The possibilities of protection of organic cabbage crops in Poland

Abstract: In Poland strict regulations are in force limiting the availability of plant protectionproducts (PPPs) for organic farming. At present, only 28 PPPs are qualified for use in this systemof agricultural production. Among them, only 16 products are registered to protect vegetablesand/or horticultural crops. There is only 1 insecticide, 13 fungicides-bactericides and 2 plantproducts for the purpose of dressing seeds (not available for individual growers). There are only 4products registered for cabbage crops and this is a main reason that in Poland the growing oforganic cabbage is very difficult. Some research in Poland is directed towards seeking of newpossibilities for plant protection. This study involved a review of all the permitted PPPs fororganic vegetable crops in Poland. In the next part of paper the results of the insecticidal efficacyof spinosad (0.2 %), neem (0.5%), rape oil (0.1%) and garlic extract (2%) under field conditionsare shown. Treatments were applied 2 times with spray intervals of 7 days. In this experiment thecaterpillars of Pieris brassicae, P. rapae, Mamestra brassicae and colonies of the aphidBrevicoryne brassicae were observed. Pest presence and percentage defoliation due to feeding byinsect pests were assessed. The degree of effectiveness of the treatments was related to changesin leaf consumption and yield. The efficacy of spinosad and neem treatments was the best,whereas two applications of rape oil or garlic extract were insufficient to protect of plants. Testswith microbial protection were involved also. A commercial product containing Trichodermaasperellum was used. Trichoderma treatments increased cabbage head weight and decreasedsymptoms of disease compared to untreated plants.