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| Archive |
Crop Production Update |
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| Jun 29, 2009 Issue Number: 4 |
| Weekly Report: |
Spring Cereals
With the warmer weather and recent rainfall, farmers and agronomists should be scouting for leaf rust (leaf rust in oats is commonly referred to as crown rust). Leaf rust overwinters in the southern United States and is blown into the southern Prairies by prevailing winds. The disease can develop rapidly with warm temperatures and humid weather conditions when moisture is not a limiting factor. Leaf rust pustules are dusty-yellow to bright-orange, small round to oval spots that are found on the leaves and sheaths. As the plant matures, the rust pustules darken and may appear black.
If conditions warrant fungicide application, there are a number of products available for leaf rust control. Please refer to the product labels for crop type and staging information, application information such as rates and water volume, tank mix options and any restrictions such as number of applications allowed per year, pre-harvest interval, and re-entry interval.
Winter Wheat
The winter wheat crop is entering the heading stage of development which means the application window for Fusarium head blight (FHB) control is quickly approaching. The winter wheat varieties grown in Manitoba have poor genetic tolerance to FHB. Early flowering is the avoidance strategy winter wheat has to escape prime infection period. However, the cool wet spring of 2009 has delayed winter wheat development which may mean the crop will be heading out and flowering in the more high risk weather conditions of early July.
The optimum time for Fusarium head blight suppression with a fungicide is at early flowering. Flowering in wheat has started when the anthers are pushed outside the spikelets that form the head. The anthers are easily recognized as a pale yellow to white tube of about 1/8 inch (3 mm) length and about 1/16 inch (1.5 mm) diameter and hanging on a very thin wire which extends from between the individual florets. Within a spike, flowering will start in the centre spikelets and progress upward and downward.
Three products are registered on wheat to suppress Fusarium head blight: Folicur 432F, Proline 480 SC and Bravo 500. In order to optimize product efficacy, the correct timing of fungicide application with quality application equipment and methods (type of spray nozzles, nozzle configurations, travel speed, water volume) is extremely important.
Corn
The warm conditions across the province last week resulted in significant corn growth. Depending on planting date, corn crop development ranges from V3 to V6 stage. Weed control measures are continuing through herbicide applications and inter-row cultivation.
Canola
Canola in the province still has a range of plant staging, depending on when the canola was seeded and/or emerged. Majority of fields are at least at the 4 leaf stage, with many earlier seeded fields starting to bolt and flower. Within fields, especially those planted in early May, staging may be variable. If a herbicide application has not yet been applied and the weed populations are a limiting factor to yield, consideration of plant staging is important in ensuring the herbicide is not damaging your canola. Please refer to the 2009 “Guide to Field Crop Protection” or call the chemical company marketing the herbicide for more information.
As canola starts to flower, decisions need to be made about using a fungicide for sclerotinia control. Most fungicide products recommend application between 20 – 50% bloom. Level of risk and potential for infection also need to be considered. This would include factors such as previous sclerotinia infection in canola, or other susceptible crops like dry beans or sunflowers. As well weather conditions (humidity, rainfall and temperature) and field conditions.
Please visit the Canola Council of Canada website at www.canola-council.org for more information on canola disease risk assessment for sclerotinia.
Flax
The flax crop in Manitoba ranges in plant stage from 4 to 10 inches tall, depending on when the crop was seeded.
As the flax crop gets closer to blooming, watch for brown-black bands on the base of the plant. This is an early symptom of pasmo and a fungicide application may need to be considered.
Sunflower
Staging of the sunflower crop is 4 to 8 true leaves in most areas. Scouting for insects such as sunflower beetles should be continued and thresholds used to help with the decision of insecticide control measures. Thresholds have been developed for many of the insects attacking sunflower in Manitoba and are available under the insect name on the MAFRI website.
Early stages of sunflower rust have been identified in Manitoba fields in the Southwest, Central and Red River Valley regions. Currently, the lifecycle stage of rust found in the fields is not yet the stage that is damaging to sunflower crops. However, it is an early indicator that there is sunflower rust in the province and Manitoba sunflowers growers will need to be watching for the development of the rust or cinnamon colored pustules on their sunflower in the next few weeks. Environmental conditions will impact the severity of the rust in the crop and how quickly the rust pustules appear. MAFRI is working closely with the National Sunflower Association of Canada, Agriculture and Agri-Food Canada and industry to monitor the development of sunflower rust and provide information on control measures.
Fruit Crops
Strawberry flowering is moving ahead quite well with the continued warm temperatures (>80%). Growers are monitoring for tarnish plant bug. Insecticide spraying continues during times when bees are not active (early morning/ evening).
Irrigation is occurring on strawberries with the hot temperatures in many fields.
Saskatoon growers continue to monitor for Entomorsporium leaf, berry spot, Juniper rust (in higher risk regions) and cytospora canker diseases.
Some raspberry flowering (< 10%) has started on many southern and central fields.
Potatoes
Reports have come in of later planted Russet Burbank potato fields emerging last week. The tallest reported Russet Burbank plants were approximately 6 to 8 inches tall. Irrigation continued last week on some fields until the rains over the weekend. Generally the rainfall this past weekend was less in the western production areas than in the eastern production areas. Recorded rainfall amounts varied from approximately ˝ inch in Carberry to 3 inches in Carman. The general changes in weather over the last 10 to 14 days have brought the P-day accumulation up in most potato production areas from between 60% and 95% of normal to between 86 and 102% of normal.
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Prepared by Manitoba Agriculture, Food and Rural Initiatives, Crops Knowledge Centre, Industry Focus Section
Phone: (204) 745-5663
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