Crop & Pest Report - All
Soybean Physiological Maturity
The soybean plants are rapidly moving to maturity. The loss of green pod color is a reliable indicator of maturity. Stage R7 according to Fehr and Caviness occurs when one normal pod on the main stem has reached its mature color. Physiological maturity (growth stage R8) is reached when 95 percent of the pods have obtained the mature pod color which can be brown, golden, yellow, or gray depending on the variety. The seed moisture will be around 35 percent. At physiological maturity the seeds will not add anymore dry weight and just have to dry down for harvest. In the NDSU soybean variety trial information the date when a variety is physiological mature is provided, unless otherwise indicated in foot notes.
Individual pods can also be checked and when the beans are separating from the white membrane lining the pod, the beans will not gain anymore dry matter. Maturity can be determined on a plant or field basis but often there is variability in the maturity in the field due to differences in the growing conditions. In a drier field, the soybean bean plants in the lower areas tend to stay green a little longer. At 95 percent mature pod color on a plant it may take 4 to 6 days to have all pods reach the mature color. It will take about another 2 weeks (depending on temperature and humidity) to get down to harvestable moisture levels. Harvest delayed to less than 13 percent moisture may cause an increase in pre-harvest shatter losses, sickle-bar shatter loss during harvest, an increased number of split beans, as well as a loss of soybean weight to sell.
Extension Agronomist Broadleaf Crops
Weather Forecast: The Rest of 2015
For the final Crop and Pest Report of 2015, instead of analyzing the weather for the next week, I thought I would summarize how similar patterns, both atmospherically and oceanically did in the past (analogs) to what is occurring globally at this time. Both spring and autumn are the most difficult seaons to project because the atmosphere is transitioning away from the yearly extreme season of summer and/or winter. Weather patterns are ever changing, but atmospheric patterns are a bit more likely to not alter widely during the warm and cold seasons as they do in the interim seasons. This autumn like many others is expected to jump from from strong positive to negative temperatures anomalies and in between these periods being the timeframe for the higher probability of widespread precipitation to occur.
The temperature and precipitation this region experience in the next 6 months will likely be influenced to some degree by the El Nino currently occurring in the equatorial Pacific Ocean. Too often this one influence is over emphasized and as a reminder there are many variables even under a strong El Nino that will and do influence long term trends in the atmosphere. The projections for the next few months are what occurred during analog years where ocean patterns (Figure 1) as well as other atmospheric variables were close to what is presently occurring around the world.
Based on comparable years in the past, with some of those years double weighted based on stronger similarities to current global conditions (strong El Nino, positive Pacific Decadal Oscillation, etc.), the 91 days from September 1 through November 30 favor a near normal temperature finish with above average precipitation especially across northern North Dakota and northwestern Minnesota in particular. Of course, “normal” in our climate means the average of many extremes, therefore, a month by month analog summation is given in Figures 2 through 9.
In quick summation, the analogs used suggest:
September being close to or a bit below average for temperatures, wetter than average north. The Labor Day weekend rains which brought widespread heavier rain to northern North Dakota are some indication that the past analogs for the month are a good match for this year. Not suggested in the graphics, but the first widespread frost risk may occur around September 20-22. October, near average temperatures, but wet, especially the first half of the month. November leaning cooler than average east, touch warmer in the west, with near average precipitation. As a bonus month, the past analogs suggest a very mild December (by our standards) with near average precipitation. I will continue to give updates on my blog, www.ndsu.edu/ndawnblog for those that are interested.
As a reminder, these are based on analogs and other techniques and does not necessarily constitute a forecast but instead gives a perspective to what occurred in the past that may give hints to the weather patterns coming up this autumn.
Assistant State Climatologist/Meteorologist
(701-231-8209) Twitter: @darylritchison
Weather/Crop Phenology Maps
Professor of Climatological Practices
A majority of small grains have been harvested with a few spring wheat fields still standing. Fall burndown should be done soon before winter wheat to control the green bridge and remove the host plants for the wheat curl mite, vector of wheat streak mosaic virus.
This year NDAWN recorded 9.14 inches of rain in Dickinson from May 1st to September 9th. In May 1.73 inches were recorded with 3.67 in June, 2.26 in July, and 0.95 in August. The only rainfall recorded in Dickinson so far in September was on September 5th with 0.52 inches.
Corn should be chopped soon for silage as moisture decreases. According to J.W. Schroeder’s “Corn Silage Management” NDSU extension publication, “the highest energy values were at the 2/3 milk line. This is due to reduced digestibility of the stover portion of the plant with advancing maturity. As a rule of thumb, corn silage quality will be optimum if the grain fill is allowed to occur until the milk line is one-half to two-thirds of the way down the kernel. Harvesting at this stage usually results in near optimum moisture content for storage of the corn silage.” Read more in the Corn Silage Management extension publication (https://www.ag.ndsu.edu/pubs/ansci/dairy/as1253.pdf).
Area Extension Specialist/Cropping Systems
Based on NDAWN, during September 1-8, rainfall has ranged from less than 0.1 inch (Linton, Marion and Robinson) to 1.3 inches (Wishek). Small grain harvest is complete, canola and flax harvest is nearing completion, and dry bean harvest is underway (at least 25% complete). The majority of corn is in the dent (R5) stage with some early planted and early maturing hybrids nearing maturity (black layer/R6 stage). Soybean growth stages range from full seed development (R6) to nearing full seed maturity (R8) stages. Factors for rapid advancement to soybean to maturity include early planting, late-season moisture stress and high air temperatures, and disease including top dieback. The later has been reported by farmers and observed in CREC trials (see picture).
Area Extension Specialist/Cropping Systems
NDSU Carrington Research Extension Center
The region received 1-4 inches of rainfall over the weekend. This rain has slowed harvest, but progress is still on time. Small grains are mostly finished. Canola and dry bean harvest is in progress. Soybeans could be harvested in next week or two in early maturing variety fields.
Variety reports will available soon on the Langdon REC website.
Area Extension Specialist/Agronomy
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