Switching it up?

Switchgrass as an alternative crop? Not quite yet.

Cellulosic ethanol production is still in its infancy, with research increasing and only a handful of pilot plants in operation. However, biomass and cellulosic ethanol crops will drive the next wave of agricultural commodities and push producers to re-think crop selection. In time, alternative crops, such as switchgrass, could be a realistic option.

“At this time, it’s grown as a cover crop on some CRP land and in some limited amount as a hay crop,” says University of Nebraska-Lincoln professor Richard Perrin. “It has received attention as a potential biomass crop for the energy market, but these markets are still in the future.”

Switchgrass is a warm-season perennial grass that is native to North America. Perrin says it is competitive with other grass crops in a wide variety of regions, throughout the Great Plains and the Southeast. Because of its native history, it is resistant to many pests and plant diseases and capable of producing high yields with very low applications of fertilizer.

Some fertilization may be necessary to maintain harvestable stands, says Ag Marketing Research Center specialist Dan Burden. The crop is proven to be very tolerant of poor soils, flooding and drought. Switchgrass is also a valuable soil protection cover crop – it binds loose soils and provides valuable wildlife habitat.

However, as a crop, switchgrass requires slightly uncommon management. For optimal output, it is harvested only every other year, rather than annually. Even though it’s common in CRP fields, switchgrass harvested for energy generation must be a relative monoculture, meaning derived from primarily a single seed type, rather than part of a mixture of grasses. Once the grass reaches maturity in harvest years, it is swathed and baled, much like other forage crops.

Soybean Aphids Surface

Start Scouting For Soybean Aphids

From the University of Nebraska

 

The first soybean aphids of the season were found on July 3 in Dixon County, NE near Concord. Aphids are generally found in late June to early July in Nebraska, so this is not unexpected. The infestation was very small and lady beetles were already feeding on them; however, current weather conditions are favorable for aphid survival and reproduction, so they bear watching. In any case, if you have not begun scouting soybeans for soybean aphids, now is the time to begin.

The aphid is light green to pale yellow, less than 1/16 in. long, and has two black-tipped cornicles (cornicles look like tailpipes) on the rear of the abdomen. It has piercing-sucking mouthparts and typically feeds on new tissue near the top of soybean plants on the undersides of leaves. Later in the season the aphids can be found on all parts of the plant. It is the only aphid in North America that forms colonies on soybean.

Soybean aphid populations can grow to extremely high levels under favorable environmental conditions. Reproduction and development is fastest when temperatures are in the 70s through the mid 80’s. The aphids do not appear to do well when temperatures are in the 90s, and are reported to begin dieing when temperatures reach 95 degrees. When populations reach high levels during the summer, winged females are produced that migrate to other soybean fields. Like a number of other insect species (e.g. potato leafhoppers), these migrants can be caught up in weather patterns, moved great distances, and end up infesting fields far from their origin. These summer migrants were most likely the major source of infestations in Nebraska during the last couple of years.

Soybean aphids injure soybeans by removing plant sap with their needle-like mouthparts. Symptoms of soybeans infested by soybean aphids may include yellowed, distorted leaves and stunted plants. A charcoal-colored residue also may be present on the plants. This is sooty mold that grows on the honeydew that aphids excrete. Honeydew in itself makes leaves appear shiny. Soybean plants are most vulnerable to aphid injury during the early reproductive stages.

In much of the soybean aphid’s range, significant aphid infestation has often occurred in the early vegetative stages. These infestations then undergo rapid population growth to reach high populations during the flowering stages (R1, R2). In Nebraska aphid populations can reach economically damaging populations in late July, but most reach economically damaging populations in August, when soybeans are in the mid-reproductive stages (R4-R5). During 2004 there were many fields where aphid populations peaked in late R5 (beginning seed) to early R6 (full seed)

Noxious Weed Awareness

LINCOLN, Neb. – June is Noxious Weed Awareness Month, Gov. Dave Heineman recently declared. The proclamation recognizes the potential that noxious weeds have to reduce Nebraska’s crop yields.

“As producers, we must protect our crops and natural resources from non-native plants that have no value,” said Nebraska Department of Agriculture Director Greg Ibach.

Noxious weeds compete with pastures and crops, reducing yields. The weeds also and have the potential to be poisonous or injurious to humans, livestock and wildlife.

Nine weeds are currently designated as noxious in Nebraska, including: musk thistle, Canada thistle, plumeless thistle, spotted knapweed, diffuse knapweed, leafy spurge, purple loosestrife, saltcedar, and phragmites.

Ibach added phragmites to the noxious weed list under a temporary designation in April.

Nebraskans are encouraged to report any noxious weed infestations to their county weed control authority. County weed superintendents are available to help identify noxious weeds and to assist with proper control recommendations.

Effective noxious weed control is the responsibility of each person who owns or controls land. If infestations go uncontrolled, legal action is set in motion by the county weed control authority.

For more information on Nebraska’s noxious weed program, contact your local county weed control superintendent.