Growers face a two-pronged challenge when trying to defeat weeds in a potato field. On the one hand, they want to kill the weeds; on the other, they want to grow potatoes.
This challenge was highlighted in two presentations Pam Hutchinson, an associate professor in the Department of Plant, Soil and Entomological Sciences at the University of Idaho, delivered at the recent Pacific Agriculture Show in Abbotsford, B.C.
Hutchinson made two key points to growers: herbicides should be matched to soil conditions to ensure developing tubers are adequately protected against competition, while being sure that the materials they’re using don’t stunt the growth of potato plants while they’re doing what they’re supposed to – suppress weeds.
Hutchinson came packing a tonne of data from research trials that underscored how tightly managed herbicide applications need to be for maximum effectiveness. The information reviewed work with Chateau, Outlook, Prism, Prowl H20, and the new offerings Lorox and Reflex.
Hutchinson said sandy soils may offer good drainage, but the same quality also lets highly soluble herbicides like Matrix and Outlook leach out of the rows, allowing weeds to take hold. She recommended Chateau and Lorox, which are not as soluble, in these conditions.
A less soluble herbicide, such as Prism or Metribuzin, can also provide adequate coverage in fields with heavier soils and prone to clodding.
She also encouraged growers to time herbicide applications as close to emergence as possible. While weeds can be taken out with a cultivator when potatoes have put out a couple of leaves, Hutchinson advised applying herbicides when the potatoes are hilled, which usually occurs four to eight weeks after planting.
“You’ll get the herbicides down where you need them and they’ll last into the growing season until a little beyond row close, when you start having a crop to help compete with those weeds,” she said.
But there’s another variable – the weather. Suppressing weeds is desirable, but potatoes are also susceptible to the effects of some materials. While they can metabolize products as diverse as Roundup and Chateau, little will happen without a good run of sun.
“The only way the potato can be safe ... is to metabolize that herbicide, break it down to a non-herbicidal chemical,” Hutchinson said. “So if it’s cloudy or cool, the potato is not growing very fast and not metabolizing anything very fast.”
Hutchinson’s trials indicate that the plants can recover, but even a brief slowdown in the plant’s metabolism can lead to short-term stunting and a slight reduction in yield.
Outlook presents a different scenario. It’s typically applied at a higher rate, particularly on coarse soils, and this can lead to early season injury – leaf crinkling and chlorosis – if the weather at application is cold and cloudy. But once it warms up and the potatoes are growing, Hutchinson said there’s no reduction in yield.
A particular challenge for growers in Idaho, however, is protecting potatoes from the carryover effects of Roundup (glyphosphate) as well as dicamba and pyralids. The problem particularly affects seed potatoes, which get a dose late in the season when Roundup is applied in adjacent grain fields. Roundup drifts on to foliage, and from there, travels to the tuber.
Carryover of the material has dogged growers. It persists for up to eight months in tubers, stunting growth the following season. While potatoes can metabolize the herbicide, the process requires sunlight and warmth – something the tubers don’t get in storage.
While a high concentration can prevent sprouting, even small concentrations can inhibit emergence and be expressed in low vigour and foliar injury.
Recovery is possible, of course. Tests of seed stock from treated Russett Burbank and Shepody plants stayed hard and intact throughout the growing season – until the eight-month window required for metabolizing the glyphosphate was up. Then they started sprouting. Similarly, the granddaughters of affected tubers were fine.
To protect themselves, Hutchinson told growers to avoid cross contamination of their equipment, having equipment dedicated to Roundup if at all possible. Talking with neighbours whose fields abut their own is also a wise move, so that everyone knows when, where, and what concentration of Roundup is going on fields.
The Wild Blueberry Producers Association of Nova Scotia were recently informed there are still many unanswered questions about spotted wing Droisophila.
“We’re still learning a lot about this pest,” admitted Peter Burgess, a pest control specialist with Perennia, Nova Scotia’s government extension and advisory service.
A high infestation rate of spotted wing Drosophila larvae makes berry fruit unmarketable, said Burgess, observing the warmer the growing season becomes, the faster the life cycle of SWD becomes.
“This is the problem with this pest; it reproduces faster as the temperature warms up.”
He added that SWD lays eggs in all soft fruit and is particularly attracted to ripening berries.
“In Nova Scotia, we are not seeing emergence of the fly until the end of July in the last couple of years,” he said.
As for a control strategy for this Drosophila species, Burgess advised wild blueberry growers to pick their fruit early, “and pick your best fields first.”
SWD larvae populations build rapidly in August, with a harvest in September being at the greatest risk of SWD larvae infestation, he added.
When monitoring for SWD, look for the males, he continued, with monitoring traps placed in wild blueberry fields by mid-July. Monitoring is important and the traps should first be placed in the tree line beside fields as SWD flies like the shade. Traps in the fields should be placed at 20 metre intervals.
“We use apple cider vinegar with or without yeast baits,” for bait traps he said, adding by 2015 an apple cider vinegar bait with a synthetic lure will be commercially available.
“It works as well as any current bait.”
Apple cider vinegar can be combined with red wine and unrefined sugar in a trap after the fruit is harvested as the flies will be drawn to the trap since there is nothing else to feed on, Burgess said.
“If the field is two weeks away from being harvested, you likely will need a pest control application, or if it is the 15th of August and you will not be harvesting until September, you probably need a control,” he advised. “But if you will be picking within a week, you can probably omit an application.”
As for insecticides registered for SWD, Burgess said there is a new product registered for spotted wing Drosophila – Exirel from Dupont. However, he added, “there are MRL restrictions on it in the Japanese and EU markets.”
Exirel has a maximum of four applications during the growing season, Burgess noted, and it is not yet fully registered – it can only be used as an emergency application.
Delegate and Malathion can also be used against SWD with a maximum of three applications during the season, he said, adding that Ripcord is also registered but should not be applied during hot weather “as it will burn the fruit.”
Assail will work well on blueberry maggot, Burgess remarked, but “it is not spectacular on spotted wing Drosophila.”
Entrust is also registered as an organic product, he added.
Spotted wing Drosophila, “will not be a one and done treatment,” said Burgess. “For control, you need to look at seven day intervals until harvest.”
Timing of the application is also important, as applying the control product just after a rainfall will reduce the application’s efficacy, he said.
SWD spreads from field to field and from fruit crop to fruit crop but wild blueberry fields are generally isolated at some distance from other berry crops, Burgess stated.
This past cold winter, which resulted in a lot of snow, will most likely protect and insulate the pest, he said, but a cold spring will delay the pest’s emergence.
“Across North America, we are seeing larvae in the fruit before we catch it in the traps,” he said.
The challenge for most growers is distinguishing between the blueberry maggot and the SWD larvae.
“Take a sample from firm berries,” Burgess said. “If a larvae is there, it is spotted wing Drosophila.”
April 22, 2014, Mississauga, Ont – The Pest Management Regulatory Agency (PMRA) in Canada recently granted additional label expansion approvals for DuPont Exirel insecticide for fruit and vegetable growers.
Fruit and vegetable growers may now use Exirel insecticide for managing black vine weevil and clay coloured weevil in bushberries, as well as flea beetles in tuberous, corm, brassica and fruiting vegetables. This label expansion comes just months after other recent label expansions that have approved Exirel for the control of spotted wing drosophila in stone fruits and blueberries.
“Until now, growers have had limited options for managing these yield-damaging pests,” says Ray Janssen, horticulture segment manager with DuPont Crop Protection. “DuPont Exirel is powered by Cyazypyr, the first active ingredient to control a cross-spectrum of chewing and sucking pests. Cyazypyr provides consistently excellent insect control, and also serves as an excellent resistance management tool.”
According to DuPont, when Exirel is applied early in the crop life, it can increase the opportunity for improved marketable yield by reducing feeding damage.
Spotted Winged Drosophila (SWD) has been present in British Columbia fields and orchards since 2010. Despite a joint effort from government and industry researchers in B.C. and throughout the Pacific Northwest, the 2013 growing season was the worst year for SWD infestation on record.
At the Horticulture Short Course, held during the Pacific Agriculture Show in Abbotsford, B.C., a grower, packer and crop consultant came together to share what they learned about managing this persistent pest and protecting B.C. berry crops and markets.
“Spotted Winged Drosophila is a very fancy name for a nasty insect that has become a palpable thorn in our back,” says grower, Sukh Kahlon. “It has complicated the harvesting process which was complex to begin with.  was a difficult year, but was that the worst, or is it going to get worse? The best thing we can do is manage SWD to mitigate it rather than eradicate it.”
Building from his own experience, Kahlon encourages other growers to keep informed, have a control program in place that includes a spraying schedule and cultural practices, and to have the resources in place to execute your program.
“One of the things we should look at is regional information and know what’s happening in the Pacific Northwest,” says Kahlon. “The fact that Oregon is a week to 10 days ahead gives us an insight into the future. Last year we got the news that Oregon was finding larva in their earliest raspberry harvest. That was a red flag for us and I think we should use that to our advantage.”
A number of different reports are available for growers online, making it easier to know what is happening with SWD in specific areas. The B.C. Ministry of Agriculture provides weekly reports on their website, and many growers subscribe to the Peerbolt report.
As in years past, maintaining regular spray intervals, and rotating chemicals used in pest control are important factors in keeping SWD numbers down while managing for pesticide resistance. Current field trials have demonstrated that growers should spray every seven to eight days.
“Work with your neighbours,” says Kalon. “There’s a lot you can learn and you can coordinate your program. With all of the chemicals that we are using, we risk overusing them. It will be to our advantage to rotate through the chemicals and use different chemistry as much as we can.”
According to Chuck Mouritzen with Southwest Consulting, infield monitoring on your farm with traps is not an effective way to coordinate spray schedule. He recommends growers take their lead from regional trapping program results.
“You’ll get an idea of trend results with the populations so you’ll have a good idea what you are going to face and can get the control measures in place,” he says.
Once fruit starts to mature, Mouritzen recommends growers do salt extraction testing to get an accurate measure of larval infestations, and to help make sure the spray program is working. If levels are high, it’s important to adjust the program. Growers also need to be prepared to start picking as soon as fruit starts ripening.
“Last season we got early heat and the early fruit wasn’t treated because it wasn’t being picked so we really missed it,” Mouritzen explains. “Prepare yourself for early pick season, or at least for early ripening before you start picking.”
Effective pruning is another tool to help growers reduce infestations. The goal is to concentrate the ripening period and eliminate canes that are not going to produce marketable fruit.
“Pruning is a simple way to reduce the pressure and concentrate the quality fruit,” says Mouritzen. “It is more of a problem with the newer growers. There are a lot of newer people in the business, and to get them pruning properly is really important.”
Ultimately, the take-home message from the 2013 season is simple – everyone has to work together to control this pest or the entire sector is under threat.
“By not having control of this pest you are really risking your own fruit as well as your neighbours fruit. The key for packers and growers is understanding the threat posed to our industry from this pest,” says Mouritzen.
Steve Phillips of Berry Hill Foods in Abbotsford, B.C., agrees. He points to close communication between growers and packers as one of the keys to success identified by, particularly when it comes to managing pesticide sprays and residues.
“We have to spray so much more now, and pesticide residue testing is really accurate,” says Phillips. “If the pesticide residue is too high in a load, it’s a total recall. It’s also important to work with packers to make sure that pesticides used in fields are registered in the countries that they are selling to.”
Picking times are as important as spray intervals when managing SWD. The days of letting ripe fruit hang and gain weight is over, says Phillips. Despite the high SWD in 2013, he came out of the experience confident that growers have the tools and motivation to keep the pest under control.
“With proper use of pesticides, communications and relationships with packers, SWD is very manageable,” he says. “If you have SWD, you are going to get downgraded and that’s less money in your pocket.”
March 18, 2014, Guelph, Ont – Bayer CropScience Canada recently announced the registration of Alion as a pre-emergent residual herbicide for grapes.
The Group 29 herbicide provides long-term residual control of annual grassy and broadleaf weeds and is currently registered for use with tree fruit. It prevents weeds from emerging by inhibiting the growth of the developing radicle in the seed germination zone.
“Canadian grape growers will see the benefits of a completely new mode of action that provides longer lasting control compared to competitive products,” explained David Kikkert, portfolio manager for horticulture with Bayer CropScience. “This unique mode of action combined with its tank-mix flexibility makes it an excellent resistance management tool especially for glyphosate, triazine and ALS-resistant weeds.”
Alion can be tank-mixed with glyphosate, Gramoxone herbicide, and Ignite herbicide in grapes to provide control of already emerged weeds. It can be applied to established grapes of at least five full growing seasons after transplanting and when soil disturbance is finished, including hilling and de-hilling operations.
Alion is now also registered as a tank-mix with Sencor herbicide or Gramoxone herbicide in tree fruit, in addition to the previous registered tank-mixes of glyphosate and Ignite.
For more information, visit BayerCropScience.ca.
March 17, 2014, Charlottetown, PEI – The P.E.I. Federation of Agriculture wants the moratorium on deep-water wells lifted, but only after the provincial government’s scientific data has been independently reviewed and proven accurate.
Executive director John Jamieson told the provincial standing committee currently examining the issue of deep-well irrigation the federation is sensitive to the tremendous anxiety this issue has raised among Islanders. READ MORE
Under this agreement, Engage will work with Heads Up Plant Protectants (HUPP) principle Joe Dutchesen to execute sales, marketing and distribution of Heads Up Seed Treatments in Canada across all of the registered crops.
Heads Up Plant Protectant is a pre-plant seed treatment registered on various crops. It is an elicitor that “turns on” the plants’ ability to fend off infection from various diseases. Heads Up provides season long protection and results in healthier, stronger plants with an improved stand. Heads Up is currently registered for use on soybeans, potatoes, and dry beans. Label expansion work is also actively being pursued.
Heads Up Plant Protectant is made from natural plant source and provides growers with a new tool to strengthen the plant against disease infection. Heads Up has both PMRA and EPA registrations, along with OMRI certification.
“It’s a nice story in that it is Canadian invented, patented, and produced – Heads Up is derived from the quinoa crop, grown in Western Canada” says Ray Chyc, president of Engage Agro Corporation. “We are excited to work with Joe in expanding the products’ current sales, and in working with the company to bring Heads Up to additional crops in Canada.”
March 5, 2014 – The 2013-2014 winter precipitation level has been higher than normal over much of Ontario.
Michigan is no different with more than 90 inches of snow have fallen on the Ridge, a well-known tree fruit growing region located northwest of Grand Rapids, Mich. Michigan State University Extension colleagues in the northwest region of Michigan’s Lower Peninsula, a region known for growing over 70 percent of the nation’s tart cherries, have had more than 180 inches In the Grand Rapids tree fruit area, snow cover is up to the lowest scaffold limbs in many tree fruit orchards, something that hasn’t been seen for many years.
Every morning after a little light snow, fresh, new rabbit tracks, trails and droppings can be seen from their overnight activities. Rabbits do not hibernate in the winter and they are actively looking for food sources. When snow levels are not high, rabbits feed on vegetation at ground level. As the snow gets deeper and food sources are limited, rabbits travel and feed on vegetation near the surface of the snow. Therefore, rabbits will likely find apple limbs that are near the snow surface to be great food sources.
Feeding damage is already being reported in orchards this year. In the winter, rabbits strip bark and debud fruit trees, conifers and other trees and shrubs. Trees clipped by rabbits have a clean, knifelike cut on the stems. Rabbits can clip stems 0.25 inches in diameter and can be especially damaging to nursery trees.
In commercial orchard systems, painting tree trunks and scaffold limbs and using repellents may deter rabbits from causing damage, but these methods aren’t feasible during the heart of the winter months. Trapping and hunting are the only viable management methods for rabbit population management during this time of year. Rabbits rely on dense vegetation such as hedges, brush piles and overgrown stream banks for protection from predators. Eliminating these helps to reduce rabbit populations.
Scientists have discovered vital clues as to how the pathogen responsible for the Irish potato famine adapted to spread between different plant species.
Researchers at Oxford University and The Sainsbury Laboratory, Norwich, looked in unprecedented detail at how Phytophthora infestans, a pathogen that continues to blight potatoes and tomatoes today, evolved to target other plants.
The study, published recently in the journal Science, is the first to show how pathogens switch from targeting one species to another through changes at the molecular level. Researchers examined the biochemical differences between Phytophthora infestans and sister species Phytophthora mirabilis, a pathogen that split from P. infestans around 1,300 years ago to target the Mirabilis jalapa plant, commonly known as the four o’clock flower. They found that each pathogen species secretes specialized substances to shut down the defences of their target hosts.
“Plants have these enzymes called proteases that play a key role in their defence systems,” said Dr. Renier van der Hoorn, co-author of the study from Oxford University’s Department of Plant Sciences. “When a plant becomes infected, proteases help plants to attack the invading pathogens and trigger immune responses. P. infestans secretes substances called effectors that disable proteases in potatoes and tomatoes. These are highly specialized to block specific proteases in the host plant, fitting like a key into a lock.”
The effectors secreted by P. infestans are less effective against proteases in other plants such as the four o’clock, as they do not fit well into the locks. The researchers found that P. mirabilis evolved effectors that disable the defences of the four o’clock plant but are no longer effective against potatoes or tomatoes.
“For the first time, we have found a direct molecular mechanism underpinning the change in host specialization,” said Dr. van der Hoorn. “We looked at specialization in the blight pathogens’ secret weapon, a key family of effectors called EPIC that can pass through plants’ defences undetected to disable the proteases. The EPIC effectors secreted by P. infestans have evolved to fit the structure of potato proteases just as P. mirabilis has evolved effectors that fit four o’clock proteases.
“If we could breed plants with proteases that can detect these stealthy EPIC effectors, we could prevent them from sneaking in and thus make more resistant plants. Within the next decade, we plan to exploit the specialized nature of these effectors to develop proteases that are resistant to their action or can even trap them and destroy the pathogen. Potato and tomato plants with such proteases would be resistant to the blight pathogens, and combined with other resistant traits, could provide another wall of defence against the pathogens.”
February 4, 2014 – The Pest Management Regulatory Agency recently announced the approval of a minor use label expansion registration for Revus fungicide for control of downy mildew of basil and phytophthora blight and root rot of ginseng.
Revus fungicide was already approved in Canada on Brassica vegetables, several bulb vegetables, several leafy vegetables, cucurbit vegetables, fruiting vegetables, potatoes, grapes and hops.
The following is a general, abbreviated outline of the new disease registrations on the Canadian label for Revus fungicide. For detailed instructions consult the full Revus fungicide label.
Basil (field and greenhouse)
For control of downy mildew, apply as a foliar spray 583 ml/ha beginning prior to disease development and continue on a seven day interval in appropriate rotations. Do not apply Revus sequentially – always rotate with other registered products from different fungicide groups. Apply in a spray volume of 95 to 280 L per ha. Maximum of four applications per year with a one-day pre-harvest interval.
For control of Phytophthora blight and root rot, apply as a foliar spray and/or drench at 583 ml/ha beginning prior to disease development and continue on a seven day interval in appropriate rotations. Drench applications are required to control root rot. Do not apply Revus sequentially – always rotate with other registered products from different fungicide groups. Apply in a spray volume of 470 to 1,400 L per ha. Maximum of four applications per year with a three-day pre-harvest interval.
Revus fungicide should be used in an integrated disease management program and in rotation with other management strategies. Follow all other precautions and directions for use on the Revus fungicide label.
January 14, 2014, Niagara Falls, Ont – Margaret Appleby was named the winner of the 2014 Chemtura Golden Apple Award.
Appleby is an Integrated Pest Management (IPM) Systems Specialist with the Ontario Ministry of Agriculture and Food and Ministry of Rural Affairs (OMAF/MRA). The award was presented at the annual general meeting of the Ontario Fruit and Vegetable Growers Association in Niagara Falls.
“Throughout her years working with the ministry, Margaret has shown her dedication to the apple industry and has always gone above the call of duty and made herself available to the growers whenever they have needed her,” says Charles Stevens, chair of the Ontario Apple Growers (OAG). “She is involved in initiating and implementing research projects that support the apple industry and has been an invaluable asset to our industry by sharing her knowledge and expertise.”
Appleby graduated from the University of Guelph in 1976 with a degree in Environmental Biology and was an apple grower for approximately 10 years before joining Agriculture and Agri-Food Canada at Smithfield where she worked in their nursery and in IPM. She was a regional IPM specialist for Quinte until 2000, when she joined OMAF/MRA as an IPM Systems Specialist.
Appleby was one of the first individuals in Ontario to scout out the popular Ambrosia apple variety in British Columbia and was very involved with cultivar trials when they were first established in Ontario in 1999. She was also responsible for organizing the international IPM conference in 2002, which brought many international experts to Ontario.
Annually, Appleby works with the Northumberland and Durham apple IPM group to hire crop scouts and run an IPM program. She has also been the lead in many in-field apple research projects, including finding a solution for managing oblique-banded leafroller (OBLR), developing scab management programs, and tracking the migration of European Apple Sawfly and looking for solutions for this pest.
“Margaret organizes grower meetings and conferences and has been instrumental in the success of the Durham apple study group, which regularly attracts 20 or more growers and industry representatives to meetings during the growing season,” adds Stevens.
The Chemtura Golden Apple Award is presented annually to a recipient who has made outstanding contributions to the Ontario apple industry.
January 14, 2014, Niagara Falls, Ont – A former government and industry crop protection specialist has been honoured for his life-long contributions to the Ontario horticulture sector.
Wayne Roberts was posthumously named the recipient of the Ontario Fruit and Vegetable Growers’ Association (OFVGA) Award of Merit, which was presented at the organization’s annual banquet. Roberts passed away suddenly in 2013.
“Wayne was very well respected in the horticulture industry and spent his entire career working on behalf of growers on any and all matters related to crop protection,” says Ray Duc, chair of the OFVGA. “He was an excellent advocate for growers and managed to interact effectively on their behalf with both regulators and the crop protection companies to help reach common goals.”
Roberts began his career with Agriculture and Agri-Food Canada, followed by a long tenure with the Ontario Ministry of Agriculture and Food as director of Integrated Pest Management (IPM) programs. In 1996, he accepted a position with the Ontario Tender Fruit Producers Marketing Board and the Grape Growers of Ontario where he directed their IPM system development and efforts related to crop protection. He also provided leadership to the Ontario Apple Growers and Landscape Ontario on research and IPM programming.
Roberts retired in 2010 but continued to serve as an industry consultant until his passing last year. Among his career achievement highlights are:
- Emergency registration for Asian Lady Bird Beetles, which threatened to devastate the processing grape industry
- Leadership to tender fruit growers, the tree fruit nursery industry and the Canadian Food Inspection Agency on the control and eradication of the Plum Pox Virus
- Establishment of the Prunus Certification Program for virus-free budwood in the nursery industry to ensure clean replacement trees that now serves as a model for other such programs, including the grape clean stock nursery stock program.
The OFVGA Award of Merit is presented annually to an individual or an organization that has made outstanding contributions to the fruit and vegetable industry.
January 13, 2014, Mississauga, Ont – BASF Canada Inc. (BASF) has received regulatory approval for Outlook, a new herbicide that will help potato growers address two significant challenges to their production.
As the amount and timing of rainfall becomes more variable, Outlook will provide consistent control of nightshade, pigweed and annual grasses, even under drier conditions. As a Group 15 herbicide, Outlook also controls both triazine and Group 2 resistant biotypes whose populations continue to increase across the country.
“Based on our extensive field-scale Canadian research program and several years of commercial use in the U.S., we see Outlook as an excellent new tool that will help growers address both inconsistent rainfall and the growing problem of herbicide resistance,” says Bruce Irons, a technical specialist for horticultural products with BASF Canada.
Outlook contains the active ingredient Dimethenamid-P, which inhibits weed root and shoot growth, controlling susceptible weeds before they emerge from the soil. Outlook is applied after potatoes are planted but before they emerge from the soil.
Tomato variety and weather can combine to make what the researchers call a "perfect storm" for salmonella to proliferate in harvested tomatoes, a new study shows.
It remains unclear how much each contributes to salmonella's spread but scientists say understanding the process is key to eventually curbing produce-associated outbreaks.
The so-called perfect storm doesn't happen often, said research assistant professor Massimiliano Marvasi, the study's first author, but can be damaging to public health and the food-crop business when it does.
During the past decade, fruits and vegetables have been among the foods most often linked to gastroenteritis outbreaks caused by E. coli and non-typhoidal salmonella, the study said. Those outbreaks resulted in public illness and multimillion-dollar losses for the food-crop industry.
Since 2006, at least 16 salmonella outbreaks have been linked to tomatoes, cantaloupes, sprouts, cucumbers, mangoes, peanut butter and peppers, in addition to frozen foods containing plant products. But UF/IFAS scientists emphasize that less than one per cent of supermarket produce contains salmonella or E. coli and the contamination becomes a problem only when it contaminates other food, or is consumed raw.
Gastrointestinal illnesses caused by pathogens such as E. coli and salmonella pathogens have been sporadic − with scientists struggling to pinpoint exact causes − and their random nature argues for a perfect storm scenario, the study said.
"It is now clear that salmonella and other human pathogens can contaminate produce at any stage of the production cycle, from farm to fork," the UF/IFAS study said.
Marvasi said the tomato industry follows strict protocols to prevent microbial food hazards in fresh fruits and vegetables.
Faculty members Max Teplitski, George Hochmuth, Jerry Bartz and Marvasi, all of UF's Institute of Food and Agricultural Sciences, wanted to find out which crop production factors are associated with tomato salmonella outbreaks. Specifically, they wanted to know how irrigation levels, waterlogged tomatoes and crop and pathogen genotypes affect salmonella's ability to multiply in the fruit.
They grew three types of tomatoes – Bonny Best, Florida-47 and Solar Fire − during three production seasons over two years in Live Oak and Citra. Tomatoes had been harvested and injected with seven strains of salmonella, Marvasi said.
Researchers chose those three varieties because, in preliminary greenhouse experiments, they showed varying degrees of salmonella resistance, said Max Teplitski, a UF associate professor of soil and water science. Bonny Best is an heirloom variety, often used as a control variety in plant pathogen experiments, he said. Florida 47 and Solar Fire are newer varieties, widely grown commercially in the Southeast.
The study, published by the journal PLoS One, showed that particular cultivars combined with drier, sunnier conditions work together to increase the chances that salmonella will spread.
Changing irrigation patterns caused little change in the potential for salmonella, researchers found.
Tomato maturity and cultivar, particular strains of salmonella and seasonal differences were the strongest factors affecting proliferation. And ripe tomatoes were more vulnerable than green tomatoes.
Salmonella infection ranks among the most common foodborne illnesses, often spread by raw or undercooked meat, poultry or eggs, but sometimes results from eating contaminated produce.
A Mount Royal potato farmer pleaded guilty to two of six outstanding charges against him and his company – one Federal Fisheries Act count of allowing a deleterious substance to enter a waterway, and one charge under the provincial Crop Rotation Act of planting potatoes in the same field twice in less than three years. READ MORE
The work is expected to accelerate basic and applied research, leading to better monitoring and control strategies for the pest.
Officially published Dec. 1 in the journal G3 (Genes, Genomics, Genetics), the open-access research has been available online for several weeks and drawing global attention.
"To enable basic and applied research of this important pest, Drosophila suzukii, we sequenced the genome to obtain a high-quality reference sequence," said molecular geneticist Joanna Chiu of the UC Davis Department of Entomology and Nematology. Chiu and Professor David Begun of the UC Davis Department of Evolution and Ecology led the genomics team of collaborative researchers from four institutions.
The posting of the genome and comparative sequence analysis on the publicly accessible SpottedWingFlyBase web portal could lead to more species-specific weapons to combat the destructive pest, Chiu said. Scientists are looking at its biology, behavior, food and odor preferences, and pesticide resistance.
"Many researchers are working hard to study the biology of this insect through basic and applied projects, and we hope our efforts in presenting our genomic data in a user-friendly web portal will democratize the sequence data and help facilitate everyone's research, especially those who do not have expertise in genome and sequence analysis," she said.
The spotted wing drosophila, a native of Asia that was first detected in the United States in 2008, is wreaking economic havoc on crops such as blueberries, cherries, blackberries and raspberries. This fly lays its eggs inside the ripe or ripening fruit, and the developing larvae feed on the soft fruit, crippling crop yields.
The spotted wing drosophila is a vinegar fly about 1/16 to 1/8 inch long with red eyes, pale brown thorax, and a black-striped abdomen. The males have a distinguishing black spot toward the tip of each wing. Females have no spots but have a prominent, saw-like ovipositor for drilling fruit to lay their eggs.
Chiu teamed with scientists at UC Davis, Oregon State University, the China National Gene Bank and the American Museum of Natural History as part of a $5.8 million project on the biology and management of spotted wing drosophila, funded by a U.S. Department of Agriculture Specialty Crops Research Initiative grant to OSU entomologist Vaughn Walton and a team of investigators including Professor Frank Zalom of the UC Davis Department of Entomology and Nematology, who is the lead UC Davis investigator.
Zalom, recently inducted as president of the nearly 7,000-member Entomological Society of America, said that the G3 article "presents a high-quality reference sequence of Drosophila suzukii, examination of the basic properties of its genome and transcriptome, and description of patterns of genome evolution in relation to its close relatives."
The SpottedWingFlybase web portal has drawn more than 3,000 page views from 20 countries, including the United States, France, Italy, Belgium, China, Spain, Japan, Germany and Great Britain.
"Scientists from all over the world are interested in knowledge locked inside the fly's genetic material," said OSU entomologist Vaughn Walton, lead investigator of the USDA grant.
He also pointed out the genome work may relieve the fears of countries wishing to import American fruit, but not the pest. By finding the fly's unique genetic signature, scientists hope that DNA testing will quickly determine if ready-to-be-shipped fruit contains spotted wing drosophila larvae.
The SpottedWingFlyBase is a dedicated online resource for Drosophila suzukii genomics but also includes comparative genomic analysis of Drosophila suzukii with other closely related Drosophila species.
For blueberry and other soft fruit growers, Delegate received an emergency use permit earlier in 2013 to protect against spotted wing drosophila (SWD), a relatively new and highly damaging pest. Delegate is used for SWD and leafroller control in cherries.
“Export markets are particularly important for blueberry and cherry growers,” says Jerry Olechowski, marketing manager with Dow AgroSciences. “Both crops are exported overseas so establishing foreign residue tolerances for these two key crops is critical to growers in Canada.”
Delegate WG is a fruit and vegetable insecticide from the spinosyn chemistry class that provides long-lasting control of a broad spectrum of insect pests. Insects are controlled two ways – by contact and ingestion – for quick knockdown and residual activity. Delegate also possesses translaminar ability, giving extra protection against insects that feed from the underside of leaves, and increased resistance to wash off by rain.
Under the arrangement, Engage Agro will be the exclusive marketer and distributor for Assail insecticide in Canada for all labeled uses. In this role, Engage will also review label expansion opportunities for Assail.
“Assail insecticide is a well-recognized brand in Canada, with proven performance among fruit and vegetable growers alike.” says Ray Chyc, president of Engage Agro Corp. “This is a great opportunity for Engage Agro Corporation as we look to grow our relationship with Nippon Soda Co., Ltd in Canada.”
Oct. 30, 2013 - Earlier this year, the Canadian Food Inspection Agency (CFIA) announced the possible detection of Apple Proliferation Phytoplasma (Candidatus phytoplasma mali) in one apple orchard near Kentville, Nova Scotia. Apple Proliferation Phytoplasma (APP) is considered to be a quarantine pest in both Canada and the United States.
As a result of this detection, four apple orchards were placed under quarantine, including the orchard where the phytoplasma was detected. Subsequent collection of samples has not produced any confirmation of the presence of APP at the quarantined site.
Between May and October of 2013, the CFIA surveyed each of the four orchards on a monthly basis for signs of APP and collected samples. A total of 121 samples were collected and tested by the CFIA for APP and the laboratory test results were negative for APP and other phytoplasmas.
The Pacific Gala trees in all four orchards were imported from the same nursery in the United States (U.S.). The trees in the U.S., that were the source of the trees in the four orchards, were tested in 2013 and all results were negative fr APP.
Through collaboration with phytoplasma identification experts from the United States Department of Agriculture (USDA), the CFIA has concluded that additional genetic information is required to confirm the identity of the phytoplasma detected.
As the identification of the phytoplasma has not yet been determined, it cannot be regulated. As a result the four orchards will be released from quarantine. With the support and cooperation of the producer, the CFIA will continue to monitor the orchard where the phytoplasma was detected.
If you have questions regarding this issue, please contact the CFIA at 905-938-8697.
Quality for the price remains the top value driver for foodservice consumers, followed by fresh ingredients and choice, according to a recent NPD Group foodservice study.1 As you strive to meet consumer demands, there is one constant threat to these factors that all commercial-scale fruit and vegetable producers face: pests. Flies,
cockroaches and rodents are prime suspects and can compromise your harvest and your bottom line.
But before jumping into exciting new digital process tools, the first step to help reduce the presence of these pests is to implement an Integrated Pest Management (IPM) program. This comprehensive approach focuses on preventive measures such as sanitation to minimize pest attractants like food and water, and facility maintenance to block pests’ access to your business. New pest control technologies can teach and help you manage such pest activities in and around your facility better than ever before. Work with your professional pest management provider to ensure that your facility stays on the cutting edge with the latest pest control technologies and that you are working smarter, not harder.
Consider these new options and stay up on the latest in TECH:
T – Training is top-notch. Hands-on training opportunities mesh with technology driven, web-based training to provide pest management professionals with the latest industry news. Digital learning networks keep professionals in the know and allow instantaneous contact with industry people around North America.
E – Electronic reporting replaces documenting pest pressures by hand. Advances allow for scanning and electronic reporting to create customized reports that measure trend data over time. This technology allows your pest management provider to determine which areas of your facility are most prone to pest activity and at what time of the year, allowing you to target hot spots quickly and effectively. Not only are they faster and easier to access than handwritten reports, but also they are readily available and more accurate. A barcoding system on pest management devices allows for quicker, easier and more accurate inspections while making the process paperless. Once you have these reports, you can share them electronically with others in your business and digitally archive information so it will always be available for audits and inspections – unlike the binders you may be using now.
C – Consider installing ultrasonic devices. Ultrasonic devices have been used for some time, but recent advancements have improved their effectiveness, especially in deterring rodents. These deterrents use specific sound pressure (frequency) and power (intensity) to deter rodents from entering your facility. They are most effective when used around the exterior of building as they create rodent-deferring buffer zones.
H – Hang insect light traps in the interior of your business in strategic locations to combat flies. These newly designed traps attract flies using ultraviolet light and capture them on a non-toxic adhesive trapping board inside the unit. The silent devices are discreet, so you can place them in virtually any location. This goes for food-storage areas as well, since the technology uses a non-toxic glue-board for trapping, meaning you don’t have to worry about airborne contamination from the insect body parts as you would with the traditional “bug zapper.” They also operate around the clock so you have a continuous defence against flies.
Other advances in more traditional tools such as pheromone traps, organic cleaners and insect bait traps have increased their efficiencies. Using technology to your advantage can ensure an effective IPM program and, more importantly, a safe and consistent product for consumers. ❦
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Farm Mentorship Gathering Sun Sep 22, 2019
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Soil Health Symposium Series 2019Thu Sep 26, 2019
Field Day - Innovation on a Vegetable FarmSat Sep 28, 2019