A production practices survey of Michigan growers attending recent winter meetings sheds new light on how the state’s sugarbeet producers are adopting research-based recommendations. At five educational meetings held in February, sponsored cooperatively by the Michigan Sugarbeet Research Education Advisory Council (REACh), Michigan Sugar Company and MSU Sugarbeet Advancement, attending growers were asked to respond to a series of questions. Nearly 200 growers provided input. Combined, their 2014 beet acreage was 54,200, which represents about one-third of last season’s entire Michigan sugarbeet acreage.
The first set of questions pertained to the use of Quadris® fungicide for control of Rhizoctonia. Of the 198 growers responding, 94% indicated they use Quadris for control of this disease — a very high percentage compared to other U.S. beet growing areas, points out Steve Poindexter, senior sugarbeet extension educator for Michigan StateUniversity.
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As to the method of applying Quadris, 96 of the responding growers (51%) said they used the “one-two punch” of a T-band in-furrow treatment at planting, supplemented by a foliar application at the six- to eight-leaf plant growth stage. “We’ve shown, over the past 10 to 12 years, that’s the best approach if you have bad Rhizoctonia,” Poindexter notes. “We’re covering the plant, from early on clear through [the vulnerable period].” Sixty-five (34%) of the growers indicated they used a onetime foliar application of Quadris; another 21 (11%) said they used the in-furrow treatment only.
Responses to the next question — “If applying Quadris in-furrow, what is your band width?” — reflected a big shift from just a few years ago. Previously, the standard recommendation called for a seven-inch band when Quadris was sprayed in-furrow during planting, and that’s what most growers followed. “But through research conducted by Michigan Sugar Company, we’ve found we can go to a three- or four-inch band, essentially reduce the rate of Quadris by half — and still get just as good control,” Poindexter states. Growers have quickly picked up on that finding, suggest the responses at this winter’s meetings. Nearly half (46%) of those who apply Quadris infurrow said they were using a three- to four-inch band width. Another 18% indicated they were in a two- to three-inch band, while 17% said they used a band width of four to five inches. Just 14% reported a band of between five to seven inches.
The next two questions at the Michigan meetings focused on nitrogen rate. “Michigan doesn’t do a soil nitrate test to make our recommendations for nitrogen,” Poindexter explains. “It’s based more on what was your previous crop. And we’ve found that when you have high-residue crops like corn or wheat stubble, the optimum N rate generally is between 150 and 175 pounds.”
That was borne out by those growers answering this question: “When planting beets after high-residue crops such as corn or wheat stubble, what is your total N applied (with a 2x2 + broadcast/sidedress application)?” Eighty growers (43% of the total) said their N rate was between 126-150 pounds/acre; another 60 (32%) reported it between 151-175 pounds/acre. Twenty-two growers (12%) said they typically were in the 100- to 125-pound range, while 7% reported 176-200 pounds and the final 6% above 200 pounds.
When planting beets after a lowresidue crop such as soybeans, dry beans or pickles, total N applied broke down as follows: 72 (41%) said 126-150 pounds/acre; 53 (30%) reported a rate between 100-125 pounds; and 38 (22%) indicated their total applied N was in the range of 151-175 pounds/acre.
BEETCast is a weather station-based Cercospora advisory system used throughout the Michigan (and Ontario) growing region. It collects leaf wetness and temperature data to develop predictions — known as disease severity value (DSV) — for Cercospora leafspot development, thus allowing growers to be timely with their first critical fungicide application as well as any subsequent ones.
Meeting respondents confirmed the widespread use of BEETCast. Eighty-seven growers (47%) said they follow BEETCast DSV intervals for timing all their fungicide applications. Another 39 (21%) said they rely on BEETCast for the timing of their first treatment; then go by the product label for timing of any subsequent spray applications. Thirty growers (16%) indicated they follow “other recommendations” for Cercospora spraying, although Poindexter points out that at least some of those “other” would consist of crop consultants who themselves follow BEETCast.
Leafspot testing in Michigan has in dicated fairly widespread strobilurin resistance, Poindexter says, “and we are trying to prevent/delay further resistance with strobilurins and triazoles.” That’s why tank mixing of fungicides is being highly encouraged, the MSU educator observes.
“Do you tank mix your fungicides with two different mode-of-action products?” One hundred fourteen growers (59% of those replying to the question) said they always do; another 36 (19%) said they do so more than half the time. As to why they do not tank mix Cercospora fungicides with every application, the biggest percentage attributed that decision to the poor mixing ability of certain products (e.g., EBDCs, some coppers), resulting in nozzle plugging and/or other problems. “In the last couple years, we’ve made major strides in encouraging growers to tank mix their fungicides, using two different modes of action,” Poindexter observes. “Two or three years ago, nobody was tank mixing.”
While the use of the “Tins” is common in the Upper Midwest for Cercospora management, that’s not the case in Michigan. “It’s been difficult to convince growers to use this product,” Poindexter concedes, “but we need it in there to prevent resistance from creeping in.” Among winter meeting respondents, 51 (27%) said they used a Tin product in 2014 and likewise planned to do so in 2015. However, 76 (40%) said they did not use a Tin last year, nor do they plan to do so this coming season. Part of the lag, Poindexter says, is due to numerous commercial applicators in the Michigan beet region not being willing to apply Tin products.
‘In the last couple years,we’ve made major strides
in encouraging growers to tank mix their fungicides.’
In response to a “subjective” question regarding the efficacy of strobilurin fungicides like Headline and GEM, just over half said they believe the strobilurins were just as effective in 2014 as they had been in prior years, while 30% said they were uncertain. Answering a similar question about the triazoles (Inspire, Enable, Eminent, Proline, TopGuard), 166 growers (87%) believed those products were just as effective last year as in prior years.
As to the number of Cercospora fungicide applications made in 2014, 114 (60%) of the respondents said “three.” Another 45 (23%) reported two applications, with 19 (10%) at four. A few were above or below that range.
Finally, the 2015 Michigan winter educational meeting attendees were asked a herbicide resistance question, specifically: “Are you practicing glyphosate weed resistance management techniques (utilizing traditional herbicides) in your corn and soybean crops?” Of the 192 growers responding, 139 (72%) said, “Yes — Always.” Another 33 (17%) said they do so more than half the time, while just 13 (7%) said they have never, to date, done so.
“We feel pretty good that 72% of growers are using some conventional herbicides with their corn and soybeans. That’s a good thing,” Poindexter remarks. “We believe the best place to manage glyphosate resistance is by using conventional products in corn and soybeans, because there are quite a few products available for those crops.” — Don Lilleboe
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