Nebraska ranked sixth in the nation in soybean production in 2004 with 220,875,000 bushels. This and the April 22 will focus on soybean production and pest management. (Photo by Brett Hampton)

April 15, 2005: Focus on Soybeans

Soybean aphid seed treatments not recommended

With a seed treatment for soybean aphids costing $12-$14 an acre, it's expensive "insurance" against a problem that may never develop.

Much of this discussion was stimulated by an insecticide efficacy trial conducted by the University of Wisconsin. In this trial a thiamethoxam seed treatment (CruiserMaxx Pak, 50g/100Kg seed) held soybean aphid populations to 250 aphids per plant until mid-August. However, the Wisconsin researchers point out that 1) this study was planted very late (June 9, up to 30+ days later than a typical planting date) to insure aphid infestation, and 2) in another study the aphid populations exceeded 250 aphids per plant in treatments with a higher rate of thiamethoxam (62.5 50g/100Kg seed) than in CruiserMaxx Pak.

Dr. David Ragsdale and Brian McCornack of the University of Minnesota have conducted soybean aphid mortality and fecundity (number of offspring) studies to investigate the questions “How long can we expect systemic activity of thiamethoxam to last in the soybean plant?” and “How successful will female soybean aphids be at reproducing on Cruiser-treated soybean leaves?”

In lab bioassays, they exposed soybean aphids to soybean leaves pulled from thiamethoxam-treated plants (50g/100Kg seed) at successively later intervals after planting. They placed aphids on treated leaves and recorded percent mortality and the number of offspring produced per female at 24 hour and 48 hour exposure/feeding times. Ragsdale and McCornack found that soybean aphid mortality was significant up to about 35 days (V3/V4 growth stages), but beyond that point, aphid mortality decreased toward zero and was no longer significant. They also found that soybean aphid fecundity was significantly reduced up to about 40 days after planting (V4 growth stage). However, beyond 40 days they saw no difference in the number of nymphs deposited by aphids on treated and untreated leaves.

Given this information, the Wisconsin researchers concluded that under normal planting dates they did not expect thiamethoxam or imidicloprid seed treatment efficacy to hold, particularly under high and/or late season soybean aphid pressure.

We agree with this conclusion, particularly for soybean aphids in Nebraska. To date in Nebraska, the soybean aphid has not been an early season pest; it has been a late season pest. Most of our soybeans are planted in May, and we generally don’t begin to see aphids until mid to late July, well past the early vegetative stages, and in most fields soybean aphid populations peak in mid to late August. This is too long a time to expect a seed treatment to have a significant effect. Although we have seen some differences in aphid populations between seed treated and non-treated soybean, it has not been enough to protect the crop.

In addition, all soybean fields in Nebraska will not have economic populations of soybean aphids, even in northeast Nebraska where we’ve seen the most soybean aphid injury. Why spend money before you know if there is actually a need? With a seed treatment costing approximately $12-14 an acre, it is expensive “insurance” with a high probability of either not being needed or not being efficacious when used to manage soybean aphid.

In conclusion, we do not recommend insecticidal seed treatments for soybean aphid management in Nebraska. Manage soybean aphids by scouting and using economic thresholds. One well-timed foliar insecticide application, based on two or more field visits with soybean aphid population density at threshold and actively increasing, will adequately control soybean aphids and protect yield.

Thomas Hunt
Extension Entomologist
Haskell Ag Lab
Keith Jarvi
IPM Assistant
Both in the Northeast REC

Many of the products are single treatments, such as inoculants, fungicides, insecticides, etc. while others are combinations or “packs.” The market for soybean seed treatments is trending toward combining differing chemistries in one “super” pack which enables the producer or retailer to apply numerous products in one application.

Although this does increase efficiency, it also increases the likelihood of applying more products than are actually needed. The key is to understand what each product is and then determine if it is really necessary for each situation.

Inoculants have been used for years to inoculate soybean with Bradyrhizobia japonicum. This strain of bacteria forms nodules on soybean roots and fixes atmospheric nitrogen for the soybean plant to use throughout the season (see related story, When should inoculants be applied?).

New products are advertised as inoculants plus “growth promoters.” These products contain both inoculants and lipochitooligo-saccharides (LCOs). Nodule formation depends on several chemical signals being sent back and forth between B. japonicum and soybean roots. This signaling requires time and suitable environmental conditions.

One of the chemical signals required for nodules to form are LCOs which are produced by B. japonicum. By adding LCOs to these manufactured products, nodules form earlier since steps in the initiation process are bypassed. LCOs may contribute to an increase in overall stand and plant appearance, although Nebraska research on these characteristics is extremely limited. If a response is seen with these LCOs, it would likely result in years where there is a prolonged cool spell during early plant establishment.

When combining inoculants with fungicides on seed, there is a natural decline in the number of bacteria present due to the presence of the fungicide. To combat this effect, products have been developed to help increase the longevity of B. japonicum on the seed. These products often are termed “protectors” or “extenders.” “Extenders” also are used to increase the life span of the inoculant treatment when it’s applied early (typically 30 days prior to planting).

Colorants and polymers also are added into combination packs, largely for cosmetic purposes. Polymers, which enable the soybean seed to be planted unusually early and “sit” in the ground until the soil reaches the correct temperature, have not been consistent in performance. In reference to these treatments, an industry Web site said that they “give (the) perception of added value to the seed.” Yet this may not equate to final yield differences!

Table 1 lists seed treatments by classification. This table is meant to give a general view of available products and is not an exhaustive source of information for these products. Due to space limitations we did not list all seed treatments; instead it is a limited representation. Reference to a certain product does not signify endorsement and exclusion of a product does not signify non-endorsement by the University of Nebraska.

Lori Abendroth
Research and Extension Associate
Roger Elmore
Extension Crops Specialist

The soybean plant requires a substantial amount of nitrogen during its reproductive stages, especially during pod fill (R3 and R4), and this is supplied largely through nitrogen fixation.

When deciding whether a soybean field should be inoculated or not, first determine whether the field is “new” or “old.” A “new” soybean field is one that has never produced soybean. An “old” soybean field is one that has produced a soybean crop within the past four to five years. Research conducted throughout the Midwest supports the inoculation of “new” soybean fields with B. japonicum. A yield increase of a few bushels (1-10 bu/ac) should be expected with inoculants on “new” ground.

There have been differing views on whether a yield increase will be achieved when inoculating ground that has previously produced soybeans (i.e. an old field). These fields can retain the bacteria from year to year.

University of Nebraska research conducted in 2003 and 2004 did not show a yield difference between any inoculation product and an untreated control. In “old” fields, a yield increase from re-inoculation will likely be found in situations where there are multiple factors deterring bacteria survival (such as extreme pH levels(i.e. less than 5 or more than 8), high sand content, high fungicide use, etc.) and not due to one lone factor.

A NebGuide covering soybean inoculation and summarizing University of Nebraska inoculant trials will be available later this summer.

Lori Abendroth
Research and Extension Associate
Roger Elmore
Extension Crops Specialist

Table 1. Cumulative water use in the Central High Plains from emergence in the fall to various stages of plant development for irrigated winter wheat grown under unlimited soil water conditions. (Adapted from Kansas State University Experiment Station Bulletin 442) Period Approximate dates Cumulative water use (in.) Emergence Sept. 25 - Oct. 5 Beginning spring growth March 15-30 4.0 Jointing stage April 25-May 5 8.5 Boot stage May 15-20 11.0 Flowering stage May 28-June 5 14.0 Milk stage of grain June 7-12 17.0 Dough stage of grain June 15-20 19.0 Complete maturity July 1-5 22.0 Total 22.0

Winter wheat water use will increase daily from around 0.1 inch/day, currently, to approximately 0.3 inch/day in early June at the milk stage of growth. As the plant continues to mature and produce grain, water use begins to drop off. This means winter wheat’s daily water use declines at a rate of approximately 0.07 inch/week from its peak level in early June to when the crop reaches maturity in early July.

We often hear that irrigation is critical during the flowering and grain development growth stages. It is more correct to say that crop water need is greatest during flowering and grain development.

Irrigation application needs to be adjusted accordingly. For example, an irrigation system with a 600 gal/min well can deliver between 0.20 and 0.25 inch/day of water on a 120 acre center pivot, depending on system efficiency. Since peak consumption of water for winter wheat can be 0.30 inch/day or more, this means the irrigation system will not be able to keep up with crop demand during these critical stages of growth.

In order to avoid crop water stress if the soil profile is deficient of water, irrigation needs to be applied prior to flowering when crop water use is less. At this time, the sprinkler system can apply more water than the crop needs and the excess water can be stored in the soil profile. The water stored in the soil profile can then be used to supplement irrigation during flowering and grain fill. As a general rule, it is usually best to apply water to fill the soil profile prior to the boot stage of growth. After the boot stage, water use will be equal to or greater than the sprinkler system’s capacity to deliver water and the opportunity for storing water in the soil will be lost.

Winter wheat is a good drought-tolerant crop but if winter and spring precipitation is limited, early irrigations will be needed to establish a good root system for efficient extraction of water later in the growing season. Later in the season, irrigation prior to the boot stage is needed in order to store water and supplement irrigation during peak growth periods.

C. Dean Yonts
Extension Agricultural Engineer

Conventional tillage or no-till

Depending on how you look at it, weed management strategies for these tillage types will either be very similar or worlds apart. Of course, while the concepts are still the same, the goals are somewhat different. Management strategies for each still focus on the bottom line – yield.

Conventional tillage soybeans

Under a conventional tillage operation, a good portion of weed management is removed from the equation. Many of the early emerging summer annuals, including giant ragweed, kochia, crabgrass, lambsquarters, and Russian thistle are removed during the tillage process, allowing the crop and any new weeds to emerge together.

Under this system, a preemergence can really work well for producers. A preemergence treatment can remove a lot of the weeds that would emerge with the crop and compete heavily with the soybeans. This gives the crop an advantage by several weeks, removing competition during the first portion of the critical period of weed control.

Figure 1. The critical period for weed control in soybeans is between the 2nd trifoliate and the beginning pod stages.

Research at the University of Nebraska has shown that each crop has a critical period during which weeds must be controlled to maintain maximum yields (Figure 1). For soybeans, this period is from the second trifoliate to approximately the beginning of pod set. This is roughly the 10th to the 40th day of crop growth. While you may save some money by going with a a single POST program in your Roundup Ready® beans, you also are hurting yields by delaying weed control. This means that you may need to consider using two applications of glyphosate or including a pre-emergent herbicide in your Roundup program to widen the application window.

This recommendation might suggest that weeds developing before this window (10th - 40th day) don’t need to be controlled; however, other factors such as reduced soil moisture and unsightly field clutter need to be taken into account. Given the recent span of dry years, controlling these early season weeds may be very important.

No-till soybeans

In dry years no-till farmers may be ahead of the game, as they are likely to conserve more soil moisture. This moisture can be a yield-limiting factor, however, in a drought year since it may allow for the germination of early summer annuals and support winter annuals that emerged last fall.

Burndown treatments will eliminate soil moisture loss from early summer annuals and existing winter annuals. Many herbicide strategies exist to accomplish this while still providing some residual control before the crop is planted.

One strategy is to apply an early preplant treatment with the burndown 10 to 30 days before planting. This removes weed competition up front while providing the residual control needed for the early part of the season. The advantage of this strategy is that most summer annuals have not emerged yet, rendering the residual herbicide very useful.

Another advantage is that more time is given for a rainfall event to occur for herbicide incorporation and activity. Finally, depending on the weed spectrum, the early preplant may eliminate the need of an additional burndown, saving money. One disadvantage, however, is that the herbicide will lose residual activity earlier in the growing season and post treatments must be planned more carefully.

A second strategy is to apply a burndown alone ahead of planting, such as glyphosate at a 32 oz/ac equivalent rate. When combined with 1.0 pt/ac 2,4-D ester, glyphosate can be reduced to 24 oz/ac. Keep in mind that there is a seven-day interval between application of 1 pt of 2,4-D and soybean planting. Any application greater than 1 pint of 2,4-D requires 30 days before planting. Dicamba should not be used before planting soybeans. A disadvantage to this strategy is the window between the burndown treatment and the treatment applied at planting. The bigger the gap, the more likely it is for additional weeds to emerge ahead of planting.

Another technique is to apply a two-third’s rate of residual herbicide with the burndown followed by another third residual at planting. This allows for a longer window between the burndown and planting in case planting is delayed. It also provides another dose of residual at planting to increase weed control at crop emergence by a few days.

Also, this system allows more flexibility in your postemergence herbicide applications since environmental conditions such as rainfall or wind may occur at your normal time of POST application and delay spraying operations.

In each management strategy, producers should keep two things in mind. First, early season weed competition can reduce yield, especially in a dry year. Second, use a strategy that will provide the most flexibility for your management style. Each strategy will have its own shortcomings, so be able to recognize them and adjust as need be.

For more information on selecting a pre-emergence herbicide for soybeans, consult the 2005 Guide for Weed Management in Nebraska. This guide is available at your local University of Nebraska Cooperative Extension office for $3.

Brady Kappler
Extension Educator Weed Science

This week on Market Journal This week's Market Journal, Cooperative Extension's television for ag business decisions, focuses on best methods for using short water supplies and strategies for marketing stored corn and soybean. Tune in as host and Agricultural Economics Specialist Doug Jose visits with farm and ranch specialists. With some areas facing their sixth year of limited water supplies or drought, Steve Melvin, UNL Extension Educator, will discuss methods to make the best use out of what water's available to producers, especially in western Nebraska. Dave Baltensperger, UNL Extension Crop Breeding Specialist, will talk about Nebraska options for oil seed crops, and Roy Smith, farmer and market consultant, will analyze the corn and soybean markets and offer suggestions on when to sell the old crop. Market Journal is available on the Market Journal Web site for web viewing, the Nebraska Educational Television NET at 6:30 a.m. Saturdays and on NET2 at 9 a.m. on Sundays, and on the DishNetwork NAUHS 9411 at 12:30 p.m. Fridays. For more information, see marketjournal.unl.edu

Weeds such as henbit and pennycress are winter annuals that generally emerge in the fall. In the spring these weeds will bolt and then flower. You will get some early spring emergence with these weeds, but most emergence occurs in the fall.

If you are planning to spray the weeds in the spring, you need to do it when these weeds are small, preferably before they start bolting. Often this opportunity only exists for just a few days. Typically, the weather will warm up a little and then after a few days of sunshine, warm temperatures and maybe some spring rain, these weeds start growing in the rosette form. After a few days of rosette growth bolting starts and the race is on between the producer and the weeds. The total time from weather warm-up to bolting may given the producers as little as a week to get ready and spray, and this doesn’t even account for potential wet fields or rainfall.

After I talk with these producers about spring control options, I tend to shift the conversation by asking them why they would even want to plan to spray in the spring when so many factors are against them. Since the weeds emerge in the fall, why not treat them then, especially given that herbicide selection is easier then. Typically, you will only need two herbicides and maybe one: 2,4-D and glyphosate. One quart of 2,4-D (4 lb) ester will do a great job of cleaning up winter annual weeds. If you have winter annual grasses, combine 24 oz of glyphosate with 1 pint of 2,4-D for good results in the fall.

I should explain what I mean by “fall” spraying, which may be somewhat of a misnomer. Fall spraying actually occurs after harvest in November or early December. Typically we have good weather for much of November and even into December. Some of our best control of winter annuals in our University of Nebraska field trials has occurred when spraying in mid to late November. Temperatures in the upper 50s to even 70s are not uncommon that time of year. As long as it is not cold (40 or below), it can be a good day to spray.

Of course some of you may be thinking that discussing the merits of fall spraying now is like slamming the barn door after the horse is already out. What good will it do me now, you may ask?

Since these winter annuals are clearly visible now, it would be a good time to make maps of these weeds for later treatment. These weeds are very small in the fall and you won’t see them without close inspection of the field. With a map you’ll be ready to attack those nasty winter annual weeds in the fall. When next spring rolls around, you’ll be surprised at how clean the fields are and how much more time you’ll have to get ready for planting instead of spraying winter annuals.

Brady Kappler
Weed Science Educator

Often the first sign of an SCN infestation is when yields hit a plateau or even start to decline and the change can’t be explained by drought, heat, insects, disease or other factors. For this reason, it is important to check for SCN before you think you have a problem.

SCN, once thought to be limited in Nebraska to the Missouri River Valley, is showing up in more areas in the state. It was first discovered in Nebraska in 1986 in Richardson County and since then has been identified in 26 more counties. It probably could be found in all counties in the eastern third of the state and will continue its spread westward, following the area where soybeans are grown. Buffalo County in central Nebraska currently is the most western site where SCN has been identified.

Table 1. Summary of eastern Nebraska research trials comparing resistant and susceptible soybeans in SCN-infested fields, 1999-2004. Average yield from 12 infested sites Resistant varieties: 47.4 bu/ac Susceptible varieties: 42.4 bu/ac Average yield from 6 non-infested sites Resistant varieties: 58.9 bu/ac Susceptible varieties: 59.5 bu/ac Average egg count post-harvest, infested sites Resistant varieties: 491 eggs/100 cc soil Susceptible varieties: 1,823 eggs/100 cc soil

This past summer, a field sales agronomist for a seed company noticed the soybeans in a strip trial just northeast of Kearney were doing poorly. He attributed it to high pH; however, as the summer progressed, two strips in the trial appeared normal while the rest of the soybeans appeared stunted and chlorotic. In checking the plot map, he discovered that these two strips were the two SCN-resistant varieties. At harvest, the resistant varieties yielded about 61 bushels/acre while the susceptible varieties yielded about 38 bushels/acre. The SCN level, about 2,000-3,000 eggs/100 cc soil, indicates this infestation had existed for a number of years and had continued to multiply on the susceptible soybeans that were grown there in a corn-soybeans rotation.

A variety of studies on the effectiveness of resistant versus susceptible soybeans in SCN-infested fields have been conducted in eastern Nebraska between 1999 and 2004. Each year the same varieties in these trials were planted on non-infested sites.

On the 12 infested sites, there was an average advantage of five bushels per acre by using resistant varieties. The advantage ranged from no difference in yields between resistant and susceptible varieties to more than 13 bushels per acre.

The same varieties were planted each year on a non-infested site. The yield potential of the non-infested site was higher which explains the difference in yields between them and the infested sites. It was not due to the presence or absence of SCN.

There was no statistical difference in yields any year and less than a bushel difference in the average yield of the six trials at the non-infested site. In three trials, the resistant varieties had a slight yield advantage and the other three years the susceptible varieties had a slight yield advantage. This shows that you do not sacrifice yield if you plant a resistant variety on a non-infested field or in a field with a very low level of SCN infestation.

What was consistent in all infested fields was the ability of resistant varieties to reduce the level of reproduction. Spring egg counts in these studies averaged about 600 eggs per 100 cc soil for both resistant and susceptible varieties. Resistant varieties decreased levels of SCN in the fields while susceptible varieties allowed an average three-fold increase during the growing season.

These research plots show we can expect a yield advantage to planting resistant varieties on an infested site, even though we may not see a yield difference every year. What we do gain, even in years where no yield occurs, is we reduce the buildup of SCN in the soil. For these reasons, we recommend planting resistant soybean varieties in ANY field where SCN has been detected, regardless of the level of infestation.

Since it may be getting too late to test soil and switch varieties based on an SCN detection now, look at soybean roots about a month after emergence this summer. If you see cysts on the roots, it has SCN; however, if you don’t see cysts, it may still have SCN. When populations are low, sometimes they can be very difficult to find. If you suspect you may have SCN in a field, the best thing to do would be to collect a soil sample and submit it for analysis.

Field trial comparing non-treated plot and Roundup Ready Alfalfa System plot in 2004, Scottsbluff.

Growers who want to use the Roundup Ready alfalfa technology will need to sign a technology stewardship agreement requiring that they

1. not save seed,
2. use only a Roundup brand of glyphosate,
3. pay a technology fee, and
4. allow Monsanto to review Farm Service Agency crop reporting information.

To prevent Roundup Ready alfalfa pollen flow, an isolation distance of 900 feet (forage alfalfa) and 1500 feet (seed alfalfa) will be required between Roundup Ready and conventional alfalfa. The isolation distances are based on research conducted by the University of California on Roundup Ready alfalfa pollen flow from leaf cutter and honey bees in seed-producing areas. Out crossing of Roundup Ready alfalfa plants with other food crops or weed relatives is of minimal concern with alfalfa.

What is the value of Roundup Ready alfalfa as compared to existing varieties and already approved weed control programs? Product information from Monsanto and Forage Genetics International suggests Roundup Ready alfalfa may offer several advantages over conventional alfalfa weed management programs, including:

Figure 1. Early season weed control in a new seeding of Roundup Ready Alfalfa, Scottsbluff, Nebraska. Figure 2. Influence of weed interference and weed removal on new seeding alfalfa yield at Scottsbluff, Nebraska, trial.

1) control of broadleaf and grassy weeds during establishment and in following years for the life of the stand; 2) Excellent crop safety -- some alternative herbicides can cause crop injury; 3) a wider, more flexible herbicide application window which should provide improved weed control and allow the alfalfa germplasm to achieve maximum yield; and 4) a 25-year history of weed management and environmental safety compared to alternative herbicides that may carry over into succeeding crops and be leached into ground water.

Nebraska research results

The Roundup Ready alfalfa system has been examined over the past three years at several Nebraska locations. Results from these studies can be used to partially evaluate Roundup Ready program benefits promoted by Monsanto and Forage Genetics International. Several studies have compared Roundup UltraMax, Pursuit, Pursuit plus Buctril, Raptor, and Raptor plus Buctril for early season weed control in new alfalfa seedings.

Roundup UltraMax provided weed control equal to or greater than alternative herbicide programs (Figure 1). Seedling alfalfa injury from postemergence herbicides is variable and depends on alfalfa vigor and temperatures during herbicide application. Roundup Ready alfalfa seems to have excellent tolerance to Roundup UltraMax, but may show a slight yellowing at the growing point 7 to 10 days after treatment if air temperatures are in the 40 to 50ºF range during and after treatment. Alfalfa injury from Roundup UltraMax was similar to crop injury from Raptor and much less than that observed from Buctril or Pursuit plus Buctril.

One of the benefits being touted is the flexibility in herbicide application. Most alternative herbicide programs require seedling alfalfa to have at least two to four trifoliate leaves before applying treatments. Removing weeds at the four-trifoliate growth stage generally has led to an increase in alfalfa stand compared to areas where weeds were not removed.

If weeds were removed with Roundup UltraMax shortly after alfalfa emergence and again in several weeks after later flushes of weeds had emerged, the alfalfa plant was protected from weed interference and stand was further enhanced. Enhancement of alfalfa stand and vigor led to an increase in alfalfa forage yield (Figure 2). Weed removal in a new alfalfa seeding was closely associated with alfalfa yield — the more weeds removed the more alfalfa harvested. Weed removal with Roundup UltraMax at the unifoliate and again at the four- trifoliate growth stage provided the greatest alfalfa yield.

The Roundup UltraMax label allows growers to use 26 to 52 ounces of herbicide per treatment in Roundup Ready Alfalfa. The rate should be dictated by the type and density of weeds. If weeds emerge with alfalfa, 26 ounces of Roundup UltraMax applied at the unifoliate or first trifoliate growth stage would be recommended. If further weed flushes occur, Roundup could be applied again in two to three weeks. Roundup also can be used to control weeds after alfalfa is established. Winter annual weeds such as mustards and downy brome can be controlled in early spring as alfalfa and weeds begin growing.

Perennial grasses such as bluegrass and quackgrass and broadleaves such as Canada thistle, bindweed, and curly dock also could be addressed with the Roundup Ready weed control program.

Robert Wilson
Extension Weed Specialist
Panhandle REC

Many top quality legume seeds are sold with a seed coating that contains these bacteria. While these are wonderful products, sometimes it may be necessary to add just a little more inoculant to ensure good nodule formation. Remember that rhizobium are living bacteria. Pre-inoculation attaches them to seed during winter for spring planting. When this seed is held over for planting later, many of these bacteria may die due to heat during storage or to the length of time between attachment and planting.

As a result, pre-inoculated seed may contain too few live bacteria to form many nodules. And, of course, seed that has not been pre-inoculated will have no bacteria for producing nitrogen.

To avoid this problem, buy a powdery inoculant prepared specifically for your legume and add it to your seed as directed just prior to planting. This nitrogen insurance will cost less than a dollar per acre. That’s a pretty cheap way to guarantee your legumes produce nitrogen every year.

Bruce Anderson
Extension Forage Specialist

Timing is important. Burning warm-season grasses too early will open up the ground for weeds to invade, soil to erode, and moisture to evaporate. The best time to burn warm-season grasses is when they start to grow, usually late April to early May. Burning then will result in rapid greenup and thickening of desirable warm-season plants.

Never burn unless weather conditions, topography, and other factors enable you to control the fire. And make sure your burn is legal. Obtain a burn permit from your local fire chief.

Bruce Anderson
Extension Forage Specialist

Western Nebraska received some short lived snow and some much needed rain at the start of the week, giving wheat and pastures a valuable early season boost. (Photo courtesy Bill Booker)

Pastures are starting to green up. With the rain and some warm weather, they should really take off.

Dewey Lienemann and Jennifer Rees, Extension Educators in Webster and Clay counties: There was a nice general rain of 0.4-1 inch across the county over the weekend with no storm damage reported. Wet conditions have delayed spring fertilizing and weed control on wheat -- a critical concern with wheat rapidly approaching or already at joint stage. Wheat is really coming on, but some yellow plants persist and some soil-borne wheat mosaic is being reported. Soil-borne wheat mosaic is fairly common in this area of Nebraska since the pathogen can survive in the soil and is active in soil temperatures of 50-60^oF.

There is an unusual amount of henbit in lawns, pastures, wheat fields and crop ground and prostrate spurge in pastures and alfalfa fields. A lot of common mullein is in the rosette stage in pastures. Wet fields are hampering fertilizer application and planter preparations for corn and soybean fields.

Pastures are greening up nicely with good cool season grass growth.

Delroy Hemsath, Extension Educator in Dakota, Dixon, and Thurston counties: There was some early corn planting last week. This is an exception, however, since most farmers are putting on fertilizer and doing some ditch filling from last year’s erosion. Good rains of 1-3 inches April 9-10 stopped any field work but assured weed growth as soon as it warms up. Many fields already had significant weed growth and need to be sprayed. Many producers will begin planting as soon as the soil dries. Pastures continue to green up with some bromegrass two to four inches high.

According to the 2005 Guide for Weed Management in Nebraska (EC130), this is true. If you don't have a black tank and need to control algae, it recommends dissolving 1 oz copper sulfate in 1 pint of water in a glass jar. Add 7.5 tablespoons of the prepared solution to each 1,000 gallons of water. This solution can be used for crop spraying and livestock watering.

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