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NATIONAL SUNFLOWER ASSOCATION OF CANADA MB Sunflower Crop Report

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Crop Wednesday July 17, 2013 Early fields are at R-1 to R-2, which is when the immature bud elongates 0.5 to 2.0cm above the nearest leaf attached to the stem. Later fields are progressing and are at V-14. Lygus bugs and Banded Sunflower Moth emergence is underway. Both of these insects are not a problem at the current crop stage, and the optimum time for insecticide control is R-5.1. The economic threshold for lygus bug is one adult Lygus per nine heads and1 adult moth per 100 plants for banded sun- flower moth. Despite no insecticide being registered for the control of Banded sunflower moth, the optimal time to spray is at R-5.1, corresponding with the optimal time for lygus bugs. Sunflower Bud Moth larvae have started to hatch. The adults deposit eggs on the terminals of immature sunflowers, the receptacle of mature sunflowers and in leaf axils. The hatched larvae begin to tunnel creating the characteristic clue of black frass (insect excrement) surrounding the entrance hole. Although activity is noticeable, Sunflower Bud Moth does not usually cause economic damage and there are no control options available. The optimum timing for control of seed damaging insects is R-5.1 or 10% flowering. REMINDER: Producers are encouraged to take the appropriate steps to reduce risk to honey bees when spraying insecticides. This is for the benefit of both sunflower growers and beekeepers. Important steps include; 1. Scout fields for seed damaging insects and beneficial insects, only apply insectides if necessary. 2. Spray in the evening when honey bees have returned to the hive and communicate with bee keepers. 3. Select insecticides that provide effective control of the targeted pests while minimizing impact on bees. 4. Communicate with beekeepers in your area. Honeybees can increase both the number and weight of sunflower seeds through increased pollination. See attached the full article from provincial entomologist, John Gavloski. MB Sunflower Crop Report NATIONAL SUNFLOWER ASSOCATION OF CANADA Manitoba Sunflower Surveillance Survey 2013 CanadaSunflower.com Insects Figure 1. Adult lygus bugs vary from light green to dark brown and have a distinctive ‘V’ on the wings. Producers are encouraged to take the appropriate steps to reduce risk to honey bees when spraying insecticides. This is for the benefit of both sunflower growers and beekeepers.” Figure 2. Adult Banded Sunflower Moths congregate in ditches during the day. The best time to scout is during the evening. Figure 3. Pollinators are busy in flowering fields. BEE-friendly; pay attention to timing and insecticide choices.
Transcript
Page 1: NATIONAL SUNFLOWER ASSOCATION OF CANADA MB Sunflower Crop Report

Crop

Wednesday July 17, 2013

Early fields are at R-1 to R-2, which is when the immature bud elongates 0.5 to 2.0cm above the nearest

leaf attached to the stem. Later fields are progressing and are at V-14.

Lygus bugs and Banded Sunflower Moth emergence is underway. Both of these insects are not a

problem at the current crop stage, and the optimum time for insecticide control is R-5.1. The economic

threshold for lygus bug is one adult Lygus per nine heads and1 adult moth per 100 plants for banded sun-

flower moth. Despite no insecticide being registered for the control of Banded sunflower moth, the optimal

time to spray is at R-5.1, corresponding with the optimal time for lygus bugs.

Sunflower Bud Moth larvae have started to hatch. The adults deposit eggs on the terminals of immature

sunflowers, the receptacle of mature sunflowers and in leaf axils. The hatched larvae begin to tunnel

creating the characteristic clue of black frass (insect excrement) surrounding the entrance hole. Although

activity is noticeable, Sunflower Bud Moth does not usually cause economic damage and there are no

control options available.

The optimum timing for control of seed damaging insects is R-5.1 or 10% flowering.

REMINDER:

Producers are encouraged to take the appropriate steps to reduce risk to honey bees when spraying

insecticides. This is for the benefit of both sunflower growers and beekeepers. Important steps include;

1. Scout fields for seed damaging insects and beneficial insects, only apply insectides if necessary.

2. Spray in the evening when honey bees have returned to the hive and communicate with bee

keepers.

3. Select insecticides that provide effective control of the targeted pests while minimizing impact on

bees.

4. Communicate with beekeepers in your area.

Honeybees can increase both the number and weight of sunflower seeds through increased pollination.

See attached the full article from provincial entomologist, John Gavloski.

MB Sunflower Crop Report

NATIONAL SUNFLOWER ASSOCATION OF CANADA

Manitoba Sunflower Surveillance Survey 2013 CanadaSunflower.com

Insects

Figure 1. Adult lygus bugs vary from light

green to dark brown and have a distinctive ‘V’ on

the wings.

“Producers are encouraged to take the appropriate steps to reduce risk to honey bees when spraying

insecticides. This is for the benefit of both sunflower growers and beekeepers.”

Figure 2. Adult Banded Sunflower Moths

congregate in ditches during the day. The best

time to scout is during the evening.

Figure 3. Pollinators are busy in flowering fields.

BEE-friendly; pay attention to timing and

insecticide choices.

Page 2: NATIONAL SUNFLOWER ASSOCATION OF CANADA MB Sunflower Crop Report

Wednesday July 17, 2013

Downy Mildew (figure 1) continues to be noted in fields around the province. Infected plants samples are

being analyzed to identify the race of downy mildew to ensure that the seed industry is abreast of the

prevalent races. The disease produces symptoms which include a lighter green color along veins on leaves

and a thickened, club like root. Some fields have up to 15% infection of plants. There are no control op-

tions for later infection of downy mildew.

Sunflower Rust pustules have not yet been noted. Continue to monitor for the brown pustules as the

disease may still develop if we receive more rains and heavy dews. A fungicide application is most

economical when disease severity is 1 percent on the upper four leave prior to or during flowering.

The incidence of Sclerotinia basal rot (figure 3) continues to increase, however levels remain low on av-

erage.

Despite the presence of basal rot, the incidence of mid-stalk rot is very low. This may be an indication

that the level of spores in the air is low. However, there have been a few precipitation events recently that

may cause for some infection.

It is currently hard to predict the risk for sclerotinia head rot in flowering fields. Despite some areas

receiving rain, significant soil moisture is required for the sclerotia bodies to germinate and release spores.

Manitoba Sunflower Surveillance Survey 2013 CanadaSunflower.com

Figure 1. Sunflower planted affected by Downy

Mildew. Underside of leaves show white, powdery

mildew.

Disease

Figure 3. Wilted plants like the middle sunflower

plant above, often contains a basal lesion that

girdles the stem reducing water uptake.

R-2 R-3 R-4 R-5.1

Figure 2. Aecial cups on underside of sun-

flower leaf.


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