F. Adnan Akyuz, Ph.D.

Assistant Professor of Climatology

North Dakota State Climatologist

South-Central ND

The region’s June 1-11 rainfall based on NDAWN stations ranges from 0.4 inches at Linton to 1.5 inches at McHenry. At the Carrington REC, alfalfa has a height range of 10-15 inches. Winter wheat is in the jointing stage. The region’s spring wheat planted the first half of May is in the tillering stage. Small grain stands generally are very good but it is fairly common to see ‘yellow’ areas in fields due to wet soils, low N, disease (primarily tan spot), etc. Corn planted the first week of May (generally south of I94) is at the V3-4 stage and corn planted during mid May is in the V2 stage. Corn generally lacks dark green color but this should change if recent warmer and drier conditions continue. Soybean and dry bean planting should nearly be complete by June 15.  Recent cooperative weather has aided herbicide application in small grain and corn. Small grain aphids have arrived in southern counties. Grasshoppers have emerged as well.

Greg Endres

Area Extension Specialist/Cropping Systems

NDSU Carrington Research Extension Center

North Dakota SLN Label Issued or Broadaxe

The ND DOA has issued a special local needs (SLN) registration to FMC Corporation enabling North Dakota dry bean producers to manage kochia and ALS-resistant kochia with BroadAxe Herbicide in dry beans.  The SLN labeling allows a pre-plant or preemergence application of Broadaxe to dry bean fields by ground or air. Application may be made up to 3 days after planting if seedlings have not broken the soil surface and if the seed furrow is completely closed or covered by soil.  The product may be applied at a rate of 19 to 26 fluid ounces per acre depending on soil texture, pH, and organic matter.  Users must comply with all restrictions, precautions and the directions found in the SLN labeling, and a copy of the labeling must be in the user’s possession at the time of application.  This SLN registration is effective immediately and expires Dec. 31, 2018. Section 24(c) of the Federal Insecticide, Fungicide and Rodenticide Act gives states the authority to register additional uses for federally registered pesticide products, or new products to meet special local needs. Minnesota issued a similar SLN registration for use in dry beans.

Do not use BroadAxe on sandy soil.  Read entire label and follow the rate chart on the label for rates for each field - one rate does not fit all fields.  If a grower is concerned about injury, do not use, or use a low rate until they become familiar with tolerance of the bean type grown.  A grower indemnification is required and growers will use Broadaxe at their own risk.  This is similar to the way FMC labeled labeled Spartan Charge on dry beans. BroadAxe has a 24 month plant back rotation restriction to sugarbeet with a successful bioassay.  Develop a rate structure on a field by field basis based on soil pH, soil OM and soil type.  The rate chart on the label is essential to help growers find the appropriate rate.

Rich Zollinger

Extension Weed Specialist

Low Herbicide Supply

Certain popular PRE and POST herbicides may be in short supply this year.  The newly registered Zidua (pyroxasulfon) is one of them. Zidua is currently registered for use in corn and soybean.  Zidua registration on wheat may occur in the future. Zidua is a residual, preemergence herbicide that controls several grass and broadleaf weeds.  The active ingredient is also included in Anthem from FMC and Fierce from Valent.  Zidua can be included in the EPOST application of glyphosate on soybean.  The majority of the Zidua supply for 2013 will be focused on the Delta area of the US to control gly-resistant Palmer amaranth which will decrease the supply in ND. BASF intends to have full product availability in 2014.

Rich Zollinger

Extension Weed Specialist

Waterpod

Each year it seems a different weed becomes the mystery weed to identify.  To this point, waterpod seems to have the crown. Waterpod (Ellisia nyctelea L.) is an annual broadleaf plant in the Waterleaf family (Hydrophyllaceae). There are no other (common) weeds in this family that infests cropland in the northern plains. My experience with waterpod has been intermittent – it has been more of a “nuisance” weed and it shows here and there and rarely in high densities. It does not seem to be tolerant to many POST herbicides.  My Extension predecessors did not leave a file on waterpod and I did not find much additional information about it on the web either.  I suspect the cool and moist conditions must be conducive to emergence and growth, and glyphosate and most POST herbicides will control it. Refer to photos below for help in identification.

Rich Zollinger

Extension Weed Specialist

Timely Post Applications

John Kringler, Cass County Extension Agent, conducted a short survey of retail agronomists that applied preplant/preemergence herbicides in corn and soybean for 2013. Response for corn was 5% to 60% of acres and 5% to 35% of soybean acres.  One agronomist indicated that a more accurate account can be made “when the pre’s are returned” that were not used.  What does it tell you?  In response to the narrow planting time frame, some growers decided not to use PREs , except for some that had equipment lined up to get things done.

Even though actual PRE application after planting may be low , many pres can also be used early-post in corn. Surestart/Tripleflex are popular herbicides that are added to glyphosate.  Glyphosate plus residual PRE herbicides can provide burndown and residual in one application. Surestart is labeled up to 11 inch corn. Other options to add with glyphosate are listed in the 2013 ND Weed Control Guide on pages 22-23 for corn and 30 and 31 for soybeans. 

Either way, a dry week is needed so ground sprayers can get though fields so timely POST applications can be made for effective weed control. 

Rich Zollinger

Extension Weed Specialist

Small Grain Disease Forecasting Site

Almost all NDAWN locations have had continuous days of weather favorable for tan spot infection in the past week. Similarly, IPM scout have reported relatively high incidence (Figure 1) but low severity (Figure 2) of the disease. Reports from Extension specialists across the state indicate that most spring wheat fields are in the 3 to 5 leaf stage, or early tillering - perfect growth stages for early season application of fungicide if needed, based on presence of tan spot symptoms and crop rotation history.

Winter wheat fields are generally in the jointing to seven-leaf stage of development.  Disease pressure, other than for tan spot, has been low in winter wheat, with no reports of stripe rust yet.  Winter wheat is at least several weeks away from concern about possible Fusarium head blight development.  The disease forecasting site currently indicates a high risk of Fusarium head blight in parts of the state, but these risk maps are based only on weather conditions.   We don’t have any crop yet in the flowering stage, the time of infection in wheat.

More information and photos about tan spot can be found in the publication Fungal Leaf Spot Diseases of Wheat.

 An electronic version of the 2013 Field Crop Fungicide Guide is available.

Marcia McMullen
Professor Emeritus, Cereal Crops

 Sam Markell

Extension Plant Pathologist, Broad-leaf Crops

Yield Potential Development During Early Growth Stages

Small Grains

Small grain planting is well behind the long term average and some of the planned acres will no doubt not be planted or will be planted to other crops that are more adapted to later planting dates. For earlier planted wheat and barley, conditions have been nearly ideal for the development of high yield potential. Relatively cool weather (like we have been having) during early development stages favors tillering, which means there is an increased potential for more spikes per unit area. Furthermore, the number of spikelets per spike is also favored by cool weather. There is a pretty strong negative relationship between the maximum daily temperature during the 4 through 5.5 leaf stages and the number of spikelets per spike. For much of the wheat we are now in or approaching this growth stage. Obviously, optimum yield potential development can only occur, even when temperatures are favorable, if there is adequate moisture and nutrients are not limiting.

 For fields that were not fertilized before planting or that lost most of their nitrogen during the recent rain events and are currently showing deficiency symptoms, additional N is needed soon if yield potential is to be enhanced. Streaming UAN prior to a rain event or with a urease inhibitor is recommended in order to ensure improved nitrogen use efficiency. N applications that are delayed to the boot stage may help enhance protein content, but in most years will not increase the yield of the crop.

Corn

Corn growth and development is proceeding at an agonizingly slow pace. In most fields, plants appear yellow, purple, and/or have bleached areas on the leaf (see attached photo). There is little that can be done at this stage to improve the appearance of the corn plant. The main reason that they appear yellow and sickly is not so much the lack of nutrients in the soil, but the plant’s inability to access them because of limited root development (associated with cool soils), and the lack of sufficient sunlight to enable optimum photosynthesis. Photosynthesis produces the energy and building blocks for chlorophyll development which give the corn plant its green color. Corn has a much longer growth cycle than small grains. Therefore, stress during a short period of the growing cycle (in this case temperature stress), is less likely to have a negative impact on yield development than for small grains. That being said, corn can be sensitive to competition from weeds during early growth stages, so early weed control can be more critical to corn yield development than early side dressing N. Currently, corn growth stages vary considerably in the state depending on the planting date. The mid-May planted fields are probably approaching the three leaf stage. During this stage, root and ear shoots develop. By the 5 leaf stage the number of rows of kernels is fixed. Row numbers, however, are usually determined by the genetics of the plant, rather than by the growing environment. It is not until the 12 to 14 leaf stage that the number of kernels per row are fixed. Therefore, the window for obtaining a yield response from side dressing if N is limiting is fairly large, particularly if some N was applied at or before planting. For practical reasons, however, side dressing is best done before the plant gets too tall (6 to 9 leaf stages). The corn plant has its greatest demand for N from the 9 leaf stage to early grain filling, so having the additional N in place by that period will ensure a high potential for its utilization. The risk of N loss is low during periods of high use, as well, so delaying splits until this period helps improve N fertilizer use efficiency.

Joel Ransom

Extension Agronomist for Cereal Crops

Buckwheat

As the 2013 planting season is nearly over, one crop which still can be considered for planting during the middle of June is buckwheat. However, when seeding buckwheat is delayed beyond mid-June, severe yield reductions may occur (See Figure 1).

Source: NDSU Extension publication A-687 (2013).

Buckwheat grows well in a cool, moist climate under a wide range of soil conditions and soil types. Stress factors like heat or drought can reduce yield, especially if they take place during the flowering period. It requires 10 to 12 weeks after seeding to reach maturity and buckwheat is sensitive to fall frost. Buckwheat has an indeterminate growth habit, and the top of the plant can still be flowering in the fall while seed at the base of the plant already may be mature. It is important to have a marketing plan before planting buckwheat. Producer selection of varieties often is dictated by the contracting company. These contracting companies may supply the seed or a seed source for purchase of high-quality seed. Only a limited number of varieties are available. Table 1 provides yield information generated by NDSU Research and Extension Centers. Under good growing conditions, buckwheat will germinate and shade the ground quickly. Cultural control of weeds is important because few herbicides are labeled for weed control in buckwheat. Buckwheat seed germinates best when the soil temperature is about 80 F, but the seed will germinate at any temperature between 45 F and 105 F. To produce good yields, adequate soil moisture must be available from July through August during the time the crop is flowering and producing seed. Buckwheat flowers require cross-pollination by bees or other insects and wind. Wind, heavy rainfall and excessive soil nitrogen can cause buckwheat to lodge, which makes it difficult to harvest and may result in yield loss.

For more details about buckwheat production see Extension publication A687.

Hans Kandel

Extension Agronomist Broadleaf Crops

Sugarbeet Root Maggot:  Emergence off to a Slow Pace

Sugarbeet root maggot (SBRM) fly activity is being monitored this year in a collaborative project between NDSU Entomology, American Crystal Sugar Company, the MinnDak Farmers Cooperative, and the Pembina County (ND) Extension office.  The trap line, consisting of 45 sites on both North Dakota and Minnesota sides of the Red River, runs from Cass and Clay counties to near the US/Canadian border.  In an average year, a significant amount of SBRM emergence usually occurs during the first week of June, and the 15-year average for peak fly activity is June 13. Thus far, fly activity has remained at very low levels since monitoring began on May 29.  Fields showing the earliest hints of activity are near Thompson, Reynolds, and St. Thomas, ND in the central and northern portions of the Red River Valley (RRV). Look at the Daily and cumulative counts for all monitoring sites. Just click on the “INSECT RESOURCES” link in the left-hand margin on the main Entomology Department page, and download the dated Adobe Acrobat (pdf) file.

Peak fly activity in beet fields occurs, on average, at about 650 Degree-Day (DD) units. All areas of the RRV are significantly below average in DD accumulations for this time of year.  The northern RRV is more behind average than most other areas within the Valley.  As such, it is difficult to precisely predict peak fly activity timing for that area. An application based on our model for monitoring DD accumulations and forecasting peak fly is located on the North Dakota Agricultural Weather Network (NDAWN). The site also includes a “help sheet” with information on how to use the model and how to optimize root maggot control efforts.  It is important to note that warm weather (around 80°F), and calm to low-wind conditions are most conducive to fly activity. Flies will remain relatively inactive in cool, rainy, or windy conditions.

An extended, preliminary forecast for anticipated DD accumulations and associated peak fly activity dates in the southern, central, and northern RRV is presented in Table 1.  Updated, more accurate forecasts will be provided during the next couple of weeks.

*Peak fly activity in current-year beets is most likely on the first calm to light-wind day to
  reach 80°F after 600 air DD are accumulated.

Growers in hotspots or high-risk areas for SBRM infestation should consider applying a postemergence insecticide, especially if an insecticidal seed treatment or a low to moderate rate of an at-plant soil insecticide was applied. Fields that received heavy downpours of rainfall after at-plant insecticides were applied also may need additional postemergence protection. Postemergence granules are usually effective if applied between 1 and 2 weeks before peak fly, but will also likely be beneficial if applied within a 1-2 days (before or after) peak.  Light to moderate rainfall after granular applications typically improves performance.  Postemergence liquid insecticide applications should be targeted for peak fly, but will provide good results if applied within 2-3 days before or after peak. IMPORTANT: If a chlorpyrifos-containing liquid spray (e.g., Lorsban 4E, Lorsban Advanced, or any generic version containing chlorpyrifos as its active ingredient) is applied, 10 days must pass before a repeat application can be made.

Table 2 provides basic guidelines for determining the most appropriate timing for postemergence insecticide applications to effectively manage the sugarbeet root maggot. 

For more guidance on postemergence control strategies, consult the “Insect Control” section of the 2013 Sugarbeet Production Guide. 

Mark Boetel

Research & Extension Entomologist