Desiccation: Why, When and What Products to Use
Posted: September 3, 2015
Why should I consider desiccating my sunflowers?
Natural desiccation can be slow and uneven. Poor weather can cause reduced quality and yield through stem breakage, shattering and predation by blackbirds. To speed up the natural desiccation process, it may be worthwhile to consider the use of a chemical desiccation. Chemical desiccants are generally typical herbicides that have achieved special registration to be used as a harvest aid.
What is the right stage to desiccate at?
Timing of desiccation is critical as application prior to physiological maturity can result in decreased quality, seed size and test weight. Sunflowers are physiologically mature at the stage R-9. At this stage, the seeds have reached maximum size and bushel weight. Visually, this is when the back of the head is yellow and the bracts are brown and seed moisture is between 30-35%.
The bract tip turns brown at 40-50%. At this stage, seed moisture is too high and the plant has not reached physiological maturity. The broadest part of the bract should be turning brown. It is at this stage that the seeds are between 30-35% moisture and
desiccation can be performed.
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Sunflowers, sclerotinia and fungicides
Posted: July 31, 2015
Sclerotinia can be a devastating disease and in sunflower it is highly dependent on weather conditions. Sclerotinia Head Rot infection is dependent on the ascospore infection.
What causes sclerotinia head rot?
Wet soil conditions over a period of 10 to 14 days stimulate the sclerotia dropped from a previous crop to germinate creating tiny mushrooms. These mushrooms produce apothecia or tiny spores which can be wind-blown to nearby fields.
The spores need dew or rain and dead or senescing plant tissue such as dead florets to germinate and infect. Wet and cloudy conditions are necessary for the disease advancement.
Like canola, there is a specific application window recommended for sclerotinia fungicide control.
Click here to read: Sunflowers, sclerotinia and fungicides
*REMEMBER: Sunflower seeds are an edible product and low quality will affect the marketability of your product. Prevention to sclerotinia is KEY!
Sunflower Morphology and Staging
Posted: July 24, 2015
Do you know the morphology of a sunflower head?
Here is a cheat sheet to help with identifying the parts and assist with staging for pesticide applications.
Click here to see the stages of sunflower development.