Fusarium Wilt
The United States released this fungus in an area; it later had devastating effects on cannabis plants even after winter had passed it stayed in the soil. Seedlings that were planted were killed several years after the fungus was released. This fungus can be air borne and transmitted like other fungus and pathogens, it gets in through susceptible plants that have been wounded through environmental factors like animal attacks, pruning, LST (Low Stress Training), pest infestation and using cutting utensils that are not sanitary that may have fungus or bacteria on them. Fusarium wilt causes internal damage to vascular lines inside the plant and blocks the plants ability to carry water and nutrients. Symptoms included wilting of the plant, leaves becoming necrotic and yellowing wilting of the leaves while the yellowing leaves may look like a nutrient deficiency, this is clearly a mask, with Fusarium wilt, leaves will yellow and stay on the plant, where with a nitrogen deficiency the leaves will yellow and fall off. While not affecting the roots, it does affect inside the plant cell walls, inside the plants walls will reveal a red brown color inside the tissue. Stems will change color from normal green and purple hue, to a dark purple to blackish color. This pathogen can get confused with root rot, because the symptoms this pathogen shows are nearly the same as root rot, but roots are not affected. This clogging effect inside is what causes the external symptoms. While this fungus is traveling inside the plant, the toxins spread to uninfected areas and causing the clogging effect internally, these toxins is what causes the other un infected tissue to start to show the 2ndary problems, which are slow wilting of the leaves, stem collapse, stem discoloration and overall droopiness (as if the plant is dry and had no water) to parts of the plant, even if they get plenty of water. This fungus is a real killer to cannabis plants, any remaining plants that are survived can be stunted. Fusarium Wilt thrives in warm moist temperatures, which is why southern states have Fusarium Wilt the worst.
Prevent and Control
Fusarium Wilt is by far one of the hardest things for cannabis to overcome, if it ever does overcome it. Your plant health, environment and strain have a lot to do with weather or not Fusarium wilt will take over your plants. This pathogen mainly affects cannabis and hemp family, but can affect other plants but does not show the damaging effect it has on cannabis, like it does on other kinds of plants. This pathogen was breed specifically to attack wild cannabis plants and growers who grow there plants outdoors’. There is no form of organic control for this type, reason for this is, because the fungus is so strong and not susceptible to much of anything unless you get it right when it starts, if you do not get it in time, it thrives in the plants and consumes and kills the plants. There is only a few ways to control this fungus, one is to fumigate the area you are growing in killing the pathogen in the soil while it is dormant, so when you grow in this area again, your plants are much less likely to get it, the only other way your plants could get this if not from the soil, is from airborne spores get in through open wounds on your plants leaves, stems and stalks. Plants that produced seeds when it was infected with Fusarium wilt should not be used, as the pathogen stays dormant on the seed and attacks it when the seedling emerges and causing the “damping off” effect and thus killing the seedling before it even has a chance to grow it’s real first set of leaves. Acidic soil helps boost Fusarium wilt. Stay away from acidic soils .Counteract this by using dolomite lime, or green sand Using potassium and calcium enriched organic nutrients can help fight off and prevent Fusarium wilt, excessive amounts of nitrogen, phosphorus can speed up Fusarium wilt.
If your plant gets this it will surely die, the only thing you can do is try to reduce the destruction by foliar feeding areas that are not infected, cut off infected areas discard them away from your growing areas and treat the wound with h202 (Hydrogen Peroxide).
Making sure you clean your tools afterwards is important. Treating with fungicides will not work in controlling this.
