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- #35,361
Okay folks, let's talk about powdery mildew (PM).
As most of you know, I've used many different sprays to try to knock down the PM that persists in my environment, and I have settled on neem until pistils, and then citric acid spray (0.25%). A little while back, canola oil was brought up as a possibility and one that I hadn't tried. It's cheaper than neem oil, and "[t]he Canadian Pest Management Regulatory Agency banned neem oil for use as an insecticide in 2012," (source) so I thought I would see if it works so our Canadian brethren will have an alternative.
@Regrowth and I had a conversation about canola oil dilution rates, and from his research he had found that there are a number of the canola oil products available with dilution rates ranging from 2-2.5%. @CBD BudMan has used another product with canola oil that is a 1% dilution, but he's of the mind that that concentration clogs the stomata on the leaves and could be creating a problem with transpiration (confirmed below*).
So I kept digging around regarding the canola spray and PM and found this research:
https://circadiancropsciences.com/wp-content/uploads/2020/04/PM-and-DM-Control-Cooking-Oil.pdf
It's a (South) Korean study from 2008 and seems well-researched and documented, and on the plus side, it's written in mostly non-technical language, dealing in percentages and ml rather than molecular weights and such.
Here are the cooking oils they tested:
They found that a 0.3% canola oil mix (with the addition of an emulsifier) worked the best among their tests without leaving the leaves oily (*as a 1% solution did). 0.3% (or 3ml/L) is much smaller percentage than in commercial products out there.
NB: The study said the effects lasted about 5 days.
There is also a discussion in the paper regarding emulsifiers to make the oil more stable in water, with an eye toward organic farming methods (you know how the Koreans are big on natural farming), but I'll be using Dr Bronner's unscented castile soap for mine.
I also learned from the paper that they emulsify in a blender (rather than just shaking a bottle), so I'll be using that, and testing out the smallest amount of Dr Bronner's that will make the mix stable.
To try and replicate their results, this weekend I'll be blending 500ml of distilled water with 1.5ml of canola oil (0.3% solution), and adding 1 drop of Dr Bronners at a time to the blender to see what it takes to emulsify it.
And in order to run this test, I have been intentionally growing PM on my Candida mother for the last week:
The things I do for y'all! Stay tuned for the ongoing results.
As most of you know, I've used many different sprays to try to knock down the PM that persists in my environment, and I have settled on neem until pistils, and then citric acid spray (0.25%). A little while back, canola oil was brought up as a possibility and one that I hadn't tried. It's cheaper than neem oil, and "[t]he Canadian Pest Management Regulatory Agency banned neem oil for use as an insecticide in 2012," (source) so I thought I would see if it works so our Canadian brethren will have an alternative.
@Regrowth and I had a conversation about canola oil dilution rates, and from his research he had found that there are a number of the canola oil products available with dilution rates ranging from 2-2.5%. @CBD BudMan has used another product with canola oil that is a 1% dilution, but he's of the mind that that concentration clogs the stomata on the leaves and could be creating a problem with transpiration (confirmed below*).
So I kept digging around regarding the canola spray and PM and found this research:
https://circadiancropsciences.com/wp-content/uploads/2020/04/PM-and-DM-Control-Cooking-Oil.pdf
It's a (South) Korean study from 2008 and seems well-researched and documented, and on the plus side, it's written in mostly non-technical language, dealing in percentages and ml rather than molecular weights and such.
Here are the cooking oils they tested:
They found that a 0.3% canola oil mix (with the addition of an emulsifier) worked the best among their tests without leaving the leaves oily (*as a 1% solution did). 0.3% (or 3ml/L) is much smaller percentage than in commercial products out there.
NB: The study said the effects lasted about 5 days.
There is also a discussion in the paper regarding emulsifiers to make the oil more stable in water, with an eye toward organic farming methods (you know how the Koreans are big on natural farming), but I'll be using Dr Bronner's unscented castile soap for mine.
I also learned from the paper that they emulsify in a blender (rather than just shaking a bottle), so I'll be using that, and testing out the smallest amount of Dr Bronner's that will make the mix stable.
To try and replicate their results, this weekend I'll be blending 500ml of distilled water with 1.5ml of canola oil (0.3% solution), and adding 1 drop of Dr Bronners at a time to the blender to see what it takes to emulsify it.
And in order to run this test, I have been intentionally growing PM on my Candida mother for the last week:
The things I do for y'all! Stay tuned for the ongoing results.
for the 1st time! She held the door open while I Schlepped In and Out! I didn't get pictures but I'm pretty sure we will do it again tomorrow!
CL
lol CL
so I can up my game. Thank you for your expertise!
