Why does the company maintain production so far away from the factory? Quantity and quality. Horse Heaven Hills beet yields commonly average 43-45 tons per acre, with sugar content typically in the high 16s. Tonnage is lower around LaGrande, but growers there “are almost always in the upper 17s or lower 18s on sugar content,” Wahlert notes. That’s a good 1% above the overall company sugar average in a typical year.
Because these two production pockets are quite limited in acreage and so distant from the main production region, no beet seed company develops varieties specifically for them. Nor is there any public or private research established in these two pockets — with one exception.
That exception is Bill Wahlert. Since the late 1990s, he has operated his own unofficial variety trials, typically planting two or three varieties from each of the seed companies that are active in the Treasure Valley (Betaseed, Crystal Beet Seed, Holly/SESVanderhave and Syngenta/Hilleshog). One trial site is in Horse Heaven Hills; the other near LaGrande. Varieties in both locations are replicated twice, and Wahlert hosts an annual field day where growers can view the plots and visit with seed company representatives. Year-end harvested results likewise are shared with local growers and the seed companies.
Within recent years, Wahlert’s trials have had an added dimension: comparing varieties for tolerance/resistance to Aphanomyces.
A liming study was conducted that same year. “Since then, growers have been applying lime — maybe not as much as they should; but if they know they have an Aphanomyces problem, they’re generally putting down about two tons of dry spent lime to the acre,” Wahlert says.
One complication in gauging varieties for tolerance to Aphanomyces is the requirement that all Treasure Valley-approved varieties have acceptable levels of resistance to curly top — long a prime disease issue in that production area. Curly top is not as consistent a problem in the Grande Ronde Valley as it is in the Treasure Valley, and some of the best curly top varieties don’t have very good Aphano-myces tolerance.
All of the area’s sugarbeet growers use Tachigaren-treated seed for early season control of Aphanomyces. But it’s agreed that for good management of the mid-season form of this disease, the long-term answer has to come in the form of tolerant or resistant varieties.
John Frisch says he’s been liming to help manage Aphanomyces in his sugarbeet fields. Just as important, though, he now takes a different approach to his center-pivot irrigation. “Bill has really hammered on me to back off on my irrigation, and I’ve resisted,” Frisch states. “But I did this year, and it made a difference.” The idea is to lengthen out the interval between irrigation cycles so that the soil has time to partially dry out — hence not being as conducive for Aphanomyces development. Frisch says higher-than-average spring rainfall made that decision easier this year. “I knew we had good subsoil moisture, so I wasn’t quite as worried about getting behind” on sprinkler applications,” he notes.
Along with Tachigaren, “it’s about the only tool we have” for Aphanomyces management.
Would longer rotations help slow the disease? Some of Weishaar’s fields go five to six years between beet crops. But Aphanomyces was evident even in a 2011 field that hadn’t been in sugarbeets for eight years. “So it’s spreading,” says Weishaar, who believes that one conveyor of the disease inoculum is soil movement from consistent winter winds.
Other than the Aphanomyces issue, the Grande Ronde Valley has proven to be a solid sugarbeet production area since beets were introduced in the early 1990s. Its growing season is shorter than that of the Treasure Valley and Magic Valley, however, which does crimp yields a bit. Frisch and Weishaar like to be planting beets by April 15; but steady spring rains pushed that back this year — as far as to May 15, Frisch reports.
“We’re surrounded here by mountains,” Bill Wahlert explains. Along with a slightly later spring and earlier fall, the environment produces cooler summer nights — “and that helps sugar content.” On the down side, though, “because it is a little cooler, we just don’t get as much growth” compared to the Treasure and Magic valleys. (Tonnage commonly averages in the upper 20s.) Late spring and/or early fall frosts can also hamper beet development. “We usually figure on getting a killing frost somewhere around the first full week in May,” Frisch says. “We had a light frost on June 22 this year.” On the other end of the growing season, the first fall frost in 2011, admittedly a spotty one, arrived on September 4.
Nitrogen management is another category where Wahlert and area sugarbeet growers are exploring and refining. Amalgamated’s local crop consultants (who used to be called “fieldmen”) have been evaluating whether the company’s standard guideline of eight pounds of available nitrogen per ton of expected yield is still appropriate.
So Wahlert initiated evaluation plots. “With the high organic matter levels here, the question is, ‘Do we get more mineralization — and, if so, do I need to stick to that eight-pound standard? Can we get by with six or seven?’ ” he asks. The 2010 results suggested that seven pounds per ton was the most-efficient level. Preliminary evaluation of his 2011 data suggests that somewhere between six and seven pounds produced the best yield.
Guy Weishaar applies less nitrogen to his sugarbeets than most growers — for a very good reason. Weishaar is a mint grower and follows mint with sugarbeets. “Mint is a shallow-rooted crop and leaves quite a bit of nitrogen behind, so I like to use the beets to go down and pick that up,” he explains. “In some years, I’ll apply just 50-80 pounds [per acre] of nitrogen for the beets because the rest of what they need is already down there.”
Weishaar also operates a mint oil extraction plant on his farm and spreads the mint sludge byproduct across fields as a form of cover against wind erosion.
John Frisch is using a ridge-till approach to help protect his fields. His beets typically follow wheat, “and we leave all the straw; we don’t bail anything off,” he says. Building ridges in the fall, coupled with all that wheat residue, has proven an effective method of over-winter erosion control. Plus, ridge tops dry out faster in the spring, facilitating a little earlier planting date. Frisch believes that the ridges also can be of benefit with Aphanomyces by helping keep the beets in them a little drier. — Don Lilleboe