my Balsamita plant has covered itself on the leaves, both on the upper and lower side, with an impressive amount of reddish vesicles. Unfortunately I can't see them with a lens. Could it be cochineal? What can I do? treatments? And then it is no longer edible. I could send you a photograph, but I don't have a vs. e-mail address Thanks
Dear Giacomo, it is difficult to understand what a parasite is on an annual herbaceous plant without having at least one photograph; this is because there are so many pests, and some plants also have a particular response simply to the climatic or cultivation conditions, which can be exchanged for parasites. In the case of insects, in general, when looking at the leaves, you should see these insects, or, if it is cochineal, which has poor mobility, if you crush the small pink pustules, they should be swollen with eggs, and then explode of pink or reddish liquid. In this case, you can use special insecticides, and since it is a plant that you will then have to bring to the kitchen, it would be better to use insecticides that are not harmful to humans; however it considers that on any product, insecticide, acaricide or fungicide, to use in agriculture is expressed the time of deficiency: that is the period of time, after the treatment, after which it is opportune to avoid consuming parts of the plant, because the product is still present and active in it or on it. So, even if you choose to use the most harmful and polluting product on the market, you will read a label on the label such as: Lack of time 15 days; this means that for 15 days you will not have to harvest and use the plant, but after 15 days only traces of the product will remain on the leaves. Usually the products that can be used in organic farming have a much lower deficiency time than more generic products; an example of the Spinosad-based insecticides, with a wide spectrum of action, have a deficiency time usually between 3 and 5 days, and to be toxic to humans we should absorb about 5 g per kg of weight, or an incredible amount, considering that this product is not accumulated in the body. Spinosad is a sort of spore produced by a bacterium, which works on many harmful insects; against cochineal it would be better to use white oil, or mineral oil. If the leaves of your grass do not have visible insects, they may have been attacked by mites, also called red spiders, which must be eradicated with acaricides; however, you should at least notice thin webs between the leaves. If there are no cobwebs, or even insects, it could be a fungal disease, which should be eradicated using products based on copper or sulfur, again choosing products made from organic farming. In any case, after the deficiency time has elapsed, collect the balsam leaves as well, but wash them carefully before using them.