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Specialist updates growers on optimizing seed piece treatment

March 27, 2009  By Myron Love

Ken Lingley knows a lot about potato spraying, including the use of
seed piece treatment applications to enhance the viability and
performance of the potato set as it grows.

Potato seed piece treatment application can help to enhance the viability and performance of the potato set as it grows.


Ken Lingley knows a lot about potato spraying, including the use of seed piece treatment applications to enhance the viability and performance of the potato set as it grows.


A specialist in crop spraying with On-Target Sprayer Services based in Prince Edward Island, Lingley was recently in Brandon, Man., to update potato growers on optimizing the application of their seed piece treatment.

Historically, most potato seed treatments have been fungicidal dusts that help to protect the seed piece during germination and early growth, explained Lingley. Dusts can be applied straight from the manufacturer’s container. The labels generally recommend thorough coverage of the seed piece. If a part of a seed’s surface has no treatment on it, the potential for disease pest problems increases.

For dust formulations, Lingley said there are two basic types of treatment methods – the auger and the drum. Both methods use relatively simple machines. For auger treatments, the capacity is determined by the width of the auger and the speed that it rotates, he said.

“The speed of the auger should be adjusted so that it runs close to, but not completely, full,” he said. “This should give good interaction and tumbling of the seed pieces as they move up the auger.”

For drum treatments, Lingley said the capacity is determined by the angle that the drum is inclined, as the rotational speed is constant. Keep the incline as low as possible to maximize tumble, he added.

Dust containment structures around the seed piece treatment equipment are important and the use of exhaust fans can help improve ventilation.


Since the dust is applied at a constant rate, Lingley recommends that the rate of potatoes going through the duster also be kept as constant as possible.

“Potato flow variations can come from numerous sources,” he said. “Using a variable speed drive on the unloading bin feeding the cutter can help keep the potato flow constant.”

Liquid seed piece treatments with insecticidal properties have been registered since 2004, said Lingley, adding new liquid treatments with fungicidal properties may be available for next spring.

“Because these products have very strong systemic action, full coverage of the potato set has not been required to get good field performance,” he said. “To obtain good performance with the new liquid fungicidal products, complete coverage of the set is required.”

If an auger treatment is used, the liquid insecticidal seed piece treatment can be sprayed directly into the inlet hopper, he said. Owners of drum dusters can apply the liquid treatment in a “wet” auger before the sets enter the drum. A wet auger is similar in concept to an auger except it does not have a dust metering mechanism.

Manufacturers of drum dusters also build drums specifically for the application of liquid seed treatments, Lingley explained.

“Currently, these are being recommended to apply the new liquid fungicidal products.”

Lingley reminded growers that potato seed piece treatments are pesticides and, as such, are regulated under numerous federal and provincial statutes. Seed piece treatments need to be registered through the Pest Management Regulatory Agency (PMRA) before they can be applied to potato seed pieces and product labels must be followed, he said. If the label states that a respirator must be worn, failure to wear it could result in adverse health effects to the applicator, Lingley stressed. In addition to conveying information about applicator safety the label also addresses environmental, food and workplace safety issues.

From a provincial perspective, growers from P.E.I. face significantly more provincial regulatory requirements than those in Manitoba, Lingley explained.

“Everyone who applies an agricultural pesticide in-field requires an applicator certificate, which can only be obtained by passing a written examination,” he said. “Additional applicator certificates are required by those handling and transporting pesticides, greenhouse applications, or fumigation applications. In the spring of 2007, new P.E.I. regulations requiring an applicator certificate for applying seed piece treatments came into effect. For the most part, these were put in place to address our provincial regulators concerns about the health and safety of the cutting crew in the seed treatment area.”

Also, in 2007, he noted, farms in P.E.I. became subject to the provincial Occupational Health and Safety Act after the death of a young farm worker. Island growers are required to follow a Farm Safety Code of Practice. To identify what personal protective equipment is required when making a seed treatment application, Occupational Health and Safety enforcement personnel refer to the product’s Material Safety Data Sheets (MSDS), not the federal PMRA product label.

“This does present some confusion at the farm level,” Lingley said. “Growers need to be aware of the differences in the regulatory systems.”

The precautions section of the product label will indicate the type of personal risk possible from using the product and the personal protective equipment that users should use to mitigate this risk, Lingley explained. Most seed piece treatments require the user to cover their legs and arms, and to wear chemical-resistant gloves, goggles or a face shield, and a dust mask, he said Some treatments (specifically those with an insecticidal component) require additional protection such as the use of a NIOSH-approved respirator, he added.

“It’s important to read the label for each seed piece treatment that you apply and follow all label instructions,” Lingley said.

For almost all potato operations in P.E.I., potato seed piece treatments are done inside a building to protect workers and the seed from the weather, he said, adding that working inside a building does introduce an array of safety concerns, specifically air quality

Good air quality can be characterized as no visible cloud of dust in the air and minimal pesticide related smell, Lingley explained.

Potential worker exposure to seed treatments can also be reduced by locating the treatment equipment away from the set cutter, he said. Installing a conveyer belt between the set cutter and the treatment area provides a buffer zone for the workers on the set cutter, he said, adding current liquid potato seed treatment labels require that a shielded spray system be used to prevent spray droplets from drifting in the treatment area.

Lingley also recommended installing dust containment structures around the treatment equipment. A simple wooden stud frame with a tight poly coating is an effective way of containing the dust, he said.

“The use of exhaust fans will also improve ventilation but the structure is the first step,” he said.

“The safe use of seed treatment also involves maintaining good work site practices,” Lingley added. “Keep the work sites clean and tidy.  If a seed treatment product is spilled, clean it up immediately. Check the label for specific instructions on decontamination procedures. Dispose of empty pesticide containers in the manner recommended by provincial authorities. Ensure that all protective shielding on the cutting line is properly installed. And, at the end of the treatment season, wash and lubricate the application equipment before storing it.” ❦

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