Extension Ag Update
November/December 2003
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Forage Yield and Nutritive Value of Selected Quackgrass

Craig C. Sheaffer, sheaf001@umn.edu, Nancy J. Ehlke, Donald L. Wyse, Donne J. Vellekson, Douglas R. Swanson, and J. L. Halgerson, Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul 55108; and R. D. Mathison, North Central Research and Outreach Center, Grand Rapids, MN 55744

Quackgrass is often considered a weed. A new quackgrass cultivar, Everett, is now available for use in soil conservation. This project compared forage yields and nutritive value of Everett quackgrass, common quackgrass, orchardgrass and reed canarygrass when each was grown in pure stands and mixture with alfalfa. Nitrogen was used to fertilize the grass stands. Plots were harvested three times each year during the 3-year study. The plots were located at St. Paul and Grand Rapids, Minnesota. Yields of quackgrass entries were similar.

They averaged a yield of 5.0 and 2.2 tons/acre at St. Paul and Grand Rapids, respectively. Reed canarygrass yielded 5.4 and 2.8 tons/acre at St. Paul and Grand Rapids, respectively. The quackgrass-alfalfa mixtures compared favorably to the yield of reed canarygrass- or orchardgrass-alfalfa mixtures. The nutritive value of orchard grass was sometimes lower than quackgrass and reed canarygrass. The researcher concluded that Everett quackgrass could be a valuable forage crop. Further information can be found in the Forage and Grazing Lands journal.

Plant Roots, Too, Know How To "Seize the Moment"

Don Comis, USDA ARS Writer, Agricultural Research Service Room 301-504-1625, Comis@ars.usda.gov

A recent discovery by Agricultural Research Service plant physiologist Richard Zobel may lead to a "rewriting of the book" on plant roots. Zobel and a colleague have found that many plant roots commonly regrow from the same spot on a root, and that they can do this on roots deep below the soil surface. Zobel, with the ARS Appalachian Farming Systems Research Center in Beaver, W.Va., and Dominick J. Paolillo, Jr., at Cornell University in Ithaca, N.Y., found evidence of roots growing this way on 22 species of plants from 12 plant families in nine orders of plants. These plants included alfalfa, carrots, chicory, clover, crown vetch, dandelion, horse chestnut, lamb's-quarters, parsnip, poke weed, rock maple, thistle and tree of heaven.

Zobel and Paolillo made these discoveries while searching for plants with so-called opportunistic, or adventitious, rooting. They found adventitious roots growing in clusters along older roots. Adventitious roots grow from a different cell layer than the regular, lateral roots, so a plant that has used up the tissue available to grow regular roots can still grow adventitious roots. These roots are called "opportunistic" because they can develop in a matter of hours, to take advantage of sudden environmental changes such as a rare rain in a desert. The discovery that adventitious roots growing this way are an everyday occurrence suggests they may play an important and unexpected role in routinely helping plants reach water and nutrients. These roots can sprout on larger roots whose lateral roots have long since died back, enabling the plant to access water and nutrients that have recently become available in those sections of the soil that would otherwise be out of reach. This information could also help scientists introduce adventitious roots to a crop like cotton that apparently is one of the few plants that doesn't have them, as a more efficient way for the crop to grow new roots when rain comes after a dry spell.

Consumer Acceptance Critical Factor in Success of Genetically Modified Crops

Shannon Hartenstein, IANR Writer, Institute of Ag and Natural Resources, University of Nebraska, (402) 472-3030

Farmers may embrace it. Companies can invest billions. Yet, ultimately, the fate of agricultural biotechnology hinges on consumers. Consumer acceptance and demand depend largely on whether people think this technology benefits them and whether they believe foods made from genetically modified, or GM, crops differ from traditional products, said Konstantinos Giannakas. The University of Nebraska agricultural economics has extensively studied the economic ramifications of ag biotechnology for consumers, producers and biotech companies. "My research looks at the market and welfare effects of introducing genetically modified products into the food system," he said. His economic analysis provides a clearer picture of what's likely to happen to GM products in the marketplace under different regulatory and labeling scenarios.

Overall, he found that consumer attitudes toward GM food and their influence on public policy will significantly affect demand for GM products throughout the food system.