Landraces and heirloom (Part 2)

Outdoor Growing
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I think you are missing a crucial part of Joe’s information.

I must admit that I did not yet succeed in exterminating it from my garden, but I’m close. The difference with last season is enormous.
The problem is that I always have plants in different stages of flowering which makes it difficult to eradicate, but I am getting confident that I will succeed.

His findings align with my experience: I started getting PM after receiving a clone. Before I did not have it at all, zero. While the squash etc had it.

Here’s my summary of his golden info:

GET TO KNOW YOUR ENEMY

  1. Powdery Mildew is very host specific. The PM you see on squash will not infest your cannabis plant and visa-versa. Even the hop PM will not infest your cannabis. That means that the PM on your plants only comes from other infested cannabis plant(material)

  2. He only found one treatment that kills the fungus colony so far and that is sulfur. Other things can knock back PM, but not eradicate the colony.

  3. This is his list of stuff that definitely won’t work:

  • baking soda
  • vinegar
  • potassium bicarbonate
  • ultra violet radiation
  • systemic fungicides
  • LABS
  • hydrogen peroxide
  • Fulvic acid
  • dr zymes
  • lost coast therapy
  • magic dance
  • water
  • urine
  • magnesium
  • copper
  • manganese
  • earthworm casting tea
  • low humidity
  • chitosan
  • silica

  1. It is a persistent myth that PM (spores) are everywhere and will come fly into your grow with the wind. Yes PM can disperse through the air, but he says only about 6 meters. Definitely not the kilometers a lot of people believe.

  2. PM finds new hosts by being dispersed from one live plant to another. Or from (dead) plant material to a live plant. Outdoors this usually happens at planting/ germination stage in early spring.

  3. It takes 40 days from the start of the colony to a colony visible to the naked eye. UV light helps to spot colonies earlier than that. As do microscopes. UV light also helps greatly by finding the overwintering PM spots on dead plant material.

EXTERMINATE

Indoors:
Restart with your whole room vegging.
Remove all plant debris. Cleaning is not necessary.
Spray all the plants 2 times with sulfur, 2 weeks apart.
1 tablespoon of 90% sulfur for a liter of water. Shake your mister constantly or add a surfactant.
Done.
Don’t bring in infected cannabis plant material again.

Outdoors:
Scorched Earth: In early spring spray the soil with sulfur on places where there were plants growing previous season. Do this two weeks apart. I’ve seen him mention you can use double the dosage, but most of the times he says just to use the normal dosage of 1 tablespoons for a liter.

If you start from seed you’re good to go.
If you start from clones you have to spray them 2 times, 2 weeks apart before putting them outside.
Done.

CAUTION
Do not spray sulfur after an oil-based spray, it will damage your foliage badly. Joe says to wait 30 days to be on the safe side. But he also says that he never tested the limit. I’ve seen other people mention to rinse the oil off with a few foliar feeds and then you can apply after about 14 days.

Do not spray sulfur on flowering plants, it’s gross.

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