This article will be devoted entirely to looking at various types of pests that can attack our marijuana plants. The pests that we can see this time will be: Botrytis, Mildew, Powdery mildew and the dreaded Fusarium. All these pests are caused by high humidity in the crop and their appearance can be controlled by varying the humidity factor. We will be able to see remedies, biological and chemical , specific to combat each of the plagues and some of the recommendations that we should follow every time we deal with some of these products. The cleaning and disinfection of both the growing area and the materials we use will be, with total security, the best way to prevent the appearance of all these fungi, since they can remain dormant for a year to another, causing damage to our beloved marijuana plants.
Botrytis (Botrytis cinerea)
This pathogenic fungus is one of the most feared pests in outdoor crops in many areas of Spain. In that case we will not be able to control the relative humidity we have, but we can choose the plants that best suit our growing area (dry areas, wet areas). Botrytis appears on plants in the flowering phase, so we should not use any type of chemical remedy , since we run the risk of this product remaining in our flowers. In the case of using chemical products during flowering, we must take into account the safety periods after applying the product, since if residues of the product remain on the buds, marijuana can be toxic to our body . In order not to find ourselves in this fatal case, we can turn to various brands that offer us biological products based on plant essential oils and concentrates that can be used as a preventive measure. In my opinion, good ventilation in the growing area will prevent or delay the appearance of this fungus. We must be vigilant during the harvest to clean the affected areas with Botryris so that it cannot affect healthy flowers.
Botrytis Photo: Cannabis Magazine
Powdery mildew (Blumeria graminis)
It is also one of the pests most feared by outdoor growers in much of the country. It is a fungus that is characterized by colonizing first the leaves and then the flowers , forming spots of a white powder. We should eliminate the powdery mildew before it colonizes much of the marijuana plant and we have to dispose of it. There are several specific phytosanitary products on the market to combat powdery mildew (chemicals), but we can only provide all of them during the growth phase. If the appearance of the plague surprises us in the flowering phase, we can resort to biological products that we can find in the Grow Shops. As with all pests prevention is essential and, in this case, we can use home remedies such as horsetail tea (fumigated). On occasion I have heard that spraying with a mixture of orange juice and water the affected areas of the plant could effectively combat this fungus. Other growers use the same method substituting the juice for skimmed milk , in order to eliminate the fungus in its entirety. These two home remedies can be applied during the flowering phase of our plants without affecting their optimal development. We should remember that if the cultivation in which the powdery mildew has appeared is being carried out indoors, we will change the intraction filters that we are using, since the powdery mildew is transported with the wind.
Downy mildew (Peronospora parasitica)
Mildew occurs less often in cannabis plants, but for this reason we should not ignore its effects and how to combat it. This is a fungus that occurs in spring and develops when humidity conditions are more favorable for it (Summer, autumn). It can be recognized by creating spots on plants with yellow tones on the upper part of the leaves and whitish on the lower part. The best way to stop the arrival of this fungus is to avoid water stress , which could favor its appearance. Prevention through applications of horsetail, chamomile, nettle and elderberry teas (fumigated) will also be very helpful. All these natural remedies will work perfectly if mildew is not yet widespread . Let's not forget that we must treat the plants with these remedies from the beginning of their vegetative phase (growth) to guarantee their effectiveness.
Fusarium (Fusarium oxysporum)
This pest affects cannabis plants and there are several points that we must take into account in order not to favor the appearance of it. To prevent the appearance of Fusarium, we should make use of Trichoderma, a beneficial fungus that will colonize the root system without allowing the Fusarium fungus to colonize it. A moist root system can be a conditioning factor for the appearance of this fungus. We can recognize the arrival of Fusarium, since once it affects the plant, it will begin to show wilting of the leaves, yellowing and sometimes it can cause the death of the plant. So far one more week, thank you very much to all the readers.
Jhonny_Pot.