Powdery mildew - help

[hazeluv69]

Hi guys; have noticed some powdery mildew. I have been using some guard ‘n’ spray a few times, rubbed them with wet towels etc, not the worst of pm but it’s present. Any help would be much appreciated ! Neem oil? Milk? P.S IM IN VEG

 

[SmokingWings]

..have noticed some powdery mildew. I have been using some guard ‘n’ spray a few times, rubbed them with wet towels etc, not the worst of pm but it’s present. Any help would be much appreciated ! Neem oil? Milk? P.S IM IN VEG

Milk, diluted with water, is often recommended but I have not had any real success with it. I figure it works best as a preventative before the mildew starts and is also better suited for outdoor gardeners growing vegetables.

Neem Oil is another one often recommended but I have had minimal success with it for Powdery Mildew. But, I use it to kill off Spider Mites. If it also slows down the mildew at the same time then it is still a winning item. Many growers say not to use it once in flower but I have not had problems and I use it at times up to the last 2 or 3 weeks before harvest.

Nuke'Em is another one that can be used for mildew but like the Neem I have had minor success. It works much better for Mites. This stuff can be used all the way through to a couple of days before harvest. Reading through the label and website the company does have a double dose recommendation for serious infestations so I use that.

What really works is Citric Acid. It is food safe and often used by home canners when processing their vegetable and fruit harvests at the end of the season. It is fairly easy to find at larger supermarkets, often in the section with canning jars and supplies. The link below goes to a msg that discusses the mixture dose, etc.

Citric Acid & Powdery Mildew Spray

When I go on the attack against the mildew I will pick one of the three, the Neem Oil, the Nuke'Em or the Citric Acid and use that for several days in a row. My schedule is something like Day 1 spray at the start of the day and again near the end of the growing day. Repeat on Day 2 and sometimes Day 3. Finish off by spraying once a day, usually near the end of the growing day until I have sprayed for a total of 5 days, sometimes 6.

Since I am doing a perpetual grow it is close to impossible to to get rid of all the mildew or mites since I cannot shut everything down to do a complete sterilization of the tent, room, and shelves, benches and anything else in the basement that needs to be treated.

Often, after even one day of spraying the mildew starts to look different. It is dead mildew and the scarring on the leaves that the mildew caused. It really cannot be wiped off the leaf. Always spray the underside of the leaves.

Good luck. You should be able to get rid of most of the problem, if not all of it.

 

[kahoona]

hydrogen peroxide foliar spray.

 

[cbdhemp808]

I'm dealing with this right now myself, check out HERE.

I think I'm gonna try potassium citrate foliar spray... also good for feeding K during flower. I'll order some K-citrate, but in the mean time I'll keep spraying with hydrogen peroxide solution, 6 fl oz. 3% peroxide in 1/2 gal water, in the pump sprayer.

Potassium bicarbonate is also supposed to kill PM.

 

[Mudballs]

link to Plant Therapy spray home recipe
There's something called the haustorium that get's into the plant, and if you don't kill that, you don't kill the PM...that's why you see brown dead tissue sometimes when you spray very harsh treatments, cuz you killed the haustorium.

there's an even harsher one i use from early veg to early flower
1/2 gal 70% iso alcohol
1/2 gal water
2-tsp sodium bicarbonate (baking soda)
few drops of castille soap
this kills hard! don't freak out if you see brown patches the next day after you spray this cuz that means you killed the PM, the haustorium, and everything else that isn't supposed to be in or on the plant. This will kill your pistils in flower, don't use in flower unless emergency.