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Story Posted: July 07, 2010 Canola Watch 11: Sclerotina control at 20% bloom In This Issue: Sclerotinia management: 3 key points, Sclerotinia management: What is 20% flower?, Consider split application for multi-stage crop, Tips to control multiple insect species at once, Keep malathion out of canola bins, Coming events, Questions and contacts. Issues of the week Crop and weather update Alberta: Isolated thunderstorms dumped 2" to 4" of rain on some areas, but others got very little. Some crops have not had rain since June 9. Crops throughout south and central Alberta look good. Early seeded canola is at 50% bloom. Read the Alberta crop report. Saskatchewan: Huge rain continues to be the story in eastern Saskatchewan. Yorkton and area got 7.5" in one shot. Pleasantdale got 5" over the weekend and another inch on Monday. Accumulation on some farms in the northeast region is up to 25" for the season. One farm reports 28". Despite this, some pockets north of Saskatoon, in the far northeast and in the southeast have decent crops coming. Canola looks good in the west, in general. Read the Saskatchewan crop report. Manitoba: Rainfall has been variable with thundershowers. Most areas got enough to keep humidity high and field conditions damp. The northwest and Interlake regions got the worst rains again, with lots of reports of spindly crop that is really struggling to fill in. Most fields are now in the bolting to full bloom stages. Read the Manitoba crop report. Quick Hitters Consider the economic payoff before trying products that claim to rescue a crop that's thin, flooded and oxygen depleted. For many of these crops, there is no sense investing more money in them. When trying a novel product, leave an untreated test strip through to yield and compare the results. Now is the time to look at your flowering fields for missing pods and to start to examine causes. For a presentation on what causes blanks or flower abortion, watch the ACPC webinar with Murray Hartman, Alberta provincial oilseed specialist. Sclerotinia management: 3 key points 1. Have conditions been moist over the past few weeks for apothecia development and survival? 2. Is the canopy thick and is yield potential high? 3. Does the forecast call for more rain and/or humidity in the next week? If the answer is "yes" to all 3, it's a no brainer to spray. If only 2 questions have "yes" answers, then the decision is more difficult. Consider canola price and overall profit potential of the crop before investing more in it. Canola with yield potential of less than 30 bushels/acre is not likely worth spraying. Crops with an open canopy could be at lower risk, particularly if warm and windy weather allows them to dry out in the afternoons. However, if frequent rains and high humidity keep the plants wet there is still a threat. Does hail raise the sclerotinia risk? Broken stems and leaves along with lodging after a hail may increase the risk of sclerotinia stem rot infection. Regrowth after a hail may also extend the flowering period, which also increases the sclerotinia risk. But should a grower automatically spray fungicide on a hailed crop? That depends. If yield potential is still high and if conditions favourable to sclerotinia stem rot persist, then a fungicide spray may pay off. Sclerotinia management: What is 20% flower? Canola can reach 20% flower in 4-5 days after first flower, so prepare to assess the sclerotinia stem rot risk as soon as flowering starts. To assess flowering progress, concentrate on the main stem only. Count all flowers, including aborted flowers and developing pods.
Click here to read NDSU's complete factsheet on sclerotinia stem rot management and canola flowering stages. Consider split application for multi-stage crop The first application can be made when the first plants reach recommended staging. If necessary, a second application can be made when the remaining plants are ready to be sprayed. Refer to current crop protection guides to determine which products are registered for split application and recommended rates of application. Click your province for your guide: Alberta , Saskatchewan , Manitoba Tips to control multiple insect species at once In the case of these two species, the answer is no. Count them separately and stick to the economic control thresholds for each. Why? Because weevils attack flowers and buds, but diamondback moth right now are eating more leaf tissue than flowers. Where an "additive" effect of multiple species can make sense is when more than one species are feeding on key yield-producing areas - flowers, buds and pods - at the same time. For example, if you have lygus bug and cabbage seedpod weevil in the same field and if they are both at 50% to 60% of their economic spray thresholds, spraying may provide an economic benefit - especially if the crop is already stressed. There has been no research to support this interpretation of the thresholds, but this is currently the best guess from experienced entomologists. Click here for more information on insect thresholds in canola. Click here for the CCC's Canola Scouting and Sweep Net Insect Identification Card. Keep malathion out of canola bins Do not use malathion to treat bins destined to store canola. Click here for more information. Coming events Canola Crop Walks in Alberta July 9 - Westlock, Barrhead. CCC senior agronomy specialist John Mayko and Alberta provincial oilseed specialist Murray Hartman will host two Canola Crop Walks in Alberta July 9. The morning walk is at Westlock from 10:00 a.m. to noon, and the afternoon walk is at Barrhead from 1:30 to 3:30 p.m. Topics include flea beetles, cutworms, canola diseases and fungicides. For more information, contact ACPC Director Colin Felstad at 780-349-6175 or the Gateway Research Organization at 780-349-4546. BCGPA's Annual Field Crop Tour and BBQ July 14 starting 4:00 p.m. at the Fort St. John research farm. CCC agronomy specialist Erin Brock is speaking. Visit the BCGPA website for contact information. Pod sealants, plant densities and reseeding decisions are canola discussion topics at 4 Saskatchewan tours this month. Wheatland Conservation Area hosts the tour July 15 at Swift Current; AAFC and WARC hosts July 16 at Scott; AAFC and IHARF hosts July 20 at Indian Head; and AAFC and NERF hosts July 21 at Melfort. Contacts are Shannon Chant for Swift Current, 306-778-8291; Sherrilyn Phelps for Scott, 306-446-7475; Daphne Cruise for Indian Head, 306-694-3587; and Kim Stonehouse for Melfort, 306-878-8807. Combine Performance Clinic July 27 and 28 in Vegreville, Alta. CCC and Alberta Canola Producers Commission present the one-day clinic with tips to cut combine losses, which can be 3-5 bushels per acre. Click here for more information or to register online. Space is limited to 250 per day. For more on combine settings, listen to Doug Moisey on ACPC radio.
Questions and contacts If you have questions on regional issues, contact one of the following Canola Council of Canada regional agronomists or provincial oilseed specialists:
This report is supported by each of the provincial canola grower associations. For more information on some of their activities, check out the following links:
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