AFTER LARGELY failing to show its face in 2005, Asian soybean rust (ASR) has been the butt of gallows humor across farm country in recent months.
But the continued threat of ASR is no laughing matter. Although the crystal ball is hazy on the particulars, the consensus points to a future with ASR as an ongoing threat in the U.S.
Whatever the ASR future brings, 2005 was a dry run that taught the industry a bit about both preparedness and panic. While farmers, agricultural retailers and distributors scrambled to procure fungicides, manufacturers were gearing up production of products that had no certainty of being used. In the end, some manufacturers took back 90 to 95% of the ASR fungicide they produced.
“If anyone still has concerns about ASR fungicide availability, I hope 2005 addressed those questions,” says Janice Smith, head of U.S. fungicide marketing for Dow AgroSciences. “The channel responded well. There were plenty of fungicides available.”
Going into the 2005 growing season, growers and dealers were anything but convinced, admits Marty Wiglesworth, technical brand manager for fungicides for Syngenta Crop Protection.
“What I heard last year early on, there was talk of tight supply and that the South would get supplies first,” he says. “We allocated product to ensure fair distribution of product across the soybean production areas. Supply was adequate for a first-year outbreak.”
For 2006, supplies should be more plentiful, especially if EPA and state regulators grant Section 18 emergency exemptions for additional products currently under review, manufacturers say (see sidebar). Assuming these Section 18s are granted, “this would assure supply for a massive outbreak,” Wiglesworth says.
2005 panic revisited
Last winter and into spring, agricultural retailers faced a near panic in some cases as growers asked to buy fungicides that weren't in stock.
That was the situation faced by Midland/Impact LLP, Danville, IN. The retailer, which recently changed its name to Co-Alliance LLP, faced a barrage of questions from growers wanting to buy fungicides. Meanwhile, availability from distributors was uncertain.
“The main thing we told our customers is not to get overanxious,” says Phil Brewer, northern agronomy division manager for the company, which has 23 locations in Indiana, Ohio and southern Michigan. “We were trying to discourage utter panic and fear. Once we had the product in place, it really squelched the nervousness.”
Brewer was nervous himself, given the difficulty of lining up fungicide supplies. At first, it seemed as if the company's goal of buying enough fungicide to treat about 60% of customer acres was unlikely to be achieved. Finally, adequate supplies became available.
Meanwhile, the company developed a plan to spray soybean acres as efficiently as possible, which included the purchase of four new self-propelled sprayers. The spraying program, along with having fungicides on hand, calmed customer fears, Brewer says.
Like a lot of retailers, Midland/Impact didn't sell an ounce of fungicide for ASR, although some growers used fungicides in programs to improve general plant health. Although it purchased fungicides with the understanding that there would be no returns, distributors eventually took them back.
“Although everyone in the channel took some risk, in 2005 the manufacturers paid most of the bill for ASR fungicide inventories,” notes Dow AgroSciences' Smith.
“In a situation like this, it probably is best that we hold the inventory versus it being out in the channel,” adds John Smith, business unit manager for fungicides and seed treatments for Bayer CropScience. “We know what inventories exist as we plan for the future.”
The winter weather factor
Because winter weather can have a huge impact on ASR spore inoculum currently in place in southern states, it's impossible to forecast the 2006 ASR infestation outlook with any accuracy. By late fall 2005, ASR inoculum had been documented from Florida across the Southeast into Mississippi, Louisiana and Texas.
If weather is hospitable to ASR over winter, many observers say conditions are more conducive to widespread ASR infestations in 2006 than was the case going into the winter a year ago. But they emphasize that a sharp freeze, which wiped out ASR inoculum in all but the southern half of Florida last winter, could happen again this year — and completely change the outlook.
“We know from experience in other countries that it takes a year or two for ASR to take a foothold,” says John Smith of Bayer CropScience. “ASR inoculum has been detected in many more locations in the U.S. than last year. That would lead us to believe that the risk is higher.”
But winter temperatures are critical, as are environmental conditions in early spring and throughout the growing season.
“Hot and dry conditions from the central Corn Belt through the Delta last year weren't favorable to ASR,” notes Gary Fellows, technical marketing manager for BASF. “We possibly overestimated the ability of spores to germinate in hot, dry conditions. If we have a cooler-than-normal summer in 2006, with adequate moisture, there could be another story.”
Plan of action
ASR will continue to be a major topic at meetings this winter, so there will be plenty of advice on planning for a potential outbreak. Fungicide manufacturers say they will err on the side of over-education.
“Because ASR didn't develop in 2005, anxiety has waned a bit,” says John Smith. “We don't want growers to panic as they prepare for 2006, but we don't want them to become complacent either.”
In addition to monitoring the likelihood of an infestation as winter and spring progress, it's a good idea to develop an action plan that assures you that your acres will be sprayed in a timely manner if ASR hits your farm.
Brewer, from Co-Alliance LLP, will be encouraging growers to consider applying fungicides on high-yield-potential fields to control diseases other than ASR that typically are present. That will give growers a head start on ASR control if it strikes, since some of their acres already will be protected. Based on experience in his service area last year, the program should yield economic responses even if ASR doesn't strike, Brewer says.
“If ASR would have hit last year, there was no way there was enough equipment to spray everything,” he says. “We purchased four new sprayers, and there were a lot of sprayers sold on the farm. But if ASR had taken place, it was going to be hard to manage it.”
Both Syngenta Crop Protection and BASF will be promoting general plant health spraying programs with their respective fungicides, Quadris and Headline, which are registered for control of many soybean diseases. Most other fungicides cannot be promoted or used for diseases other than ASR because their Section 18 Emergency Use Permits are specifically granted for only ASR.
Both manufacturers recommend applying registered fungicides at the R2 to R3 stage, regardless of whether diseases are present.
“You will find some level of many diseases in practically any soybean field anywhere in the U.S.,” says Wiglesworth from Syngenta. “Over the last five years in trials and demos, we are getting anywhere from a 5- to 8-bu./acre increase.”
Adds Fellows from BASF: “In the Midwest over the past two years, we have seen fairly consistent yield responses from fungicide treatments. We have seen yield increases all the way from Group 00 to Group 9 beans.”
FUNGICIDES IN THE EPA PIPELINE
AT LEAST 10 additional fungicide brands could be available for control of Asian soybean rust (ASR) in soybeans in 2006, pending EPA approval of Section 18 emergency exemptions.
Assuming that federal Section 18 exemptions are granted, and that individual states also approve them, the following new products will join an ASR control lineup that includes at least 16 products with Section 3 (full registration) or Section 18 registrations.
Absolute (Bayer CropScience) contains both a strobilurin and a triazole as active ingredients. The combination provides both preventive and postinfection activity.
Alto (Syngenta Crop Protection) contains the active ingredient cyproconazole, a triazole.
Charisma (DuPont) contains the active ingredients flusilazole, a triazole, plus famoxadone. Famoxadone, a contact fungicide, belongs to the oxazolidinedione class of chemicals and is active against spore germination and mycelial growth of sensitive fungi.
Dithane (Dow AgroSciences) contains mancozeb. This broad-spectrum fungicide binds to many fungal proteins and has no specific mode of action. As a protectant, it must be applied prior to disease infestation.
Fenbuconazole (Dow AgroSciences) is a triazole and offers both preventive and curative control, as do other triazoles. The same active ingredient is sold in the U.S. under the Enable and Indar brands in other crops. Its name has not been announced.
Flutriafol (Cheminova) is a triazole. Its U.S. brand name has not been announced.
Metconazole (BASF) is a triazole. Its U.S. brand name has not been announced.
Metconazole co-pack with Headline (BASF) contains metconazole, a triazole, plus pyraclostrobin, the strobilurin contained in Headline. Its U.S. brand name has not been announced.
Punch (DuPont) contains the active ingredient flusilazole, a triazole.
Quadris Xtra (Syngenta Crop Protection) contains azoxystrobin, a strobilurin and the active ingredient in Quadris, plus cyproconazole, a triazole and the active ingredient in Alto. The combination product is marketed as Priori Xtra in Brazil.