Crop & Pest Report - All
Weather/Crop Phenology Maps
Professor of Climatological Practices
The Autumn Weather Outlook
Traditionally in this space I attempt to give an accurate weather outlook with potential impacts in agriculture for the next 7 days. As this will be the last Crop and Pest Report for 2016, instead, I will give some of my current thoughts on the weather pattern through the end of October. Earlier this week (September 13/14) frost (36° or lower) was recorded over a wide portion of North Dakota with several locations even dropping to 32° or lower. If you are curious, 36° is considered a frost because temperatures are generally recorded at five feet above the surface and often temperatures are a few degrees cooler near the surface, meaning if the 5 foot temperature is 36° there will likely be frost nearer to the ground. If your area suffered no crop damage from these events, the next threat of frost looks to be holding off until the end of next week (September 23/24).
The period from September 15 through October 31 has been quite dry the past two harvest seasons, with the exception of far northern North Dakota in 2015 (Figure 1). That overall drynesss in combination with above average temperature lead to some excellent harvest weather. A commonly asked question is will 2016 make it three in a row? Although I do not expect these next six weeks to be as warm as either 2014 or 2015 (Figure 2), I do expect above average temperatures during this period in 2016 as well.
The one element of the weather that may be more noticeably different this year is rainfall. Both 2014 and 2015 for most locations were very dry, near 50% of less of normal rainfall during this period. Even if Harvest 2016 were to record average rainfall it would seem wet in comparison to the past couple of years and would cause harvest delays. Plus, considering the big rain event earlier this month hit the same wet areas again with heavy rain and overall the pattern has not shifted that much in the past few months, eastern North Dakota and northwestern Minnesota would favor at least average if not above normal rainfall through October. Plus, most of my analog years (past years with similar conditions) had between 100-130% of normal precipitation. One storm often is the difference this time of year between too wet or good harvest weather, plus as the old saying goes “timing is everything”, and of course the timing of rain is always important this time of year and those two factors are difficult to forecast long term.
(701-231-8209) Twitter: @darylritchison
A majority of corn in the region has dented and a large amount has reached black layer. Some are working on silage and a few are still cutting hay. We received some frost on Monday night into Tuesday morning with NDAWN showing a low of 34 September 13th. The frost shouldn’t have caused any issues. A majority of crops were far enough along with the back of sunflower heads already yellow to brown in color. Winter wheat in the region should be going in soon. It can’t be stressed enough to make sure to kill the green bridge to proactively avoid wheat streak mosaic virus issues next year.
Weather this growing season was warm and dryer than normal, however some would say that this season was more “normal” than the past couple of years. The lack of moisture allowed for minimal disease pressure, however there were areas that suffered from drought stress.
Area Extension Specialist/Cropping Systems
NDSU Dickinson Research Extension Center
Based on NDAWN, the region’s rainfall during September 1-13 ranged from 0.4 inches (Brampton) to 4.6 inches (Jamestown). The abundant rainfall received during the last half of summer has produced saturated areas and generally soft soil conditions in fields – hampering harvest besides having wet crops. Hail was still occurring last week (e.g. LaMoure County). On September 14, NDAWN air temperatures reached below freezing (31 degrees F) at Brampton and Harvey.
Dry bean and flax harvest is in progress, with dry bean acres about half completed. Soybean growth stages range from R7-8 (1 pod to 95% pods/plant with mature color) and would expect harvest to begin next week throughout the region (with cooperative weather and soil conditions). Corn will reach maturity the last half of September and sunflower are nearing or at maturity (see picture).
Goss’s wilt (in corn) appears more common in the region this season. As an example, a field in Foster County was infected early with this bacterial disease, resulting in heavy damage (see picture) and currently the plants are completely dried down. Late-season rust can be found in sunflower at significant but not economic (due to late crop stage) severity levels.
Area Extension Specialist/Cropping Systems
NDSU Carrington Research Extension Center
Harvest is progressing in dry beans and canola. Soybeans are turning colors and loosing leaves. Heavy dew mornings and cold fronts with rainfall have slowed harvest. On Wednesday morning, we had the first look at frost in low laying or open areas. Rolla was the region’s low at 32 degrees. At Langdon, the frost recorded at 34 degrees but it was not a hard freeze.
Variety trial information is being published at the Langdon REC website. So far, winter wheat and winter rye are available. There has been a curiosity about utilizing winter rye as a cover crop in the region. Last winter was warm, so all varieties survived.
On September 28th at the Langdon REC, there is a Soil Health Tour at 8:30 am. After a lunch, Tillage Expo will occur with demonstrations of reduced tillage equipment. CEU’s are available.
Area Extension Specialist/Agronomy
NDSU Langdon Research Extension Center
The first days of September and Labor Day weekend brought rain to most of the Northwest counties. Crosby had about 0.5” on Friday and another almost 0.7” on Wednesday the 7th. Williston got about 0.25” on Labor Day and about 0.4” the following day. Watford City received a total of 0.75” between Sunday and Labor Day and another almost 0.5” on Wednesday the 7th. Almost all small grains in the region had been harvested prior to the rain but this moisture has delayed the harvest of later-maturing crops like soybean, corn, and sunflower. Similarly, most flax and canola were harvested before the rain, but for those fields still standing, it may be a few days before the ground dries out enough to allow combines back in the field.
Cooler temperatures came in to the region over the weekend of the 10th and gave some areas their first frost of the season overnight of the 12th. Cooler temperatures and the rain will likely push back soybean harvest, but warmer temperatures are expected to return over the weekend and into the first half of next week.
For growers considering planting winter wheat, I strongly advise them to “break the green bridge” and control volunteer wheat and grassy weeds prior to planting. Wheat Streak Mosaic Virus (WSMV) was confirmed in many fields in Williams, Mountrail, and McKenzie Counties this summer and caused substantial yield loss and crop failure in some cases. WSMV is carried by the wheat curl mite which cannot be controlled with insecticides. The wheat curl mite needs green, living plant tissue to survive and moves from small grains to grassy weeds as crops dry down. To prevent the mites from entering newly-emerged winter wheat, ensure that all volunteer wheat plants and grassy weed hosts (cheat, Japanese brome, jointed goatgrass) are dead for at least two weeks prior to planting winter wheat. Also avoid planting winter wheat next to late-maturing, still-green corn as corn can also host the mites. If your field or neighboring fields had WSMV this year, consider rotating to a broadleaf crop such as canola, flax, or soybean that is not susceptible to WSMV and gives you multiple grass weed control options.
Event Alert: The Divide County Crop Improvement Association and NDSU Extension will be hosting a 2016 Crops Meeting in the Crosby Community Center Wednesday, September 21 from 5:30 to 8:00 pm. Come meet Brandon Biwer, the new Divide County ag agent and hear presentations on scab in wheat, small-grain variety trial results, and herbicide options for crop safety and weed control in pulses. This meeting is free to attend and a hamburger supper will be served starting at 5:30.
Area Extension Specialist/Cropping Systems
NDSU Williston Research Extension Center
Small grain harvest has wrapped up for most of the North Central region. Corn, soybean, and sunflower fields are looking good as they continue to dry out. Rainfall amounts have varied across the region over the past week. Here are the weekly totals from select NDAWN stations across North Central North Dakota: Minot: 0.63”; Berthold: 0.65”; Bottineau: 0.25”; Garrison: 1.25”; Harvey: 0.40”; Mohall: 0.33”; and Rugby: 0.25”.
Area Extension Specialist/Crop Protection
NDSU North Central Research Extension Center
Pea and Lentil Disease Survey 2016 Season Summary
A new scouting program for peas and lentils in northwest North Dakota was successful at detecting several diseases this summer and determining their distribution across the region. Support was provided by the Northern Pulse Growers Association for a full time crop scout (Adam Carlson, NDSU) to survey fields in Williams, Divide, Mountrail, McKenzie and Burke Counties from late May to mid-August. Below is a summary of what was observed in pea and lentil fields this season.
Lentils: Ascochyta Blight and Anthracnose were found in most fields scouted, however severity levels remained low over the course of the season (Fig 1). In North Dakota, Stemphylium Blight of lentils typically develops in the last third of the season from late bloom through pod fill. During this time period, low levels of Stemphylium were observed in most fields scouted. White mold was assessed at crop maturity, and was found sporadically at low to moderate levels (Fig 2). Fields were also assessed for Botrytis Gray Mold, however this disease was only identified in one field this season.
Pea: Ascochyta Blight was found in most fields scouted but severity levels were low, limited to only a few scattered lesions per leaf. Bacterial Blight increased in incidence over the course of June and was found in all fields scouted in mid-July, most likely due to frequent precipitation, but again severity remained low (Fig 3). Powdery Mildew was identified in central and north central McKenzie County (Fig 4), and was severe at the WREC pea variety trial planted near Arnegard. White Mold was found in central Williams County and north central Divide County (Fig 4).
Samples were collected from pea and lentil fields for analysis of root rot over the course of the entire growing season. Root samples were assessed for root rot severity and the presence of the root rot pathogens Rhizoctonia solani, Pythium sp., Fusarium sp. and Aphanomyces euteiches (Dr. Julie Pasche and Dr. Kim Zitnick-Anderson, NDSU).
Lentils: Root rot symptoms were mild in May, but severe in some fields by early to mid-June (Fig 5). Fusarium sp. and Pythium sp. were isolated from symptomatic roots. One field in southern Williams County was also positive for Aphanomyces. Rhizoctonia solani was not present in any samples. 170 root rot samples were analyzed in total.
Peas: Over 50 root rot samples were taken from pea fields and root rot was either absent or mild in most samples tested. However, five fields contained moderate to severe root rot late in the season at the R5-R6 stage. Pythium sp. and Fusarium sp. were most commonly isolated from symptomatic roots. No Aphanomyces or Rhizoctonia solani were isolated from any sample.
Plant Pathologist, NDSU Williston Research Extension Center
Assistant Professor, NDSU
Department of Plant Pathology
Post-Doctoral Research Associate, NDSU Department of Plant Pathology
Corn Disease Survey Update
The NDSU corn pest survey scout has visited 21 fields over the past month. The most common disease detected has been common corn rust, followed by Goss’ leaf blight, then northern corn leaf blight. Common corn rust is considered a superficial disease in ND as most hybrids have tolerance that offset any potential yield loss. Goss’ leaf blight was identified in four fields, but in low incidence within each field. Yield loss attributed to Goss’ leaf blight can be substantial if severe disease development occurs prior to tasseling (Figure 2). Management of Goss’ leaf blight is best accomplished using crop rotation (avoid corn on corn), tillage (where appropriate) and tolerant hybrids (often most effective management tool).
Extension Plant Pathology, Cereal Crops
Late-Season Sunflower Stem Diseases
Over the last several weeks, several stem diseases of sunflower have showed up prominently in some areas of the state. There is nothing that can be done to manage these diseases now, but it is important to accurately identify the diseases in order to manage them in the future (if possible and if needed). Below is diagnostic information and images of three key stem diseases that are appearing. More information about these and other diseases are available in the original publication: Sunflower Disease Diagnostic Series - PP 1727.
Phoma Black Stem
Importance: Very common stem disease but rarely economically important.
Key Symptoms: 1-2 inch coal-black lesion centered on a petiole, usually superficial. Many lesions may occur on the same stem
Phomopsis Stem Canker
Importance: Disease appears to be increasing in the region. Lesions may degrade the pith, resulting in yield loss and lodging. High disease pressure early in the season can devastate a crop.
Key Symptoms: Large (often greater than 6 inches) brown lesion centered on a petiole. Stem becomes hollow underneath the lesion, and is easily punctured with thumb pressure. Lodging may occur.
Sclerotinia Mid-Stem Rot
Importance: Common disease that causes can cause yield loss and lodging, high disease pressure will result in yield loss. Caused by the same pathogen that causes head rot in sunflower and white mold in other broadleaf crops (for example, soybean, dry bean, canola, pulse crops, etc.).
Key symptoms: Large (often greater than 6 inches) tan to cream colored stem lesion centered on a petiole. White fungal growth and black fungal bodies may appear on or in stem. Stem frequently shreds and lodges.
Extension Plant Pathologist, Broad-leaf Crops