July 15, 2005

The key is to base irrigation timing on current soil water content, the amount of water available for irrigation and the potential for rainfall to supplement irrigation.

Watch for spider mites in corn

Identifying species

Twospotted spider mites (left) and Banks grass mites (right). Notice the difference in the pigment patterns between the two insects.
Banks grass mites, Oligonychus pratensis.
Twospotted spider mites, Tetranychus urticae.

Two species of spider mites, the Banks grass mite and twospotted spider mite, commonly feed on Nebraska corn. Banks grass mites feed almost exclusively on grasses, including corn and sorghum. Twospotted spider mites not only feed on many species of grasses, but also on soybeans, fruit trees and a variety of vegetables and ornamental plants. Although these two species are somewhat similar in appearance, they differ in several biological characteristics and in their susceptibility to pesticides.

Banks grass mites usually appear earlier in the season, feed mostly on the lower leaves of the corn plant, and in Nebraska are moderately susceptible to many of the commonly used miticides. On the other hand, twospotted spider mites tend to appear in mid to late season, increase rapidly, feed over the entire plant, and often are not consistently controlled by available pesticides. The most useful characteristics for identification are the overall shape of the body and the pattern of pigmentation spots on the back (see figure). The dark green spots on both species are caused by food particles that accumulate in their gut. Because of differences in gut structure, these pigment spots accumulate in slightly different patterns. In Banks grass mites the pigments accumulate along both edges of the body near the rear and along the sides of the body. In twospotted spider mites, the pigments accumulate along the sides of the body in two distinct spots and do not extend back more than halfway on the body. The Banks grass mite is also slightly less robust than the twospotted spider mite and is slightly flatter from top to bottom.

Mites damage crops by piercing plant cells with their mouthparts and sucking the plant juices. The first evidence of mite feeding, which can usually be seen on the top of the leaf, is a yellow or whitish spotting of the leaf tissues in areas where the mites are feeding on the lower leaf surface. Because many other things can cause similar discoloration, it is important to check leaves closely to make sure mites are actually causing the damage. Leaf discoloration caused by mite feeding can be easily identified by checking the undersurface of leaves for the presence of mites, eggs and webbing. Both Banks grass mites and twospotted spider mites produce webbing, and a fine network of silken webs will likely be associated with mite colonies. A magnifying glass or 10X hand lens is helpful in examining plants for mites.

Management

The economic injury level indicated in Table I provides a method for deciding when to treat, taking into account the value of corn. This table works for both twospotted spider mites and Banks grass mites. The first row refers to the expected value of the crop ($/acre), determined by multiplying the expected yield (bu/acre) by the expected crop price ($/bu). For example, if the expected yield is 200 bu/ac and the expected price is $1.50/bu, then the value per acre is $300.

Deciding whether to treat involves two steps. First, determine the percentage of leaves infested with mites. (An infested leaf has one or more live mites.) Compare that number with the first number in the table. If the field average is less than the table value, you don't need to treat, but do continue to monitor the field. If the field average exceeds the table value, then estimate the percentage of total leaf area damaged by mites. If the field average exceeds the table value, it is likely that treating for spider mites will increase yield above the cost of treatment.

Also, note that control costs are a factor in this table. Depending on the product chosen, the critical values may change greatly. For example, under the column $300 market value, the critical value for percent infested leaves varies from 20%, if control costs are $10, to 49% if control costs are $25. Products labeled for spider mite control on corn include dimethoate (several formulations), Comite 6.55EC and Capture 2EC. Dimethoate has performed reasonably well in Nebraska against Banks grass mites, but not twospotted spider mites. If twospotted spider mites are present, either Comite or Capture would provide better control. See the Department of Entomology web site on spider mite control or product labels for specific rates and restrictions. With the exception of Comite, pesticides do not kill mite eggs, and there is a possibility of re-infestation of the fields as eggs hatch out. Since many of their natural enemies were probably killed by the initial pesticide application, these populations may build up rather quickly and should be monitored carefully. Corn is unlikely to benefit from treatment for spider mites after the dent stage.

Twospotted spider mites also may develop on soybeans. No research has been conducted that would allow calculation of an economic injury level for twospotted spider mites on soybeans. Iowa State University Extension specialists have suggested that control may be warranted when infested plants have substantial spotting or leaf yellowing and live mites, but before mites cause browning and leaf drop. Damage from mites may be confused with that caused by drought and several foliar diseases, so be sure to base treatment decisions on the presence of mites, rather than just apparent injury symptoms. Especially watch soybean fields treated for soybean aphids, as these insecticides reduce the population of natural enemies which help reduce spider mite numbers.

Fields may be spot treated if the infestation is localized, but check other areas for mites (especially downwind of infestation) and extend treatments into these areas if large numbers of mites are found. Although late season infestations may accelerate soybean senescence and increase pod shattering, use caution when evaluating whether to treat with pesticides because many of the pesticides used for mite control have 21-28 day preharvest intervals.

Controlling weeds after winter wheat harvest will be a challenge in some fields this year, especially where there were a lot of late spring and early summer rains.

Oat production is forecast at 4.38 million bushels, up 17% from last year. Acreage for harvest, at 60,000 acres, is up 9% from 2004. Average yield, at 73 bushels per acre, is equal to the record high yield set two years ago.

As of Sunday, July 10, the Nebraska Agricultural Statistics Service (NASS) reported that 26% of the state’s corn crop was in the silking stage. This was ahead of the five-year average of 14% and last year at 16%.

Silking and pollination . . . are critical to the corn crop’s viability and yield, but unlike pests and weeds, are something you can’t control. If you’re a little hazy on the details or need a refresher, don’t blush. Bob Nielsen of Purdue University has developed several online articles which illustrate the process. Sex in the Cornfield: Silk Emergence and Sex in the Cornfield: Tassel Emergence and Pollen Shed are available online at his Chat ‘n Chew Café. You also may be interested in a July 9 article by Nielsen, available on the same site: Suggestive Behavior in the Corn Field: A Fast and Accurate Pregnancy Test for Corn.

As temperatures soar and with tasseling in progress, we are republishing the following article, originally published in the July 13, 2001 CropWatch, on pollen viability and silk receptivity.

Pollination is a critical period for corn development and yield. The following summarizes information from various sources on how this stress affects corn at this critical stage.

Pollen shed occurs over a two-week period. For kernels to develop, silks must emerge and be fertilized by viable pollen. Silks grow about 1 to 1.5 inches a day and will continue to elongate until fertilized. Temperatures greater than 95°F with low relative humidity will desiccate exposed silks but not impact silk elongation rates greatly. Pollen is killed by temperatures in the mid 90s or greater, especially with low relative humidity. Fortunately, pollen shed usually occurs from early to mid-morning when temperatures are lower.

Drought stress slows silk elongation but accelerates pollen shed. This can result in pollen shed occurring before silk emergence. Any stress such as inadequate water, low soil fertility, or too thick of a planting rate can delay silking two or more weeks and reduce seed set if pollen is not available. This is potentially a major problem although I have not heard of it happening often. The fact that pollen from one plant in ten is sufficient to pollinate a field provides a degree of compensation and improves the opportunity for fertilization in stressful environments.

The bottom line is that high temperatures will not severely stress corn if soil moisture is adequate. Reports of subsoil moisture across the state indicate that levels are varying widely, with some sites reporting their lowest of the growing season and others reporting two to four inches of moisture in the top two feet. Obviously we don’t have to tell farmers to keep up with irrigation at this time of year. It is one of the best ways to reduce the impacts of high temperatures on corn pollination and fertilization.

Note: This story was written by Roger Elmore, UNL Extension Crops Specialist, in 2001. A regular contributor to CropWatch, Roger left UNL July 1, 2005 to take a faculty position at Iowa State University as a corn specialist. We wish Roger the very best in his new position.

Rain-fed fields are more of a concern. Drought stress with high temperatures at pollination and silking can have serious effects. If the current dry-hot conditions continue, I would expect to see major differences among fields based on management practices and hybrids. Practices that conserved soil moisture this spring or last year such as no-till or reduced till will improve a crop’s performance during drought. Early season hybrids probably will do better than other hybrids if pollination occurred before temperatures soared or moisture reserves were depleted. Full-season hybrids with good stress tolerance may do better than others with less stress tolerance.

Roger Elmore
Former UNL Extension Crops Specialist

No-till bus tour, field day No-till on the Plains, a Kansas no-till organization, is offering two no-till events in Nebraska in coming weeks. A Whirlwind No-till Expo will be held at 9:30 a.m. on July 28 at the Duane Lange Farm 10 miles south of Ord. The farm has used a no-till system for 25 years. Cost is $10 if registering by July 25 and $20 for walk-ins. The second event will be the South Dakota No-Till Bus Tour August 1-3, which will include two stops in Nebraska. Participants can talk with other producers and see production practices and management challenges solved by long-term no-till users. Tour stops will cover a spectrum of soils and climates and will include the University of Nebraska-Lincoln Rogers Memorial Farm near Lincoln with Paul Jasa, UNL Extension Engineer; Dakota Lakes Research Farm at Pierre, S.D. with producer Dwayne Beck and Ward Labs at Kearney with owner Ray Ward, as well as other farm stops. For more information visit the No-till on the Plains Web site or call 888-330-5142. Tour cost is $295 and covers transportation and lodging.

The bright spots for precipitation have been the Panhandle and extreme north central Nebraska, where precipitation has been above normal the past 30 days. Although individual events haven’t covered a broad area, the cumulative effect has been an above-normal precipitation trend across the region. Temperatures have been in the 90s for most of the last two weeks as the corn crop approached pollination. As of July 10, the Nebraska Agricultural Statistics Service reported that 26% of the state corn crop was in the pollination stage with 60-75% expected to be at this stage by July 17. Unfortunately, no widescale precipitation events are forecast prior to that date.

Reports are beginning to filter in concerning leaf rolling across east central and southeastern Nebraska, particularly in the Seward, Mead, and Auburn areas. Expectations are that these reports will increase dramatically over the next week.

Weather models through this weekend don’t offer much hope for major precipitation as the high pressure ridge over the central United States remains firmly in place. Temperatures throughout the period should easily hit the low 90s, with mid to upper 90s possible by this weekend. A weak cold front may move through the state late Sunday into Monday, offering the state its best shot of organized precipitation during the next 10 days. Temperatures will briefly cool into the upper 80s early next week, then quickly rise back into the 90s through July 23.

Widely scattered thunderstorms are possible across the western quarter of the state during the next week as monsoon moisture tries to move into the central Rockies from the desert southwest. This is a common event during July and August and can account for more than half of the normal precipitation that falls across the western third of Nebraska from late July through August.

There is a slight chance that hurricane Emily will move through the Caribbean and into the Gulf of Mexico as early as July 18. If any of her moisture is to benefit Nebraska, the hurricane will need to move onshore between Galveston and Houston. If this occurs, moisture could move into Nebraska about July 22.

Allen Dutcher
Extension State Climatologist

Figure 1. Corn planted in late April in central and eastern Nebraska is entering the VT or R1 growth stage this week. VT indicates the final vegetative stage and R1 shows the beginning of the reproductive stage.

The plant’s pollination and fertilization processes take place during R1 (silking). R1 occurs when silks have emerged from the tip of the ear shoot on at least 50% of the plants. Emerged silks are viable and receptive to pollen up to 10 days. Each silk is connected to a potential kernel on the cob. During pollination the female portion of the plant (ear) receives pollen from the tassel, resulting in fertilization of the ovule (kernel). Typically, silks attached to potential kernels at the base of the cob will emerge first with tip silks emerging last. The kernel is white on the outside and the inner components are clear. Poor pollination can result in non-fertilization of kernels. Since silks emerge in different increments based on which potential kernels they are attached to, it is possible to have variability in the fill pattern.

The program will update participants on UNL research on corn and soybean yield potential and optimal management practices for high-yielding systems. The program includes brief presentations and field visits at the UNL high-yield research site on East Campus.

Participants are asked to assemble at 1 p.m. in room 327 Keim Hall (Department of Agronomy and Horticulture seminar room). For more information contact Achim Dobermann by email at adobermann2@unl.edu or by phone at 402-472-1501.

Western corn rootworm beetle

There are no thresholds for silk-clipping damage based on beetle numbers because damage levels are not correlated well with beetle densities. Usually an average count of at least 10 beetles per ear is required to seriously affect pollination. Severe silk feeding at 25-50% pollen shed may indicate a need to apply insecticide, especially in seed production fields. Visit the UNL Department of Entomology Web site at entomology.unl.edu for a list of insecticides labeled for adult rootworm control.

Traditionally we have talked about the value of rootworm beetle scouting to determine the need for insecticides the next year if a field is to be planted back to corn. With the registration of YieldGard Rootworm corn, beetle scouting also can be used to determine where it would be most profitable to use this technology. Unlike European corn borers, we can predict where the greatest likelihood for rootworm injury will be, and beetle scouting information from this summer can be used to target placement of transgenic corn hybrids next year for rootworm control.

Average number of western corn rootworm beetles present in cornfields that may produce an economically damaging rootworm population in corn the following year. Plants per acre Average number of rootworm beetles Continuous corn1 First year corn2,3 Per plant Per ear zone Per plant Per ear zone 14,000 1.28 0.64 0.96 0.48 16,000 1.12 0.60 0.84 0.42 18,000 1.00 0.50 0.75 0.37 20,000 0.90 0.45 0.68 0.34 22,000 0.81 0.40 0.61 0.30 24,000 0.75 0.37 0.56 0.28 26,000 0.69 0.34 0.52 0.26 28,000 0.64 0.32 0.48 0.24 30,000 0.60 0.30 0.45 0.23 32,000 0.56 0.28 0.42 0.21 1Based on a 50:50 ratio of females to males. 2Based on a 70:30 ratio of females to males. 3Use this threshold for continuous corn fields that did not have larval populations earlier in the season (adult beetles are immigrants, similar to first year corn).

During late July and August these beetles will lay eggs in corn fields. These eggs overwinter in the soil, hatch into rootworms in the spring, and feed on corn roots if continuous corn is grown. However, not all continuous corn fields have economic infestations of corn rootworms. Weekly scouting of adult rootworm beetles in July and August will provide the information needed to decide whether rootworm control is needed next year. With adult beetle control programs decisions as to whether to treat and if so, when to spray, should be based on information from field scouting. Start scouting for corn rootworm beetles soon after beetle emergence begins and continue scouting weekly until threshold levels are exceeded or beetle activity stops. Examine 50 plants per field, taking samples from each quarter of the field. Sampled plants should be several paces apart, so that examining one plant doesn’t drive beetles off of the next plant to be sampled. The most reliable method is to examine the whole plant for beetles.

Beetles may hide behind leaf sheaths or in the silks, so care is required to observe all beetles present. An alternative method is to check for beetles only in the ear zone (the area including the upper surface of the leaf below the primary ear and the under surface of the leaf above the primary ear).

Figure 1. Sunflowers use about 22 inches of water during the growing season and will take more water at deeper depths if the surface water is depleted.

Sunflowers are generally considered a dryland crop but as irrigation water supplies decline, they are being considered for inclusion in normal crop rotations. Sunflowers are well adapted to dryland conditions because they can extract water stored deep in the soil profile. It is not uncommon for sunflowers to remove water from as deep as 6 feet or more, if soil conditions are good for root growth.

Sunflowers, under fully irrigated conditions, will use approximately 22 inches of water during the growing season. Throughout the growing season there are times when water needs are more critical and a decision must be made as to whether to irrigate or allow the crop to undergo stress. Like most crops, having adequate soil water during plant establishment is critical. If soil water is deficient and good germination and plant establishment is not likely, irrigation should be used at this time.

During bud and full flower, water use is near peak levels so the greatest amount of irrigation is normally needed at these times. In some situations you might hear that irrigating just at these growth stages can produce yields nearly equal to full irrigation. Keep in mind that these irrigations will fill the soil profile and can more easily be accomplished with furrow irrigation. When using a center pivot, the challenges are different. Water application is dictated by system capacity. During peak water use periods, system capacity may not be adequate to keep up with crop demand. In this case, irrigation must begin prior to these critical periods to ensure adequate water is available later. If system capacity is greater and more water can be applied with each turn of the pivot, use caution as runoff can result.

If water stress occurs early or late in the growing season, yield reduction will be relatively small because the need for water is small; however, mid season water stress will result in greater yield reduction because water demand is high. Regardless of when crop water stress occurs, some yield reduction can be expected. Because of the difference in crop water demand through the season, yield reduction will generally be higher when crop demand is higher.

The key is to base irrigation timing on current soil water content, amount of water available for irrigation and the potential for rainfall to supplement irrigation. This year conditions are slightly different than in the past. Adequate spring and early summer rains have provided good soil water deep in the soil profile. Not irrigating early and saving water makes good sense this year. In years when soil water is not replenished early, limited water supplies likely may need to be used early to avoid significant yield reduction.

Finally, if rainfall occurs during the growing season, make sure you have a rain gauge near your field to know how much moisture you received. You also may need to estimate how much infiltrated the soil, especially if the rain came fast and runoff was evident. A soil probe is always handy to help you determine just how deep the rain penetrated into the soil.

C. Dean Yonts
Extension Irrigation Specialist

Most gated pipe systems have leaks. People sometimes dismiss small leaks, assuming it doesn’t amount to much water and after all, the leak is watering a row, right? Wrong on both counts! Logic tells you that one or two gallons per minute isn’t going far down a furrow. If you could irrigate with that flow rate, you wouldn’t need sets. Regarding the amount of water loss, losing 150 gpm is common on one-half mile of pipe. A single leak of 1.5 gpm on each 30-foot length of pipe plus 3 gpm loss on six gaskets adds up to 150 gpm.

Table 1. Impact of repairing irrigation pipe leaks to decrease losses from 150 gpm to 50 gpm.1 GPM Well GPM Total Rows Sets leaks output furrow rows in set2 in field 150 1000 16.0 1056 106 10 50 1000 16.2 1056 117 9 1 For the purpose of demonstrating potential savings, several assumptions were made: 1) the leaks are evenly dispersed along the length of the pipe, 2) the pipe is full, and 3) an entire set is opened at one time and closed at one time, although many people do not irrigate this way. Finally, we realize that number of rows in a set changes depending on which set you are talking about. It shouldn’t change the outcome. The example assumes quarter-mile long rows and irrigating every other row. It is an 80-acre field with 2640 feet of pipe extending in one direction from the well. This is not an uncommon amount of leakage. We are assuming repairs fix all but 50 gpm of the leaks. 2 Every-other row irrigation -- half of these rows carry water.

Table 1 shows the impact of a system with 1000 gpm well that is losing 150 gpm to leaks that could be corrected to 50 gpm loss. This example assumes full pipe with no shut-offs and every-other-row irrigation. The big savings in this example is realized by reducing the number of sets for this field. Over the course of the season, it could easily amount to three fewer days of irrigation expense and labor.

Fixing leaky gates and gaskets is one of the topics addressed as part of the University of Nebraska program, Ten Easy Ways to Boost Profit $20/acre. Look for more workshops in this series this winter. If you want to learn how much water your system is losing, contact your local NRCS or NRD and see if they have an ultrasonic flow meter. The meters work on full pipe and can be attached along obstruction-free lengths of pipe. It might be the easiest thing you can do to add profit to your system.

Andrew Christiansen
Extension Educator in Hamilton County

"Nebraska has become a national leader in ethanol production," said Gov. Dave Heineman. "Now we need to build on that success and find ways to achieve similar success in using the state's other biomass resources -- soybeans and landfill and feedlot waste."

A keynote address from Heineman will be followed by presentations by nationally recognized policymakers, scientists and industry leaders, as well breakout sessions that will help develop a vision for Nebraska's future in biofuel energy production.

Presentation titles:

• Biofuels Production: Implications for the Grain Industry and Consumers, Roger Conway, director, U.S. Department of Agriculture Office of Energy Policy and New Uses.
• Iowa's Vision and Roadmap for a Bioeconomy, Robert C. Brown, director, Center for Sustainable Environmental Technologies.
• Efficiency and Energy Yield of Nebraska Corn Ethanol Systems, Dan Walters, soil science professor, UNL.
• A Biorefinery for Mead, David Hallberg, chief executive officer, E3 Biofuels.
• Opportunities and Challenges for Biodiesel, Loren Isom, UNL Industrial Agricultural Products Center
• A Starch and Biomass Conversion Pilot Plant in York, Asif Malik, plant manager, Abengoa Bioenergy Corp.
• Imperial Biomass Energy Project: Meeting Biorefinery Feedstock Needs: A Regional Approach, Bob McGrath, executive director, Chase County USDA Farm Service Agency.
• Nebraska's Bioenergy Future: A Roadmap Based on Comparative Advantages and Opportunities, Ken Cassman, agronomy professor, UNL.

"This workshop provides a tremendous opportunity for citizens, industry professionals and government policymakers to identify Nebraska's comparative advantages in the biofuel industry, and to help prioritize future investments needed in research and development to move Nebraska to the forefront of the biofuel industry," said Cassman, who is chair of the steering committee for this event. "Given increasing concerns about energy costs, the potential contributions of the biofuel industry to rural economic development are truly astounding."

Presented by the University of Nebraska-Lincoln West Central Research and Extension Center (WCREC), this conference offers a unique opportunity for producers to learn how to get more from the water they have, see the results of various practices in the field, and hear from key players and policy makers on water issues affecting Nebraska agriculture today and in the future.

Participants are invited to attend one or both days. On day one, speakers will describe the state’s water history and current water status and present tested strategies that producers can implement. On day two, participants will hear from groups affecting water use and water policies and take field tours to view the results of recommended practices.

Presentations will be at the North Platte Community College South Campus at 601 West State Farm Road. Field tours will be at the UNL WCREC.

Speakers will include specialists from the University of Nebraska-Lincoln and state agencies as well as natural resource groups.

Register now

For more information about the conference or to register, call the WCREC at (308) 696-6727 or email llehmann1@unl.edu Advance registrations made by Aug. 1 are discounted. Following are the early (by August 1) and late registration rates for the various options:

Both days: $40/$50

First day, afternoon only, no barbeque: $20/$25

Second day only: $20/$25

Wednesday

10:30 a.m.-12:00 p.m. Registration
(Lunch on your own)
12:05 p.m. Welcome
12:15 p.m. Nebraska and Water
12:45 p.m. Nebraska Water Resources – History and Status of Groundwater and Surface Water
2:00 p.m. Response of Crops to Water
3:30 p.m. Strategies to Improve Water Use Efficiency – Taking the E out of ET
4:00 p.m. Center Pivots – Fine Tuning to Conserve Water
4:30 p.m. Furrow Irrigation Management to Conserve Water
5:00 p.m. Limited Irrigation – Improving Productivity
7:00 p.m. Barbeque -- Comments on Nebraska water issues from dignitaries

Thursday

Representatives from the following organizations will participate in the two discussions on Thursday: Nebraska Department of Natural Resources, Ann Salomon Bleed; NRDs, Kent Miller; Bureau of Reclamation, Alice Johns, Area Manager; Nebraska Public Power District, Frank Kwapnioski; Nebraska Game and Parks Commission, Darrol Eichner; U.S. Geological Survey, Bob Swanson; NRCS, Steve Chick; Central Nebraska PPID, Don Kraus; farmers, Mark Spurgin; ranchers, Tom Hansen; McCook City Manager, John Bingham; North Platte City Manager, Jim Hawks; Farm Service Agency, Brian Wolford; Nebraska Department of Agriculture, Greg Ibach; and Nebraska Department of Health & Human Services, Jack Daniel.

8:00 a.m. What are the various agencies doing to deal with the Nebraska water situation? Representatives of 15 groups will address the topic.
10:00 a.m. Morning Field Tours at West Central Research & Extension Center including drip irrigation, lateral move, skip-row corn, weather stations, and irrigated grass
12:00 p.m. Lunch
1:00 p.m. Continuation of 8 a.m. program
2:30 p.m. University Response to the Water Situation in Nebraska

Soybeans are in the beginning to full bloom stage, with most fields approaching full canopy. Conditions were dry as the alfalfa second cutting was removed, but fields will begin to show water stress as the hot July winds blow. Pastures are showing the effects of no rain and are beginning to turn brown in some areas. A few soybean aphids have been found in scattered fields, but they’ve been in very low numbers. A few grasshoppers are showing up in the grassy areas.

Paul Hay, Extension Educator in Gage County: We have a light trap up and running and being monitored by several crop consultants. It shows a low degree of corn borer moth activity. Some areas which have received little rain since the last week of June are starting to show drought damage. Insect and disease activity are on the low side. Wheat yields ranged from 20 to 80 bu/ac with frost damage apparent in low yielding fields. The average was a bit above expectations at 42-45 bu/ac. Bunt or common smut were detected in a few instances – a reminder to treat the wheat seed prior to planting.

Wheat conditions remained stable and rated 5% very poor, 12% poor, 33% fair, 39% good, and 11% excellent. Eighty percent of the crop was ripe, ahead of 74% last year and 77% for the average.

Corn condition rated 1% very poor, 2% poor, 16% fair, 52% good, and 29% excellent. Irrigated fields rated 88% percent good or excellent; dryland fields declined to 70%.

Fifty-two percent of the soybean crop has bloomed, ahead of last year at 41% and the average at 25%. Conditions declined and rated 1% very poor, 5% poor, 29% fair, 48% good, and 17% excellent.

Sorghum conditions rated 3% poor, 28% fair, 55% good, and 14% excellent. This is above previous year and average.

Oat condition rated 2% poor, 21% fair, 53% good, and 24% excellent. Ninety-six percent of the crop had headed, just behind 97% last year and 98% for the average. Seventeen percent of the crop had been harvested.

Alfalfa conditions rated 1% very poor, 5% poor, 28% fair, 46% good, and 20% excellent. Second cutting was 66% complete, ahead of 46% last year and 53% average.

The Auto-Guidance Field Day will be from 7:30 a.m. to 7 p.m. Thursday, Aug. 18, at the Agricultural Research and Development Center near Mead. Participants will learn the purpose and main components of auto-guidance systems for agricultural vehicles, what technical solutions are available for systems and the benefits and drawbacks of alternative auto-guidance equipment options, said Viacheslav Adamchuk, UNL precision agriculture engineer.

The day will begin with a brief introduction to the auto-guidance concept followed by an outdoor demonstration of a hands-free vehicle operation along a predefined course.

After the demonstration, representatives of major auto-guidance products will share technical details about current and upcoming systems. The main program will conclude at 4 p.m. after which participants can talk with company representatives or operate tractors in the auto-guidance mode.

More information about the field day and updates can be found online at bse.unl.edu/adamchuk/guidance.html or by contacting Adamchuk at (402) 472-8431, e-mail Registration is free, but reservations are required by Aug. 12 as space is limited and a lunch count is needed. Make reservations by calling (402) 727-2775 or e-mailing dvarner1@unl.edu.

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