Black light traps in northeast Nebraska this week had the highest capture of 1st generation European corn borer moths that they'd had in the last four years -- slightly more than 100 in one night.

European corn borer moths are flying

Reported problems have been in areas surrounded by wheat or grasses where the slow growing corn has had a difficult time staying ahead of the mites. Treatment would be necessary if plant survival is being threatened. It is important to treat only when necessary and only the area of the field that is affected. Mite problems this early can be serious, and we will need help from predators to keep these populations at bay for the summer. Widespread treatments will set predator populations back. Two years ago we had early sightings of mites, but they did not continue to be a problem through the summer as natural enemies helped to provide control; however, the prospect of water shortages and spider mites is a dangerous combination.

Stinkbug found damaging corn in eastern Nebraska. (Photo courtesy of Walker Luedtke, Precision Consulting of Wahoo)

"We have a field where up to 50% of the plants show signs of stinkbug feeding. Seventeen percent of the plants in the same field have been stunted and it is expected that these plants will experience a severe yield reduction," Glewen said. "Stinkbug activity and damage was reported in tilled and no-till fields."

York County Extension Educator Gary Zoubek also reported finding some stinkbugs in corn fields.

Bob Wright, Extension entomologist at the South Central REC near Clay Center, said he had found some stinkbugs in NU corn plots there and "low levels of damage possibly caused by them."

While stinkbugs have not historically caused major crop damage in Nebraska, the following report from Phil Sloderbeck, a Kansas State University entomologist in southwest Kansas, is included to aid in identification and treatment.

Sloderbeck reported finding unusual damage in a no-till corn field in Kingman County. Plants were buggy whipped, had holes with yellow borders in emerged leaves and "suckering" (the production of tillers from the base of damaged plants). Closer inspection revealed a few stinkbugs believed to be causing the damage.

"According to information from Illinois and Kentucky this problem was first recorded in Kentucky in 1985. Brown and one-spotted stink bugs are the most common ones in corn. Stinkbugs are 1/2-inch long, shield-shaped insects with piercing-sucking mouthparts. The upper side of the body ranges from light to dark brown.

"The underside varies from light yellow to green. Usually only a few fields are affected by these insects, however damage has been seen across a wide area of Kentucky and parts of neighboring states. They report that stink bug damage is most severe in no-till fields. Stink bug damage can be found in conventional fields, but the incidence of damaged plants is usually limited to border rows.

"Thresholds for stink bugs in corn have not been developed. Once injury becomes evident it is probably too late to treat. Most injury happens when plants are small and the pest can pierce the base of the plant and reach the growing point.

Much of the wheat is short of moisture or out of moisture, with fields rock hard. Yields will be low. The dry spring has resulted in very short plant stature. This will make it difficult to leave good wheat stubble for soil moisture retention following harvest. It would be a good year to use a stripper header if one is available. The short wheat will also be noncompetitive with late emerging weeds, which could cause harvest problems if we get some late rains.

The one advantage to the high temperatures and recent high winds is that disease problems have been limited. Generally, wheat in the northern Panhandle where they received rain is looking better while that in the southern Panhandle and southwestern Nebraska is in poor to fair condition. Wheat planted after summer fallow has fared better so far this spring than wheat that was planted into stubble following the 2001 summer crop. However, even wheat behind summer fallow will perform poorly if no rain is received in the next week or two. Rain would help.

With the recent heat waves wheat is filling rapidly, too rapidly, and harvest is quickly approaching. Due to a lack of moisture, much of the wheat is relatively short and producers may be tempted to do what they can to ensure they get every head of wheat; however, cutting the wheat too short may be costing you money in the long run.

Allan Schlegel, research agronomist at Kansas State University, conducted a study in 2001 at Tribune, Kansas to examine the effect of height of wheat stubble and time of spraying on no-till corn yields the next year. Moisture was very limited at Tribune in 2001.

With a stubble height of 15 inches vs 7.5 inches and initial weed control in July the corn yield increase was 15 bushels per acre or 2 bushels per inch of additional stubble height (Table 1). Each filled wheat head per square foot is equal to about 1 bushel per acre. If wheat is worth $3.00 my additional costs for custom harvest is $0.13 for harvest plus $0.13 to haul or a total of $0.26 cost per bushel for a return of $3.00 per bushel or a gain of $2.74.

These results indicate you can give up at least one head of wheat per square foot to get an additional inch of stubble height.

The table also indicates the value of starting weed control in July vs. mid-August with yield increases of 19 to 21 bushels depending on stubble height.

After harvest begin weed control as quickly as possible so weeds can't get an early foothold, stealing valuable moisture from the crop and producing seed. Consider using a glyphosate and adding 2,4-D, preferably an amine formulation to avoid volatilization with ester formulations.

Then in early September, apply atrazine and use a burn down herbicide to take care of winter annuals and volunteer wheat.

In summary, cutting the stubble at 15 inches instead of 7.5 inches and starting weed control in July vs. mid August combined for a yield increase of 34 bushels per acre. Standing residue offers more benefits than cut residue, which will deteriorate more quickly.

Stripper headers are best used with the semi-dwarf varieties with good straw strength and can leave more standing residue. When used with the taller wheat varieties and/or shorter varieties with poor straw strength the stubble tends to lodge, making it difficult to plant or seed.

Good distribution of the crop residue also is important to making this system work. This includes spreading both the long straw and fines. With poor crop residue distribution you lose twice. One, is you have too much residue in one area and two, not enough residue in another area. Too much residue makes planting difficult and complicates control of volunteer wheat. In areas with too little residue you lose the benefit of residue suppressing weeds and, in most of Nebraska in most years, dryland crop yields are maximized at crop residue levels of 5000 lbs or more if good crop stands are obtained.

Since 1998, the trials have grown from three farmers in Hamilton County learning more about technology to about 20 farmers in the four-county area. Coordinating Extension educators are Chuck Burr, Clay County, Terry Hejny, Fillmore County, Andy Christiansen, Hamilton County, and Gary Zoubek, York County.

Todd Roehrs, who farms corn and soybeans in Hamilton County near York, has been participating in the project since its inception and says he values the educational benefits it's provided.

"Every operation is a little different and I'm willing to try it here and see if there's a yield effect and if it would work for me."

This year Roehr is participating in three studies related to Gaucho seed treatment, planter speed, and anhydrous rates.

Each year the producers and educators join to discuss ongoing projects and plan new projects. Roehrs said the educators then work with producers to set up the protocols and how they wanted the research laid out and conducted so that the results are reliable.

"It takes a little more time, especially at harvest, but the harvest results are what you're after - that's the important information that helps you assess whether the practice affected yields and by how much," Roehrs said.

York farmer Jerry Stahr said the trials have helped cut his overall production costs and improve his bottom line.

"If you don't try different things, you don't learn anything. (Farmers) will be in trouble in the future if they're not willing to change."

Stahr said the research trial he conducted on nitrogen rates assured him that the university's recommended fertilizer rate was right.

Comparison of two early planted soybean trials photographed May 28, 2002. The plot on the left was planted May 1 and the plot on the right was planted April 15.

"From an environmental standpoint, it's ridiculous to put on an extra 50 pounds of nitrogen," he said.

This season the group is conducting research on several topics, some of which were continued from previous years.

Several producers have planted replicated, field length plots to evaluate the effect of planter speed on plant spacing and yields. This is the second year of the study; the 2001 results were reported in the May 17 Crop Watch.

The effectiveness of Gaucho for wireworm control and its effect on yield also will be studied in six fields in the four-county area this season. Prior to planting, wireworm bait stations were placed in the participants' fields to access the level of wireworms before planting. Stand counts and signs of wireworm damage were recorded for each field and harvest yields will be recorded this fall.

One of this year's projects resulted from a local crop consultant's question: "Would we see an effect from phosphorus fertilizer between rows in fields with a history of ridge-till and banded phosphorus application?" Six sites were sampled at 0-4 inches and 4-8 inches on the ridge and in the furrow (see below). Three sites with furrow phosphorus averaging less than 13 ppm were selected. The multi-year study will test three treatments:

1. ridge starter band,
2. furrow surface applied, and
3. furrow sub-soil band of phosphorus.

Another project is studying the effect of planting date on soybean yields. Five repetitions of soybeans were planted on April 15 and again on May 1. With all the cold weather, this should be a good year to evaluate this.

Most studies on mid-season application of nitrogen to soybeans have indicated that the greatest potential for effect is under high yield conditions. Many irrigated growers have broken the 70-bushel mark with soybeans, making them prime candidates for a nitrogen supplementation study. Several sites will have replicated plots testing the yield effect of applying supplemental nitrogen at the R3 growth stage.

The need to demonstrate nitrogen rates based on soil samples also is being addressed. Three locations will demonstrate the UNL approach with replicated plots comparing the UNL recommendation with other recommendations that are generally 30 to 50 pounds higher.

Other trials are informational or for demonstration. These include: using an ultrasonic meter to measure irrigation well output, checking center pivots for water distribution patterns, conducting anhydrous ammonia applicator uniformity checks and comparing the effect of narrow vs wide row spacing on soybean yields. The research plots are designed and analyzed with support from UNL Extension specialists and results are published locally and shared at county educational events.

Control can be achieved by mechanical means (e.g. inter-row cultivation) and herbicides. Timing of inter-row cultivation should depend on the weed pressure. If volunteer corn is a predominant weed, cultivate at about the 5- to 6-leaf growth stage. The growing point of corn remains in the ground until the 6-leaf stage. Any cultivation done much before that may result in corn regrowth and require a second cultivation. It is especially true with shallow cultivation. If you have Roundup-Ready soybeans, Roundup will control volunteer corn, unless you planted Roundup Ready corn last year. Roundup will not control volunteer Roundup Ready corn.

Other herbicides can be used to effectively control volunteer corn. Several grass herbicides (graminicides) can be used postemergence in both conventional and RR-soybean: Assure, Fusilade, Fusion, Poast, Poast-Plus, and Select. Best control is achieved when herbicides are applied by the 3- to 4-leaf stage of corn. These herbicides also will control many grassy species, including barnyardgrass, green and yellow foxtail, fall panicum and sandbur.

Several postemergence herbicide treatments are available for sorghum with most providing broadleaf weed control. Postemergence grass control, especially green foxtail, is available with Paramount and Paramount + Atrazine.

The EPA has granted a Section 18 exemption (registration) for the use of Ally + 2,4-D amine on grain sorghum. This Section 18 requires the user to obtain a permit from the Nebraska Department of Agriculture before using this treatment.

This year the "tour" will begin at the South Central Research and Extension Center near Clay Center. Two field days scheduled for June 19 have been canceled due to the dry weather - the 8:30 a.m. field day at the West Central Research and Extension Center at North Platte and the 3:30 p.m. field day at the High Plains Agricultural Laboratory near Sidney.

While most participants are from the agricultural chemical industry, the field days are free and open to the public. Individuals may attend all or part of the field day tour.

The revised itinerary is:

Tuesday - June 18

Owners of agricultural assets who can answer "yes" to each of these questions may be eligible.

• Are you a Nebraska resident?
• Did you derive at least 50% of your gross annual income for income tax purposes from farming or live-stock production for more than 5 out of the last 15 years?
• Did you provide the majority of the day-to-day physical labor and management of your farm or livestock operation during 5 out of the last 15 years?
• Are you or your spouse not related to the beginning farmer to whom you will be renting or leasing?

• Are you a Nebraska resident?
• Do you have a net worth less than $100,000?
• Do you have livestock/farming experience or education, plan to seek a livelihood in the sector, and plan to provide the majority of the day-to-day physical labor and management of the livestock/farming operation?
• Are you willing to participate in a board-approved financial management and educational program?
• Are you and your spouse not related to the owner of agricultural assets from whom you will be renting or leasing under this program?
• Have you farmed or raised livestock for less than 10 out of the past 15 years? For more information visit the Nebraska Department of Agriculture Web site at http://www.agr.state.ne.us and click on Beginning Farmer or contact the Beginning Farmer Program staff at the Nebraska Department of Agriculture at 800-446-4071 or 402 471-6890 or Dave Goeller, NU transition specialist, 402-472-0661 or email dgoeller@unl.edu.

• Alternative spring crops, David Baltensperger, alternative crops specialist;
• The new farm bill, Paul Burgener, agricultural economist;
• Transitioning from summer crops to winter wheat, Drew Lyon, dryland cropping systems specialist; Jurg Blumenthal, soil fertility/nutrient management specialist; Bob Harveson, plant pathologist; and Paul Burgener, agricultural economist;
• Spread of wheat curl mites and occurrence of wheat streak mosaic virus, Gary Hein, entomologist;
• Wheat variety update, Stephen Baenziger, plant breeder; David Baltensperger, plant breeder, Bob Graybosch, plant breeder, and Drew Lyon, dryland cropping systems specialist.

Monday, June 17

A fifth winter wheat plot is available for viewing in Lincoln County at the University of Nebraska's West Central Research and Extension Center (WCREC) Dryland Farm, two miles south of North Platte on Dodge Hill Road. To view, call WCREC at (308) 532- 3611, Ext. 144.

The morning meetings will begin with breakfast and have workshops on how to select winter wheat varieties followed by a tour of the plots. At the plots the various wheat varieties and the agronomic production practices used will be discussed. The winter wheat disease situation for 2002 also be discussed.

According to Robert Klein, cropping systems specialist at WCREC, each plot features common varieties to the area, new varieties he thinks producers ought to consider, and experimental varieties being developed for future use. Older varieties are also planted to measure newer varieties against for progress. "Each variety is planted six times at each location. This is so we can run the statistics on each variety and calculate the number of bushels it takes for one wheat variety to be better than another wheat variety 95 percent of the time," Klein said.

The Furnas County and the Perkins County Plots were seeded after the corn was harvested last fall. The Red Willow, Keith, and a plot in Lincoln County were seeded after a fallow period.

Following is the schedule of tours:

Tuesday, June 18, 8 a.m. CDT, Red Willow County

Jack Cecil, research scientist at the University of Wyoming, will discuss his observations of chickpea production practices during his research trip to Australia.

Other topics will include farm program considerations, marketing decisions, a High Plains Dry Pea Growers Association update, and travel to field plots with discussion of variety trials. Questions about the tour can be directed to the University of Nebraska at 308-762-5616 or 308-632-1230.

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Copyright 2002 by the University of Nebraska

Published by University of Nebraska Cooperative Extension in the Institute of Agriculture and Natural Resources Cooperating with the counties and the U.S. Department of Agriculture

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