Crop & Pest Report - All
Although some of the warmest temperatures of the summer have been recorded in the past couple of days and today, and for some locations even Friday having 90° plus potential, the general trend this coming week will be for cooler rather than warmer temperatures. This transition to cooler temperatures will have two noticeable impacts. The first will be a high likeihood of thunderstorms, probably widespread over much of North Dakota on Friday into Saturday. After that system exits, cooler and drier air will move into the northern plains. That will bring the second notable feature of the next seven days; fewer hours with high relative humidity (Figure 1). It appears that most locations will record between 10-20 fewer hours where relative humidity values are above 85% during this period than were recorded during the past week.
Even with a transition to cooler, but far from cool, temperatures, the number of growing degrees days (GDDs) are expected to be greater than in the past week (Figure 2). Although it has been quite warm these past couple of days, it was cool of course for several days before this brief “heat wave” started. Therefore, expected GDDs this week will be slightly higher than the previous seven days, plus, once we get into this weekend and into next week, the temperatures will be at a more optimal level for good plant development without worries of heat stress. It appears that minimums will mostly be around 60° or in the 60s with maximums in the low to middle 80s.
Beyond this seven day period, current indications are that temperatures near normal, or even slightly below normal, will continue through the first part of August. This period of “normal” temperatures looks to be occurring not only in our region, but throughout much of the north central part of the lower 48 states, including Iowa, Illinois and Indiana. Higher heat will likely return in August, but the next 10 days does not show any signs of high heat returning once we get through this weekend.
(701-231-8209) Twitter: @darylritchison
Harvest has begun in pea and winter wheat fields. Some are still working on their first cutting of hay, it is not only hay ground that is being baled as some hail damaged and droughted grain fields are being baled. Some rain fell in the last week. NDAWN recorded 0.20 inch in Dickinson between July 12th and July 19th. High temperatures are forecasted and with the heat, be sure to be well hydrated and stay safe.
On July 13th we had our agronomy field day in Dickinson. Topics covered were tile drainage, seeding rates, weed control, disease management, and marketing.
Area Extension Specialist/Cropping Systems
NDSU Dickinson Research Extension Center
Based on NDAWN, the region’s rainfall during July 12-18 ranged from none (several locations) to 0.5 inch (Oakes). Daily water use by corn is ranging from 0.25-0.33 inch. Corn planted April 29 has accumulated 1040 to 1340 growing degree day units through July 18.
Harvest is beginning for winter cereals, barley and field pea. Spring wheat is physiological mature. Corn is in the VT (tassel) to silk (R1) stages. Soybean is in the full flower to initial pod-development (R2-3 stages). Dry bean are flowering and sunflower are nearing this stage (R5). Harvest continues of grass hay and second cutting of alfalfa. Bacterial disease is appearing in dry bean with recent heavy rain, wind and spotty hail.
Area Extension Specialist/Cropping Systems
NDSU Carrington Research Extension Center
Hit and miss rain chances have continued throughout parts of North Central North Dakota over the previous week: Minot: 1.04”, Rugby: 1.27”, Berthold: 1.08”, Bottineau 1.08”, and Mohall: 0.30” (July 11th – July 19th).
As winter wheat harvest approaches, consider your plan in Wheat Streak Mosaic Virus (WSMV) management. Destroy volunteer small grains, grass weeds, and other WSMV hosts at least two weeks prior to seeding winter wheat. Always avoid wheat-on-wheat rotation to help break the green bridge to help limit the movement of wheat curl mite (Aceria tosichella Keifer).
Pea Aphid “hot spots” have been found in Ward County. Continue scouting protocols to monitor thresholds. If economic thresholds are met, consider the stage of your crop to determine if chemical treatment is warranted. Refer to the NDSU North Dakota Field Crop Insect Management Guide (E-1143) for threshold and treatment recommendations or reach out to me at the NCREC to discuss field observations and possible plans of action.
Yesterday (July 20), growers were welcomed to the North Central Research Extension Center near Minot to attend the 2016 Field Day focusing on “Improving Efficiencies of Spring Wheat Production.” Attendees were updated on several topics including, but not limited to, pesticides, cover crops and saline soils, and a pest clinic. Furthermore, field days will take place in Renville County on July 21st and Pierce County on July 22nd. We hope you can join us!
Area Extension Specialist/Crop Protection
NDSU North Central Research Extension Center
New Pollinator Bee Gardening Extension Fact Sheet Available
H1811 Bee-utiful Landscapes: Building a Pollinator Garden is now available from the NDSU Distribution Center or you can download the publication as a pdf from their website. Both native bees and European honey bees are in trouble in the United States. Homeowners can have a major impact on pollinators by planting a pollinator garden and providing suitable habitat. This publication will help you identify major pollinators, choose plants that will provide a continuous source of nectar and pollen, and safely use pesticides.
Herbicides Safe to Cover Crops
Question: Had a customer inform me this morning he is setting up a Valmar system on his side dress fertilizer rig so he can broadcast his cover crop mix while side dress application in corn. Is there a cheat sheet yet for what I can recommend for herbicides when considering there will be seeding of cover crop approximately 30 days later?
Answer (including comments from Dr. Abbey Wick): This is where weed science is lacking in information. We have started to build a guide to herbicide residue and fall cover crop establishment on page 105 in the NDSU weed guide, and we will build on it as we get more information. Also, a guide from the University of Wisconsin is a good place to start. If you click on the link on that webpage it should bring up the circular.
Lee Briese (ND consultant) has produced an excellent resource of genus and species of cover crops so that it can be compared to the different crops in the weed guide to estimate rotation intervals.
Greg LaPlante (ND Consultant) identified another resource from the University of MN:
Extension Weed Specialist
Protect Bees from Pesticide Poisoning
If you need to spray flowering sunflowers or other flowering field crops, please remember to PROTECT BEES by notifying bee keepers before an insecticide application (at least 1 day notice if possible), using least toxic insecticide products to bees, and spraying in late evening.
To find bee keepers, see the North Dakota Bee Map on the North Dakota Department of Agriculture website and zoom in on the area of interest to find names and contact information of bee keepers. An NDSU YouTube video is available on Protect Bees from Pesticide Poisoning. Always read, follow and understand the label in regards to pollinator protection.
Research Specialist & IPM Coordinator, Extension Entomology
Weather/Crop Phenology Maps
Professor of Climatological Practices
Wheat Foliar Disease Update – IPM Survey
The IPM scouts are reporting increasing levels of foliar diseases in the wheat crop. Although most wheat fields are beyond the window for effective foliar disease management, producers are encouraged to scout for foliar diseases in late-seeded wheat fields. Tan spot incidence and severity have both been higher in areas with no-till production systems (Figure 1). Bacterial leaf streak incidence has been higher in areas that have received damaging winds and hail (Figure 2). For rust diseases, leaf rust has been reported in a few fields and stripe rust incidence is highest in the southcentral and southeastern portions of the state (Figure 3).
Extension Plant Pathology, Cereal Crops
Conditions are Favorable for Sunflower and Dry Edible Bean Rusts
Heavy and/or frequent dews and warm temperatures provide a favorable environment for both sunflower rust and for dry edible bean rust. We have recently received (and/or confirmed) reports of rust on sunflowers and dry beans. Given the environmental conditions we are experiencing, I expect to see more rust appear soon. The two rust diseases are caused by two different pathogens (which are specific to their crop), but the way they look, infect, spread and are managed are similar. Below is a review of the rusts.
Signs and Symptoms. Rust is usually first observed as dusty cinnamon-brown pustules on leaf tissue (Figure 1). The spores (urediniospores) can be rubbed off the tissue easily, leaving a dusty brown streak (Figure 2). Pustules on the upper sides of the leaves will sometimes have a small yellow halo around them (Figure 3). Commonly, rust is easier to find on the undersides of the leaves because they have more rust pustules (Figure 4).
When a rust epidemic begins, symptoms usually are only found on the lower leaves and in ‘hot spots’, which are clusters of plants with relatively severe damage (Figure 5). Hot spots are often small and may be a few feet to several yards in diameter. Hot spots can occur anywhere in a field, but are more common near shelter belts (where plants have dew longer), near last year’s crop residue (the sunflower and dry edible bean rust pathogens overwinter in North Dakota), or near wild sunflowers (sunflower rust only).
Spread. Rust spores are easily and quickly dispersed by wind. Once rust is established and reaches the upper canopy, it will spread very quickly through a field and to nearby fields. If conditions remain favorable for infection, a rust spore can be dispersed, cause an infection and produce a new pustule with spores in as little as 7-10 days. A ‘hot spot’ can turn into an epidemic very fast.
How do you manage sunflower rust? If rust reaches approximately 1% severity on the upper four leaves at or before bloom (R5) yield loss can occur (Figure 6). If that level of severity is reached at or before sunflower bloom, a fungicide application should be considered. Triazoles (Folicur, etc…) and Strobilurins (Headline, Quadris, Aproach) chemistries are among the most effective on rust. At R6 or later (after bloom) fungicide applications have not had impact on yield in our trials.
For severity guides and other information on sunflower rust, please consult the NDSU Extension publication on sunflower rust or visit the National Sunflower Association website [sunflowernsa.com] and search for rust.
How do you manage dry edible bean rust? Dry edible bean rust can cause significant yield loss when the disease occurs early in the growing season and conditions remain conducive for infection and spread. If bean rust occurs, a fungicide application should be considered. The best timing for a fungicide application to manage bean rust is shortly after it is first found. Strobilurin fungicides [FRAC 11] (Aproach, Headline, Quadris, etc.) and Triazole fungicides [FRAC 3] (Folicur and generics, Proline, etc.) have consistently been the most effective in our research trials. Once pintos begin to stripe (or the equivalent growth stages in other beans) management is not necessary.
For more information on dry edible bean rust visit http://www.ag.ndsu.edu/pubs/plantsci/pests/pp1601.pdf
Extension Plant Pathologist, Broad-leaf Crops