Spraying at Bloom with a Ground Rig
Friday, January 1, 2010
filed under: Insects
Can you spray for sunflower head insects with a high-clearance ground sprayer? Of course you can, affirm Wayne Drangsholt and Jeremy Huether. You just need sufficient clearance to avoid contact with the blooming plant heads.
Drangsholt, who farms in north central North Dakota near Mohall, used his John Deere 4730 high-clearance sprayer last summer to apply a tank mix of Folicur® and Headline® fungicides along with Cobalt® insecticide. The fungicides were applied as an insurance policy against sunflower rust, while the Cobalt went on to control seed weevils and grasshoppers. The treatment took place at the recommended plant development stage for seed weevil management, i.e., early pollen shed.
Drangsholt was able to safely apply the pesticides with the sunflower at their full height because he had installed a new high-clearance bundle offered by Deere. The bundle increased the sprayer height an additional 16 inches (thus up to 76 inches of under-frame clearance). It consisted of four assemblies — one per wheel — that attached between the chrome spindle and the casting that houses the wheel motor. Shields also were included to help keep the sprayer’s radiator and grill clear of pollen (or, in the case of corn, of tassel).
The Renville County producer used the same type of nozzles as he does when spraying wheat for Fusarium Head Blight (scab) — the European-developed Amistar reverse-angled nozzle, providing both forward- and backward-facing droplet distribution. He applied between 15 to 20 gallons of water per acre from the 4730’s 800-gallon tank.
Drangsholt, who grew 2,000 acres of sunflower in 2009 on 30-inch rows, figures he recouped his investment in the Deere bundle kit in a single application. Along with saving $6.50 to $7.00 an acre in aerial application costs, he estimates he also saved about $1.00 per acre by purchasing the chemicals himself.
Most importantly, he was very satisfied with the results. “I’m putting on a lot of water, which is one reason I wanted to do it myself,” Drangsholt states. He believes his application was particularly timely, too, since he didn’t need to wait to fit into the schedule of a busy commercial applicator.
Were there any downsides? Drangsholt’s RTK could not hold the sprayer satisfactorily between the rows, so he was unable to rely on the auto-steer. Also, driving through field headlands naturally resulted in some plants being damaged. But with plenty of height clearance and careful “hands on” steering, there was no damage to any other parts of the field.
“To me, it’s a no-brainer,” Drangsholt says of his decision to use the high-clearance sprayer for applying fungicide and insecticide in mid-season sunflower fields. “With a high-value crop like sunflower — even in this past year when our contract price wasn’t quite as good [as the prior year], it doesn’t take long to pay for itself.” Though he traded off his JD 4730 sprayer for a newer 4830 model, “I’ll be getting another high bundle kit,” Drangsholt affirms — and, no doubt, driving it through his 2010 sunflower fields.
Jeremy Huether has similar sentiments regarding the feasibility of running a high-clearance sprayer across blooming sunflower acreage. Huether, who farms with father Burnell and brother Nathan near Mott., N.D., applied a tank mix of Headline fungicide and Delta Gold® insecticide (primarily for seed weevil control) in the summer of 2009.
The Huethers own a Miller Nitro 2275, which has a clearance height of about 73 inches. Though not quite as high as Wayne Drangsholt’s sprayer, Jeremy says he incurred no damage to blooming sunflower plants in their 30-inch rows — except when driving across the headlands.
The field he sprayed was located about 20 miles from the Huether farm; but fortunately the Nitro 2275 has a 1,400-gallon tank, so Jeremy was able to spray the entire field with a single load. He went with 15 gallons of water at between 50 to 60 psi. Angled flat fan nozzles provided adequate coverage — both of the plant heads (for insects) and the foliage below (for rust). “The seed weevil control was great,” Huether reports, adding that the Headline went on as a protectant, and he’s not sure whether they would have had an economic rust problem had it not been applied.
Other than the wheel-damaged plants on headlands, the only downside to the “high boy” sprayer experience for the Huethers was that it had to be done during their busy wheat harvest. Even so, “I would definitely do it again,” Jeremy confirms.
— Don Lilleboe