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Curriculum and Instruction

2002

Crops

Articles 1 - 9 of 9

Full-Text Articles in Life Sciences

Ec02-177 Purple Loosestrife, Stevan Z. Knezevic Jan 2002

Ec02-177 Purple Loosestrife, Stevan Z. Knezevic

University of Nebraska-Lincoln Extension: Historical Materials

Purple loosestrife (Lythrum salicaria) is an introduced invasive weed that isover running thousands of acres of wetlands and waterways in the Midwest. Once purple loosestrife invades a wetland, natural habitat is lost and the productivity of native plant and animal communities is severely reduced. These losses in turn interfere with various levels of the ecosystem and area recreational activities such as fishing, boating and hunting, diminishing revenue from tourism and impairing the social and economic well being of local communities. A single control measure cannot provide long-term, sustainable control of this weed. An integrated approach, using a variety …


Ec02-173 Spotted And Diffuse Knapweed, Neil L. Heckman, Ryan M. Goss, Roch E. Gaussoin, Stevan Z. Knezevic, John L. Lindquist Jan 2002

Ec02-173 Spotted And Diffuse Knapweed, Neil L. Heckman, Ryan M. Goss, Roch E. Gaussoin, Stevan Z. Knezevic, John L. Lindquist

University of Nebraska-Lincoln Extension: Historical Materials

Spotted knapweed (Centaure amaculosa Lam. = C. biebersteinii DC.) and diffuse knapweed (C.diffusa Lam.) are two of Nebraska’s seven noxious weeds. They are also noxious in at least 17 other states. These are closely related species that are well adapted to a variety of habitats including open forests, rangelands and pastures, Conservation Reserve Program lands, roadsides, and ditch banks. Centaurea is a large genus of over 400 species, 32 of which are common weeds of the United States and several of which [e.g., yellowstar thistle, C. solstitalis L, and Russian knapweed, C. repens L. =Acroptilon repens (L.) …


Ec02-172 Plumeless Thistle, Kara L. Hilgenfeld, Alex Martin Jan 2002

Ec02-172 Plumeless Thistle, Kara L. Hilgenfeld, Alex Martin

University of Nebraska-Lincoln Extension: Historical Materials

Plumeless thistle (Carduus acanthoides L.) is one of seven noxious weeds in Nebraska. An introduced invasive broadleaf weed native to Europe and Asia, plumeless thistle currently infests about 65,000 acres in Nebraska. Infestations of plumeless thistle may reduce productivity of pastures and rangeland, where infestations tend to be the largest. Plumeless thistle competes with and suppresses growth of desirable species. Heavy infestations prevent livestock from grazing the area and lighter infestations prevent livestock from eating plants growing near the thistle. Estimates place the annual loss in Nebraska agricultural production due to plumeless thistle at $162,000. Although plumeless thistle is …


Ec02-171 Canada Thistle, Robert G. Wilson Jan 2002

Ec02-171 Canada Thistle, Robert G. Wilson

University of Nebraska-Lincoln Extension: Historical Materials

Canada thistle [Cirsium arvense (L) Scop.] is one of the seven species defined by Nebraska law as a noxious weed. At least 35 other states also have determined by law that Canada thistle poses a threat to the economic, social, and aesthetic well-being of the residents of their state. Canada thistle is probably the most widespread of all the thistle species and many land managers consider it the most difficult thistle to control. In Nebraska, Canada thistle is estimated to infest 460,000 acres.


Ec02-176 Musk Thistle, Fred Roeth, Steven R. Melvin, Irvin L. Schleufer Jan 2002

Ec02-176 Musk Thistle, Fred Roeth, Steven R. Melvin, Irvin L. Schleufer

University of Nebraska-Lincoln Extension: Historical Materials

Musk thistle (Carduus nutans L.) is an introduced invasive broadleaf weed native to Europe, North Africa, and Asia. In these areas it is a minor weed because natural enemies keep its population low. When the plant was introduced into North America, its natural enemies were left behind. Without these natural checks, the thistle is able to thrive and compete with native vegetation.

Musk thistles aggressively invade all lands in Nebraska. Typical cropland weed control methods are very effective against them; however, land with permanent cover (pasture, range, roadway ditches and wasteland) that is not tilled or treated with a …


Ec02-174 Leafy Spurge, Robert A. Masters, Brady F. Kappler Jan 2002

Ec02-174 Leafy Spurge, Robert A. Masters, Brady F. Kappler

University of Nebraska-Lincoln Extension: Historical Materials

Leafy spurge is an invasive weed that infests over three million acres in the northern Great Plains and the prairie provinces of Canada. It is commonly found in rangelands, pastures, roadsides, rights-of-way, and woodlands. Leafy spurge can reduce rangeland and pasture carrying capacity by as much as 75 percent because it competes with forages and cattle avoid grazing areas infested with this weed. In North Dakota where leafy spurge infests about 900,000 acres, estimates of direct and indirect losses exceed $100 million each year. In Nebraska, the direct loss in forage value attributed to leafy spurge has been estimated at …


Ec02-178 Precision Agriculture: On-The-Go Vehicle-Based Soil Sensors, Viacheslav I. Adamchuk, Paul J. Jasa Jan 2002

Ec02-178 Precision Agriculture: On-The-Go Vehicle-Based Soil Sensors, Viacheslav I. Adamchuk, Paul J. Jasa

University of Nebraska-Lincoln Extension: Historical Materials

Imagine that you are entering an unknown field and would like to estimate the productivity of the unfamiliar soil. You may pick up a handful of soil to evaluate its color and texture. You also can feel how difficult it is to break a clod apart, roll it into a ball or press out a ribbon. After repeating this procedure at different field locations, soil depths and times, you get a feeling of both spatial and temporal soil variability. Some of this variability can explain the non-uniformity of crop yield. If you collect soil samples and send them to a …


G02-1451 Climate Change And Winter Wheat: What Can We Expect In The Future?, Albert Weiss, Cynthia J. Hays Jan 2002

G02-1451 Climate Change And Winter Wheat: What Can We Expect In The Future?, Albert Weiss, Cynthia J. Hays

University of Nebraska-Lincoln Extension: Historical Materials

This NebGuide will explain how climate changes at the end of this century will affect winter wheat production. Although it doesn't make daily headlines, global warming that results from climate changes will present challenges for current and future generations. While scientists may disagree about what causes current climate change, there is general agreement that a change is happening now and will continue for some time. As humans, it doesn't matter much whether the air temperature is 92 degrees or 97 degrees - either way we tend to be uncomfortable. However, a 5 degree temperature change can have dramatic implications for …


Ec02-1763 How Windbreaks Work, James R. Brandle, Laurie Hodges, Xinhua Zhou Jan 2002

Ec02-1763 How Windbreaks Work, James R. Brandle, Laurie Hodges, Xinhua Zhou

University of Nebraska-Lincoln Extension: Historical Materials

Windbreaks are barriers used to reduce and redirect wind. They usually consist of trees and shrubs but also may be perennial or annual crops and grasses, fences, or other materials. The reduction in wind speed behind a windbreak modifies the environmental conditions or microclimate in this sheltered zone.