Crop & Pest Report - All
Small grain harvest has been completed in most of the region. Some areas farther north and west still have standing fields. Also, crops such as canola, lentil, and field pea have been harvested. Much of the flax is ready to swath or desiccate. Sunflower and corn remain green. Soybean fields have started to change color and drop leaves, depending on maturity and planting date.
Rainfall totals for the last week have ranged from 0.76” to 2.19” in Minot and Berthold, respectively. Crosby received 4.16” of rainfall in the last week. Many areas were very dry and the moisture was welcome, unless producers were attempting to harvest.
Accumulated corn GDD for the Minot area, based on a May 1 planting, are 1963, which is higher than the long-term average of 1844 for the same time period.
Area Extension agents are assisting with the national sunflower survey. So far, diseases such as rhizopus and sclerotinia head rot (Picture 1) have been identified. Also, insect damage from banded sunflower moth has been identified in all fields surveyed.
Area Extension Specialist/Cropping Systems
We’re not Iowa
I think many consultants and growers understand that just because we grow corn and soybeans we are not Iowa, but some appear to be confused. There are two important differences that I need to stress for those who think the capital of North Dakota is Des Moines, and both are related.
The soil fertility of Iowa is very different than that of North Dakota. From the early 1930’s until today the fields of North Dakota have lost the equivalent of 70 years of P application at today’s historic high P application rates. So the result is that soil P levels in North Dakota are generally low to medium in soil test. Iowa soils have had some erosion, but not nearly the loss that most of our have experienced. In addition, the higher historic rainfall in Iowa led to far less chance of crop failure compared to North Dakota, so fertilizer application strategies have always been more aggressive, with risk of lower yield due to inadequate fertilization greater than risk of operating capital loss due to drought. The result is that from the 1960’s the strategy in Iowa has been maintenance-buildup, today’s Iowa soil test P and K levels mostly in the high availability range.
There are two results from high soil tests- one is that precision nutrient management of P especially and often for K can be done with a less dense soil sampling grid, about one composite sample for 2 ½ acres. The second is that corn can be fertilized with enough P and K for both corn and soybean years, and soybeans do not have to be fertilized separately. (cont. next page)
We should not do either of these practices. Our field P and K levels, as well as residual nitrate, zinc, other, are related to natural fertility drivers, particularly topography, so zone testing works far better for us than it does in Iowa. Interestingly, in Iowa, a zone approach also worked well for K and pH, but no P. Soybean in North Dakota should be fertilized separately as a separate crop. Those few growers in ND that have high P levels can surely fertilize the crop before and soybean will be fine with the residual, but if a grower has low to medium P tests, than the soybean crop should be fertilized separately. Fall fertilization of soybeans with P is fine, but two falls previously is not fine.
I hope this helps people remember where we farm. We grow corn and soybean, but we have to consider our particular soils and environment in order to best achieve highest yields.
NDSU Extension Soil Specialist
IPM Survey – Wheat and Sunflower Disease Summary of 2015
There were several diseases detected in wheat and sunflower this year. Some diseases were found consistently throughout the state, while other diseases were more localized to a particular region. Regardless, the timely information obtained by the scouts is critical in updating growers and agricultural professionals throughout the state. Below is a summary of the disease data from the 2015 growing season for wheat and sunflowers.
Tan spot was the most common disease reported this year and was frequently observed when the wheat crop was tillering to flag leaf emergence (Figure 1). Severity was generally low across the state and the highest levels of tan spot pressure were observed in wheat on wheat ground. This can be expected as the tan spot pathogen overwinters on wheat residue. Stripe rust was observed sporadically during the early stages of crop development, but incidence levels increased as the crop approached flowering (Figure 2). The highest levels of stripe rust were found on the eastern half of the state (100% incidence in some fields), and the lowest levels were found in the western half of the state.
Fusarium head blight (scab) was documented in 37% of the wheat fields when the crop was in milk to early dough development (Figure 3). Although scab levels were generally low within fields, higher levels of scab were found in northcentral ND. Ergot was frequently detected in southwest ND with several fields having incidence levels above 10% (Figure 4).
Downy mildew of sunflower was observed sporadically across the state this year. The disease was found in 74 out of the 237 fields visited by the scouts (Figure 5). Incidence levels within a field varied from 1% to more than 50%.
Extension Plant Pathologist, Broad-leaf Crops
Extension Plant Pathology, Cereal Crops
Late Season Soybean Stem Diseases
We are seeing several late-season stem diseases show up in North Dakota; notably, brown stem rot and charcoal rot. As a result, I am reprinting this article from last year.
Now is a great time to examine your soybeans for diseases; particularly stem disease whose symptoms appear late in the season; brown stem rot, charcoal rot and sudden death syndrome (not yet found in North Dakota).
To maximize your ability to check for soybean diseases bring a knife, and if needed, a magnifying glass.
Brown Stem Rot (BSR)
BSR has been found in multiple locations in North Dakota. Symptoms and signs of begin to occur in mid-August.
Leaf symptoms may or may not occur, and are not particularly diagnostic. Leaf symptoms of BSR rot include a yellowing (chlorotic) and browning (necrotic) between the leaf veins (Figure 1).
Stem symptoms are much more important. To check plants for brown stem rot take a knife and slice the lower stem longitudinally. Brown stem rot will cause a browning of the center of the stem. Plants with BSR have ‘lead in a pencil look’; only the center of the stem is dark (Figure 2).
Charcoal rot is caused by a pathogen that can infect soybeans, corn, and sunflowers. Symptoms of the disease don’t generally appear until the reproductive stages of growth, and the disease is more common when the latter half of summer is dry.
Field-wide symptoms appear as patches of plants that matured quicker than healthy plants, resulting in prematurely dead soybeans. The top leaves may turn brown and premature leaf drop will occur.
Stem symptoms. The roots and lower stem of plants with charcoal rot may appear may appear gray. Scrape or shave off the outer tissue of the lower stem with a knife. Infected plants will be covered with black microsclerotia, giving the appearance of being dipped in charcoal dust (Figure 3). Microsclerotia can be observed with a magnifying glass, but they are very small.
Sudden Death Syndrome (SDS)
SDS has not yet been confirmed in North Dakota, but it has been found in Ottertail County, MN. SDS is not usually observed until early August, is typically associated with soybean cyst nematode, and when the two act together significant yield loss can occur.
Foliar symptoms of the SDS include chlorosis and necrosis between the leaf veins (Figure 4). Unlike BSR, these foliar symptoms consistently occur when plants are infected with SDS.
Stem symptoms. Take a knife and longitudinally slice open the lower stem AND root ball. With SDS, the center of the stem remains white, but a light brown discoloration may occur on the outer stem tissue.
Several excellent resources are available at
Extension Plant Pathologist, Broad-leaf Crops
Thinking about Sampling for SCN?
Soybean cyst nematode can cause 15-30% yield loss before any above ground symptoms appear and we know that it is spreading in North Dakota. Whether or not you take advantage of the North Dakota Soybean Council sampling program, we encourage soybean growers to sample for SCN. Below are some quick facts about SCN and SCN sampling.
Q: Where is SCN in North Dakota?
A: SCN has been confirmed in 19 counties and it is likely in other counties as well. The highest egg levels have been reported in Richland, Cass and Traill Counties.
Q: What’s the most common symptom of SCN?
A: Healthy looking soybeans. Typically, the first thing you will notice is a spot in the field that doesn’t yield well. After you have relatively high egg levels in a spot, you may start to see stunting or yellowing that appears in August.
Q: When is the best time to sample?
A: Just before or after harvest. The nematode population builds through the season, so sampling at the season ends maximizes your chances of detecting it.
Q: Where do I sample?
A: Anything that moves soil can move SCN. Consequently, we tend to find SCN in places where soil is deposited from other sources, such as the field entrance (soil moves on equipment), low spots (from overland flooding) or shelter belts / fences (from wind-blown soil). Additionally, consistently low yielding patches or yellow spots that appear in August may be a result of SCN. Lastly, SCN likes high pH; if you have a low yielding and yellowing high pH spot, it could be SCN.
Q: How do I sample?
A: Use a small soil probe or a shovel and aim for the roots. Take 10-20 small samples, mix up, and fill soil bag with the composite sample. Keep the bag relatively cool and get to the lab in the next few days.
Q: What do the results tell me?
A: Your results will be reported in eggs / per 100cc of soil. Essentially, this is how many eggs you have in about half a cup of soil. Positive egg counts mean you should begin managing SCN, negative egg counts mean you should be happy, and sample again when you put soybeans back in the ground. One point of note, very low numbers could be false positives (50 or 100). Resampling may be a good idea.
Extension Plant Pathologist, Broad-leaf Crops
2015 Soybean Cyst Nematode Sampling Program
The NDSU Extension Service and the North Dakota Soybean Council are working together to coordinate a SCN soil testing reimbursement program again in 2015.
The North Dakota Soybean Council (NDSC) has agreed to fund 2,000 SCN soil test bags on a first come first serve basis. Growers can pick up SCN soil test bags and an instruction sheet at NDSU County Extension offices or several SCN field days. Sample fields, fill out the submission sheet and send the bag into the lab. You will receive your data in the mail and the NDSC will cover the bill.
Just like in 2013 and 2014, NDSU will use egg levels and geospatial positions of samples to create a map of SCN in North Dakota (Figure 1). Importantly, NDSU does not have access to any personal information – just the egg level and geospatial data to generate a map.
Extension Plant Pathologist, Broad-leaf Crops
Protect Your Investments from Cercospora Leaf Spot
Although we have had a warm and relatively wet July and August, Cercospora leaf spot was not a major problem in most production areas early in the season up to mid-August. Since mid- to late-August, there were reports of some fields, especially in the southern Red River Valley and southern Minnesota, becoming infected. Warm and wet conditions in late August have also resulted in more leaf spots developing in fields in the northern Red River Valley. Fungicide treatments should continue until at least mid-September in fields with active leaf spot symptoms. Fungicides such as Headline, Proline, and Super Tin/Agri Tin with 7 day pre-harvest intervals can be used to help control the disease and fields sprayed (until around September 21 if conditions remain favorable for disease development) will still be ready for the full campaign which typically starts around October 1.
The forecast is for cool nights, which will not be favorable for new infection by Cercospora beticola. However, relatively warm days and the presence of moisture in the form of rain or dew will result in continued development of current infections. Late season leaf spot should be controlled or it will result in significant reduction in sugar concentration and increase processing costs to remove increased impurities. We need to keep the leaves of the sugarbeet crop as healthy as possible to maximize sunlight interception during September and increase sucrose concentration in the roots. Fungicides such as Proline and Headline with translaminar activities will help to control any current infections. Please follow pre-harvest restrictions for fungicide use in fields or areas of fields which will be harvested during pre-pile and in preparation for the full campaign. Consult your agriculturists for the best advice for controlling Cercospora leaf spot in your factory district and further information on pre-harvest interval.
Extension Sugarbeet Specialist
NDSU & U of MN
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