The warm conditions has slowed the harvest of some processing fields, to prevent bringing warm tubers into storage. The seasonal accumulated precipitation has been 50-70% of normal in the potato growing areas (Fig1). The soils are generally on the dry side (Fig 2), but irrigated fields have sufficient moisture for a good harvest. READ MORE
Researchers are hoping Canadian potato growers will soon be able to use an innovative approach to control wireworms. This method uses just a few grams of insecticide per hectare applied to cereal seeds that are planted along with untreated seed potatoes. It provides very good wireworm control for the whole growing season, with a lower environmental risk than currently available insecticide options.
"We're into our second week of wet weather and really there's nothing being done at the present time," says Rodney Dingwell, chair of the P.E.I. Potato Board. | READ MORE
Just because black cutworms don’t overwinter in Canada doesn’t mean they aren’t a threat to potato crops. The insects spend their winters in the southern United States but travel north on low-level jet streams and, once they cross the border into Canada, they look for a tasty food source. Black cutworm moths prefer some of the weeds that grow in and around fields and, while potatoes are not their favourite food, they will adapt and can wreak havoc on an unmonitored field.
A researcher at the University of Minnesota says the cutworms’ new interest in potatoes could be the result of a change in potential host plants. If the moth’s desired weed is being well controlled in a field, it will eat what is available where the wind sets it down.
“Black cutworm moths are active flyers,” explains Ian MacRae, the extension entomologist at the university’s Crookston research station. “These insects can travel hundreds of miles in a short period of time aided by an extremely efficient bug highway [a jet stream].”
MacRae says if the wind and temperature are conducive and Canadian potato producers are able to get their crop planted in good conditions, there is a chance the moths will arrive about the same time as the plants are emerging. The possibility exists that early arrival could spawn a second generation of the insects later in the season. He says, once landed, reproduction occurs when the moths lay eggs. The emerging larvae will feed on the foliage, but once at the fourth or fifth larval stage they will begin actively eating near the base of the host plant, cutting it off.
“The first you might notice a cutworm problem will be plants that are cut at the base or wilting,” MacRae explains. “At night, the worms burrow into the soil and if the tubers are close to the surface, they will burrow into the tuber. They can do more damage to tubers in dry conditions because cracks in the soil will give the cutworms access to what is underneath.”
Damage to potato crops early in the season can be a greater problem because the young plants will not recover from being chewed off. There is a possibility that the seed piece might send up another shoot, but the crop will be set back. MacRae suggests early scouting will help identify the problem and allow time for control. There are effective insecticides for control of black cutworm and there are sources of natural mortality, such as predators or parasitic wasps. Birds may be less effective because of the location of the worms and their habit of eating at night.
“If you find yourself at a threshold of about 30 per cent of your plants cut, you may want to apply an insecticide,” MacRae says. “If defoliation is this high, it may be that natural mortality sources are not functioning well.”
Ensure proper identification of the larvae as black cutworms so the correct product can be chosen for control. Combining regular field scouting with pheromone or light traps to catch the male moths is an effective way to identify the insects.
“When scouting, look for stalks at an odd angle or wilting,” MacRae suggests. “Look in the evening when the cutworms come out to feed, and look as much as a half metre away from the plant because they are good walkers. Black cutworms are aptly named because they are a dark caterpillar with a waxy appearance. They will often curl into a C if disturbed. They hang out during the day under clods of soil or in cracks.”
MacRae says climate change may be the reason black cutworms are being seen farther north. He doesn’t believe they will begin to overwinter in Ontario or the Prairies, but a warmer climate means they develop faster and may overwinter in more northern states, making the migration north earlier and causing greater problems.
“Black cutworms have certainly become a problem in Ontario in the last few years,” MacRae says. “They can be a significant pest issue.”
MacRae adds there are some cultural practices that may minimize the impact of black cutworms when they arrive. Planting late can put new, young plants directly on a collision course with the moths and their offspring, so plant early, if possible. He says controlling weeds will reduce the areas where the moths might lay eggs. Growers in the United States use pre-plant tillage to turn over the soil to destroy potential habitat.
To date, there is no accurate monitoring system in place for potato crops, according to MacRae, but the cutworms also like corn and the corn growers in some states, such as Iowa, have a black cutworm monitoring network. “The moths seem to appear in Ontario about three weeks after they are seen in the United States,” he says. Ontario growers could tap into the monitoring networks south of the border and use that information as an early warning system, he suggests.
Black cutworms could be considered a stealthy yield robber because by the time you begin to notice a problem, it could be a challenge to execute effective control. The best defence is early and frequent field scouting and adopting cultural practices that could minimize the attractiveness of the crop. MacRae believes Canadian potato growers will see black cutworm more often in the coming years, so preparation for and understanding of the pest is a wise approach.
What is late blight?
Late blight is a disease caused by an organism that produces a white fuzz on the underside of leaves which releases millions of spores that float through the air to infect other plants. The spores land on a susceptible leaf, germinate, and cause brown oily lesions. The spores splash on the ground and infect potato tubers, which become brown and rusty looking, with a granular texture. Crop losses due to late blight can cost the Canadian potato industry tens of millions of dollars annually.
Protecting the potato industry
AAFC late blight specialist Rick Peters says taking steps to prevent the disease from infecting potato crops is important to help protect the health of the industry. He advises home gardeners to ensure their tomato seeds are resistant to the US-23 strain of late blight. Resistant seeds can be purchased at most garden centres. Certified disease-free seed potatoes can also be found at garden centres or purchased from a local seed potato grower. Peters says potatoes grown from last year’s garden or those bought from the grocery store are not suitable for planting as these tubers have not been tested and certified as disease-free and could be susceptible to a variety of potato diseases.
AAFC has partnered with industry leaders to identify and track late blight strains in production areas across the country. Scientists are also looking at biological characteristics of the different strains including how they respond to treatments. This knowledge allows for better management and control of the strains in Canadian potato and tomato production areas. While scientists continue to study the disease, they maintain that an ounce of prevention is worth a pound of cure and home gardeners have an important role to play.
If you spot a suspected late blight infection in your garden this season, please contact the Department of Agriculture, Aquaculture and Fisheries at 1-866-778-3762 for information on how to properly dispose of infected plants.
Bayer has launched Velum Prime nematicide, the first non-fumigant nematicide registered for potatoes in Canada.
Velum Prime is a new mode of action and chemical class (pyridinyl ethyl benzamide) for nematode protection. It offers growers effective nematode protection that helps sustain plant vigor and maximize crop yield potential, according to a press release.
Recent trials of Velum Prime demonstrated consistent yield and quality increases and reduction in plant parasitic nematodes, including root lesion, root knot and potato cyst nematode.
Velum Prime is applied in-furrow at planting. It comes in a liquid formulation that offers reliable efficacy at low application rates making it ideal for use with existing in-furrow application equipment. Applied in-furrow, Velum Prime offers the added benefit of early blight protection.
Maximum residue limits for Velum Prime applied in-furrow are in place supporting trade in North America and Europe. Additional MRLs supporting trade in other key export countries, including Japan, are expected early in 2017.
For more information regarding Velum Prime, growers are encouraged to talk to their local retailer or visit cropscience.bayer.ca/VelumPrime.
Ambra variety potatoes harvested by C&V Farms in October. Photo courtesy of Eugenia Banks.
Oct. 27, 2016, Ontario – Each growing season is different, but the 2016 season was unlike any season seen before in Ontario. Planting started later than usual due to the cold weather. The early crop planted by the middle of April in southwestern Ontario took more than three weeks to emerge due to cool soil temperatures. Growers were caught off guard when snow fell by the middle of May. The season was off to a bumpy start.
There was only limited rain up to the end of May. Then the heat and drought started relentlessly – too early in the season.
Studies have shown that a healthy crop of potatoes needs an inch of rain a week. That adds up to about 16 inches of rain from May through August for the potato crop to show its full potential. Environment Canada data indicates that the water deficit in Norfolk, Simcoe and Dufferin counties was above 60 per cent. Norfolk County was the hardest hit by the heat and drought, with a total rainfall close to four inches near Delhi.
Where available, irrigation was the order of the day during the summer. However, growers could not keep up with irrigation due to the extremely high evapo-transpiration rate. Irrigation increased the cost of production dramatically. By July, there were reports of some irrigation ponds that were completely empty and not filling up. One producer said, “With the heat and drought we are experiencing, irrigation is simply keeping the crop alive. Rain water does way more for the crop than irrigation.”
There were many days in June, July and August when the temperatures were above 30 C. Such heat puts the potato plants in a dormant state, unable to photosynthesize efficiently, the activity that keeps plants functioning well.
Some rainfall by the middle of August did not help the early crop, which was too far gone to benefit from rain.
Ontario Potato Distributing in Alliston started packing early potatoes from Leamington on July 19. Quality was excellent. The harvest of the early crop continued in August but yields were down at least 50 per cent in non-irrigated fields. In irrigated fields, yield reduction was at least 35 per cent.
Dry weather brings good quality. Diseases such as late blight, pink rot and leak did not develop. These diseases, also known as storage rots, reduce quality and can cause significant storage losses.
Hot, dry weather also induces second growth. A few table varieties with short dormancy aged rapidly in the field and showed some sprouting before harvest.
Mark VanOostrum reports that the chip processing crop yielded as low as 60 per cent of normal yield. The best yields were reported from the Shelburne area in the late-planted crop and late-season varieties. Harvest was difficult, because it took more than five to six weeks to get good skin set after topkill or natural death. Because the fall was very warm, storages temperatures are just starting to drop below 13 C. Typically, the temperature would have been down to 9 C on many bins for a few weeks by this time of the year. Higher storage temperatures will age the crop (one that was already aged in the field due to the heat and drought).
The processing of the storage crop started earlier than anytime in recent history due to the shortage of field fry crop. Some heat necrosis was seen in Atlantics, but minimal in other varieties. So far, the quality of the storage crop has been very good. Some stem end sugar defect is present, but less than normal for this early in the storage season. One real concern is how the long-term effect of the heat and drought stress affect the chipping quality. Stem end sugar defect incidence and severity is highly correlated with extreme heat, and the question remains: will we be able to burn off all the stem end? Also, the heat and drought stress is correlated with chemical and physical aging. Will a variety that typically has a seven-month life span be shortened by weeks or months? Time will tell.
By Thanksgiving, nearly all the table and processing crop had been dug and stored with no risk of storage rots.
Ontario potato growers will remember 2016 as one of the hottest and driest year in Ontario. Our potato growers should be commended for their resilience and capacity to produce a high-quality crop in what was an extremely difficult growing season.
Oct. 6, 2016, Ontario – A quick survey indicated that about 80 per cent of the provincial potato crop has been harvested by Oct. 5, according to Eugenia Banks, Ontario potato specialist.
On the chipping front, Mark Van Oostrum from WD Potato expects that most processing growers will be done by Thanksgiving.
Growers in the Simcoe, Ont., area are close to completing the harvest. Joe Lach, who farms near Delhi, Ont., will finish this coming week, and told Banks his remaining potato crop is all sold.
About 60 per cent of the acreage near Shelburne, Ont., has been dug. This area plants a bit later than other areas due to cooler spring weather and lower soil temperature.
On Oct. 5, Banks harvested a variety trial in Honeywood, Ont. Standard processing varieties such as Lamoka (chipping) and Waneta (chipping and table) did very well. There was no second growth or tuber malformations. By contrast, many of the new varieties under evaluation showed the effects of a hot, dry summer: second growth, bottlenecks, cracks and knobs. 2016 was a great year to see how new varieties perform under heat and water stress.
Sept. 29, 2016 – Second growth is a physiological potato problem induced by soil temperatures of 24 C or above and water stress. These two factors interact to limit the tuber growth rate, causing second growth. Inadequate soil moisture alone does not result in the initiation of second growth.
Heat and drought prevailed during the 2016 Ontario growing season, which explains why second growth has been reported in some fields.
Potato varieties differ in their susceptibility to second growth. European varieties appear to be more susceptible because they were bred and evaluated in countries where the growing seasons are rarely hot.
There are three distinct types of second growth:
Tuber chaining: A series of small tubers are produced on a single stolon.
Heat sprouts: Sprouts develop from stolons or daughter tubers. The sprouts may emerge from the hills developing into leafy stems.
Secondary Tuber: Small tubers form on daughter tubers. The secondary tubers are formed on short sprouts or directly on the tuber surface. This disorder is usually associated with physiologically old potatoes. High temperatures and water stress during the growing season are major factors contributing to the physiological aging of potatoes.
Cultural practices that promote uniform growth of plants and tubers throughout the season help minimize second growth. Among them are:
● Do not plant physiologically old seed in cold, dry soil.
● Space seed pieces as uniformly as possible at planting.
● Apply an adequate amount of fertilizers.
● Maintain uniform soil moisture sufficient to meet crop needs (this was easier said than done this past season!).
Sept. 23, 2017, Prince Edward Island – Harvest is underway in Prince Edward Island. Greg Donald, general manager of the P.E.I. Potato Board, estimates less than five per cent of the Island's crop is out of the ground at this point, mostly right into production or onto the fresh market. | READ MORE
August 23, 2016 - Approximately 250 growers, crop consultants and potato-industry personnel gathered at the 2016 Ontario Potato Field Day on Aug. 18 in Alliston, Ont., to see the latest potato equipment, new potato varieties and a trade show. The day was hosted by HJV Equipment, supported by the Ontario Potato Board and organized by Eugenia Banks, Ontario potato specialist.
There were over 100 new potato varieties on display; varieties for the fresh, processing and specialty markets. For the fresh market, the variety Actrice (Real Potatoes) caught the attention of many growers because of its attractive tubers with smooth, shiny skin. Actrice is an early, yellow-fleshed variety that is very tasty. Primabelle and Panamera (HZPC Americas) are two yellow-fleshed varieties that got good reviews from potato growers.
Among the russet potatoes for the French fry market, Alta Strong (Real Potatoes) and Pomerelle Russet (Pommes de Terre Laurentiennes) were well rated by growers.
There was interest in Kalmia (La Patate Lac Saint-Jean) a white-fleshed, fresh-market variety that could also be used as a French fryer.
Double Fun (HZPC Americas) had the nicest skin among the purple-fleshed varieties. It also has very good culinary traits.
Among the trade show exhibitors, the Quebec Company Lab’ Eau-Air-Sol demonstrated the use of spore traps for foliar diseases of vegetables.
Douglas Ag. Services provided the latest information on chloropicrin application to control soil-borne diseases. Maximum H2O System (Mississauga) restructures water and minerals at a molecular level to make them more bio-available to plants.
The displays of Gorman Controls and GRB Ag. Technologies focused on storage management.Potato growers attend this important annual event because they obtain practical, up-to-date information on varieties and the latest potato-production technology that allows them to remain competitive.
The day is also a chance for growers to meet in a friendly, informal setting to discuss problems.
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Irrigation Show 2017 Mon Nov 06, 2017 @ 8:00AM - 05:00PM
Alberta Potato Conference & Trade Show Tue Nov 14, 2017 @ 8:00AM - 05:00PM
South West Ag ConferenceWed Jan 03, 2018 @ 8:00AM - 05:00PM
Potato Expo 2018Wed Jan 10, 2018 @ 8:00AM - 05:00PM