The invention relates to a novel bag system containing materials intended for the treatment of plants, including materials that actively affect the growth of parasites or protects against them. These bag systems protect and isolate the active substances. They make it possible to obtain the final preparation intended for the treatment and care of plants without dosing and without the user coming into contact with the active substance or substances. The bag according to the present invention comprises a volume of between 5 and 1500 ml. The ratio between the length of the transverse and the depth, T/P, has a value between 30 and 1. The ratio of the transverse length, T, and the longitudinal length, L, has a value between 1/1.1 and 1/16. The minimum length of L is 16 mm and the maximum length is 210 mm.
