Successful growers from across the country share their thoughts on Best Management Practices in potato production.
Seed treatments provide insurance for potato growers to help protect their investment until the first seedlings emerge. These days, farmers can choose from a growing number of insect and disease control products for seed potatoes, as well as strategies for getting the best results for their seed treatment programs. Spud Smart magazine is ushering in 2014 with the addition of ROUNDTABLE, a new special series in which we ask growers from different regions of the country for their insights and opinions on Best Management Practices in potato production. Planting season is around the corner — so we thought it appropriate to start things off with a discussion of BMPs for seed potato treatment.
With more options available, there’s value in knowing the best practices employed by successful potato growers. Using chemicals is one of the tools, but best management practices also play an important part in integrated pest and disease control and are key to a healthy start for potato crops.
The question of best management practices in seed potato treatment was posed to three growers from across the country: Alberta’s Jake Hoogland, Karl Smallman of Prince Edward Island, and Manitoba’s Steve Jonk. This is their take on the best of the BMPs.
Liquid Versus Powder
Seed treatments for potatoes come in both powder and liquid forms, and in recent years new liquid products that combine both an insecticide and fungicide component in a single package have been growing more popular. For example, Hoogland, Smallman and Jonk all tried the new Titan Emesto fungicide/insecticide combo offered by Bayer CropScience last year, and all say they had good results with it.
Liquid seed treatments offer the advantage of more precise application than powder treatments, but some growers resist the idea of adding moisture to potato seed pieces, fearing bacterial growth.
Some experts offer “cut, treat and plant” — planting seed pieces immediately after they’ve been cut and treated, in other words — as the best advice for avoiding bacterial infection in storage.
Smallman, however, says he’s achieved the best results by not following that rule. “In this neck of the woods, we have high, high humidity,” he says, “and we can get some pretty damp, cold days in planting time. If our seed pieces aren’t in excellent condition, then we can get into a world of hurt.”
Smallman says numerous growers in his area followed the cut, treat and plant axiom last year, but an unforgiving spring resulted in a higher amount of seed decay in their fields then normal.
“Planting seed that has just been cut, in my opinion is a no-no,” he says. “My program going forward from hereon is going to be cut it, treat it and put it on air for five to seven days, and then put it in the field after that.”
Putting the seed pieces on air essentially dries them out and reduces the possibility of infection and decay that can set in on the newly cut tuber, Smallman says. He accomplishes this by storing the potatoes in an area with excellent air circulation.
“I have a warehouse that has culverts. … I’ll spread [the treated seed pieces] over the culverts, the same as if I was filling the building in the fall,” he says.
“When that culvert’s covered with four feet of potatoes, I’ll move to the next culvert so I have a kind of V-shape in-between each culvert that almost goes down to the ground. Then I’ll start the system up and just run air for about five to seven days, and that seems to really give me a good skin set. It kind of suberizes the cut side of the seed piece, and when it hits the ground it’s got a better chance of surviving and not rotting through the cut side.”
Hoogland says he’s had some luck drying out his treated seed pieces in a similar fashion prior to planting in the past, but because the process also corresponds with the busy shipping season, it’s a timing issue. “I’ve stored them too for a week or so, but [often] I just don’t have the time to do that,” he says.
Much of Jonk’s potato seed is sold to other farmers, so there usually isn’t any time to store the treated seed before it’s shipped out. “Often when you’re custom-cutting, the grower is planting them immediately,” he says.
“But I know some guys who do use that practice; they’ll take [the treated seed pieces] in early, they’ll dry them up,” Jonk adds, “and that works really well for them.”
Hoogland believes the best way to reduce the risk of bacterial disease is to avoid cutting seed potatoes in the first place — which is why his farm uses whole seed rather than seed pieces.
“That’s one of our Best Management Practices, using whole seed,” he says.
Follow the Label
Jonk says applying seed treatment products at the recommended label rates is always sound advice for farmers wanting to get optimal results in-field. “You don’t want to over-apply and you don’t want to under-apply,” he says.
Smallman says rotating products to fight resistance is another important BMP in seed potato treatment, as it is in other areas of chemical pest control. “That’s been long known in the industry — that if you want to save a product and get the most life out of it, it’s important to change your family [of products] and rotate active ingredients.”
Hoogland maintains the introduction of new seed treatment options has made it easier for farmers to put proper rotations into practice. “With the newer products,” he says, “it’s easier to alternate between products.”
Hoogland suggests growers could also consider in-furrow chemical applications at planting as part of their seed treatment program.
“We use an in-furrow treatment at planting on our whole crop, always,” he says. “I think it’s a must for the seed. It will reduce our rhizoctonia, big-time.”
Importance of Equipment
All three of the growers we canvassed agreed that using the right equipment can make a big difference.
Smallman says he had good success with the Milestone Potato Seed Liquid Treater he purchased last year. “It’s a tumbling barrel and it has a mister inside [that applies] a very, very fine mist to the seed piece, and that works really well,” he says.
Jonk, on the other hand, has a custom-built system that uses a couple of nozzles to apply liquid seed treatment to potatoes at his farm. “We get pretty good coverage,” he says. “But I know some people who use a drum applicator, and that seems to work well for them too.”
Hoogland has also constructed his own equipment for applying liquid seed treatment that incorporates a rolling table and an overhead sprayer. “The tricky part, especially [dealing with] the whole seed tuber, is trying to get the product on as evenly as possible and on all sides. … We found the chemical spread out over the tuber quite nicely” resulting in 75 to 85 per cent coverage, Hoogland says.
All three growers appreciate the value of seed potato treatment. It isn’t something Hoogland uses on all of his potatoes prior to planting every year, but there’s usually a good portion of them that get treated before they go into the ground. That’s because Hoogland knows seed treatments can help reduce in-season risks and have the potential for boosting the quantity and quality of potato crops.
“I’d say that’s by far the biggest thing,” he says. “[Potato seed treatments can help to] optimize yield and tuber quality when it goes to our customers.”