Vol. 21, No. 3, April 20, 2006

The EPA has approved a Section 18 application for Avitec, a non-lethal crane repellent, on corn in Wisconsin, Minnesota, and Michigan. The Section 18 was developed by Eileen Cullen at the University of Wisconsin and the Wisconsin Department of Ag, Trade and Consumer Protection, in conjunction with many other agencies and groups. The Section 18 was supported by the several Audubon Society chapters as well as the International Crane Foundation. The Section 18 is effective from March 31 to August 15, 2006.

Avitec contains 9,10 anthraquinone, a reduced risk, natural bird repellent produced by plants. Anthraquinone is already used in several products as a goose repellent for parks, golf courses, schools, lawns etc. For agricultural use, the product Avitec will be available as both a powder and a liquid, so producers will be able to apply it as a planter box treatment or have seed treated by a commercial applicator. Avitec is not a restricted use pesticide.

Cranes pluck corn seed and seedlings out of the ground early in the season. Because sandhill cranes are a threatened species, Avitec seed treatment provides a way to repel the birds without harming them. Cranes detect the Avitec, and thus avoid feeding on the corn seed. However, cranes may still be present in a treated field eating other seeds or insects. Note that the Section 18 is to reduce crane damage in newly planted corn seed. It is not for use against any other bird species at this time.

International Crane Foundation - supported the Section 18
Baraboo, WI 1-608-356-9462
http://www.savingcranes.org/

Michigan Department of Agriculture – has Section 18 labels on the web
http://www.michigan.gov/mda/0,1607,7-125-1569_16988_35290-127656--,00.htm

Nitrogen fixation is a result of the symbiotic relationship of Rhizobia bacteria and soybean plants. These bacteria fix atmospheric N 2 into the NH 4 form, which is useful to the plant. In return, the plant provides the bacteria with carbon photosynthesis products (dicarboxylic acids), which the bacteria use as food. Establishing rhizobia or inoculation in a field that has never grown soybean is needed to ensure nitrogen fixation. Elmore (1996) suggests when and how soybeans should be inoculated and provides recommendations on inoculate type to use. Soybeans grown on soils without a rhizobia population will use available soil nitrogen, and if soil nitrogen levels are low because of soil type, soil erosion, etc., the symptoms of nitrogen deficiency may occur. Field studies in Northern Michigan showed 45% and 23% soybean yield increases in 2004 and 2005 where inoculant was used and fields had not seen a previous soybean crop. Soybean plant coloration differences were obvious in this study, as inoculated plots appeared much greener. On other Michigan sites with a history of soybean cropping, soybean seed inoculation increased yield by an average of 1.3 bushels with significant increases at 6 of 14 sites from 2003 to 2005.Because most commercially available inoculant products are relatively inexpensive, the 1.3 bushel/acre expected average yield increase will generally cover application costs. Therefore, it is recommended to apply Rhizobium inoculant to soybean seed each time you plant soybeans. This is especially true on sandy soils, where it is more difficult for the Rhizobia to survive from one season to the next. Also, it is important to inoculate on any soil if soybeans are to be grown for the first time. Two types of inoculants can be used: seed-applied and soil-applied. The seed-applied inoculate is more effective when mixed with water to form a slurry that is used to coat the seed. This should be done as close to planting time as possible, preferably within several hours. The soil-applied inoculate may be easier to apply than the seed-applied inoculate, but it is more expensive on a per acre basis. Thus, seed applied inoculant is generally the method of choice for most growers.

In addition to the recommended short time period between seed applied inoculant application and planting, there are other potential challenges associated with proper soybean seed inoculation. Care should be taken in applying inoculant to fungicide or insecticide treated seed. Fungicide and insecticide labeling should be checked to ensure that the particular pesticide product is compatible with Rhizobium inoculant. Potter (2004) conducted a field trial to examine the effects of inoculating soybean seed with rhizobium, seed applied insecticides and fungicides, and combining bacterial inoculant, insecticidal and fungicidal products in southwest Minnesota. For the trial, one bacterial inoculant, two insecticidal products and two fungicidal products were used. There were 12 treatment combinations among the 5 different products tested. The results showed that crop injury was not observed with any treatment. Figure 1.

Further, differences in root disease, soybean height, nodulation or yield were not observed among treatments. A three year Michigan study tested the effects of combinations of seed inoculant, fungicidal seed treatment, and insecticidal seed treatment. Inoculant was used alone, in combination with either Apron Maxx, Cruiser, or Gaucho and in combination with Apron Maxx and one of the two seed applied insecticides. Results of the trial showed that in fields where soybean seed inoculation did significantly increase yields versus non-inoculated seed, the addition of insecticidal and fungicidal seed treatments did not significantly negate the observed yield increases.

Finally, Rhizobia do not function below pH 5.0 and molybdenum, which is important for Rhizobia nodule formulation, can be deficiencient at pH levels below 6.0. Liming of low pH soils is the best solution for these challenges.

2. The safest approach is to buy fresh inoculate each year.

3. Seed should be planted within four hours of inoculation. New products are being developed with a longer preplant application interval but data on the performance of these products is somewhat limited.

4. When applying a fungicide or using fungicide-treated seed, be sure the fungicide has dried before applying inoculate to the seed. Inoculate should not be mixed with fungicides and applied together. Refer to product labels for specific handling recommendations

5. When loading a drill or planter using an auger, inoculation materials (liquid or dry) should be added to the seed as it enters the auger for thorough application. 

6. When loading a drill or planter from bags, fill the seed box to a depth of three inches and scatter the appropriate amount of inoculate over the seed and mix it in thoroughly. Continue to add seed in six-inch deep layers, treating each until the seed box is filled.

7. With some dry materials it may be desirable to slightly moisten seed to increase the adherence of inoculate. Individual seeds need no more than a 3 to 5 percent coating of dry material. Liquid materials will usually cover most of the seed.

8. Seeding equipment should be calibrated using treated seed. 

9. Lime soils used for soybean production according to soil test recommendations.

Elmore, R. W. (1996). Soybean Inoculation—When is it necessary? University of Nebraska. [WWW document].URL: http://ianrpubs.unl.edu/fieldcrops/g737.htm

Potter, B. (2004). Yield effects of seed applied fungicide, insecticide and Rhizobium inoculants on soybean. University of Minnesota. Southwest Research and Outreach Center. [WWW document]. URL:
http://swroc.coafes.umn.edu/SWMNPEST/04publications/yieldeffects/innoculant.htm

Before you schedule your vacation this summer, make sure to get these two dates on your calendar. The 2006 MSU Weed Tour will be held on Wednesday, June 28 and thefourthannual MSU Crop Diagnostic Day will be held on Friday, July 21. These field days offer you the latest information in weed management and other crop protection and crop management strategies. Stay tuned to future Field Crop CAT Alerts for details and registration forms for each of these events.

Recent rains and warm weather coupled with some of the earliest planted sugar beets in Michigan history has started the clock for postemergence weed control. Along with sugar beet emergence, weeds like common lambsquarters and velvetleaf have started to emerge in sugar beet fields. Starting now, timely postemergence herbicide applications will be critical for effective weed control programs, particularly for growers who will be using micro-rates. Micro-rate herbicide applications can be a cost effective strategy for weed control in sugar beets, but again timing is everything. The first micro-rate application should take place when weeds are less than 1/8-inch tall (cotyledon stage). If weeds get larger than 1/4-inch, micro-rate applications are less effective and standard herbicide rates should be used.

For standard-split herbicide applications, the first application should be made when the weeds are 1/2-inch tall which will generally occur between 350 and 400 GDD. This is the time when growers should start scouting for that first standard-split application.

Taking all of this information into consideration after the first micro-rate herbicide application is made, there are some general guidelines for timing micro-rate herbicide applications using GDD. These recommendations are listed below.

General recommendations for GDD micro-rate applications
After the first micro-rate application is made, MSU research has shown applying micro-rates on a 225 GDD schedule has shown the most consistent weed control across species while reducing the potential for sugar beet injury. However, in fields with sandy or darker soils (high organic matter) and high weed pressures, it is suggested to check fields at 150 GDD and time applications for 175 GDD. For growers who want to adjust the timing of micro-rates relative to weed emergence, it may be possible to lengthen the spray interval early in the season (April) to 275 GDD when common lambsquarters is the predominant weed. In May this interval should be shortened to 225 GDD until pigweeds (redroot pigweed and Powell amaranth) start to emerge, then micro-rate applications should be made every 175 to 200 GDD. If timing is missed, it is important to scout to determine the size of the weeds out in the field and reevaluate what the next weed management step should be.

Where do i get GDD calculations?
There are several good calculators out there to help calculate GDD for scouting and for micro-rate herbicide applications. Michigan Sugar Company through the use of BeetCAST (http://www.michiganbeets.com) and the Michigan Automated Weather Network or MAWN (http://www.agweather.geo.msu.edu/mawn/) are two websites where there are excellent calculators to help determine GDD in the different sugar beet growing areas or you may choose to calculate your own.

GDD Formula = (High Temp + Low Temp)/2 - 34°F

Establishing productive Roundup Ready (RR) alfalfa stands require close attention to details, especially when the plants are young. An early-season application of glyphosate will significantly help alfalfa establishment in two ways. First, glyphosate will remove many of the weed seedlings competing with the new alfalfa seedlings for nutrients and space. By targeting weeds when they are small, excellent control can be expected for almost all weed species.

The second reason for an early application of glyphosate in RR alfalfa is to remove the alfalfa seedlings that do not have the glyphosate-resistant trait. As new alfalfa stands mature, natural thinning takes place, which reduces the total number of alfalfa plants. As surviving plants grow, they fill empty spots in the crop canopy until a healthy, productive alfalfa stand is established (Figure 1). In a typical bag of RR alfalfa seed, a small portion of the seeds do not carry the glyphosate-resistant trait. These seeds will germinate and grow into plants indistinguishable from the glyphosate-resistant alfalfa plants. If an application of glyphosate is made, the non glyphosate-resistant plants will be controlled. By applying glyphosate early in the development of an alfalfa stand, the susceptible plants are removed, allowing the glyphosate-resistant plants to remain (Figure 2). Delaying the application of glyphosate will increase the chance of a non glyphosate-resistant alfalfa plant becoming an established plant in the alfalfa stand. When this occurs, the susceptible plant will suffer severe injury and/or death after the first application of glyphosate, leaving an empty spot in the stand (Figure 3). These open areas allow weeds to become established, possibly leading to reductions in yield and alfalfa quality.

MSU recommends applying glyphosate at a rate of 0.75 lb ae/A before the 4 th trifoliate growth stage to eliminate seedlings not containing the glyphosate-resistant gene. This practice encourages the development of a health population of RR alfalfa plants and prevents susceptible plants from becoming established. When making any pesticide application, always read and follow all the directions found in the label.

There are currently a large number of winter annual and perennial weeds present in no-till corn and soybean fields. It is important to control these weeds prior to crop emergence. These weeds may become very competitive if not controlled.

In some cases, it may be desirable to control these weeds several days prior to planting. With high weed density, excessive plant material can also interfere with seed placement and may slow planting. Table 1G and Table 2C (both in the 2006 Weed Control Guide for Field Crops,E-434) list rates and effectiveness ratings for burndown herbicides in no-till corn and soybeans, respectively.

Herbicide selection for broadleaf weeds in winter wheat past Feeke's Stage 6
Once wheat has passed Feeke’s Stage 6, the risk of herbicide injury from 2,4-D, MCPA, Banvel/Clarity, or Curtail increases and application of these herbicides is not recommended. In this situation, the remaining herbicide options for broadleaf weed control are Harmony Extra, Harmony GT, Express, Buctril, Stinger and Starane. Harmony Extra, Harmony GT, Affinity BroadSpec and Express can be applied to wheat until the flag leaf is visible (before Feeke's Stage 8). Buctril, Stinger and Starane can be applied to wheat up to boot stage (before Feeke's Stage 9).

Each spring there are questions about the risks associated with 2,4-D or MCPA application to wheat past Feeke's Stage 6. Wheat tolerance of 2,4-D is highest between Feeke's stages 3 and 6 and is lowest in Feeke's Stages 9 and 10. Between stages 6 and 9, sensitivity to 2,4-D gradually increases as wheat growth stage advances. Thus, the risk of injury increases as wheat growth stage advances between stages 6 and 9. Severe injury is highly probable when 2,4-D is applied at Feeke's stages 9 and 10.

MSU recommends that application of 2,4-D to wheat be made after wheat has reached Feeke's stage 3 but prior to Feeke's stage 6. If growers choose to apply 2,4-D at later stages, they need to understand the associated risk. This risk can be minimized by applying the amine form of 2,4-D or reducing the rate of a 2,4-D ester. A much better alternative on wheat past Feeke's stage 6 is to use another broadleaf herbicide with a wider application window that is effective on the weeds present in the field.

Herbicide selection for grass weeds in winter wheat
Several growers have reported problems with grasses such as cheatgrass, windgrass and annual bluegrass in their winter wheat. The control options for grass control in winter wheat is limited. Osprey, Olympus 70% and Everest are products labeled for use in Michigan up to the jointing stage; however, special attention needs to be made to the rotational restrictions found on their labels. The weeds controlled by these products will vary, so proper identification of the problematic species is important. The lengthy rotation restrictions associated with these products will restrict the rotation options for growers. Of the three products mentioned, Osprey has the shortest rotation restrictions for most crops grown in Michigan. MSU currently has limited experience with these products and cannot advise farmers on how they will perform in Michigan. Farmers should be advised to read and understand the information found on the label. Windgrass control can also be achieved using Puma. More information about Puma’s use in winter wheat can be found in the 2006 Weed Control Guide for Field Crops,E-434 (page 86).

Herbicide carrier selection
Liquid urea-ammonium nitrate fertilizer (28%N) is a common carrier for herbicides in wheat. The most common herbicide to be used in this manner is 2,4-D ester (2,4-D amine is difficult to mix in 28% N). Application of herbicide in 28% liquid nitrogen can cause leaf burn from the nitrogen, especially under hot, humid conditions. This risk increases with later wheat growth stages because more leaf area is exposed to the treatment and recovery time is shorter. In addition, the use of surfactant (required with herbicides such as Harmony Extra) greatly increases leaf burn potential. MSU research has demonstrated that excessive leaf burn from high nitrogen rates combined with surfactant can reduce wheat yield. To minimize this risk:

• Do not apply more than 20 lbs of nitrogen per acre in the form of 28% N when using a surfactant with herbicide.
• Do not apply more than 40 lbs of nitrogen per acre in the form of 28 % N when no surfactant is used.
• Avoid high-temperature, high-humidity days. Late afternoon applications carry less risk of leaf burn.

The use of postemergence (POST) glyphosate in Roundup Ready soybeans has been the primary weed control program used by many Michigan soybean growers. While this system has seemed to simplify weed management, relying on total postemergence herbicide programs can be difficult to manage if not properly implemented. The flexibility in application timing that glyphosate offers may make it easier to control larger weeds, however the benefits of early-season weed control to protect crop yield can be lost if applications are not made in a timely manner. Additionally, untimely applications can lead to a reduction in weed control. Another thing to consider is by relying only on glyphosate as the weed control strategy this system puts tremendous selection pressure on the weeds that could possibly lead to the development of herbicide-resistant weeds.

One way to help overcome some of these concerns is to implement the use of a soil-applied or preemergence (PRE) herbicide into your soybean weed control program. Using a planned PRE residual herbicide followed by a POST glyphosate application can result in more consistent weed control, reduces the size and number of weeds present at the POST application timing, and offers greater flexibility in the POST application window. One of the concerns that many producers have in implementing a PRE herbicide is the economics. While a PRE herbicide may increase the cost of your weed control program, resulting benefits often make up for the cost by increasing weed control and yield. Below are some of the benefits realized by PRE followed by POST weed control programs.

Reduced early-season weed competition
Using a PRE herbicide will control a number of weeds that would have emerged and competed with the crop as it becomes established. While early-season competition may not be a factor if the POST application is timed appropriately, (remember that weeds can increase in size in a number of days and if you are trying to spray a large number of acres or you become delayed in your applications due to rain) early-season weed competition can become a problem. Remember, for timely POST applications to avoid yield losses due to early-season weed competition, MSU recommends weeds should be controlled before they are 4-inches in height in 7.5- and 15-inch rows and 6-inches in height in 30-inch rows.

Consistent control of weeds that continually emerge
Several weed species have continual emergence or emerge only later in the season. These species can include: annual grasses, giant ragweed ( Southern Michigan), eastern black nightshade, pigweeds and common lambsquarters (occasionally). Because of the later emergence of these weeds, they may actually emerge after the POST herbicide application and can produce seed and become a problem at harvest. PRE herbicides allow for a delay in the POST applications, which will result in more effective control of these late-emerging weeds.

Consistent control of hard-to-control weeds
In Michigan, we have seen a few weeds that have become harder to control with one POST glyphosate application. Common lambsquarters and giant ragweed are examples of weeds that are not always effectively controlled with glyphosate. A PRE herbicide can aid in control by providing effective control and/or suppression of these weeds so they are easily controlled with the POST application. For example, over several MSU trials a PRE residual herbicide followed by POST glyphosate treatment has provided more consistent control of common lambsquarters than 1- or even 2-application of glyphosate (Figure 1).

Effective control of perennials
Control of perennial weeds is more effective in the later stages of growth (bud to flower stage). Because PRE residual herbicides will provide initial control of annual weeds the POST glyphosate application may correspond more appropriately to the stage of growth needed for perennial weed control.

Michigan’s Section 18 exemption for Folicur 3.6F (tebuconazole) to control Fusarium head blight (scab) on wheat has been granted. The Section 18 begins on May 15 and expires on June 25. Last year there were some issues with not getting the exemption early enough for growers in the southern tier of counties to make a timely application of Folicur to their wheat fields, but this year there should be enough time, even with what seems to be shaping up as an early spring.

A Section 18 label for Michigan should be available soon; we anticipate by sometime next week. The label allows for one application of Folicur 3.6 F per year, at a rate of 4 fluid ounces of formulated product per acre. The product can be applied up through the beginning of flowering (Feekes 10.51).

Pre-harvest and pesticide application reentry information will be on the label.

Nitrogen fertilizers are expensive and may become unavailable to your crop. Because of this, corn producers will need to manage nitrogen fertilizer carefully to remain profitable in 2006. Listed below are some strategies for getting the most from your investment in nitrogen fertilizer.

Understand what happens to the nitrogen fertilizer you apply
Studies have shown that only 40 to 60% of the nitrogen you apply is taken up by your crop. Another 20 to 30% remains in the soil after harvest and 10 to 20% becomes unavailable to plants during the growing season. The losses are due to three processes, volatilization, leaching and denitrification. Volatilization occurs when fertilizers containing urea undergo rapid hydrolysis in the soil. Significant losses of ammonia gas can occur. Nitrate-nitrogen is susceptible to losses from leaching and denitrification. Leaching is most likely to take place in coarse-textured soils. Denitrification of nitrate-nitrogen occurs under saturated conditions on fine-textured soils. Over 100 lbs. of nitrogen per acre can be lost from denitrification in five days under the proper conditions.

Select your nitrogen fertilizers and understand their management requirements
The three main nitrogen fertilizer sources are anhydrous ammonia, urea and urea ammonium nitrate solutions (UAN). Anhydrous ammonia is still the least expensive form of nitrogen. It must be injected 6 to 8 inches deep and the slot must be sealed to prevent losses. If applied properly, it is the most stable nitrogen source as it is the slowest fertilizer to be converted to nitrate. Urea is subject to volatilization losses. Volatilization occurs rapidly under warm air temperatures in fields having low CEC’s, heavy residues and adequate moisture. These losses can be reduced by incorporating the fertilizer with tillage at least 1 to 3/4 inches deep or by at least 3/4 of an inch of irrigation or rain fall. Urease inhibitors are available to mix with the fertilizer and prevent volatilization for 10 to 14 days following a surface application. The urea will not be available to plants during this time. UAN solutions are comprised of half urea and half ammonium nitrate. Therefore, half of the nitrogen is subject to volatilization losses. About 25% percent of the nitrogen is in the nitrate form at the time of application and is subject to losses from leaching or denitrification.

Identify the most economical nitrogen application rate
The first step is to determine your price per pound of actual nitrogen and the market price you expect to receive for your corn. Determine the corn to nitrogen price ratio from Table 1. Next you will need to set realistic yield goals for your fields. A realistic yield goal is the average yield you attained in the field for the last five production years for that crop. Find the point on Table 2 where your yield goal and your corn to nitrogen price ratio intersect. You may have to interpolate between rows and columns. This is the most economical nitrogen rate for this field.

Table 1. Corn: Nitrogen Price Ratio

Corn growers can reduce their nitrogen fertilizer application rates by taking credit for the nitrogen contributions from legumes, manure applications and the soil. The credits should be subtracted from the most economical nitrogen rate determined above. Soybeans will contribute 30 pounds of actual nitrogen to the following corn crop. Established alfalfa and clovers will contribute between 40 and 90 pounds of actual nitrogen, depending on the plant population. Manure can be an excellent source of nitrogen. The pre-sidedress nitrate test is a proven method for determining the nitrogen contributions from manured and non-manured fields. Do not take nitrogen credits when growing wheat. Wheat’s peak demand for nitrogen occurs earlier in the growing season before organic nitrogen has been converted to plant available forms.

Apply nitrogen fertilizers at the optimum time
Always apply at least 20 pounds of actual nitrogen per acre in a 2 x 2 band at planting time. Increase this amount to 30 to 40 pounds per acre when planting into heavy residues. Ideally, the rest of your nitrogen should be applied in early June as this coincides with the beginning of the crop’s peak demand for nitrogen. By applying most of your nitrogen in June, you will significantly reduce the potential for nitrogen losses due to leaching and denitrification. If you must apply your nitrogen prior to planting, consider using a nitrification inhibitor. These products can delay the conversion of ammonium to nitrate by 4 to 10 weeks. Nitrification inhibitors will work best if the nitrogen fertilizer rate is slightly deficient. Please see Table 4 to determine the probability of realizing an economic return from nitrification inhibitors.

Table 4. Probabilities of realizing an economic return from nitrification inhibitors

Farmers planting Bt rootworm corn (YieldGuard Rootworm and Herculex RW) in 2006 are required to plant a refuge area within each field or in an adjacent field. The refuge area should be planted to non-Bt corn and cover at least 20% of the acreage in the field. The purpose of the refuge area is to prevent or significantly delay rootworm resistance to Bt. Some rootworm larvae will survive after feeding on the roots of Bt rootworm corn. The best way to keep the population of these resistant rootworm beetles low is to increase the odds that resistant beetles will mate with susceptible beetles. The refuge area is important as it ensures that a large population of susceptible beetles will be present to mate with the few resistant beetles in each field.

Research conducted at Purdue University indicates that a refuge area created by splitting the planter supplies twice as many susceptible beetles as a refuge planted as a single block. The refuge strips must be at least 6 rows wide. If you operate a 12-row planter, you can achieve a 25% refuge by simply dedicating the last three planter units on one end of the planter to non-Bt corn. If you operate a six-row planter you can achieve a 25% refuge by dedicating half of the planter to non-Bt corn and strip-plant half of the field.

The non-Bt hybrid planted in the refuge area must have a similar relative maturity rating as the Bt hybrid. The refuge area should be planted at the same time and managed in the same manner as the Bt field or area. Matching the hybrid maturity and the planting date will ensure that the corn rootworm larvae in the field and the refuge area will develop at the same rates and emerge as adults at the same time. If an adjacent field is used for the refuge, it must be owned or managed by the same grower. A ditch or road can separate the refuge area from the Bt field. Always protect the non-Bt corn in the refuge area with treated seed or soil insecticides at planting.

There is an increasing interest in planting soybeans early. This article summarizes the risks and benefits of early planting. Specific management practices for early planted soybeans are also provided.

One of the biggest advantages of early planting is that it provides a longer planting window for attaining maximum yields. Data from the University of Wisconsin and The Ohio State University indicate that beans planted on May 1 will yield about seven bushels per acre higher than beans planted during the last week of May. Beans planted during the last week of April have produced slightly higher yields than those planted on May 1. University agronomists have also found that the newer soybean varieties are more tolerant of adverse, early-season conditions than older varieties.

The primary risk of early-planting is that the beans will be damaged by freezing temperatures. This risk is mitigated to some degree by the fact that germination is delayed under cooler soil temperatures. Soybean tissue is also more resistant to freezing temperatures than corn tissue. Typically, temperatures must reach 28°F for damage to occur. There is also risk that soil-borne diseases may damage soybean seed planted into cool soils. Sudden death syndrome and bean leaf beetles are also more likely to attack early-planted beans.

If you decide to plant soybeans in the last week of April, you should consider the following recommendations.

Don’t plant unless the soil is dry enough to support equipment. Shallow soil compaction will haunt you the remainder of the growing season.

Plant seed that has been treated with a fungicide.

Plant high quality seed.

Till the field or clear the residue away from the row to allow the soil to warm up faster and reduce the likelihood of frost damage.

Plant in fields at higher elevations with good air drainage to reduce the likelihood of frost injury.

Weather
Warm temperatures have prevailed and precipitation has been spotty over the past week creating ideal conditions for field work.

Commodity reports
Corn planting has just begun on some of the largest farms in the area. Growers should take advantage of the excellent planting conditions and get as much corn planted as possible before the end of April. If you need rootworm control and plan to plant in April, consider planting transgenic hybrids as soil-applied insecticides and seed treatments may leach or break down before rootworm hatch is completed.

Wheat planted in early October has reached growth stage 6 (jointing). This has two management implications. First, it is too late to apply growth regulator herbicides such as 2,4-D, MCPA or Dicamba once the first node is detected. Also, all of the nitrogen should have been applied by now or be applied as soon as possible to maximize fertilizer efficiency.

Alfalfa has survived the winter well and is growing well.

Southwesterly flow aloft during much of the first half of April led to warmer than normal temperatures and a surge of early GDD accumulations across the Great Lakes region. Mean temperatures during the previous 30 days generally ranged from 2 to 6 degrees F above the climatological normals. The mild temperatures resulted in significant early phenological development of most overwintering crops. Seasonal GDD accumulations thus far are generally running 5 to 10 days ahead of normal and a day or two ahead of last year. Mean two-inch bare soil temperatures rose above the 50°F mark for the first time this season across most southern and western sections of the Lower Peninsula during the weekend (April 15-16). Precipitation totals for the past 30 days ranged from near to below normal levels over most of the state, countering a trend of above normal precipitation totals that has persisted in some areas since late last fall. Regardless, topsoil and subsoil moisture levels across most of the state continue at adequate to above normal levels over all but some northern and extreme southwestern sections of the state. While extra moisture may delay fieldwork in the short term, it is a positive from a strategic standpoint. It may serve as a reserve for crops later in the growing season should rainfall totals fail to keep up with plant demands, a situation which occurs in the majority of growing seasons in Michigan.

Looking ahead, jet stream flow across North America is forecast to shifts considerably during the next week with formation of a large ridging feature over the west-central United States and troughs along west and east coasts.

In the short term, weather in Michigan will be heavily influenced by an upper air feature referred to as a “cut-off low,” which is expected to slowly drift west to east across the Great Lakes region over the next several days. Weather conditions with this feature will likely be unsettled, with a continuing chance for mainly scattered showers and a few rumbles of thunder each day into early next week. Best chances for rainfall over most of the state will be Saturday (April 22). Rainfall totals during the next five days will be scattered and on the light side with totals likely remaining in the 0.25 to 0.50 inch category and heaviest totals in northern and eastern sections of the state. After at least 3 days of 70+ degree highs across many sections of the state, temperatures will gradually fall back to daytime highs in the 50's north to 60's south Saturday through Monday. Low temperatures will be in the 40's through Saturday, falling to the 30's to low 40's by Monday. Some frost and freezing temperatures are possible early next week in northern sections of the state.

Further ahead, medium‑range forecast guidance strongly reflects the upper air pattern mentioned above, with Michigan under the eastern edge of a large ridging feature over central North America.

The official NOAA 6-10 day and 8-14 day outlooks (covering April 25-29 and April 27 through May 3) call for below normal precipitation totals statewide. Mean temperatures are expected to range from below normal levels over eastern sections of the state to near normal in the west. Overall, following a period of wet and unsettled weather this upcoming weekend the medium-range guidance strongly suggests drier weather again by late next week, which should in turn lead to an extended period of favorable conditions for spring fieldwork and planting activities through much of the remainder of April.