CLUBROOT OF CANOLA ALERT

Canola growers are strongly encouraged to scout canola fields for clubroot; particularly growers in Cavalier County.
In North Dakota, confirmation of clubroot has been limited to few localized fields in Cavalier County. However, clubroot likely occurs in more fields than currently detected and favorable conditions for disease development and symptom expression at the end of the season have opened a critical window for scouting.
Infected plants are less tolerant to warm and dry conditions because their root system has been compromised by clubroot (Fig. 1). The dry conditions that prevailed during the past several weeks have stressed canola plants with clubroot, accentuated disease symptoms and made them much more visible. As stressed plants die prematurely, patches in fields that may resemble drought-stress appear (Fig. 2). Infected roots have galls that are brittle and may disintegrate easily when plants are pulled from the ground (Fig. 3).

NDSU Extension and canola pathology personnel, with support from the Northern Canola Growers Association, are conducting end-of-season field surveys to identify infested fields, but surveyors typically scout a relatively small number of fields in each county. We suggest growers investigate ‘dry spots’, use a shovel to dig out plants, and investigate roots for galling. Growers who suspect clubroot are encouraged to contact Dr. Venkata Chapara at the Langdon REC (701-256-2582), Dr. Anitha Chirumamilla at the Cavalier County Extension office (701-256-2560) or Dr. Luis del Río Mendoza in the Department of Plant Pathology (701-231-8362) or through NDSU Extension (701-231-8363). The NDSU canola pathology program led by Dr. del Río Mendoza has the capability to perform laboratory tests to verify clubroot presence in soil samples.
Growers who know their fields are infested with clubroot should take precautions to reduce its spread to other areas. Some of these precautions include working the ground of infested fields the last and cleaning the equipment before leaving the infested fields to avoid moving chunks of dirt in it. Tillage operations, like disking, plowing, and harrowing, facilitate the distribution of clubroot resting spores from galls into the soil profile and may bring some spores to its surface; thus, we recommend using no-till practices in infested fields. Spores located in the soil surface may be spread by equipment, wind, water overflow, and on boots. When walking on infested fields, we recommend wearing disposable shoe covers to minimize transport of soil.
In the upcoming year, growers who grow canola in areas where clubroot is known to occur are encouraged to plant clubroot-resistant hybrids and consider extending crop rotations to three years with non-host plants like wheat, barley, soybeans, or corn before planting canola again.

 

 

 

Sam Markell
Extension Plant Pathologist, Broad-leaf Crops

Venkat Chapara
Area Extension Specialist/Crop Protection
NCREC, Minot, ND-58701

Luis del Rio Mendoza
NDSU Plant Pathology Professor

NCGA Requests Canola Be Included in Aid Package

The Northern Canola Growers Association has sent in a request to the North Dakota delegation that canola be included as an eligible commodity under the proposed $12 Billion Aid Package that was announced recently by USDA Ag Secretary Sonny Perdue.  Canola prices have dropped significantly recently along with soybeans in reaction to the trade dispute with China.  While canola has not had a tariff imposed upon it, canola growers are still suffering the same drop in revenue and inclusion of canola would be equitable for growers.  Below is the text of the request:

The Northern Canola Growers Association wishes to express its grave concern that canola has not been listed as an eligible commodity under the proposed $12 billion aid package.  We assume that one of the reasons is that canola has not had a tariff imposed on it.

While it is true that a tariff has not been imposed on canola by any major importing countries, this does not mean canola growers have not seen severe negative impacts to their bottom lines as a result of the vicious drop in canola price.  Historical prices prove the strong relationship between canola and soybean prices and as the soybean price has dropped, so has canola.

Local cash prices at ADM Velva for new crop canola dropped from $17.31 on June 1 to $15.21 by mid-July.  Based on an average yield of 1,850 pounds/acre, canola growers will receive $38.85 less per acre.  This means a revenue loss of $64 million for North Dakota canola growers!

We therefore request that canola be included in the announced aid package as an eligible commodity so that canola growers can share in the recovery of some of the lost revenue as a result of the ongoing trade dispute.

Thank you for your consideration of our request.

SUMMER FLEA BEETLES FEEDING ON CANOLA PODS

The summer population of flea beetles has emerged in large
numbers this year. Flea beetles are being observed in maturing canola
fields (North Central ND; Source: Brady Schmaltz, Arthur Companies),
Brassicas crops being used as cover crops (i.e., radishes) and in backyard
gardens. For canola, there is no established Economic Threshold for flea
beetle feeding injury on pods. Flea beetle feeding injury on pods is
usually most significant on late-planted canola and on the upper pods.
Fortunately, the lower pods of canola are the primary pods that provide
most of the canola yield. However, flea beetle feeding injury on pods can
result in poor seed fill, premature pod drying, or pod shattering. If the
canola is mature, pass the 5.2 growth stages (when seeds in lower pods
have turned translucent to green), then yield will probably be less
impacted by flea beetle feeding. In a flea beetle trapping study of freshly
swathed canola, the number of flea beetles per trap decreased
dramatically after 7-days of drying in swath. Flea beetles are mobile
insects and fly around to find ‘greener’ canola fields (late-planted) for
summer feeding.
Insecticides registered for flea beetle control with a short, 7 day Pre-Harvest Interval (PHI) include: Delta Gold
(deltamethrin), Declare (Gamma-cyhalothrin), Warrior II and generics (lambda-cyhalothrin), and Mustang Maxx (zetacypermethrin).
Insecticides that are labeled to control flea beetles on canola are listed in 2018 North Dakota Field Crop
Insect Management Guide E-1143.

SCOUT FOR BERTHA ARMYWORM IN CANOLA

Mature bertha armyworm larvae were found feeding on the pods of canola in northcentral McHenry County (Source: Kristine Keller, Farmers Union Oil of Velva, Butte, Drake and Anamoose). Older larvae reach a length of ¾ to 1½ inch and are velvety brown to black with a yellowish band along each side of the body. As leaves dry, these larvae begin feeding on pods or flowers. The greatest risk of crop injury occurs in August as the worms are mature. Larvae chew holes in the pods, eat the seeds and cause premature shattering. Mature larvae eat approximately 85% of the plant materials consumed during their larval development. Larvae feed at night and often hide underneath leaf litter and clumps of soil during the day, which makes them difficult to see when scouting.
The Economic Thresholds is an average of 20 to 32 larvae per square yard with insecticide + application costs of $6.50 to $10 per acre, respectively. However, thresholds may need to be lowered if larvae are feeding on maturing pods at high population densities.
Fields above the economic threshold level should ideally be sprayed once the hatch is complete and when larvae are small about ½ inch. Apply a well-timed insecticide in early morning or late evening when larvae are actively feeding. High volumes of water should be used for good coverage of the dense canola canopy. Insecticides that are registered to control bertha armyworm on canola are listed in 2018 North Dakota Field Crop Insect Management Guide E-1143. When larvae are mature, 1½ inch long, they are close to the pupal stage, which is a non-feeding, resting stage. So, no insecticides are necessary this late in the insect’s development and the feeding damage is already done.
Please see the NDSU Extension publication on Bertha armyworm in Canola: Biology and Integrated Pest Management E1347 (revised) for more information.

Ag alert: Early detection of Clubroot in Canola during flowering stage

Venkat Chapara, Plant Pathologist, NDSU/Langdon Research Extension Center, Langdon, ND 58249

Clubroot in Cavalier County

Ag Alert: Early Detection of Clubroot in Canola during Flowering Stage

Venkat Chapara, Plant Pathologist, NDSU/Langdon Research Extension Center

Clubroot on Canola has been identified in five out of six canola fields at flowering stage scouted over the last five days in Cavalier County. Last year it was noticed in six out of 59 fields scouted at the end of the season (swathing). By the end of this season it may be in more fields than expected!

Clubroot on Canola is caused by a soil borne pathogen which has the characteristics of plant, animal and fungi for which there is no silver bullet for control. Once in the soil, it can live up to 17 years!

Management:
Sanitation of equipment, longer crop rotations (at least 2-3 years) and using resistant varieties can minimize yield losses.

Please call the Langdon Research Extension Center (256-2582) or the Cavalier County Extension Office (256-2560), if you suspect any abnormality in the growth of your canola crop.

Picture 1: Severely infected field with clubroot- Notice stunted growth and death of the plants.

Picture 2: Galls on canola roots infected with Clubroot.

UPCOMING RESEARCH TOURS

Minot – Wednesday, July 18th, the NDSU North Central Research Center will hold its Annual Crop Tour.

 

The tour begins at 8:30 a.m. and will conclude by noon.  A major focus will be on intercropping, weed control in canola and managing soil salinity.  Center scientists are studying 34 intercropping combinations, and include canola and field peas.  In addition, NDSU will host a crop pest diagnostic clinic. Producers are encouraged to bring in plant samples. They’ll also have an opportunity to have one-on-one consultations with experts on weed, insect and disease control issues.

 

Langdon – The Northern Canola Growers Association is hosting a tour in conjunction with the Langdon Research Extension Center on Thursday, July 19th at the station just east of Langdon.  Diseases and insects affecting canola are among the issues that will be covered during the annual field tour July 19.

 

The program begins at 8 a.m. with doughnuts and coffee provided by the Northern Canola Growers Association. The tour starts at 8:30.

 

Topics and presenters include:

 

* Canola growing season insect update – Lesley Lubenow, NDSU Extension cropping systems specialist at the center

 

* Clubroot/canola disease update – Venkat Chapara, research assistant professor at the center

 

* Unmanned aerial systems imaging demonstration – John Nowatzki, NDSU Extension ag machine systems specialist

 

The tour also includes a presentation on the center’s research on weed and blackleg pressure in canola cropping systems; and a noon lunch sponsored by the Northern Canola Growers Association.

WHITE MOLD OF CANOLA RISK

Recent rains and canola entering bloom have prompted questions about white mold and fungicide applications on canola. Below we try to answer some questions about white mold on canola.

Why is canola susceptible at bloom?

Unlike many other pathogens, Sclerotinia (the white mold pathogen) needs flower petals to cause infection. The ascospores can easily digest flower petals, and once the process starts, the disease will quickly spread into branches and stems and can result in yield losses and lodging. Recommendations for fungicide applications begin at early bloom (usually 20-50%) because the earliest infections have the longest time to develop. Consequently, they tend to be lower on the plant and cause greater yield loss.

What conditions are favorable for infection?

Essentially, the answer is cool and wet.

Prior to bloom that pathogen needs water in the soil. Wet soil will allow the sclerotia (the hard black overwintering structure) to germinate, form small mushroom (apothecia) and release ascospores. A minimum of 1-2 inches of rain 1-2 weeks before bloom can initiate germination.

During bloom, anything that keeps the canopy wet for prolonged periods of time will facilitate infection. Multiple days of rainfall, very heavy dews, fog, etc… will provide enough water for infection to start. The wild card here is temperature. We rarely see much white mold when daytime highs are 85 F or higher, but the disease can run rampant when high temperatures are in the 60’s and low 70’s F.

What’s the risk now?

Often, it is a mixed bag across the region. Fields that have had more rainfall, a history of disease, and cooler conditions are at greatest risk. The NDSU Sclerotinia stem rot (SSR) Risk Map and Risk Calculator for Canola, operated by NDSU Canola Pathologist Dr. Luis del Rio and funded by the Northern Canola Growers Association, are useful tools that can be used to help producers determine risk. However, please remember that this map is only relevant when canola is in bloom and that the map is only as good as the weather data used to generate it. NDAWN (North Dakota Agriculture Weather Network) is a fantastic resource, and the envy of most other states, but rainfall can be extremely variable even at a field level.

The most recent risk map (6/26/18) indicates that risk is highly variable throughout the state, and that can change quickly. The risk map and risk calculator can be found online at http://www.ag.ndsu.edu/sclerotinia and through the Northern Canola Growers Association website, http://www.northerncanola.com/. The map and calculator are also available through the Canola Doctor application for Android and iOS-based devices. The application is free and can be downloaded from Google Play Store and the iTunes App Store. The risk maps are updated daily between June 16 and July 31.

Fungicides. If growers determine that a fungicide application is warranted, application timing is very important. Targeting the early bloom stages is ideal (commonly 20%). Pictures and descriptions of bloom stages can be found in the NDSU Extension Publication Sclerotinia of Canola PP-1410 http://www.northerncanola.com/wp-content/uploads/2014/05/Sclerotinia-Control-in-Canola.pdf. Our data demonstrates that multiple fungicides can be effective.

UPDATES TO ‘NDSU CANOLA DOCTOR’ AND ‘SUGARBEET PRODUCTION GUIDE’ APPS

The “NDSU Canola Doctor” and “Sugarbeet Production Guide” mobile apps are now available for installation on both Android and iOS devices. Previously, the Canola Doctor app was available for android, while the Sugarbeet Production Guide app was available only for iOS devices. The apps deliver critical information to make timely management decisions and optimize crop production for canola and sugarbeet growers, respectively. The apps can be installed by following the short links:

https://itunes.apple.com/us/app/ndsu-canola-doctor/id1397239260

 

For more information contact:

Kishore Chittem

Post Doctoral Research Scientist

 

Luis del Rio

Professor of Plant Pathology

 

Janet J. Knodel

Extension Entomologist

June 26 Canola Tour in Minot Cancelled

Due to drought conditions and poor test plot conditions, the Canola Research Tour planned for the North Central Research Center in Minot on Tuesday, June 26th has been cancelled.  The Northern Canola Growers Association will join with the Research Center at its Annual Research Tour on Wednesday, July 18th to offer canola information.  Please join us on July 18th to view updates on canola research.

NCGA’s 19th Annual Golf Tournament

Register now for the Northern Canola Growers Association Golf Tournament to be held July 19th, 2018 at the Langdon Country Club. Registration for the 4-man best ball tournament is $50/player or $200/team. You may register individually and be placed on a team or register a complete team. Registration fee includes 9 holes of golf, a golf cart, refreshments, and supper at the club house. Prizes will be awarded. Registration for the Langdon tournament is limited to the first 132 players, so register early! This tournament is made possible by the support of our industry sponsors.

If you would like to register for this year’s tournament please fill out the registration form and return along with payment to:

Northern Canola Growers Association
125 Slate Drive Suite #4
Bismarck, ND 58503

Or if you would like to pay online visit: https://squareup.com/store/NCGA

If you have any questions call us at #701-223-4124.

2018 Golf Registration Form