Alfalfa

Roundup Ready Alfalfa Trial Indicates No Yield Drag

Sun, 15 Nov 2020 21:22:16 GMT

Source: University of Wisconsin Extension New Release

The performance of Roundup Ready alfalfa varieties is being evaluated in University of Wisconsin-Madison Extension alfalfa variety trials, according to Dan Undersander, UW-Extension forage agronomist.

He noted that only seeding year data is available since no one could plant Roundup Ready alfalfa varieties prior to this year due to a court injunction prohibiting such planting.

The highest yielding commercially available variety in the 2011 seeding at Arlington Agricultural Research Station was a Roundup Ready variety in the treatment receiving Roundup. However, due to field variability, alfalfa varieties must have a least significant difference of at least 0.5 t/a to be truly different and several conventional and Roundup Ready varieties were not significantly different from the top variety.

“Roundup Ready varieties were generally in the upper half of the yield range at Arlington,” said Undersander. “This would indicate that alfalfa varieties have no yield drag due to the Roundup Ready trait.”

The trial was conducted both with Roundup Ready varieties planted with non Roundup Ready varieties in a standard trial and treated with the same herbicides. Butyrac 200 and Post Plus were used to control weeds in these trials to minimize herbicide injury. The Roundup Ready varieties were also planted in a separate trial treated with Roundup.

Undersander said, “Yields of the Roundup Ready varieties were not significantly different whether Roundup Ready alfalfa varieties were treated with Roundup for herbicide control compared to those receiving the Butyrac 200 and Post Plus.”

More information about forage variety trial results can be found at http://www.uwex.edu/ces/forage/alf11.htm

Prevent Alfalfa Winter-Kill

Sun, 15 Nov 2020 21:20:53 GMT

Source: Pioneer Hi-Bred

Timing the final alfalfa cutting before mid-September offers regrowth opportunities to reduce the risk of winter injury, say experts at Pioneer Hi-Bred, a DuPont business.

“Whether a grower is in a three- or four-cut alfalfa program, cutting from Sept. 10 to Oct. 1 in most northern climates rarely allows the crop enough regrowth time to withstand winter months,” says David Miller, Pioneer alfalfa research director. “Poor fall harvest timing can negatively affect stored root food reserves, which can lead to poor winter survival.”

Generally, an alfalfa stand needs about six weeks of regrowth time after the last cutting to gain appropriate nutrients to avoid winterkill. During winter months and the following spring, alfalfa utilizes regrowth nutrients gathered by the roots.

“It’s a matter of arithmetic,” Miller says. “Depleting the energy source prior to dormancy will not allow the plant enough energy for adequate spring growth. If a final cutting is a necessity for ample feed, growers should wait until two consecutive days of a hard freeze - 24 to 26 degrees.”

According to the University of Wisconsin, the hardening process in preparation for cold weather begins when temperatures drop below 40 F. This process allows the plant to tolerate freezing temperatures for extended periods.

“Following a hard freeze, growers have the opportunity for a final cutting,” Miller says. “Leaving more stubble than typical summer cutting is recommended. For all fall cuttings, leave at least 4 inches of stubble to help catch insulating snows.”

Fall Fertilizer, Weed Options

Fall is also an excellent time to start reviewing fertilizer and weed management options.

“Growers should make sure soil fertility is adequate, especially potash,” Miller says. “An application in the fall or spring is fine. Typically, the best time is after the third or fourth cutting - depending on yield levels during summer months - to help maintain conditions for winter survival.”

Weed management is applicable in the fall as well. Autumn is an optimal time to control perennial weeds.

“It’s smart to kill weeds before they establish,” Miller says. “The majority of the time, a great spring alfalfa stand is due to applying weed control measures in the fall or early spring while the alfalfa is still dormant.”

Genetics also are an important aspect of producing quality alfalfa. Pioneer® brand varieties are equipped with characterization charts that offer growers information on disease and pest resistance as well as maturity and yield information.

Alfalfa Reinvented Bioengineering could improve fiber, protein digestibility

Fri, 20 Nov 2020 02:19:20 GMT

Alfalfa, once the queen of forages, has lost its crown. Dairy producers are growing and feeding more corn silage due to its higher yields, higher digestibility and consistent performance.

But researchers at the U.S. Dairy Forage Research Center (USDFRC) and the Consortium for Alfalfa Improvement hope to bring some of the sparkle back to alfalfa.

Specifically, alfalfa breeders are looking to improve fiber digestibility and slow down the rate of protein digestibility in the cow’s rumen, says Neal Martin, USDFRC director. They hope that these improvements will renew interest in alfalfa and increase planted acres. That, in turn, will be better for erosion control, soil nutrient cycling and cow health.

“One goal is to decrease the amount of lignin by silencing genes in some cells of the plants but not others,” Martin says. Lignin is needed in stems to hold the plant upright, but not in leaves, where it inhibits digestibility.

Initial research with reduced-lignin alfalfa varieties shows neutral detergent fiber digestibility increasing 4 to 11 percentage points. Milk production, because cows digest more, jumps nearly 3 lb./cow/day. Longer cutting intervals might also be possible, which could improve yields and the consistency of the resulting feed.

Conversely, the protein in alfalfa is often too highly digestible, resulting in wasted protein and excessive nitrogen excretion. Here, researchers are looking at two avenues of attack:

Birdsfoot trefoil, another legume, produces tannins—phenolic compounds that bind with proteins—in its leaves and stems, with the result that more protein bypasses the rumen. Martin reports an increase of 11 lb./day of milk from cows fed birdsfoot trefoil over cows fed alfalfa silage. “It may be possible to engineer alfalfa to produce tannins that provide protein protection in the rumen and lead to less bloat,” he says.
Red clover has compounds that inhibit protein breakdown during fermentation. If these could be bio-engineered into alfalfa, ruminal protein digestion might be slowed and more protein made available to the small intestine, where it is directly absorbed and utilized.

Alfalfa Reinvented Bioengineering could improve fiber, protein digestibility

Wed, 05 Oct 2022 18:44:12 GMT

Birdsfoot trefoil, another legume, produces tannins—phenolic compounds that bind with proteins—in its leaves and stems, with the result that more protein bypasses the rumen. Martin reports an increase of 11 lb./day of milk from cows fed birdsfoot trefoil over cows fed alfalfa silage. “It may be possible to engineer alfalfa to produce tannins that provide protein protection in the rumen and lead to less bloat,” he says.
Red clover has compounds that inhibit protein breakdown during fermentation. If these could be bio-engineered into alfalfa, ruminal protein digestion might be slowed and more protein made available to the small intestine, where it is directly absorbed and utilized.

Bonus content:

More on re-engineered alfalfa:

Overview

Improving protein utilization

Consortium for Alfalfa Improvement

USDA Extends Comment Period on Roundup Ready Alfalfa

Fri, 20 Nov 2020 02:18:59 GMT

USDA announced today it was extending the comment period for the draft environmental impact statement (EIS) on Roundup Ready alfalfa by 15 days to March 3. The comment period was to have ended today. No reason for the extension was given.

USDA has also held public meetings on the EIS in Nevada and Nebraska earlier this year. A final meeting will be held in Riverdale, Md., February 24.

For more details on the extended comment period and the February 24^th meeting, click here .