Wednesday, February 15, 2006
filed under: Hybrid Selection/Planting
Bruce Due recalls talking with a sunflower grower in central N.D. last year who questioned the seed treatment performance in his ‘flowers. The grower had half of a field planted with Cruiser® (a.i. thiamethoxam) treated seed and half of the field untreated, and didn’t observe any difference between the treated and the untreated – so was the cost of the sunflower seed treatment justified?
“I told him, ‘you should be pleased. Because if there would have been problems, you probably would have lost half your stand, the half you left untreated,’” says Due, an agronomist with Mycogen Seeds. “Growers want to see that visual damage to see if it’s working. But it’s only going to happen if you have a problem. You probably won’t see a difference if the pest environment isn’t there. So a seed treatment is like car insurance. It isn’t necessarily something that’s going to give you a payback every year. It’s protection against problems that you don’t want to have.”
Namely, protection against problems with early-season insects (key among them: sunflower beetle, flea beetle, and wireworms – particularly on no-till) and early-season disease protection (with Cruiser DM Pak) against Pythium, Fusarium, Rhizoctonia, damping-off, seedling blight and downy mildew suppression (more about that later).
Many say the seed treatment helps increase stand, uniformity and vigor to protect yield potential, and since the product is commercially treated, it saves time (and mess) at planting.
It’s estimated that Cruiser was used on more than 70% of the sunflower crop last year. Prospective economic return makes it an easy decision. Due points out that the seed treatment cost is about $5 to $6 per acre. Early-season insect and disease problems can easily steal 200 to 300 or more lbs/ac of yield. So an additional 200 to 300 lbs/ac treated versus untreated on sunflower at $11/cwt is $22 to $33 – not a bad investment. There’s also less likelihood of a need to replant, the expense and time (time replanting, as well as lost growing days) which also needs to be considered.
Jeff Herr, who includes sunflower in his crop rotation near Wishek, N.D., says he focuses on good stand establishment from the start.
“Emergence is really critical,” he says. “We’re only talking about 23,000 plants per acre. If you get 10% knocked out, it lessens your stand. Compensation is only so good, especially if you get an area – a half-acre or quarter-acre spot – where the population has dramatically dropped, it can cost you a lot.”
A strong start helps set the pace for a healthy crop all season long. “Emergence is 99% of the problem,” says Jim Purintun, who grows sunflower near Hazelton, N.D. “Once the plants get up to six or eight inches tall, you don’t have to worry about them getting damaged by cutworms or grasshoppers.”
With all the benefits of this seed treatment, however, realize its limitations. Sunflower growers shouldn’t expect Cruiser to control insects and diseases beyond those listed on the product label.
Cutworms and stem weevils, for example, are not pests listed on the Cruiser label. Some have observed that Cruiser may help protect plants from cutworms early in the season. But the product shouldn’t be expected to offer complete control, especially as the growing season progresses, since it is not labeled for cutworms.
“Thiamethoxam, the active ingredient in Cruiser, is extremely effective on many insects that feed on treated seed or seedlings, and the protective effect can last well into the growing season,” explains Cliff Watrin, technical crop manager for Syngenta Seed Treatment, which makes Cruiser. “But cutworms are best managed through scouting and treating with a foliar insecticide. Pyrethroids, including Warrior, are very effective for controlling cutworm, but growers can’t rely on Cruiser to do it.”
As well, there is consensus among experts that Cruiser won’t be effective in controlling stem weevils, which also is not on the Cruiser label. Scouting and control measures for stem weevils generally take place between late June and mid July, when residual activity of the seed treatment will have waned.
Know too that the fungicide component of Cruiser DM Pak (Apron XL, Maxim 4FS, and Dynasty fungicides) will protect against early-season diseases, but may not offer complete control of downy mildew. On the Dynasty label for sunflower, downy mildew is listed as a “target disease.” There is general agreement that the product can be expected to help protect young sunflower plants from downy mildew, suppressing the fungal disease. But damage may still occur if disease conditions and symptoms are severe, with systemic activity wearing off as the growing season progresses.
Again, the seed treatment can be compared to insurance – even a comprehensive or multi-peril insurance policy has its limitations. There are still many benefits, however, including early season peace of mind.
That peace of mind is important for Wishek grower Gene Rudolf, who farms with Herr. “If you’re going to spend a little more for the security of something that you know is going to work, then it makes sense,” Rudolf says. “It simply means more profit – that’s the bottom line. We had close to 3,000-pound ‘flowers last year.”
Seed companies may offer different seed treatment options, such as Cruiser alone or in combination with fungicides. Consult with your seed dealer about the options. – Tracy Sayler, Steve Werblow