I've been waiting for the citric acid discussion to continue but it hasn't.This is utter nonsense. Sulfur to control pm is well established and something everyone knows about. It is used by every commercial tomato and cucumber greenhouse and has been for a long time.
This thread was supposed to be about citric acid for this purpose. Less well known or at least more recently adopted. Maybe not as effective but also has some benefits.
I agree with keeping that discussion open and rolling along as it would be excellent to prove out something growers can use during flower. Hypochlorous (spelling?) Acid is another one that many are diving into and I follow those discussions as well.
Many products can assist the plant in resisting PM but no product I have seen or tried actually eradicated it from the localized environment..... not a single one. Until I took the chance and tried the sulphur spray.
Yes, gardeners have been deploying sulphur in various methods to try and "control" PM.
Sulphur burners/foggers in grow rooms have been used for years n years but yet the PM would return. That is because those forms of using sulphur do not present it to the plant in a form that kills the parasite.
Neems and other oils only provide a barrier of protection , they do not kill the parasite.
Baking Soda sprays raise surface PH which is beneficial to apply to fusariums but Baking soda soes not kill PM though it does.... like neems and other oils, provide an unfavorable coating on the leaf that the spores will have a hard time infecting the tissue. These products have thier place but they do no eradicate the parasite, they only delay infection and delay fruiting.
We can run around in circles here for those that are seemingly in denial but there's no need for that.
I grow in a harsh climate here at 52N, 3000ft elevation , in western Canada where everything is trying to infest or kill my cannabis plants. Growing here is a challenge and I have to practice light dep to run the multi strain gardens I run. My greenhouse is basically a cold frame as it is just wood covered in plastic with lots of open spots. There is no exhaust system , just 2 cheap 16" oscillating fans. The plants get shoved into a 12x12 shed with no intake or exhaust, just those two fans. To say that I provide the optimal conditions for fusarium, boytris, and especially PM would be an understatement. I have struggled with these pathogens before in my grows posted online.
My grow threads these days are on overgrow and I don't have one here this year but if anyone followed last years grow and this years..... they would see what I am talking about.
I had a PM infestation last season in the grow room and at the tail end of my out greenhouse run. I nearly lost my marbles as I had not seen Powdery Mildew on my plants since the early 2000's when all we could do was cut and burn and bleach everything and then run commerical ozone generators to sanitize equipment and grow rooms. Anyways...... if I follow the arguments in this thread that PM is systemic and that all these other products mentioned are better than micronized sulpjur spray....... it only stands to reason that I would still have PM and that I am lying to you all for sport...... right?
Well, I have a 100% PM free garden inside and out after perfoming spray downs in the fall inside and out and repeating the same this spring. That is two applications of micronized sulphur spray used as directed by JoeCrowe ...... and that systemic PM is mysteriously no where to be found..... and I've looked hard for it. It ain't there..
and ounce of Cure is worth how many ounces of Prevention???? You guys tell me LOL