RICHARD COOPER HOLDS semidwarf varieties he devel­oped and used to break the 100-bu. barrier in his plots at the Ohio Agricultural Research and Development Center.

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P resent soybean varieties, and some others that will soon be released, hold the poten­tial for 100-bu. soybean yields, according

to studies conducted last summer by agronomists Roy Flannery and Richard Cooper.

Working in high-yield environments, with limit­ing factors removed as much as possible, the two men became the first scientists to break the 100-bu. soybean yield barrier. Flannery, of Rutgers Uni­versity, produced yields of 108.6, 103.6 and 102.7 bu. per acre. Cooper harvested 102.2, 101.6 and 100.3 bu. per acre at the Ohio Agricultural Re­search and Development Center.

Flannery achieved his 100-bu. yields with As-grow A3127. Cooper's came with three experi­mental semidwarf lines (two of which may be re­leased as varieties within a few years). Both men harvested replicated plots of 1/1,000 acre.

The scientists' efforts provide some insight on what may be required to push yields to 100 bu. per acre.

They had built fertility in preparation for their high-yield studies. Soil test levels (measured by the double acid extractant method) for Flannery's plot stood at more than 300 lb. per acre for phospho­rus and 300 to 350 lb. fpr potassium.

The Rutgers agronomist compared two fertilizer treatments, with the 100-bu. yields at the highest

Photo: Darrell Smith rate: 125 lb. of nitrogen, 200 lb. of phosphate and 250 lb. of potash.

Flannery's 100-bu. yields came with two dif­ferent seeding rates: 150,000 (103.6 bu.) and 225,000 (108.6 and 102.7). During the three years of his study, maxi­mum yields came from both the high and low rates. "But it appears that we are getting little addi­tional yield by seeding at the higher level," he says.

There were no signifi­cant lodging problems at either seeding rate, says Flannery. He planted in 7" rows at both rates.

Flannery eliminated moisture stress with drip irrigation. He thinks the higher nitrogen rate, early planting (May 12—10 days earlier than 1981), a fungicide application and a good growing season all may have helped boost 1982 yields.

In Ohio, Cooper ap­plied 180 lb. of P205, 360 lb. of K20 and 200 lb. of nitrogen before planting his soybeans. After har­vest, the Pi test was 205 lb. per acre and the K test was 483. The pH was 6.4.

Cooper planted both 7" and 30" rows. He seeded the indeterminate varieties and lines at 150,000 seeds per acre (8 per ft.) in 30" rows and 225,000 seeds per acre (3 per ft.) in 7" rows. With the determinate semidwarfs, he planted 225,000 seeds per acre (12 per ft.) in 30" rows and 300,000 seeds per acre (4 per ft.) in 7" rows. "Lodging of the indeterminate varieties was se­vere at both row widths and seeding rates," he says. "The semidwarfs stood well in all trials."

Both Flannery and Cooper recorded some re­markable yields that fell just short of the 100-bu. mark. Flannery got 99.8, 96.5 and 93.0 bu. per acre from Hobbit, a determinate semidwarf.

In Cooper's trials, out of 54 established varieties or lines, 27 yielded more than 90 bu. per acre in 7" rows and 45 topped 80. In 30" rows, nine va­rieties or lines yielded more than 70 bu. and 30 topped 65.

Both agree that 100-bu. farm yields will require ideal conditions—either irrigation or rain at the proper times plus ideal temperatures. "But," Flan­nery adds, "in this vast country, there are areas every year where the weather is almost perfect." <

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Photo: Harris Barnes

HARRY YOUNG Christian County. Kentucky

• How do you consis­tently produce better than 40 bu. of soybeans per acre without irrigation? Ask Christian County, Ky. grower Harry Young and son, John, and you get an answer of no-tillage and crop rotation. Only once since 1979 have their no-till beans yielded less than 40 bu. per acre, and that was a drought year.

"New herbicides, fungi­cides, varieties, and har­vesting machinery rank right at the top for us as high-yield getters," says Harry. The Youngs have a full rotation going: 650

acres of corn, all followed with small grains. Then 650 acres of soybeans are double cropped behind the small grain. No-tillage goes for all crops except for a light working before planting small grains.

Last year the Young Farm was in the midst of a dry tier of counties. John says they were able to harvest an average yield of 48 bu. of beans per acre, primarily because of the rotation and the moisture conserved by no-till. "In fact, Dad and I are very 'disappointed' when we don't combine at least an average of 40 bu. per acre from the entire 650 acres."

Look over the crops on the 2,000-acre Young farm and you see the results of years of good weed control. Behind their 18-row no-till planter (two AC's hooked in tandem) they spray a tank mix of Lexone and Dual for the residual and Para­quat or Roundup for the knockdown work. Once in a while they get a breakout of grasses and weeds in the low lands. They report good soybean yields using the tried and proven over-the-top her­bicides Basagran and Blazer, and the newcomers Poast and Fusilade.

"We like having good nematicides in the arsen­al to combat the foliar and pod diseases especially during the years of high humidity and rainfall. An­other contributor to our high yields has been the Essex variety, a real workhorse over the years on this farm," says Harry.

In concluding, the Youngs say they would men­tion keeping the soil fertility levels high for top soy­bean yields.

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• South Carolina Coastal Plain grower Roy Phil­lips grows high-yield soybeans with tight manage­ment in a conventional system. "We plant only full-season soybeans. They yield a good 15 bu. more than doublecrop beans in our area, and I avoid the mess of harvesting wheat and planting beans at the same time," he says. "We think there's more profit in full-season beans alone."

Phillips uses a mixed fertilizer, even though not always called for in his soil tests, and inoculates ev­ery bean. "We use something like 300 lb. of a 0-10-30 or a 5-10-30 each year. I think there is a payoff in having that P and K, and perhaps a little shot of N to get the crop off to a good start.

"We have a man at planting with nothing to do but inoculate the beans and load the hoppers. I'd prefer to be safe."

Although a preplant herbicide such as Basalin or Treflan is a must, Phillips has had success in cleaning up rented land and new ground, full of coffeeweed, pigweed and morning-glory with a preemergence treatment of Lasso and Sencor.

"And if necessary, to get rid of weed competi­tion later we have found an over-the-top applica­tion of Blazer and dinitro or a new material, Tack­le, used under an experimental use permit, with dinitro to be very effective. But I underscore using either combination when the plants and ground are dry so as not to damage the soybeans."

The Race 3 soybean cyst nematode is gaining ground in South Carolina.

Phillips injects Soil-brom 90 at a 15" level from the subsoiler shanks on his ripper-planter. In addition to the nemati-cide he uses a fungicide.

This year on his 800 acres he'll use 4 different bean varieties: Centenni­al, Coker 317 and 488, and Wright to stagger ma­turity dates.

He sees no need for cultivation for weed con­trol, but figures the prac­tice "breaks up" the soil after hard packing rains, allowing the roots to "breathe" for better bean growth. They use two combines to harvest fast, yet efficiently.

Photo Harris Barnes

ROY PHILLIPS Clarendon County, South Carolina

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• "Your total program makes the yield," says Willis Fiscus who farms with sons Mike and Mark in Marshall County, Iowa.

They want a good seedbed (at least in the row) that will allow even, firm placement of seed. Of course you need equipment that will do that job. Then—good, "no-breakthrough" weed control. And careful harvest that minimizes losses.

The Fiscuses have pushed their yields into the 50-bushel area with this season-long approach —when weather cooperates . . . and sometimes when it doesn't. Willis shakes his head over 1982:

"We had the longest plant­ing season in my experience. We planted beans through June 22. But we had our best check yield so far from a field planted June 5. Acreage we cut from that for a yield contest made 58 bu. per acre."

They had drilled that field in 10" rows. They usually drill fields with lower weed pres­sure; plant others in 30" rows,

paid off on our later-planted

ILIS FISCUS shall County, Iowa

"Drilling really beans," Willis says. "We had drilled beans June 22 that produced 40 bu. per acre, while 30" beans planted the same date yielded 36 bu. None of them reached knee-high. We just had more plants in the drilled areas."

The Fiscuses use a 14' Crust Buster to drill beans—now have three years experience with it. They think the close-spaced beans and quick can­opy help reduce erosion. Still, they hesitate to drill everything because of concern about weeds.

Drilling makes good weed control essential. The Fiscuses follow the same program for drilled and row beans. They put down Treflan or Lasso for grass, and follow up postemergence with Basa-gran for broadleaves. They always incorporate or surface-blend the grass killers. "We don't risk de­layed action in case we get a dry spell."

That postemergence Basagran treatment—on the drilled beans, too? Yes. Willis has found that he can drive over the young beans without caus­ing lasting damage. The wheel tracks persist for a time, but plants recover, he says. They walk fields when volunteer corn is troublesome.

They help broadleaved weed control in beans by using Banvel-2,4-D in corn. Willis and his sons grow 500-plus acres of corn, 400 of soybeans.

• Switching to narrow-row soybeans helped Frosty Hofmann make a big jump in yields—from the 36-bu. range in 1976 to 44 bu. per acre in 1977. In 1981, he average 45 bu. per acre, com­pared to a county average of 36. Last year, he av­eraged 47 bushels. Soybean production is more than a job to him, Hofmann admits. "You get yourself wound up in it, and it gets to be kind of an obsession at times," he grins. "I find soybeans to be more of a challenge than corn."

Key steps in production? "I don't know what could be more important with close-row soybeans than weed control. Yield reduction from heavy foxtail or broadleaf infestations is unbelievable, and harvesting weedy beans is a bear. With close rows, chemicals are the only method you have."

Knowing what weeds are present is essential for control, says Hofmann. He has several fields scouted by professionals and he walks some him­self. "Last year I found some common ragweed and some nightshade," he says. "So we sprayed Blazer along with Basa­gran and it worked well. Nightshade can become a problem rapidly if you let it go."

Matching herbicides to the weed species is also essential, says Hofmann. "The information is right on the label of every herbicide," he notes.

Hofmann thinks he's found a way to eliminate the difference in herbicide performance caused by varying organic matter content within a field. He'll eliminate his usual DNA herbicide on some acre­age—perhaps almost half—and go entirely with postemergence products. If it's too wet for ground equipment, he may go aerial.

He has begun analyzing varieties more closely. "There seems to be more difference now than when I started growing soybeans," he says. He studies university yield trials first, then other sources.

"Except for universities, it's hard to find unbias­ed yield data," says Hofmann. But he has discov­ered one other source: Chemical company trials. "They're testing herbicides, so they have nothing

Photo: J C AllenS Son

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WILLIAM "FROSTY"HOFMANN Clinton County, Indiana

to gain by promoting a variety," he says. <3

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