Crop & Pest Report - All
The weather over the course of the next 7 days could probably be summed up with the the famous Glenn Fry song, “The Heat is On”, made famous by the “Beverly Hills Cop” movie starring Eddie Murphy. This push of much warmer air that began in many locations yesterday comes after a few days of very chilly weather that even brought some patchy frost to western North Dakota on Monday morning.
The transition to the cooler weather that occurred over this past weekend did bring with it the first measurable rainfall to some North Dakota Agricultural Weather Network (NDAWN) stations of the month, although, in some locations far too much of a good thing fell, with over 7 inches recorded just east of Grafton. There will be a slight risk of a thunderstorm today (Thursday), otherwise, besides an isolated thunderstorm that is always possible during any given day of the summer, no widespread rain is expected until the first half of next week.
Temperatures are expected to average 3° to 5° Celsius (5° to 8° F) above average over this forecast period. In places without moisture stress concerns this will clearly give a late season boost to area crops as the growing season slowly winds down. One possible limitation to the upcoming heat will be the possible impacts of the smoke streaming across the region from the forest fires in the northern Rocky Mountains that will probably be impacting the area for the next several days. The smoke on some occasions this summer has lowered temperatures by as much as 5° to 10°, although most days with a smoky sky had temperatures reduced closer to just a couple of degrees. With that one caveat, maximum temperatures should be in the 80s most of the next seven days with today (Thursday) being one exception for some locations in the Red River Valley. Central and western North Dakota in particular will have a few days with 90° plus potential during this stretch.
Beyond the next 7 days, current projections are for a brief period of cooler air near Labor Day weekend, but overall, the first one-half of September seems to be on track to record above average temperatures overall. In the final Crop and Pest Report to be released on September 10, I will give my personal thought on probable weather conditions for this autumn into early winter. The projected Growing Degree Days (GDDs), base 50°, 44° and 34° for the period August 27 through September 2, 2015 are presented in Figure 2 and the number of hours when the relative humidity is expected to be at or above 85% can be found in Figure 3.
Assistant State Climatologist/Meteorologist
(701-231-8209) Twitter: @darylritchison
Weather/Crop Phenology Maps
Professor of Climatological Practices
Row Crop Tour at Carrington Rec on Sept. 3
This year’s event will have two parts: a one-hour tour beginning at 3:15 p.m. and the main tour at 4:30.
The 3:15 p.m. tour will provide a review of current research and recommendations for managing white mold (Sclerotinia) in dry beans, soybeans, and sunflowers.
Topics for the 3:15 p.m. tour will include:
- Balancing soybean plant populations and row spacing for white mold management and soybean yield
- Irrigation management in fields where white mold is a constraint
- Optimizing fungicide application timing
- Prospects for improving fungicide coverage and white mold disease control through the use of drop nozzles
Topics for the 4:30 tour include:
- Corn plant populations and nutrient management
- Dry bean plant establishment and nutrient management
- Soybean variety selection and planting dates
- An overview of disease management in dry beans and soybeans, with an emphasis on white mold and soybean cyst nematode
Small grain harvest is nearing completion for the year. Spring wheat harvest is in progress and should be nearing completion by the end of the week. Winter wheat and barley fields are harvested along with most canola fields. Sunflower fields have reached the R6 stage with ray flowers wilting.
There was some rainfall over the weekend with NDAWN reporting 0.44 inches in Dickinson on August 22nd. Some areas in the region have received more than 1.5 inches over the past two weeks. This rainfall has helped the few soybean fields in the region and has greened up some corn fields.
Be sure to check out the southwest ND crops blog for county reports and crop related posts: https://ndextensionswcrops.wordpress.com/ and follow me on twitter @drecagronomy or on Instagram at drec_agronomy for updates on information in the Dickinson area and agriculture.
Area Extension Specialist/Cropping Systems
Based on NDAWN, during August 12-25, rainfall has ranged from 0.3 inch (Robinson) to 1.5 inches (Harvey). The past two weeks have generally been favorable for small grain harvest, but stressed row crops, especially the high temperatures during Aug 11-15. Corn that emerged on May 15 used about 0.15-0.18 inches of moisture per day, during the past two weeks.
Spring wheat harvest is nearing completion. Farmer and elevator reports indicate variable but generally good seed yield and quality. Carrington REC dryland HRS wheat variety trials at Carrington, Dazey, and Wishek have yields averaging 57.4, 69.6 and 51.9 bu/acre, respectively (data available at www.ag.ndsu.edu/varietytrials/carrington-rec/2015-trial-results).
The majority of corn is in the dough to dent (R4-5) stages and soybean in the seed development (R5-6) stages. We need roughly another month of growing season for corn and sunflower, and less than a month for soybean. Dry bean and flax are nearing or at maturity.
Area Extension Specialist/Cropping Systems
NDSU Carrington Research Extension Center
Small grain harvest progress is completed to nearing completion along the northern counties. Rainfall finally came to our area. Most areas received between 0.75" to 1.25", but it was too late for soybeans who had been struggling in the near month without rain. The Grafton area was an outlier with over 7 inches of rain over two days.
Dry edible beans are nearing harvest. Most of the canola is swathed. Harvest progress has been quick with lack of rainfall. I've been working on end-of-the-season canola and sunflower surveys. Initial observations are that I am finding more white mold infection with these crops in our region as compared to last year, but levels are still low. Blackleg can found in the canola but the incidence is less than the 2014 survey results (at 50% of north-east canola fields surveyed).
Area Extension Specialist/Agronomy
Consider Pros, Cons of Alternative Grain Storage Methods
With some of last year's grain crop still in storage and a bumper crop expected this year, the demand for grain storage is high.
"Grain can be stored in many types of facilities," North Dakota State University Extension Service agricultural engineer Ken Hellevang says. "But all storage options should keep the grain dry and provide adequate aeration to control grain temperature."
Grain must be dry and cool (near the average outdoor temperature) when placed in alternative storage facilities because providing adequate, uniform airflow to dry grain or cool grain coming from a dryer is not feasible, according to Hellevang.
Grain pushing against the walls can damage buildings not built for grain storage. The walls must be anchored securely, and their structural members must be strong enough to transfer the force to the building poles or support structure without breaking or bending excessively.
Typically, you'll need additional poles and a grain wall to support the grain force in a pole building. Hellevang advises hiring an engineer to complete a structural design or analysis, or contacting the building company for guidance to prevent a structural failure.
Before placing grain in a building previously used for grain storage, look for anything out of alignment, such as a bowing wall. Also check the roofline.
Bowing or bending indicates the load on the building exceeds the load for which it was designed and built.
Examine connections for separation or movement. A connector failure can lead to a building failure. You may need to reinforce the connection by adding a gusset or splice.
Storing in Bags
Storing grain in poly bags is a good option, but it does not prevent insect infestations or mold growth in damp grain, Hellevang says. Grain should be placed in the bag at recommended storage moisture contents based on grain and outdoor temperatures. Heating will occur if the grain exceeds a safe storage moisture content; grain in a bag cannot be cooled with aeration. The average temperature of dry grain will follow the average outdoor temperature.
Select an elevated, well-drained site for the storage bags, and run the bags north and south so solar heating is similar on both sides. Sunshine on just one side heats that side, which can lead to moisture accumulation in the grain on the cool side. Wildlife can puncture the bags, creating an entrance for moisture and releasing the grain smell, which attracts more wildlife. Monitor the grain temperature at several places in the bags.
Never enter a grain bag because it is a suffocation hazard. If unloading the bag with a pneumatic grain conveyor, the suction can "shrink wrap" a person so he or she cannot move and will limit space for breathing.
Grain frequently is stored short term in outdoor piles. However, precipitation is a severe problem in uncovered grain. A 1-inch rain will increase the moisture content of a 1-foot layer of corn by 9 percentage points. This typically leads to the loss of at least 2 feet of grain on the pile surface. A 1-foot loss on the surface of a 25-foot-high cone-shaped pile is about 13 percent of the grain.
Hellevang strongly recommends using a cover to prevent water infiltration. Aeration and wind blowing on the pile will not dry wet grain adequately to prevent spoilage.
Prepare the ground surface where grain will be piled using lime, fly ash, cement or asphalt to prevent soil moisture from reaching the grain. The storage floor should be higher than the surrounding ground to minimize moisture transfer from the soil into the grain. Make sure the ground surface is crowned so moisture that does get into the pile drains out rather than creating a wet pocket that leads to grain deterioration. Also examine the entire area to assure that flooding will not occur during major rain events.
A combination of restraining straps and suction from the aeration system holds grain covers in place. However, you must provide inlets for adequate airflow through the grain to control its temperature. Place perforated ducts on the grain under the cover to provide a controlled air intake for the aeration system and airflow near the cover to minimize condensation problems.
Properly sized and spaced ducts should be placed on the ground under the pile to pull air through the grain. If you use a perforated grain wall, the aeration ducts near the wall should not be perforated or the airflow through the grain will be limited to near the wall.
Cooling Stored Grain
Cool grain with aeration to reduce the insect infestation potential. Insect reproduction is reduced at temperatures below about 60 F, insects are dormant below about 50 F, and insects can be killed by extended exposure to temperatures below about 30 F.
Cooling grain as outdoor temperatures cool reduces moisture migration and the condensation potential near the top of the grain pile. Grain moisture content and temperature affect the rate of mold growth and grain deterioration, with the allowable storage time approximately doubling with each 10-degree reduction in grain temperature.
The grain should be cooled whenever the average outdoor temperature is 10 to 15 degrees cooler than the grain. It should be cooled to near or below 30 degrees for winter storage, depending on available air temperature.
Aeration ducts need to have perforations sized and spaced correctly for air to enter and exit the ducts uniformly and obtain the desired airflow through the grain. The maximum spacing for aeration ducts is equal to the grain depth to achieve acceptable airflow uniformity.
For more information, do an online search for NDSU grain drying and storage.
This news release may also be found on the Web at: http://www.ag.ndsu.edu/news/
Review Your Weeds Management Strategy Before and at Harvest
Wheat has been harvested and sugarbeet farmers are participating in the preharvest campaign. And corn and soybean harvest will be right around the corner. Before you lose the opportunity, I suggest walking your fields to observe weed escapes. Identify and document weeds and make hand-drawn maps of areas of the field that are particularly weed infested. You may find that the map of weed escapes aligns with an early-season or past-season event. For example, a farmer in West Central Minnesota indicated the map of waterhemp escapes was closely aligned to the portion of the field that had standing water during the 2014 season.
Lists of weeds and spatial maps of fields are extremely valuable field records. Following harvest, you will have time to review these data, consider future crop sequences and review your weeds management strategy to determine if you are on-track or if adjustments need to be made to the strategy. I frequently indicate in my presentations that there is nothing wrong with reviewing and adjusting the strategy since ‘data’ will either verify that what has been selected is working or will indicate that slight adjustments are still needed.
Review the herbicides used in the field in 2015 and determine if the weeds management approach represented herbicides with multiple sites of action. NDSU extension weeds personnel promote the use of herbicides from thee unique herbicide family sites of action during a field season. Contrast the herbicides and site of action with herbicides to be used in crops in the sequence in 2016 and beyond. And of course, attend meetings to learn about new herbicides and weeds management systems and evaluate how they can be potentially integrated into the weeds management strategy.
Finally, continue to manage field perimeters, drown out area, and non-crop areas, since weeds that may have survived a partial herbicide dose on field borders will produce seed and can be a repository for the introduction of resistance weeds into a field.
Extension Sugarbeet Agronomist
NDSU & U of MN
2015 Soybean Iron-Deficiency Chlorosis Ratings Available
Iron-deficiency chlorosis (IDC) in soybean was a major problem early during the 2015 growing season in eastern North Dakota and northwestern Minnesota. IDC symptoms are interveinal yellowing of the leaves with the leaf veins staying a dark green. Chlorosis is caused because the plant cannot take up enough iron (Fe), even if there is sufficient Fe in the soil. The symptoms might be present during the two- to seven-trifoliolate-leaf stages. Plants tend to recover and will turn green at the end of the vegetative and reproductive growth stages. However, IDC during the early vegetative stages can substantially reduce yield potential. Variability in the tolerance level to IDC exists among soybean varieties. On soybean ground with high pH soils with known chlorosis problems, the best way to manage IDC is to select a tolerant variety of suitable maturity that is high yielding. For soybean varieties tested by NDSU in 2015, the Roundup Ready IDC and Conventional / Liberty Link IDC scores are now available at the NDSU variety trials result web site at: https://www.ag.ndsu.edu/varietytrials/soybean.
Data from 2015 is based on field studies which were conducted at three locations with known IDC problems. The resistance to IDC was measured for 257 Roundup Ready soybean varieties and 63 non-Roundup Ready, including Liberty Link varieties. Visual ratings were made on a 1 to 5 scale, with 1 representing no chlorosis and 5 the most severe chlorosis. Ratings were taken at the 2- to 3- and 5- to 6-trifoliolate stages.
Significant differences in IDC scores were observed. Variety selection is the number one management strategy to reduce IDC expression in the field. Farmers are encouraged to pick the most tolerant, high yielding variety for their most severe IDC fields.
Soybean Aphid Decline
Soybean aphids are decreasing or stagnant in most soybean fields. You can see this in the final soybean aphid map (below) from the IPM scouting program. Few fields are above the E.T. of an average of 250 aphids/plant. According to the USDA NASS, 98% of soybeans are setting pods (R6) and 19% are dropping leaves in North Dakota (USDA NASS News Release – August 24, 2015). It’s that time of year when reduced photoperiod and temperatures, and maturing soybeans triggers large numbers of winged soybean aphids to be produced. The reproduction of soybean aphid also changes to sexual reproduction where both winged female aphids and winged male aphids (for the first time this season) are produced on soybean. These winged aphids leave soybean fields and fly to their overwintering host, buckthorn, for mating. Mated females will deposit eggs near the base of buckthorn buds. The eggs overwinter and can survive very cold temperatures (-29 F). Winged soybean aphids are being observed in buckthorn in North Dakota and SW Minnesota (Source: B. Potter, SWROC).
Although most fields are below the economic threshold now (average of 250 aphids/plant, 80% incidence, and increasing populations), it is prudent to continue scouting any late-planted soybean fields, which could be at increased risk for soybean aphid colonization. Remember, populations must be increasing to justify any late season insecticide application. Please read, follow and understand the soybean insecticide labels which indicate that pre-harvest intervals are 21 days or longer.