July 31 & Aug. 8, 2003

Nebraska water issues With little precipitation in much of Nebraska in July, the drought is worsening, dryland crops are deteriorating and irrigation is almost nonstop in some areas. Photo by Brett Hampton

Drought worsens; dryland crops at their limit

According to the National Drought Monitor, western Nebraska, most of the Panhandle, and southwestern, south central and southern Nebraska are in a severe drought, with much of the rest of the state in a moderate drought. In many areas subsoil moisture is limited or gone and crops are dependent on precipitation, which has been spotty. Scattered thunderstorm activity this week was beneficial, but limited.

Some fields have already been severely damaged by the drought and high temperatures, while others are now entering a critical time, said Bob Klein, Extension crops specialist at the West Central REC in North Platte.

Surface water resources drying up

The irrigation canals provide recharge to replenish the groundwater. The drought over the past few years has caused irrigation districts to delay their start up in the spring and shut down early in the fall. With a reduction in surface water diversions over the last couple of years, less water is available for recharge and demand for groundwater has increased. The result has been declining groundwater in the valley, resulting in some shallow domestic and stock wells going dry.

Hopefully, by late season the maturing crops already should have established a good deep root system that can efficiently extract soil water held in the profile. Given there’s adequate soil water through August, cooler temperatures and increased probability for precipitation, most crops should reach maturity with minimal yield reductions due to water stress.

At the end of August, most dry beans will be maturing and require less than 1.0 inch of additional water. In western Nebraska corn will need 3.5 - 4.0 inches of water to finish after the end of August. Remember that a medium-textured soil can store nearly 3.0 inches of water in the top 3.0 feet of soil. This means a field irrigated the last week in August will store approximately 80% of what corn needs to finish out the year. Of course coarser textured soils will store less and experience more water stress. For alfalfa producers, water use continues until frost. A key factor will be getting some regrowth after the final cutting as you move into the winter season. Sugarbeets will need 5.0 - 6.0 inches of additional water after September 1. Without water, stress and yield reductions will likely occur. Most critical is whether enough precipitation occurs late in the season to facilitate the harvest process.

Like last year, some valley producers will likely decide to plant a portion of their acres to winter wheat in anticipation of another water-short year in 2004. Planting winter wheat after dry beans or corn harvested for silage will likely be most common. In either case, available soil water likely will have been used by the previous crop and the winter wheat will be dependent upon fall precipitation.

Common corn smut

Factors favoring smut

Poor pollination: This would be for smut occurring on the ear. This also tends to be why we see smut at the ear tips when we have incomplete pollination.

High nitrogen: it is possible that the drought last year resulted in higher nitrogen in the soil for some fields depending on the cropping history.

Physical injury: Hail or sandblasting or soil in the whorl can often result in more smut as any of these will create a wound and allow the fungus to infect.

Genetics: There are differences in hybrids. Most hybrids are not rated for common smut, but you will see differences among genetics.

At this point in the season there is no practical control measure for this disease. The main control is growing resistant hybrids. In some seed company catalogues there will be ratings for “head smut,” which should not be confused with “common smut.” We rarely see head smut in Nebraska at any significant level.

Cropland value increased $20 per acre from last year with dryland acreage averaging $1000 per acre and irrigated cropland averaging $1,680. Pastureland, at $260 per acre, was $10 per acre above a year ago.

Cash rents for cropland increased from last year. Irrigated cropland rent averaged $123 per acre, up $2 per acre, while dryland rents increased $1 to $67. Pasture rented for cash, which averaged $11.50 per acre, increased $.30 from 2002.

Timely and accurate scouting is the key to managing European corn borer in standard (non-Bt) corn hybrids. Remember that conditions are localized and fields must be scouted individually to make accurate decisions. We have had it easy the last few years with relatively low ECB flights; however, this cannot last forever. Last year's flights were up a little from the previous few years.

Fields with green silks during the peak moth flight period are most susceptible to second-generation egg laying. The white, flat eggs overlap each other like fish scales and are laid in masses of five to 40 eggs. Eggs are most likely found on the underside of leaves, near the mid-rib, on the ear leaf and the three leaves above or below the ear leaf. Approximately 90% of the egg masses will be found on these middle seven leaves. A black spot is visible on the eggs for about 24 hours before they hatch. The spot is the head of the developing corn borer; this stage is often referred to as the black head stage.

Cowpea aphid (University of California IPM Project)

During the past few years, this insect, Aphis craccivora Koch, has been extremely abundant in alfalfa fields throughout arid parts of the Southwest, including Arizona, California, and Texas. Commonly referred to as the “black aphid”, it has been in the south for many years, usually in low numbers on cotton, alfalfa, and weeds. In addition, outbreaks of cowpea aphid have been reported sporadically throughout Kansas and Oklahoma, all within the past year. Infestation levels in these areas reportedly ranged from 50-125 aphids per stem and there was noticeable yellowing and stunting. In Nebraska in 2002 the aphids were noticeable but were not quite at economic levels in most fields. Since many growers were in the process of harvesting the third cutting when the aphids popped up, we advised them to take the cutting and watch the regrowth.

Identification

The cowpea aphid is easily distinguished from other aphids in alfalfa largely because it would be the only black aphid. In general, it is a relatively small aphid, less than 2 mm long. Non-winged and winged adults are usually shiny black while the smaller nymphs may appear to be a dull gray to black. The first half of the antennae is white, and the legs are usually a creamy white color with blackish tips. In alfalfa, these aphids obviously feed on young terminal growth, but can be found infesting leaves, blooms, and stems. Damage symptoms include yellowing, wilting, and dieback. In general, legumes can be seriously damaged, either by direct insect feeding or by the transmission of virus diseases.

Distribution

The cowpea aphid is generally distributed across North America and has been reported in at least 28 states and in three Canadian provinces. This aphid species also has an extensive host range with a marked preference for legumes. Other known host plants are apple, carrot, cotton, cowpea, dandelion, dock, goldenrod, kidney bean, lambsquarters, lettuce, lima bean, pinto bean, peanut, pepperweed, pigweed, red clover, shepherdspurse, vetch, wheat, white sweet clover, and yellow sweet clover. These aphids live throughout the year without producing sexual forms and are always parthenogenetic viviparous females (ready to produce offspring at birth).

Monitoring and treatment guidelines

Because the cowpea aphid has only recently become a problem in alfalfa, no monitoring guidelines or economic thresholds have been developed for it. An Oklahoma State University entomologist provided the following information. “Normally, we do not worry much about cowpea aphid, and if temperatures increase, predators will feast heavily on them; however, if damage (yellowing and stunting) is evident, then insecticide treatment may be appropriate.” Based on his observations, cowpea aphids damage alfalfa and feed on the plant similarly to the pea aphid; therefore, thresholds are likely similar. OSU Cooperative Extension recommends that on alfalfa less than 10 inches tall, 50 aphids/stem should be used as a threshold. On alfalfa taller than 10 inches, 100 aphids/stem may be used. The Texas Web site, however, suggests a threshold near or below that of blue alfalfa aphid: 1) plant height less than 10 inches: 10-12 aphids per stem or 50 per sweep; plant height more than 10 inches: 40-50 aphids per stem or 200 per sweep. These thresholds have not been verified locally, but may be helpful in making treatment decisions.

Control

Cutting alfalfa Third cutting of alfalfa was 26% complete, behind last year at 38% but ahead of average at 20%. Photo by Brett Hampton

Regardless of when you harvest, cut it high, leaving 8 to 10 inches of stubble. Tall stubble pays off three ways — it helps plants begin regrowth quicker, holds hay off the ground so air can help dry underneath, and keeps many nitrates out in the field rather than in the bales.

And finally, always crimp cane hay. Even when stems are small, the waxy coating on the stem causes slow drying. Crimping breaks open these stems, allowing water to escape and evaporate more quickly.

So cut it early, cut it high. Crimp the stems and they will dry.

Farmers examine a soybean plant in one of the demonstration plots viewed during the 2002 Soybean Management Field Days.

The event will be held at four sites across the state Aug. 12-15, with each site including demonstration plots, lunch and time for questions. Presenters include university specialists, educators and industry consultants. Topics include: managing weeds to cut costs and increase yields (including how to turbocharge your glyphosate), strengthening financial position (including how to act locally to compete globally), understanding soil water and managing irrigation (including recommendations on getting the most bang from your water inputs), and unlocking the mysteries of high soybean yields (including tips for getting the most from organic matter and soil nutrients).

"By attending the Soybean Management Field Days growers will take home unbiased, research-based answers to these important topics that will have a direct impact on the profitability of their soybean enterprise," Glewen said. Past participants have placed an average value on the knowledge gained and/or anticipated changes in practices at $8.89 per acre, he said.

"Soybean Management Field Days is the premiere information source for the latest research management recommendations in Nebraska," said Norm Husa of Barneston, chairman of the Nebraska Soybean Board. "By participating, producers will see their checkoff dollars at work brining leading technology and ideas to producers."

The field days begin at 9 a.m. and conclude at 2:30 p.m. Free registration is available the day of the event. Dates, locations and directions are:

• Aug. 12 -- Luther Farms, from Overton, located one mile south from Highway 30 and Road 44 intersection. From Interstate 80, Exit 248 and then 2 miles north on Road 444. Field site is on the west side of Road 444.
• Aug. 13 -- Keith Neumann farm, from DeWitt, located four and three-tenths miles south on Highway 103, west side of the road. Field site is half a mile south of Tricounty School or 1.6 miles north of the Highways 4 and 103 intersection.
• Aug. 14 -- Greg Whitmore farm, from Shelby at the Highway 92 and 69 intersection, one mile west and half a mile north on County Road T. Field site is on the east side of Road T.
• Aug. 15 -- Chuck Beermann farm, from Dakota City, three miles west on Highway 35, one mile north on Highway 110 and half a mile east on 164th Street. Field site is on the south side of the road, two miles west of the intersection of Highway 77 and 164th Street.

Continuing education credits for the Certified Crop Advisor program will be available.

Registration will begin at 11 a.m. and the program will begin at 11:30 a.m. with presentations by Dr. Harvey Perlman, chancellor of the University of Nebraska-Lincoln, and Dr. Charles Hibberd, director, NU Panhandle Research and Extension Center. Lunch will be provided by the National Sunflower Association.

Speakers and topics include:

• Crop Rotations Involving Sunflower with Drew Lyon, Extension dryland cropping systems specialist;
• Sunflower Bird Control with Leonard Askham, director of research and development for Bird Shield Repellent Corp.;
• Sunflower Varieties: Irrigated and Dryland, Oil and Confection with David Baltensperger, Extension alternative crop specialist, and representatives of the National Sunflower Association and the sunflower industry;
• Chickpeas with Tom Nightingale, farm manager, NU High Plans Ag Lab, and Baltensperger;
• Waxy Proso with Rob Heyduck, UNL graduate student, and Baltensperger;
• Summer Annual Forages with Jerry Volesky, Extension range specialist, and Baltensperger; and
• Progressive Producers - Blue Sun with Karen DeBoer, Exension educator, Cheyenne County.

Program topics and speakers will include:

• Nebraska Natural Resource Conservation Service (NRCS) Carbon Sequestration Activities with Tim Schaaf, NRCS;
• 2003 On-farm Test Plots with Andrew Christiansen and Gary Zoubek, NU Cooperative Extension educators; and
• Considerations to Improved Soil Health with Schaaf, Christiansen and Zoubek.

For more information, contact Zoubek at the York County Extension Office at (402) 362-5508.

Keith Glewen, extension educator in Saunders County, coordinates many of the educational programs offered at NU's Agricultural Research and Development Center near Mead. The programs, Glewen said, were first offered at the request of agribusiness interests.

"Industry approached the university and asked them why we weren't providing educational opportunities for their employees -- the people who service many of the products that they were selling across Nebraska," Glewen said. "They were leaving the state, going to places like Iowa State and Kansas State to receive their training."

To meet the need for in-state training, Glewen and others developed an intensive curriculum focusing on four main areas: crops, water, soil fertility and nutrient management, and pest management. The range of program participants now covers the entire spectrum of agriculture, from certified crop advisors to individual producers to government employees. The impact of the university's crop management programs can be measured in both acres and dollars, Glewen said.

"Each session, we survey the audience to find out what the impact was of their experience," Glewen said. "On an average, we're probably looking at $5 an acre." Glewen estimates the 400 to 500 annual program participants account for approximately one-quarter to one-third of all the row crop acres in Nebraska.

"Therefore, it's reasonable to assume that the programs have an economic impact in the millions of dollars," Glewen said.

NU's crop management curriculum offers both classroom and in-the-field training. The use of satellite and Internet technologies allows classes to be taught year round. Course content, scheduling and costs also will be discussed in detail.

Early registration is $115 until August 13. After that, registration is $165. Approximately nine Certified Crop Advisor credits are expected in soil and water (1.5); soil fertility (1.5); pest management (3); and crop production (3).

An Introductory Precision Farming Clinic will be held on September 3 starting at 7:45 a.m. This program is designed for producers and consultants looking for assistance in launching their precision agriculture program. Anyone interested in implementing precision agriculture technologies or just beginning to use them should plan to attend this clinic.

Topics include: introduction to precision agriculture, GPS, GIS, new technologies, hardware and software; yield monitor set-up, calibration, and operation; handheld GPS/GIS computer applications; accessing digital data sources; using aerial and satellite imagery for crop management; on-the-fly electrical conductivity and pH sensors; and light bar navigational aids.

Early registration is $115 until August 27. After that, registration is $165. Approximately six Certified Crop Advisor credits are anticipated in soil fertility (1) and crop production (5).

NU Cooperative Extension, a division of the Institute of Agriculture and Natural Resources, is sponsoring these clinic. To register, call (402) 624-8000 or (800)529-8030, via fax at (402) 624-8010, via e-mail at cdunbar2@unl.edu, or write to NU ARDC, CMDC Programs, 1071 County Road G, Ithaca, Neb. 68033.

Pesticides that can be turned in include all types of herbicides, insecticides and fungicides; and all types of agricultural, livestock, home, lawn and garden, structural and commercial pesticides, including those in aerosol containers. Farmers can dispose of old electrical transformers left over from irrigation system renovations. These transformers can contain PCBs, which have been linked to certain cancers and other health problems. Items such as oil, antifreeze, paint, varnish, thinners, cleaners and solvents are not accepted. Neither are pesticide products in pressurized cylinders.

There is no charge for quantities of pesticides up to 1,000 pounds, Schulze said. Anyone who anticipates turning in more than a half tone of waste products should notify Rich Reiman at the state agriculture department, in advance, by phoning, (402) 471-2394. Products brought to a collection site totaling over 1,000 pounds require a nominal fee of $1 per pound for each pound over 1,000 pounds, Schulze said.

People turning in pesticides or transformers are encouraged to:

• Leave pesticide labels on containers.
• Handle containers with chemical resistant gloves and in a way to prevent them from spilling.
• Wash hands with soap and water after handling.
• Take pesticide materials in for identification and disposal if containers' labels have been removed or are not legible.
• Transport smaller quantities of pesticides in fragile containers in a plastic bucket or other container that will contain the pesticide if it begins leaking.
• Do not transport pesticides in the passenger compartment of vehicles.

In addition to these cases, the American Red Cross reports 31 positive blood donors, giving Nebraska the highest number of positive blood donors in the country. None of these have been confirmed by the CDC but may be further tested if the donor has symptoms of West Nile fever. Dr. Richard Raymond, the state’s Chief Medical Officer, stressed that for most people the risk of becoming seriously ill with West Nile virus is low. West Nile is transmitted through the bite of a mosquito that has picked up the virus by feeding on an infected bird.

West Nile fever includes flu-like symptoms such as fever and muscle weakness. Symptoms of West Nile encephalitis include inflammation of the brain, disorientation, convulsions and paralysis. People over 50 and those with weak immune systems are especially vulnerable to the disease.

To reduce the risk of exposure:

• Avoid being outdoors when mosquitoes are most active -- dusk and dawn.
• While outdoors, cover up by wearing long-sleeved shirts and pants, shoes and socks and use mosquito repellent.
• Eliminate mosquito breeding sites, such as standing water in tires, plastic containers, or similar water-holding containers.

Aurora hailstone takes the title

A hailstone with a 7-inch diameter and a circumference of 18.75 inches was recently named the largest hailstone ever recovered in the United States. It fell in Aurora on June 22. Courtesy of NOAA

Three criteria were used to rate the hailstone, explained Al Dutcher, NU state climatologist. Its diameter, circumference, and weight were measured and compared to those of the previous record-holder. The previous record-holder had a diameter of 5.7 inches, a circumference of 17.5 inches and was found in Coffeyville, Kan., on September 3, 1970.

“Were it not for the quick thinking of local residents, who found the hailstone and kept it from melting, we would have not known it existed,” said Jay Lawrimore, who chairs the NOAA National Climate Extremes Committee responsible for validating national records. Lawrimore added that the Aurora hailstone didn’t break the record for the heaviest hailstone.

“It was hard for us to get an accurate weight for this stone because a chunk of it hit the gutter of a house and 40% of it was lost,” he said. “We also think some of the stone’s mass might have melted before it was preserved in freezing conditions.”

Radio show & call-in hour to address Nebraska water issues tonight

NPRN reporter Carolyn Johnsen presents "Nebraska Connects: Troubled Waters," a half-hour documentary followed by an hour-long call-in program featuring water specialists who will discuss water-quantity issues and water policy concerns affecting all Nebraskans. "These issues won't go away when the drought is over and it starts to rain," said Johnsen.

Among the states, Nebraska is second only to California in the number of irrigated acres of cropland. With declining water tables in some areas and increasing friction between users of surface water and ground water, policymakers are faced with the challenge of both protecting the resource and ensuring economic growth and stability. Just as Nebraska is coming to terms with a long dispute with Kansas over water in the Republican basin, federal law will require more adjustments from Nebraska water users on the Platte and Missouri Rivers.

Panelists will be Central Platte Natural Resources District Manager Ron Bishop, Assistant Attorney General David Cookson, Duane Hovorka of the Nebraska Wildlife Federation, and Nebraska Department of Natural Resources Director Roger Patterson. Funding for this program is provided in part by the Nebraska Environmental Trust. Listeners statewide should call 800-290-6850 to have drought and water policy questions answered.

Featured speakers include Greg Simonds, a ranch management consultant who will describe many successful low-cost grazing strategies and Professor Fred Provenza from Utah State University, who will describe how understanding factors that affect your animals' grazing behavior can help you design and management your grazing system. Also on the program are Nebraska beef specialists Don Adams and Jim Gosey, Bob Budd from the Nature Conservancy, and over half a dozen Nebraska ranchers and farmers with unique perspectives on how to make grazing pay.

Registration at the door is $90 for the full conference and includes lunches, the Monday evening banquet, and the conference proceedings. One-day registration is available for $45. For more information, contact your local extension office.