this info from many sites and many other experts. [and my experiance]
Budrot (Botrytis) is a very common worldwide fungus that attacks both indoor and outdoor crops under certain conditions.
“Budrot” is also known as “brown rot”, “grey mold” and other names. Airborne Botrytis spores can be found everywhere, all times of the year, and will attack many different species of plants. Botrytis will attack flowers, and eventually leaves and stems.
growers running sea of green, perpetual harvest, remote grows, outdoor, or multiple strains (each with different flowering periods) should keep an eye out for Botrytis near harvest time.
Outdoor growers need to be hypersensitive to weather conditions near harvest time. Rain, morning dew, frost and cool fall nights may increase the risk of budrot and powdery mildew.
Fully developed marijuana buds provide ideal conditions for spore germination: warm and moist plant tissues. Botrytis will initially attack the largest and densest buds in the garden, because they provide the ideal conditions for germination. Weak plants will also be attacked rapidly.
Identifying and preventing budrot
Budrot will infect and turn colas to mush in a matter of days and may destroy a crop in a week if left unchecked. Botrytis loves warm, and humid (50% or over humidity) conditions. Lowering humidity will slow and stop spore germination.
Good ventilation and decent air circulation help prevent infection.
A grow room may smell noticeably moldy if Botrytis has attacked one or more colas. Once a cola has been infected, Botrytis will spread incredibly fast. Entire colas will turn to brown mush and spores will be produced, attacking other nearby colas.
Ventilation may spread viable spores throughout the room.
Measures to prevent budrot in the final stages of flowering:
Early veg and flower pruning of undergrowth to promote air circulation
Hepa filter room and intake air sources.
Introduce low levels of ozone into room air. Ozone is effective against pollen, podwery mildew and other airborne spores.
Lowering room humidity (warming nighttime air and venting frequently or using a dehumidifier)
Decreasing watering cycles and amounts to reduce room humidity
Large, dense colas should be periodically inspected. Brown tissues deep within the bud will smell moldy and may become liquid. Removing fan leaves during the last few days before harvest to promote air circulation Serenade (thanks vaaran)
"Serenade controls the following: ....Botrytis, Powdery mildew, Downey mildew..."
"Certified organic by OMRI and EPA/USDA National Organic Program,
Serenade offers growers the luxury of application without weather or timing restrictions and there are no phyto-toxicity issues"
"To apply, simply spray on leaves and shoots to provide complete coverage. Best results will be had be pre-treating plants before signs of disease set it and then every week to protect newly formed foliage"
What if budrot is found?
Once budrot has been detected, the grower should isolate infected buds by removing them from the growroom immediately and harvesting the infected colas,
followed by a rapid dry of the harvested colas. Take immediate steps to reduce room humidity. Afterwards, the entire crop should be carefully inspected for infection and damage.
The grower may want to harvest early if more than one rotting cola has been found. Spores may have spread and are germinating deep within other colas.
Can I salvage budrot-infected colas?
Yes. Remove the infected colas from the main room,
Trim out the infection (Trim more than you can see – Botrytis often infects adjacent tissues) and quick-dry them. Re-inspect buds – they should not smell moldy.
Smoking infected buds is not recommended.
If you already have an issue, there are several methods of treatment/eradication.
Chamomile - is also effective in preventing damping off. (high sulfur content)
Brew a weak batch of chamomile tea, one tea bag to two cups of boiling water.
Allow the infusion to cool, then dilute it so that it is a pale yellowish color.
Add the cooled, diluted tea to a spray bottle and use as needed. This mixture will be good for about a week.
Spray the seedlings regularly until they are transplanted, to ensure that you don't have any problems with damping off.
Compost Teas - can also be effective for the control of fungus by introducing beneficial bacteria,provides nutrients that can help a plant protect itself from pathogens and increases vigor and growth.There are many commercial preparations and formula's nad many recipe's available online. But compost teas should be used fresh, and preferably within hours of being prepared. Maintain the aerobic properties by keeping the mix well aerated during the process. The tea should be dark brown, and not smell sour. If the tea smells of ammonia or smell rotten, discard. It has become anaerobic, and potentially hazardous. (e-colli, salmonella...)
Milk - is also effective against powdery mold, but scientists are still unable to determine why.Milk spray can be made from 2%, whole, or skim. Effective at a 1:9 ratio (1 part milk : 9 parts water) but the ratio is effective up to about a 1:3 ratio. (30% milk) A solution of 30% of milk or greater, and a benign mold will form on the tops of the leaves.
Neem Oil - is an all-purpose natural pesticide. It works on arthropods, and provides protection from fungal and bacterial diseases, (including gray mold) and can be used prophyllactically against powdery mildew, preventing spores from germinating.
Neem oil must be used with dishsoap per the instructions. It can be sprayed directly on the plant(s), or if there's a risk of 'blowing' the spores with the spray, (infecting other plants) it can be painted on both sides of all leaves and stems. (or both)
a) Latex gloves, it just seems like a good precautionary measure to wear these while “operating” on a Botrytis site.
b) A dampened paper bag to contain the offending bud once it’s removed and it’s billions of spores.
(Nothing like carrying an infected bud out of your garden in your bare hand while it showers your healthy babies with deadly spores.)
c) Dampened paper towel. I use these to cover over the healthy area immediate around the infection site to capture any
dislodged spores while I am removing the infected bud.
d) Sharp Scissors washed in hot soapy water and dipped in alcohol. (I am not 100% sure if alcohol kills these spores but it seems a reasonable precautionary measure).
e) Once I have the above in place, I gently pull/bend the stem slightly so as minimize disturbing the offending bud,
slide my scissors tight to the base of the stem and snip off the bad bud, it is gently put into the damp paper bag.
f) I than treat the “infection” site and associated stem area with a
copper sulphate solution on a Q-TIP to help stop the Botrytis from literally crawling up or down the stem to the next buds.
Identifying mold on marijuana
You can identify mold by looking closely for black spots, dark green spots, white/grayish stringy matter or other unusual coloring.
The mold will also noticeably effect the smell of the marijuana, turning it a more musty and unpleasant smell.
Mold spores sometimes resemble the crystal looking trichomes that naturally occur on marijuana which can cause
some novice users to mistake signs of mold for characteristics of higher grade marijuana. The best way to identify
mold on marijuana is to view it under a black light. Mold spores will appear a distinctive green hue when put under a black light.
Preventing / Treating mold on marijuana
Mold needs at least 15% moisture to survive, so the best way to prevent mold is to keep all harvested marijuana in the ideal 10%-15% moisture content level. Growers should always allow enough time for freshly cut plants to dry in a dark ventilated area. Marijuana being cured in jars should be opened every 12 to 24 hours to allow proper air flow. Always be careful when attempting to re-hydrate over-dried buds by adding orange peels or water because it’s very easy to add too much moisture and fruit peels are an easy breeding ground for mold.
Bud rot or Botrytis is one of the nastiest diseases your plants can get. It is a fungus that attacks the plant and then spreads quickly through the buds, destroying everything in its path. The onset of bud rot is mainly caused by four factors:
1. High-humidity (>50%) in a low-temp room (<70 degrees)
2. Lack of sufficient air circulation
3. Dirty pruning scissors
4. Improper removal of fan leaves where small portions of their stems are left un-removed.
Bud rot only shows up indoors when the conditions are right to facilitate its growth. To prevent it from showing up, keep the temperature of your grow room above 70deg and the humidity below 50%. Be sure to water during the beginning of the light cycle and always mop up all standing water. This will help cut down on humidity during the dark hours when it is colder in the room.
The reason the bud rot always seems to attack the biggest colas is because the biggest colas are always the highest points of the plant. There is a constant flow of water and nutrients that originate in the plant’s roots and work their way up through the plant and out the tops (Colas). The nutrients are left behind for the plant to use and the water evaporates away. This process is called transpiration and it is how plants feed themselves. Sometimes though when the buds start to get really big and dense, the water doesn’t evaporate away like it is supposed to and just collects inside the bud. This is a giant invitation for bud rot. The only thing you can do to prevent this in addition to maintaining proper climate is to install proper circulation.Put as many wall-mounted oscillating fans as you can fit in your grow room and keep them blowing on the plants. Not only will this help prevent bud rot,it will also strengthen the plants and help prevent pests as well.
Make sure to keep your pruning scissors sanitized at all times. You wouldn’t want a surgeon to use the same tools he used on the last guy on you without cleaning them first right? Sanitize your garden tools in order to prevent the transmission of diseases.
Don’t just hack away at the plants either. If you have to remove a fan leaf or take a clone, be sure to finish the job properly.Never leave any part of what you are removing intact. Make your cuts as close to the main stalk or branch as possible and make sure it is a clean cut. Remember you are creating open wounds on the plant that are very susceptible to disease like Botrytis, so do it nicely.
If done improperly, these wounds will not heal. Buds will eventually grow around these unhealed wounds and create an ideal place for bud rot to thrive and ruin all your hard work.