|
Spider mites building up in corn Timely rains continue to aid eastern Nebraska while drought worsens in southwest areas Research update: Irrigation management strategies to conserve water Does genetic engineering reduce crop pesticide use? Diagnostic Clinic Update Price index down slightly in July Avoiding harvest losses part of Soybean Management Field Day Biotechnology Field Day August 17 Dry bean field day offers latest research results Sustainable ag tours to explore state's agricultural diversity Field updates
The economic injury level table (see below) accounts for the low value of corn and can be used to help decide whether to treat. This table works for both two-spotted 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/acre and the expected price is $1.50/bu, then the value per acre is $300.
The decision process 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 should 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 treatment cost.
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 $300 market value column, the critical value for percent infested leaves varies from 20% if control costs are $10, to 49% if control costs are $25.
Labeled products for spider mite control include dimethoate (several formulations), Comite 6.55EC and Capture 2EC. Dimethoate has performed reasonably well in Nebraska against Banks grass mites, but not two spotted spider mites. If two spotted spider mites are present, either Comite or Capture would provide better control.
| ||||||
For more information see:
Bob Wright
Extension Entomologist
South Central REC
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
The latest satellite imagery (July 30) indicates that severe vegetative stress conditions are most significant in southwest Nebraska, west of McCook and south of North Platte. There are additional isolated pockets along the Kansas-Nebraska border from McCook to Fairbury, northeast of Grand Island, west-northwest of Columbus, and across the southern third of the Panhandle.
Outside of the eastern three tiers of counties and the extreme northern tier of counties, most locations are showing moderate stress to normal conditions. However, the overall vegetative health for the state is much worse conditions than for the similar time frame of last year. Some of the vegetative information is probably contaminated from constant irrigation.
Eastern Nebraska counties continue to show the benefits of heavy downpours since mid-June. High satellite vegetation index values, indicating no stress, appear with the Missouri River Valley north of Omaha and from Nebraska City south to just north of Falls City. Another pocket is south of Lincoln to Beatrice and eastward to Pawnee City.
As good as crop conditions appear on satellite imagery, I have witnessed a slow deterioration over eastern Nebraska during the last 14 days. Precipitation has returned to a more normal pattern and crops are now extracting moisture at a faster pace than is being replenished by rainfall. With crop water use at .20-.30 inch per day, timely rains will be needed for these conditions to persist or improve.
Another interesting point gleaned from this satellite imagery of vegetation is that the amount of area in the central United States with fair to excellent vegetative health is considerably smaller this year than in 1999, although average yields are projected to be greater in 2000. The August USDA field surveys should shed crucial information on whether yield model projections for this year are obtainable or just wishful thinking.
Looking into the future, long-lead models have been inconsistent at best for use as predictive tools this growing season. What appears to be established is a persistent storm track that favors the northern and eastern tier of counties. As one moves south and west, precipitation tendencies have decreased along with higher temperature tendencies.
If a dry and warm pattern reestablishes itself in August like the last two years, crop damage in southwestern Nebraska will further intensify, especially when one considers that irrigators are working with limited water allocations. This would also mean that irrigators in central Nebraska would face additional costs in an already expensive watering year. Some deterioration would be expected across eastern dryland sections of the state, with the extent dependent on how much rain is received through the end of the growing season.
Long-lead outlooks indicated a cooler August for the entire state, with above normal precipitation over the southwest and southern panhandle. Forecasters at the National Weather Service felt that the southwest monsoonal flow would be stronger than normal; however so far it has been virtually nonexistent, as the tremendous outbreak of forest and rangeland fires over the inter-mountain west will attest.
Short-term precipitation deficits have been alleviated for the most part across the eastern third of the state. Incipient to moderate drought conditions assigned to this area are attempting to capture precipitation shortfalls from last fall, as precipitation departures for the last 12 months are still running 3-6 inches at most locations.
Moderate to severe drought conditions across central Nebraska are reflecting dry fall conditions, and sporadic dry conditions from this spring and summer which have not been eliminated by periodic heavy rains. Severe to extreme drought conditions across southwestern Nebraska reflect that 10 of the last 12 months have seen below normal precipitation, with many locations receiving less than 50% of normal precipitation during the last 4-, 9-, and 12-month periods.
If forecast models are correct, August should bring substantial relief to Nebraska producers; however the monsoonal flow would have to begin quickly. Otherwise, we can expect stress problems to continue.
Al Dutcher
State Climatologist
Note: This year's demonstration trials on irrigat on management (described in detail below) are pushing the previously defined research to the limit, providing valuable information on how limited soil moisture as well as limited irrigation will affect crops under the four management strategies being demonstrated. This is the first time in this five-year project that soil moisture profiles were low at the beginning of the season.
In 1996, a project was initiated in the Republican Basin to demonstrate:
There are certain growing season periods, such as the vegetative and late grain fill stages when, in general, irrigation amounts can be reduced with little or no effect on grain yield, given there is a full profile of water.
This demonstration project is located in six areas within the basin with soil types ranging from Valentine fine sand to Holdredge silt loam. Four irrigation management strategies have been conducted at each site: current farmer management (FARM); university best management practices (BMP); late initiation (LATE); and allocation (ALLOC). These four strategies are as follows:
The following results are from years where extreme dry periods of 30 or more days occurred. Unlike the situation this year, these fields started with a full profile of moisture.
Joel Schneekloth
Extension Educator
Republication Valley Water Management, North Platte
Planting genetically engineered crops appeals to producers because of the potential to simplify pest management, reduce pesticide use, and help control costs. Analysis by USDA's Economic Research Service indicates that adoption of genetically engineered corn, soybeans, and cotton is associated with a decrease in the number of acre-treatments of pesticides (number of acres treated multiplied by number of pesticide treatments).
Reduction in volume of active ingredients applied is less consistent, since adoption alters the mix of pesticides used in the cropping system, as well as the amounts used. Comparison of different mixes of pesticides involves evaluating tradeoffs between the amounts used and the environmental characteristics, primarily toxicity and persistence. For example, the herbicide-tolerance trait in soybeans allows substitution of glyphosate herbicides for other synthetic herbicides that are at least three times as toxic as glyphosate and that persist in the environment nearly twice as long.
USDA Economic Research Service Report (July 20)
Alfalfa disease diagnosed was nutritional (Buffalo County). Corn diseases diagnosed were bacterial stalk rot (Dodge County), common rust (Adams county), drought (Dawson County), eye spot (Dodge County), maize chlorotic mottle virus (Franklin County), and nutritional (Adams County).
Soybean diseases included bean pod mottle virus ( Dodge and Saunders counties), Phytophthora rot (Saunders County), Rhizoctonia stem rot (Lancaster County), and stem canker (Buffalo County).
Jane A. Christensen
Plant and Pest Diagnostic Clinic
The preliminary All Farm Products Index of Prices Received in July was 98 based on 1990-92=100, down 1 point (1.0%) from the June index. The USDA Agricultural Statistics Service reported Wednesday (Aug. 2) that lower prices for corn, wheat, soybeans, and eggs more than offset price increases for milk, cucumbers, onions, and potatoes.
The seasonal change in the mix of commodities farmers sell often affects the overall index; however, these changes were essentially offsetting in July.
Compared with July 1999, the All Farm Product Index was 3 points (3.2%) higher. Price increases from July 1999 for hogs, cattle, wheat, and soybeans more than offset price decreases for milk, corn, grapes, and oranges.
On average producers lose 10% of their yield during harvest, according to research. Improving combine and harvest efficiency to reduce losses and kernel damage is one of several topics being featured at this year's annual Soybean Management Days Aug. 15-18.
Other topics will include weed management technology, soybean value enhancement and disease and soil fertility management.
The field days, which run from 9 a.m. to 2 p.m. and include lunch, are scheduled for:
For more information about the program see the July 28 Crop Watch or the Web site at http://www.ianr.unl.edu/ianr/ardc/soydays.html.
The event is sponsored by the Nebraska Soybean Board, United Soybean Board, and NU Cooperative Extension.
The Haskell Ag Lab field day, "Biotechnology: Global Issues, Local Decisions", is fast approaching. The University of Nebraska and local business are sponsoring the field day on August 17 from 9 a.m. to 3:30 p.m. The field day is in response to a variety of questions that have been raised concerning the impact of biotechnology on Nebraska agriculture. We believe all Nebraskans, not just rural citizens, will find the day informative.
Registration and morning sessions will be at the Dixon County Fairgrounds near Concord. Registration and lunch are free. Afternoon sessions, which begin at 12:45 p.m., will feature a tour of the NEREC Haskell Agricultural Laboratory near Concord where participants can view biotechnology research.
Speakers at the morning session include:
CEU credits have been applied for and further information will be available at the field day. For more information contact Tom Hunt, Extension Entomology Specialist, Haskell Ag Lab, (402) 584-2863.
Tom Hunt
Extension Entomologist, Haskell Ag Lab, Concord
If you're currently producing dry beans or are interested in adding them to your operation, you can learn the latest information about production research at this year's Nebraska Dry Edible Bean Field Day. The field day will be at the NU Panhandle Research and Extension Center near Scottsbluff, beginning at 1 p.m. Wednesday, Aug. 16. The event is being co-sponsored by the Nebraska Dry Bean Grower's Association and the University of Nebraska.
Nebraska currently has about 200,000 acres planted to dry edible beans, much of which is in the Panhandle or southwest Nebraska, although pockets of production are developing in central and eastern Nebraska.
Nebraska ranks third nationally in dry bean production and first in great northern production. (About 70% of the national crop of great northerns is grown in Nebraska.) Dry edible bean production in the state is divided mainly among great northerns, 40%, pintos, 40% and light red kidneys and others, 20%.
In recent years there has been increasing interest from a wider group of potential producers. Several groups of farmers in eastern Nebraska have done well producing it as a specialty crop, managing production for a specific quality or attribute and selling to a previously arranged market, said John Smith, Extension machinery systems engineer at the Panhandle Research and Extension Center.
Traditionally we think of dry edible beans doing best with lower rainfall and lower relative humidity; however, if a person selects the right variety, population, row-spacing and soil and provides good water management, dry beans can be grown across the state.
"Dry beans may required increased management in central and eastern Nebraska, but it can be done," Smith said.
The Aug. 16 field day will offer growers and potential growers an opportunity to learn the latest on dry bean production while developing a network of resources with other producers, processors and dealers.
Tour stops
Tour topics and the NU faculty presenting at each stop:
The tour will be followed at 5 p.m. by a hog roast with baked beans and a bean dessert. For more information on the tour or a specific tour topic, call the Center at (308) 632-1230.
Other sources of information on dry bean production in Nebraska include:
John Smith
Extension Agricultural Engineer
Panhandle REC, Scottsbluff
The Nebraska Sustainable Agriculture Society is hosting the following tours to showcase the diversity of ag enterprises in Nebraska.
Bob Wright
Extension Entomologist, South Central REC
Foliage feeding, which may seem heavy now, would still need to reach high levels (35% leaf loss or higher) to justify an insecticide treatment. Be aware that most people tend to greatly overestimate true leaf loss since feeding is concentrated on the upper leaves, while feeding in the mid and lower canopy is usually much less. The vast majority of fields should not need treatment at this time. However, now would be the ideal time to scout for beetles to determine if treatment would be necessary for the next generation of beetles which will begin feeding on pods in about three weeks. For more information on this, see the July 21 Crop Watch.
Irrigated crops are doing well but the irrigators are certainly getting tired of pumping water. Most rains have avoided our area and irrigation has continued since early June with little or no relief. Hail damaged corn and soybeans continue to create challenges in determining what to do with certain fields.
Unusually high temperatures during pollination likely led to some of the problems. Silk clipping by rootworm beetles may also have been a contributing factor. Some consultants also thought the extent of the problem varied with different hybrids.
Field updates
|
About Crop Watch |
Agricultural News Events | Archives | Markets | Research Ag Links | Weather | Photos Search | Editor Rural Routes | Publications | IANR |
 | ||
| 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 | ||
| University of Nebraska Cooperative Extension educational programs abide with the non-discrimination policies of the University of Nebraska-Lincoln and the United States Department of Agriculture. | ||
