ASK ED MARIJUANA GROW TIP #45: THE BOTRYTIS SOLUTION

There was a slight attack of botrytis due to humid conditions and stagnant air—circulation was minimal with only passive ventilation during part of the day.

We immediately went into protective mode—using Ed Rosenthal’s Zero ToleranceTM Herbal Fungicide diluted by 25%, and adding Serenade concentration at half the recommended dosage. Our reasoning was that the ERZT would kill the botrytis immediately and leave a fungicidal residue of potassium bicarbonate, which is a fertilizer usable by the plant. The Serenade also attacks the botrytis directly, thus creating a redundant kill situation. In addition, the active organisms in the Serenade continue to have residual benefit.

This has several advantages over physically removing the infected tissue while the cola is still on the plant. The first is that in removing the dead tissue there is a good possibility of damaging the healthy tissue and infecting it, since you are handling the infected area and reproductive spores may disburse to surrounding plant tissue. The second problem with it is that it is often hard to distinguish between infected and non-infected areas, especially in large buds with crevices.

This picture was taken two days after the plants were sprayed. The areas infected with botrytis fungus have dried up instead of being moist and mushy. The fungus has been killed, leaving a clear distinction between the healthy, uninfected plant tissue and the dead but no longer contagious area.

Using this combination of ERZT and Serenade, during manicuring there is a clear distinction between infected and non-infected areas, so it is easy to separate the two.
Slight damage to leaves from the fungicide, but the buds are untouched.

Comments
7 Responses to “ASK ED MARIJUANA GROW TIP #45: THE BOTRYTIS SOLUTION”
  1. Jeff says:

    Ed, it seems this year the bugs are walking through all the natural sprays in your garden saver book and my neighbors gardener blew debris all over my ladies late in flower recently so now I have some powdery mildew on one plant and a little septoria on 2 others. I sprayed them with hydrogen peroxide and iso alcohol diluted It’s late in flower and I hesitate to spray anything on them further. Thoughts?

    • Ed Rosenthal says:

      In the books MJ Garden Saver and the new MJ Pest & Disease Control you’ll see solutions that can be applied late in the season. Have you tried the combination discussed in the blog? That’s very effective and can be used within 10 days of harvest.

      Another solution uses milk. Use one part milk to nie parts water — any kind of milk is OK, whole, skim, etc. Per quart of water add 1 teaspoon potassium or sodium bicarbonate (baking soda). These create a more alkaline leaf surface and fungi can not grow in an alkaline environment.

      Best to spray early in the day or early in the light period so that the liquids have a chance to dry before dark.

      For septoria this late in the game try controlling by removing infected leaves. The powdery mildew solutions may also help with this disease.

      • Ed Rosenthal says:

        Disregard typo — here is corrected recipe for the milk solution:

        Another solution uses milk. Use one part milk to nine parts water — any kind of milk is OK, whole, skim, etc. Per quart of water add 1 teaspoon potassium or sodium bicarbonate (baking soda). These create a more alkaline leaf surface and fungi can not grow in an alkaline environment.

    • Jeff says:

      I went to the store and noted everyone copying you so I bought some serenade and made a fresh batch of your magic spice tea (with a touch of neem and canna cooking oil) for bugs and I can say the serenade kicked butt and the infected parts dried up and shriveled off nicely without impacting the good part of the flower. I can now finish them without worrying about dew. I also added Bt and found one caterpillar dead with little damage. This year I added silica to my fert schedule and it seems to help the plant resist any problem spreading.
      Thanks again

  2. David says:

    Hi There ed. Just finished ur book, the one with the leaf on the front. Great read and well edited. I’ve forever had a problem with mould being close to the equator. I have tried everything and the only thing that works for me is weak diluted clove oil ad a foliage spray, what was ur secret recipe.
    ,

  3. tony says:

    hi ed,
    I have what I think are two northern lights clones PH 6.6 or so. I gave them some bone meal. I use distilled water to irrigate. I can’t seem to get rid of the anthocyanin. The leaves are green, stems are green but soon turn purple. The stems also become woody and hard to pinch. Using G&B potting soil. They don’t seem to be growing as vigorous as the camelot kush. Temp equals 72-75 day, 65 or so at night. Help. So you have any advice? I would appreciate any help. Thanks in advance.

    Sincerely,

    A. L.

  4. Tony says:

    Hey Ed,
    What’s the deal with Northern Lights? I have what I have been told are 2 NL clones, PH is cool. Night 65, Day 72-76.Gave them some bone meal about a week ago. They maybe have gone from darkish purple/red to light lavender branch tips to medium lavender stems. The leaf stems are starting to turn purple too now. Stem tips are softer now than before. They will take a pinch. Before they were like trying to pinch a bamboo skewer, I am reluctant to give them anything. Any help you can be would be greatly appreciated. Thanks in advance Ed.

    Sincerely,

    A.L.

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