...no man, you don't need to chop and i seriously doubt powdery mildew would pose any risk to human health, ...but with nearly 4 weeks to go you have plenty of time to treat it.
...first, you need to do some research on the lifecycle of pm so you'll know better how to prevent it in the future, pm spores are ubiquitous so if the conditions are right, pm will occur.
...anyway, if your op is not too large then you can successfully treat it with milk, just mix it with water at a 10 to 1 ratio, water to milk, then spray ALL your plants, even any that are in veg or in another room, and try to avoid spraying directly on the buds, just all the leaves, both on top and the undersides.
...you will be amazed to see the pm disappear instantly but don't be fooled, it isn't gone, pm is a systemic disease like an infection so you'll need to re-apply every 3 days or so until you harvest to keep it in check, ...it can take more than a month of repeated sprayings to completely rid yourself of pm to the point it doesn't come back but you'll be harvesting by then.
...btw, if you treat all your vegging plants with Eagle20 it will cure them in one treatment but you can't use it on your flowering plants as it is unsafe for human consumption.
peace, bozo
btw, here is some info on milk where you can see that the milk actually boosts your plants immune system.
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Milk is a useful fungicide in the garden, and is more effective than standard chemical brands.
Researchers believe the potassium phosphate in milk boosts a plant's immune system to fight the fungi.
Where most organic gardeners use a baking soda, soap and oil solution, milk may be substituted to combat the unwanted fungus.
Preparing a Milk Solution and Spraying Schedule
The correct dilution and spraying schedule for garden plants depends on the situation and takes some trial and error.
A milk fungicide solution can range from 1 part milk to 9 parts water, to a strong, milk-only solution. A 1:1 dilution may work for a week, but a 1:8 solution requires spraying every 3 or 4 days.
Skim milk may work better than whole milk, as the higher fat milk may clog a sprayer; even reconstituted powdered milk works.
Uses for Milk Fungicide
Milk was originally used in the garden to treat powdery mildew on squash plants. It is now also commonly used on flowers such as rudebekia (Black-eyed Susans) and Begonias to cure powdery mildew.
Milk has also been used to cure Botrytis on a Cyclamen houseplant. This was applied full strength every morning (leftover breakfast milk). Rotten leaves were picked away and the plant pulled through with no more Botrytis.
Black spots and rust on roses can be controlled but not cured with milk. Fortunately, milk can prevent the spread of these fungi to other plants and new leaves. This can be very useful when bringing home a plant from the nursery and finding a black spot.
The copyright of the article Milk as a Garden Fungicide for Powdery Mildew, Botrytis, and Black Spots in Organic Gardening is owned by Deborah Turton. Permission to republish Milk as a Garden Fungicide for Powdery Mildew, Botrytis, and Black Spots in print or online must be granted by the author in writing.
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by Arzeena Hamir
Powdery Mildew
Less than 3 years ago, researchers in South America discovered a new alternative to controlling powdery mildew. Wagner Bettiol, a scientist from Brazil, found that weekly sprays of milk controlled powdery mildew in zucchini just as effectively as synthetic fungicides such as fenarimol or benomyl. Not only was milk found to be effective at controlling the disease, it also acted as a foliar fertilizer, boosting the plant's immune system.
Powdery mildew in the cucurbit family is caused by the organism Sphaerotheca Fuliginea. It is a serious disease that occurs worldwide. For decades, organic gardeners had to rely on making a spray from baking soda to control the disease. Now, instead of measuring out the baking soda and combining it with a surfactant (a "sticking" substance) of either oil or soap, gardeners need only head for their refrigerators.
In his experiments with zucchini plants, Bettiol found that a weekly spray of milk at a concentration of at least 10% (1 part milk to 9 parts water) significantly reduced the severity of powdery mildew infection on the plants by 90%. While some gardeners may be tempted to increase the concentration of milk for more control, Bettiol found that once concentrations rose above 30%, an innoccuous fungus began to grow on the plants. How does milk control powdery mildew?
Scientist aren't 100% sure how milk works to control this disease. It seems that milk is a natural germicide. In addition, it contains several naturally occurring salts and amino acids that are taken up by the plant. From previous experiments using sodium bicarbonate, potassium phosphate, and other salts, researchers have found that the disease is sensitive to these salts. It is possible then, that milk boosts the plant's immune system to prevent the disease.
Milk used around the world
The benefits of using milk to control powdery mildew haven't been isolated to Brazil. Melon growers in New Zealand are saving thousands of dollars every year by spraying their crops with milk instead of synthetic fungicides. The melon growers in New Zealand have been so successful that the wine industry is taking notice and beginning experiments using milk to control powdery mildew in grapes.
What kind of milk should be used?
In Bettiol's original experiment, fresh milk was used, straight from the cow. However, this is obviously not feasible to most home gardeners. The research work in New Zealand actually found that using skim milk was just as effective. Not only was it cheaper, but the fact that the milk had no fat content meant that there was less chance of any odours.
Wagner Bettiol's original article was published in the journal Crop Science (Vol. 18, 1999, pp. 489-92).
