Some of the diseases caused by water molds or oomycetes (Pythium damping-off and downy mildew) can also be seen periodically. Based on my experience as a vegetable Extension pathologist and onion disease specialist in Georgia, I generally see a seasonality to some of the important diseases. This article covers points that relate to disease seasonality and management.
SEPTEMBER/OCTOBER PROBLEMS
Onion seeds are sown around mid-September to early October on seedbeds. Some of the diseases that are normally seen during this period are Pythium damping-off and foliar blight caused by Xanthomonas leaf blight and Pantoea sp.
Bulb rot symptoms of sour skin on onion. Photo credit: David B. Langston, University of Georgia, Bugwood.org
Fungicides labeled for onion are effective against Pythium and can be used as a soil application according to the label. Use of optimum watering and avoiding seedbeds in low-lying areas of the field can also help in managing this disease.
In terms of bacterial blights in seedlings on seedbeds, some growers use copper-based bactericides that are effective. Normally, nature takes its own course. When these seedlings are transplanted in the field, carry-over bacterial disease issues from seedbeds are seldom seen. This is in part due to the cooler conditions that are prevalent during December and January, which these bacterial pathogens do not prefer.
Onion seedlings are transplanted after Thanksgiving or in late November and continue until mid-December. Diseases are not so common during these months; however, Vidalia onion growers use a preventive spray of broad-spectrum fungicides that provides a general level of protection against foliar fungal pathogens.
Foliar symptoms of yellow bud disease on onion include intense chlorosis on emerging leaves and severe blight on the older leaves. Photo credit: Ronald D. Gitaitis, University of Georgia, Bugwood.org
JANUARY/FEBRUARY DISEASES
Fungal diseases are rare during December and January, but some bacterial diseases like bacterial streak and bulb rot (causal organism: Pseudomonas viridiflava) and yellow bud (causal organism: Pseudomonas coronafaciens) can be observed in late January to late February. Use of copper-based bactericide spray, optimum nitrogen fertilization and optimum irrigation generally help in managing these diseases.
WHAT TO WATCH FOR IN MARCH
As the temperature becomes moderate in March, along with frequent rainfall, Botrytis leaf blight (causal organism: Botrytis squamosa) and purple blotch (causal organism: Alternaria porri) can be observed. Stemphylium stem blight (causal organism: Stemphylium vesicarium) can also be seen in fields that are infected with either of these fungal pathogens. In general, Stemphylium sp. appears to be a weak pathogen under Georgia conditions, and it generally follows after Botrytis leaf blight, purple blotch or other diseases. A comprehensive fungicide program [as recommended by University of Georgia Cooperative (UGA) Extension] beginning in early March until harvest maturity (mid-April) effectively manages these three fungal diseases.
During the same time, the dreadful downy mildew disease (causal organism: Peronospora destructor) can also occur. Downy mildew is sporadic but aggressive. This disease is favored by prolonged leaf moisture and cooler night temperatures.
The fungicides that are labeled for use on onion against downy mildew are either moderately effective or less effective. Rotation of some of the moderately effective fungicides from different modes of action can help. Management practices that reduce prolonged leaf moisture and promote aeration can also help. The Vidalia Onion & Vegetable Research Center and UGA Extension specialists provide weekly forecasts of conditions that are conducive for downy mildew. These weekly alerts help onion growers to preventively spray against this pathogen.
Symptoms of slippery skin include white and bleached leaves (A) and soft-rot symptoms in bulbs (B). Photo credit: Howard F. Schwartz, Colorado State University, Bugwood.org
Bacterial diseases appear to be prevalent and problematic during the third week of March to harvest (late April) and can carry-over to storage (cause post-harvest losses). Some of the important bacterial diseases that Vidalia onion growers encounter are center rot (causal organism/organisms: Pantoea species complex), sour skin (causal organism: Burkholderia cepacia) and slippery skin (causal organism: Burkholderia gladioli pv. allicola). Sour skin and slippery skin are generally observed around harvest maturity.
Some of the minor bacterial diseases that can also be seen around harvest maturity are Enterobacter bulb rot/decay (causal organism: Enterobacter sp.), Rahnella bulb rot (causal organism: Rahnella sp.) and Pectobacterium soft rot (causal organism: Pectobacterium sp.).
Center rot outbreaks in Georgia generally coincide with the prevalence of thrips, which usually appear in late March and continue to increase in population throughout the rest of the crop growth period. Pantoea sp. can be acquired and effectively transmitted by thrips and hence, it is postulated that center rot appears in the Vidalia onion region when both thrips and Pantoea sp. are present together. Pantoea sp. can also be seed-borne, but its importance in disease outbreak may not be significant.
The bacterium is also present on asymptomatic weeds as an epiphyte, and in most of the cases, the bacterium in non-pathogenic. However, some of the Pantoea sp. on weeds can be pathogenic on onion seedlings/plants. As far as management of this disease is concerned, an effective weed and thrips management program along with a bactericide spray (program during susceptible onion growth stages) can effectively reduce the incidence and severity of disease in foliage and bulbs.
Onion bulbs reveal damage by infection with Enterobacter cloacae. Photo credit: Howard F. Schwartz, Colorado State University, Bugwood.org
Sour skin and slippery skin management are quite challenging; in most cases, use of a bactericide program does not seem to effectively manage these diseases. Crop rotation may provide a limited benefit, but due to the pathogen’s natural widespread prevalence in soil, real benefits of this cultural practice are hard to achieve.
Soil amendments with solarization, biofumigants and biocontrol also provided limited benefit, especially for sour skin. The UGA Extension Bulletin on bacterial disease management recommends avoiding overhead irrigation near harvest time. Another critical recommendation is harvesting onion at the optimum level of maturity followed by field curing for a minimum of 48 hours. Infected bulbs should be graded and discarded prior to storage with other healthy appearing onions. Evaluation of cultural practices, nitrogen fertilization, irrigation regimes (type, frequency) and post-harvest treatments are underway with support from the U.S. Department of Agriculture National Institute of Food and Agriculture Specialty Crop Research Initiative (2019-51181-30013) and the Vidalia Onion Committee grants. Production practices that generally reduce weeds, thrips and/or other insect pests, preventing injury to the foliage/bulb, avoiding over-irrigation, along with diligent use of a fungicide and bactericide spray program will help manage these diseases.
In a time when prices are low and expenses are high, pecan producers need to cut costs, not corners. Lenny Wells, University of Georgia Cooperative Extension pecan specialist, believes farmers can hold back in applying certain nutrients this year, if there is an abundant supply already in the orchard.
UGA photo/Shows young, immature pecan trees at the Ponder Farm on the UGA Tifton Campus in 2016.
Take phosphorus for example.
“Most of our orchards are high in phosphorus. Once you get phosphorus levels up in an orchard, they tend to stay there a long, long time,” said Wells during one of his winter production meetings. “For pecans, basically if your soil phosphorus is less than 30 pounds per acre, then you need to broadcast phosphorus in the orchard. If it’s more than that, a broadcast application is just not going to do you any good.
“We have situations where we have orchard soils that are that are higher than 30 pounds per acre and your leaf phosphorus is low. What’s happening there is, there’s something going on in that soil that’s tying up that phosphorus and it’s not available to the tree. The only way to get around that is to do a narrow band application of phosphorus over the drip emitters in the wet zone where the irrigation is. A broadcast application is not going to help. This narrow band application overwhelms that spot with phosphorus. The tree can then take it up in that zone where you’ve concentrated it.”
If farmers can avoid applying phosphorus, it will save them about $18 per acre.
Photo by Bayer/Shows the new fruit and vegetable seed distribution center in Valdosta, Georgia.
A new fruit and vegetable seed distribution center will provide seed to Southeast produce farmers in a timely and efficient fashion.
Bayer Vegetable Seeds announced the opening of its new distribution center in Valdosta, Georgia, located about 10 minutes from the Georgia-Florida state line. It will provide access to its Seminis branded large seed portfolio.
Currently, the distribution center is offering large seed varieties for sweet corn and beans, says Logan Burkhart, U.S. and Canada Customer Operations and Distribution Manager.
“I think for our customers down in the Southeast, it’s a direct to grower market. Having this physical location in the region just shows our commitment to those customers, and having that local supply available to them really helps put their mind at ease,” Burkhart said. “I would say in our Southeast region, it’s interesting because with the large seed portfolio difficult to move around, but having that delivery available locally is something that our customers really need. They’re not able to store it themselves so we’re able to have that distribution center to really be able to get it to them when they need it.”
Facility Size and Location
The facility has a physical cooler space of 3,000 square feet where the seed is stored. It is situated in the heart of the Southeast region. Valdosta is also not far from Alabama.
“This is actually our second distribution center in the region. We do have one in South Florida. We noticed that we really wanted to get a physical location to service the more local Georgia area,” Burkhart said.
He added that seed can continued to be ordered through the company’s sales representatives, who work closely with the growers.
The facility is located at 615 James P Rodgers Drive, Valdosta, Georgia 31601.
To learn more about the new distribution center or place an order, growers can call Oxnard Customer Service at 1-866-334-1056. The distribution center is open for appointment only Monday – Friday.
If you’d like to learn more about Seminis, visit the website at Seminis-us.com.
Seminis is the Vegetable Seeds business of Bayer’s Crop Science division.
Photo by Chris Tyson/UGA: Here is a large botrytis leaf blight lesion that has sporulated and the “cloudy halo” appears around the initial spot on the leaf. The development of these symptoms increases during periods when leaves stay wet for several hours at a time.
University of Georgia research trials show that two fungicides may be losing their efficacy in the control of Botrytis Leaf Blight of Vidalia onions.
Chris Tyson, University of Georgia Extension Area Onion Agent at the Vidalia Onion & Vegetable Research Center in Lyons, Georgia, informed onion producers and industry leaders during a webinar last week that Scala and Luna Tranquility have shown reduced efficacy in controlling Botrytis, a disease onion producers contend with every year.
“Most of this information has not changed but (Bhabesh Dutta) did stress and wanted me to mention to you about Scala and Luna. Within the last year or so, he says they have started to slip a little bit in how well they worked for Botrytis,” Tyson said. “Don’t misunderstand us. He’s not saying not to use these products. But we just want to make you aware we may take them off this list. We may rearrange them in the future to reflect that. They’re still good products. We still want you to use them.”
Disease Symptoms
Botrytis Leaf Blight infects onion foliage. Initial symptoms include white, necrotic spots surrounded by pale halos. Leaves with severe symptoms may lead to reduced bulb size.
The most updated list of effective fungicides includes Omega 500 and Miravis Prime, both of which provide high-to-moderate control. Scala provides high-to-moderate control as well, and Luna provides moderate control. But if the trend continues, UGA may adjust their recommendations to reflect the diminished efficacy of those two options.
“Keep in mind the only change in Botrytis control from last year is that those (two treatments) haven’t looked quite as good. They’re still providing control, just not at the level we thought they might be,” Tyson said.
Omega 500 is a valuable option since it controls Downy Mildew as well.
Weather forecasts call for sunshine every day but Monday this week in South Georgia. It’s not a moment too soon for vegetable farmers itching to get in the field.
Picture by Chris Tyson/UGA: Shows an onion field flooded.
Unfortunately, the excessive winter rains have delayed work for producers. It could have a snowball effect heading into next fall, says Sam Watson, managing partner of Chill C Farms in Colquitt County, Georgia.
“We’re still not through planting cabbage, so we’re going to kind of have a mess there with that. We’re behind on planting cabbage,” said Watson, who hopes to plant the rest of his cabbage during the middle of this week. There are still plants in the greenhouse that should have been planted Feb. 1.
“Of course, we haven’t laid any plastic yet. We usually start planting about the second week in March. We’ve got a lot of decisions to make when we get to the point where we can lay plastic.”
Key Decision Forthcoming
Watson and other producers face a key decision moving forward. Normally a fumigant like Telone is applied before plastic is laid. The fumigant is trapped under the plastic, and farmers normally wait three to four weeks before planting.
However, that may not be ideal with growers who want to stick to their planting schedule – which for Watson is around March 15. If it stays sunny most of this week , it won’t be until next weekend before Watson can start the process. If he utilizes a fumigant at pre-plant, it wouldn’t be until the end of March before plants get put in the ground.
“Timing is pretty critical because you’ve got certain things that need to happen before you can even put the plant in the ground. Not being able to lay plastic is going to cause a lot of delays,” said Watson who has about 100 acres that need plastic applied. “If you plant two weeks late in March, that means it’s going to come off two weeks late, which means you’ll go two weeks later in July. It just starts snowballing on you. Timing is critical with these vegetables. If you’re late in the summer with your vegetable crop, then you feel like you’ve got to pick it later but then that gets you behind on your fall crop.”
Telone’s Importance
Telone provides control of nematodes. If growers bypass applying it in their first vegetable plantings, there are other management options they can use during the growing season, but none are ideal, Watson said. But that may be the route he has to use if he wants to stay on schedule.
“We need to be harrowing. We’ve got to get everything harrowed and get the dirt ready and then you’ve got to get fertilizer spread and be locked, loaded and ready to go laying plastic,” Watson said. “Of course, everybody’s going to be doing it at the same time, so you’ve got to get your fertilizer man there. There’s going to be more equipment go to running here next weekend and the week after than you can shake a stick at.”
According to the UGA Weather Network, Moultrie, Georgia received 15.75 inches of rain from Jan. 1 to Feb. 18; compared to 6.51 in 2020 and 6.61 in 2019.
Some things are inevitable every year for Southeast peach producers. That late-season frost event that could damage peach production for the upcoming season unfortunately tops the list.
Pictured are peach blossoms.
Even though chill hours are no longer a concern, peach farmers are worried that if temperatures warm up in the next several weeks their crop would be vulnerable to a late freeze.
“Unfortunately, that’s exactly what happens every year to a different extent. How bad it’s going to be is going to depend on two major factors. What exact temperatures we’re going to experience and what is going to be the phenological stage of flower and development at this point of time,” said Elina Coneva, an Extension specialist in the Horticulture Department at Auburn University.
Management Options
Producers have limited options if they encounter a late-season freeze. Coneva said the best protection against high wind speeds is to establish barriers. When establishing orchards, try to plant near wooded species like pine trees. These serve as wind breaks against high winds.
If a freeze event occurs and temperatures are higher during the day and diminish during the evening, heaters can be used. Producers can also utilize wind machines that provide air inversion, taking warm air from higher elevations and pushing it down to the trees.
Growers can also protect against future frost events by planting orchards near water sources, like a pond or lake. Water retains higher temperatures longer. During such events, it can radiate some of those temperatures, added Coneva.
“If the trees are dormant, we can expect some damage, if it’s 5 to 20 degrees Fahrenheit. But if they’re in the next stage of calyx green or calyx red, temperatures of 21 to 23 degrees Fahrenheit can cause some damage,” she said. “If the trees have already experienced some temperature fluctuation, like cold temperatures followed by warming periods of time and then experiencing some cold again and then warm-up events, this is pre-disposing the trees to advancing their development… we can expect more damage to occur.”
Visible Sporulation of Downy Mildew on Vidalia Onion Leaf. Photo Credit: Chris Tyson
It was March 23 in 2020. In the prior season it was Feb. 28. In 2018 it was March 19. All were dates that Downy Mildew disease was initially discovered in Georgia Vidalia onions. If past seasons are any indication, the disease could soon be ripe for a problem for Vidalia onion producers.
“Downy is always on our minds this time of year and going to the end of the season,” said Chris Tyson, University of Georgia Extension Area Onion Agent at the Vidalia Onion & Vegetable Research Center in Lyons, Georgia. “It can be bad, and I want you to be prepared for it and make sure you’ve got the tools you need to fight it. As growers you know this is a tough disease. Sometimes when the weather conditions are right, sometimes it seems like there’s nothing we can do to stop this.”
Effective Products?
The most effective products available for protection are only moderately successful. Omega 500 and Orondis Ultra provide moderate control. Bravo and Zampro provide moderate-to-low efficacy. Growers are encouraged to incorporate Bravo and Phosphites into their spray program now for added protection.
“We’re recommending that everybody, if they haven’t already, start including products like Bravo and Phosphites … these are good protective products and they’re economical to use. We just need to be putting those in spray program as much as we can,” Tyson said.
Disease Impact
According to the UGA Extension Vegetable Blog, Downy Mildew can be a devastating disease to onion producers. It can cause losses in yield and bulb quality. Though the disease does not survive year-round in the Southeast Georgia region where Vidalia onions are produced, it moves into the area from wind currents from warmer areas.
In a prior VSCNews article, UGA Extension Plant Pathologist Bhabesh Dutta said the disease’s first symptoms occur on older leaves as light green to pale yellow, which turn to tan or brown as the lesion ages. Lesions may girdle the entire leaf. In severe cases, 100% yield losses have been reported.
“We’re already watching the weather conditions to look for conditions that are favorable for disease development,” Tyson said. “It’s time to be watching out for it. I would urge you to go ahead and consider stocking up on some Omega or Orondis or calling your retailer and seeing if they have some on hand or whatever you need to do.
“If we find Downy, there’s no time to go around and hunt for chemicals if you need one. Just be ready.”
Torrential rains this year have impacted farmers across the Southeast. Vegetable farmers are unable to get in the fields to apply plastic in preparation for the upcoming season.
File photo shows a pecan orchard flooded.
One commodity group that could also feel the sting of excessive rainfall this winter are pecan producers. While trees are currently dormant, their production could be affected this year and years to come.
“Pecans actually adapted in areas that got seasonal floods. They kind of evolved their natural range in areas that have seasonal floods this time of year. The big caveat on that is they grew on well-drained soils,” University of Georgia Cooperative Extension pecan specialist Lenny Wells said. “They can stand water-logging for a little while, especially when they’re dormant. But that soil needs to be well-drained so that it can drain off quickly. Ideally, they wouldn’t be in standing water for more than a few weeks. This time of year, there’s a little bit of leeway. They’re a little more tolerant of it this time of year. The worst time for something like this to happen would be anytime during the growing season, really; bud break especially, as the new foliage and the crop load is developing, that’s the worst time for it.”
Young Trees At Risk
Standing water is especially harmful to young orchards in poorly drained soils. Those trees that are newly planted, a couple of years old or younger. If they’re in soil that doesn’t drain well, in standing water for weeks up to bud break, they’re going to be stressed and more attractive to ambrosia beetles.
According to the UGA Weather Network, Tifton, Georgia received 13.66 inches of rain from Jan. 1 to Feb. 17, compared to 6.72 in 2020 and 5.8 in 2019. In Albany, Georgia, there were 11.1 inches recorded, compared to 8.15 in 2020 and 8.34 in 2019.
UGA CAESNewswire photo/Apple trees can add a nice backdrop and bounty to your garden. Although the northern half of the state is best suited for the more “conventional” apple varieties, you can have success in the southern half of Georgia with adapted varieties.
By Becky Griffin for CAES News
Americans recognize Arbor Day in April. However, Georgia celebrates Arbor Day on the third Friday of February each year because this is a better time to plant trees, giving roots time to grow before the heat and drought of our summer months.
Georgia’s Arbor Day falls on Feb. 19 this year and University of Georgia Cooperative Extension has many resources available to help you select, plant and maintain trees in your landscape.
Fruit trees in particular can add a nice backdrop to your garden, provide a bit of shade during the very hot summer days and, of course, produce delicious and nutritious fruit.
Be warned, however, that fruit trees can be a lot of work. There are a few points to think about before you decide to plant fruit trees in your home or community garden.
Find the Right Location
When planning fruit trees in limited space, location is the key. Fruit trees require at least six hours of sunlight to be healthy and to produce fruit. Eight to 10 hours of sun is optimal.
Also, although the shade a fruit tree provides during August may be welcome, you do not want to create unwanted shade on vegetable plots. Dwarf trees may be the best answer here. They are also easier to care for than full-sized trees. Remember that what you plant will get bigger and taller.
Maintenance Matters
Realize that fruit trees involve more care than vegetables. They may need to be properly pruned, thinned and fertilized regularly. Apples, peaches and plums will get diseases and insects in Georgia, and this must be addressed with the use of pesticides, fungicides and traps.
If you are avoiding using pesticides, growing traditional fruit trees such as apples, pears and peaches may not be for you. Instead, you may want to try other fruit crops such as blueberries and figs. UGA Extension Circular 1027-10, “Growing Fruits,” by UGArden Director David Berle and consumer horticulturist Robert Westerfield, is a great resource on these issues.
You May Need More Than One
Many trees need cross-pollination to produce fruit. You will need at least two different apple trees and, depending on the variety, you might need two different pear or plum trees.
Most peach trees self-pollinate, so one will still produce fruit.
Other Considerations
Many fruit trees are purchased as bare-root trees that have no soil or planting medium around the roots. For information on planting these, see UGA Extension Circular 1061, “Planting Your Bare-Root Fruit Tree.”
If these points haven’t scared you off, check out other Extension publications, including Circular 742, “Home Garden Pears,” and Circular 740, “Home Garden Apples.”
Another way to think about trees is their value to pollinators. There are many “trees for bees” and other pollinators that do well in our Georgia ecosystems. Did you know that several native trees are larval host plants for butterflies? Extension Bulletin 1483, “Selecting Trees and Shrubs as Resources for Pollinators,” is a wonderful resource for Georgia gardeners.
Contact your UGA Extension agent for more information on planting trees by calling 1-800-ASK-UGA1 or visiting extension.uga.edu/publications.
