Fusarium wilt is most prevalent in indoor gardens and greenhouses is where it does happen outdoors. Reservoirs where nutrient solutions are above 75° F (24° C) create a perfect condition for Fusarium to flourish to keep the reservoir cooled.
If water is an issue, then you will need to drain the reservoir and refill it up with fresh water as well as nutrients. Fusarium wilt starts as showing small spots on older lower leaves.
Interveinal chlorosis develops on the leaves very quickly and leaf tips may curl before wilting along with dying off. With fusarium wilt on either part of the plant will wilt and even possibly the whole cannabis plant.
You can check your plants for this, by cutting one of the main stems in half and look for a reddish-brown color inside. Cleanliness is the best prevention, along with using fresh, sterile growing mediums.
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