Georgia blueberry growers overwhelmingly voted to extend the assessment of $5 per ton of marketed blueberries for an additional three years. The extension was passed with nearly 82% of the eligible ballots returned with a ‘yes’ vote. The balloting period for the market order was conducted from March 1-30, 2021.
The Georgia Agriculture Commodity Commission for Blueberries utilizes funds for blueberry research, education and promotional projects. The Georgia Blueberry Commission has been actively supporting efforts to encourage the Federal Trade Commission to investigate trade practices of other countries for dumping blueberries into the U.S. market.
The Commission was established by the Georgia State Legislature in 2008 and has continued to support important projects for Georgia blueberry growers, with most of the funds committed to research projects on fertility, variety evaluation, insects, disease management and weed control.
Figure 1. Southern red mite adult female and male mating (top) and one egg (bottom).
Photo by L. Buss, UF/IFAS
By Oscar E. Liburd, Lorena Lopez and Doug Phillips
Mites can cause significant damage on blueberry plants if not properly managed. Mite species that feed on southern highbush blueberries (SHB) include the southern red mite (Oligonychus ilicis) and the false spider mite or flat mite (Brevipalpus yothersi). The southern red mite is the primary mite pest feeding on blueberry plants in the southeastern United States and is common in fall and early spring. The false spider mite, first reported on SHB in 2016, is more common during summer months.
SOUTHERN RED MITES
In Florida, southern red mite populations increase under dry weather conditions with warm temperatures (60 to 86° F) and reach their peak during the fall. Their life cycle can be completed within two weeks under these conditions, and populations can double within five days with overlapping generations, increasing their potential for significant yield impact.
Adults are similar in appearance to the red form of twospotted spider mites (Tetranychusurticae) and other red Tetranychus species, about 0.4 millimeter in length, red or brown to deep purple in color, with lighter colored legs (Figure 1). Females are slightly larger than males and have a more rounded body shape. Red to brown spherical eggs hatch into pale six-legged larvae. In the nymph stages, mites develop eight legs and are darker and larger.
Figure 2. Female adult flat mite
Photo by: R. Akyazi, University of Ordu
FALSE SPIDER MITES
False spider mites can complete their life cycle in about 19 to 20 days at around 77° F and 60 percent relative humidity. Adult flat mite females are flat and oval, approximately 0.3 millimeter in length, with red-orange coloring (Figure 2). Males and immature stages (larvae and nymphs) are similar in appearance and color pattern to the females but smaller. Eggs are bright red to orange and elliptical in shape.
DAMAGE
Southern red mites primarily live and feed on the lower side of SHB leaves. An accumulation of shed white skins can be observed when populations reach high numbers (Figure 3). Bronze coloring of leaves is the primary symptom accompanying southern red mite injury, with the intensity of bronzing increasing with the level of internal leaf damage (Figure 4). The southern red mite feeds on plant tissues by inserting its mouthparts into the leaf and removing cell contents, resulting in a decrease in the rate of photosynthesis.
In SHB, leaves heavily infested with flat mites typically develop necrotic brown spots (Figure 5).
Figure 3. Southern red mites shed their white skins on leaves.
Photo by D. Phillips, UF/IFAS
MONITORING
In addition to differences in body shape and color, there are other distinctions between southern red mites and flat mites to consider when monitoring for these pests. Flat mites are smaller, move more slowly and are best observed with a hand lens or under a microscope. Southern red mites move more rapidly and can be observed with the naked eye on blueberry leaves. Southern red mites tend to feed over the entire surface of the underside of leaves and produce a web over the infested surface to protect them from predators. Flat mites typically feed near the midrib or secondary veins on the underside of leaves and do not produce a web.
Mite populations tend to increase during hot, dry conditions. Frequent scouting for the presence of mites is recommended for early identification of infestations. Although southern red mites can be seen with the naked eye or a 10x hand lens, flat mites will need a higher magnification lens (20x) for identification.
Typical symptoms of mite feeding (bronzed leaves for southern red mites and necrotic spots for flat mites) are also a good indication of mite infestations. However, monitoring for adults in addition to symptoms is important since by the time symptoms appear, infestation has already occurred and defoliation risk is increased.
Closely examine the underside of leaves with the appropriate magnifying glass to look for adults, shed skins and webbing. Another way to scout for the presence of mites is to sharply tap the foliage onto a sheet of white paper to observe any adult mites.
Figure 4. Bronze-colored blueberry leaves are associated with southern red mite damage.
Photo by D. Phillips, UF/IFAS
The pests favor dusty conditions, and drought-stressed plants can be more susceptible to infestations. In addition to supplying plants with sufficient irrigation, applications of water should be made regularly to roadways or other dusty areas during hot, dry periods.
MANAGEMENT
The flat mite is an important pest of citrus and its biology and ecological interactions have been studied in that cropping system, as well as most of the management techniques used for its control. Because it was only recently reported in blueberries, there are no established guidelines for the control of this mite in blueberry plantings. There is also no available information on miticide performance against flat mites infesting blueberries.
The southern red mite is now an important pest in both protected and open-field SHB plantings. Three miticides — Magister (fenazaquin), Portal (fenpyroximate) and Kanemite (acequinocyl) — have recently been registered for use in highbush blueberries. These miticides target tetranychids and not specifically southern red mites, although Kanemite specifically mentions southern red mites on its label. The miticides control all developmental stages including larvae, nymphs and adults of southern red mites. In addition, Magister provides control of eggs by contact while controlling other stages by both contact and ingestion.
Data from University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) 2020 field trials (where eight miticides were evaluated) indicate that Magister and Portal continue to be the best-performing miticides as shown in 2019 trials. Both products suppressed southern red mite populations and allowed bushes to recover from mite injury. Growers can only make one application per year using Magister and two applications per year with Portal. Kanemite was also effective at reducing southern red mites in 2020.
Additionally, two sulfur-based products were evaluated in the 2020 field trials. Sulfur-CARB, a suspended sulfur soil amendment (elemental sulfur and molasses), is sometimes used for foliar applications to repel mites and insects. It provided good performance for control of mites only after a second application (14 days apart), as well as lower levels of bronzing at the end of the experiment. However, this product is not labeled specifically for southern red mites in SHB. Cosavet DF (sulfur) was not effective at reducing southern red mites.
Figure 5. These necrotic brown spots on blueberry leaves are caused by flat mites.
Photo by: R. Akyazi, University of Ordu
Early identification of mite infestations and implementing management techniques before populations reach high numbers are recommended to avoid yield impacts. Although predatory mites have been an important tool that is used for controlling spider mites, to date they have not been successfully evaluated in blueberry systems.
For more information, see UF/IFAS Electronic Data Information Source Publication ENY-1006, Mite Pests of Southern Highbush Blueberry in Florida (edis.ifas.ufl.edu/in1284).
Oscar E. Liburdis a professor, Lorena Lopez is a post-doctoral research associate, and Doug Phillips is a blueberry Extension coordinator — all with UF/IFAS.
Alabama Extension will hold a virtual webinar on weed management in strawberry, peach and blueberry production systems on Tuesday, May 4 at 11 a.m. (EST). Alabama Extension specialist Steve Li will discuss weed management on blueberry, peach and strawberry farms.
A late crop, a topsy-turvy market and a consistent influx of produce coming in from Mexico – just another challenging year for Florida’s blueberry growers.
Chuck Allison, blueberry farmer and owner of Wild Goose Farms in Umatilla, Florida, said the cooler winter has delayed harvests this year.
“We’re getting started. We picked last week a couple of times. We’re getting back this week, probably, and then next week we’ll probably be picking every day,” Allison said. “With the cool weather this past weekend, it kind of slowed things down again. A lot of early varieties are probably 7 to 14 days later than last year. It’s all about heat units. We just didn’t get the same heat units this year.”
As harvests begin to increase for Allison and other Florida farmers, the question is how will the market play out over the next month or two? That’s really unpredictable.
“It’s so hard to tell with the marketing and stuff. There’s so many dynamics going on with Mexico now, when Georgia would come in behind Florida; Chile’s going to end and be out of the market, which will help significantly. We’re hoping that Mexico will get some of their volume through the marketplace instead of storing fruit and leading it into the market later on,” Allison said. “We think Georgia may be late like we are, so there will be a normal transition there, and North Carolina even later. We may get a more normalized market with the transitions between states. I don’t know, it’s so hard to tell.”
What was once a booming industry in Florida is now running on fumes. Mexican imports and the U.S. International Trade Commission (USITC) have made it almost impossible for Florida blueberry producers to compete like they used to.
“Florida went through an increase from 2000 to 2015 or so. Now, I don’t know of anybody that’s putting blueberry acreage in because they see the writing on the wall,” said David Hill, owner of Southern Hill Farms in Clermont, Florida and vice chairman of the Florida Fruit and Vegetable Association. “What’s happening now is the smaller guys, they can’t hang. The margins aren’t there. They’re selling out. They’re either selling to developers trying to find somebody to buy their farm for cheap. Now you can get a blueberry farm cheaper than you can put one in. But I don’t see a lot of people wanting to get in the blueberry business.”
Why would any farmer want to try their hand in blueberries? Especially when the USITC decided in early February that blueberry imports were not a serious injury to the domestic market. The USITC voted 5-0. It was a devastating blow to Florida blueberry producers longing for relief.
Statistically Speaking
According to University of Florida Associate Professor Zhengfei Guan, Mexican imports of blueberries were non-existent before 2009. But in 2019 they totaled a little more than 90 million pounds, compared to Florida’s approximate 24 million pounds of production.
Hill compares the state of the blueberry industry to Florida’s tomato industry which was also decimated in recent years.
“It’s the same kind of thing. You’ve got to be big, and there’s only so many people that can be big, but the smaller guys, you just can’t afford to keep losing money. Things are looking worse,” Hill said. “Mexico is ramping up. The government is subsidizing the industry. The obvious is look at the labor costs. It makes it very difficult to compete.
“You’ve got all of this infrastructure you put in and you can’t get the returns. If you sell it as a blueberry farm, you’re selling it at a huge discount. That’s the only way you’re going to entice somebody to buy it as a blueberry farm.”
Site selection remains a pivotal decision for all potential blueberry producers. Alabama Regional Extension agent David Koon discussed various site-selection factors that will impact whether a grower experiences success.
“When we think about site selection of where you’re going to plant your blueberries, just like every other vegetable or fruit producing plant, full sun is a must. Partial shade, you can still grow them and get some fruit, just not near as much,” said Koon during a webinar on the Alabama Extension Commercial Horticulture Facebook page. “Full sun should be the No. 1 factor for any kind of production for a vegetable or fruit crop.”
It is also important to remember that freeze damage may occur in low areas.
“Think of low areas, just like water. Water flows downhill. If there’s a dam at the bottom of the hill, it’s going to pool. That cool air does the same thing,” Koon said. “If it’s in a low spot that’s got high ground all around, that cool air tends to settle in that hole. When you’re thinking two to three degrees difference between 32 and 29 degrees when you get damage, that low place can give you some problems.”
Producers may need to consider planting on the south side of a slope.
Water is Essential
Water accessibility is also an important factor. Blueberries need moisture but won’t tolerate standing water. Raised beds may be required.
“Blueberries do need water. They like to be watered, but they do not tolerate wet feet. If you’ve got some drainage problems or some areas that don’t drain well, you may want to look at some raised beds,” Koon said. “Anytime we talk vegetable production or fruit production, how are you going to get the water to it? Is there a water source readily available? Will it supply enough water for the number of plants that you’re considering?”
Georgia blueberries are progressing this season but don’t expect them to be ready for an early harvest, says Renee Holland, University of Georgia area Extension blueberry agent in Alma, Georgia.
“It depends on the weather between now and then. It’s quite warm right now, so things are progressing very quickly, Holland said. “I don’t think we’re going to be two weeks early like we sometimes are. I think we won’t really start picking until May. There may be a little bit in late March for the earlier varieties. But overall, I’d say most of our picking is going to come on in May.”
Colder temperatures this winter slowed the growth of Georgia blueberries. Weather will still play a role in how quickly the blueberries mature between now and May. Cold and warm temperatures could “push” and “stop” the growth of the plants, Holland said.
“We’ve had some years where we’re like two weeks early. But I think we’re going to be right on time, as they say, this year,” Holland said. “We’re not running behind, but we’re not early, so more kind of a moderate year.”
As far as the what the crop looks like now, Georgia producers couldn’t ask for much a better crop status.
“It looks like we have a nice, large crop load. Most everything’s in full bloom by now, depending on the variety of the plant and the species of the plant. A lot of things are in bloom. We have the blooms out. Some of our mid-season stuff is still in the earlier bloom stages,” Holland said. “We’re in a good place right now. Of course, we’re just waiting to see if we get any freezes.”
UGA photo/Mummy berry disease is caused by the fungus Monilinia vacciniicorymbosi and is an important fungal disease of blueberries.
South Georgia blueberry producers need to be wary of mummy berry disease. University of Georgia Extension advises growers to initiate sprays for the disease to protect plants that are vulnerable.
“Growers usually know around green tip, when new leaves are developing and then through bloom, they need to be putting out effective fungicides for control of mummy berry,” said Jonathan Oliver, University of Georgia (UGA) assistant professor and small fruits pathologist. He added that while the disease typically impacts rabbiteye blueberries, it may be a problem this year for southern highbush varieties as well.
“On southern highbush blueberries, those berries tend to develop a little earlier than rabbiteye, and usually, the mummy berry life cycle doesn’t quite match up right with the southern highbush life cycle. Usually our southern highbush (varieties) escape,” Oliver said. “But our blueberry development right now is several weeks behind where it’s been the last couple of years, and so a lot of our southern highbush happen to fall right in the window where perhaps they also could get infected with mummy berry this year. While it’s usually not a problem for southern highbush, this year maybe a year where it could be.”
Symptoms
“It’s a fungus species that first will infect the young leaves and then it will spread to the blooms. After it infects the blooms, any blooms that get infected that produce berries, those berries will be filled with fungus tissue,” Oliver said. “A fungus will grow in the berry and suck all of the moisture out. It basically ends up with a mummified berry. That’s where the disease name comes from.”
Additional information on fungicides that are available to control mummy berry can be found in the Southeast Regional Blueberry Integrated Management Guide at www.smallfruits.org.
“Growers of southern highbush don’t always spray, I mean they spray fungicides that probably are going to have efficacy against mummy berry but they don’t spray, specifically targeting mummy berry, usually because they don’t have to. But this year may be a year where they need to,” Oliver said.
Florida Grower: It’s not going to be like it was last year
File photo shows highbush blueberries.
It’s a tale of two seasons for Florida blueberry growers. Producers were early with last year’s crop but encountered COVID-19 that kept prices low.
This year’s cooler weather has slowed the growth of the blueberry crop, which means it’ll likely be ready for its normal timeframe. Hopefully, that’ll mean better prices for growers like Ryan Atwood.
“The weather was colder for January and for a good bit of February. Weather’s been warming up of late. We’re probably catching up here a little bit lately. It’s not going to be like it was last year,” said Atwood, who lives in Mount Dora, Florida and farms 56 acres of blueberries, manages another 350 acres and is part-owner of the largest packing house in the Southeast United States. “That was horrible the way that all played out last year. It was almost like the rug getting yanked out underneath your feet. But you live to fight another day.”
Warmer Temperatures in 2020
A milder winter last year accelerated growth in last year’s blueberries. Atwood started picking high volumes of blueberries around March 18. But it also coincided with the pandemic shutting down the country. Market prices reflected the pandemic’s impact.
Early harvests have already begun for this year’s crop.
“We started scrapping, lightly picking on Evergreen stuff,” Atwood said. “We’re a ways off from the main part of our crop. We grow a small acreage of evergreen production. But most of our production is deciduous production, and that won’t crank up til later. “We picked 400, 500 pounds two weeks ago. Then we picked 1,800 pounds last week. Now, we’re picking 3,000 pounds this week.”
Georgia’s blueberry producers can vote until March 30 on the continuation of the Georgia Commission Blueberry Marketing Order. This allows for the assessment of blueberries produced in Georgia.
Growers who annually produce and market 2,000 pounds or more of blueberries are eligible to vote. The current assessment amount is set at $5 per ton.
Growers can vote and return the addressed envelope with the ballot by March 30, 2021. They must also sign and fill out the back of the envelope to certify they are a qualified Georgia blueberry producer, so the ballot can be counted.
A percentage of two-thirds of the returned eligible ballots are required for the continuation of the market order.
The Georgia Agriculture Commodity Commission for Blueberries uses the funds for research, education and promotion of Georgia blueberries.
If a grower does not receive a ballot, please contact:
Andy Harrison Manager, Commodity Commissions Georgia Department of Agriculture Andy.harrison@agr.georgia.gov (404) 710-1196
