Clubroot of crucifers is main disease in the brassica production in the Metropolitan Region of Curitiba, Paraná State. Favorable environmental factors, lack of resistant varieties and efficient chemical control along with successive plantation of the same family species have collaborated to inoculum dissemination. Aiming to control this disease with the lowest environmental impact, the present study verified the effect of pre-plantation medicinal and aromatic plants in the reduction of Plasmodiophora brassicae inoculum. Two experiments were carried out under greenhouse conditions at 'Ciências Agrárias' sector at ´Universidade Federal do Paraná', from June to November 2003 as well as from July to December 2004. The experiment was installed in a completely randomized design with nine treatments and six replications. Medicinal and aromatic plants used in the treatments were mint (Mentha piperita L.); basil (Ocimum basilicum L.); bardana (Arctium minus Hill); calêndula (Calendula officianalis L.); chive (Allium fistulosum L.); parsley (Petroselinum hortense Hoffm) and salvia (Salvia officinalis L.). As control samples, inoculation and infested soil, both inactive, were used. Pots with 3 kg of steam-sterilized soil were used, and as an inoculum of P. brassicae 2,5 g of galls were used per pot. Rudbeckia (Eruca sativa Mill) was the susceptible host. Forty days after rudbeckia plantation, fresh foliar mass, the incidence and disease severity index were determined. The greater fresh foliar mass and lower severity index were obtained in the 2003 experiment with the treatment pre-plantation of "bardana", parsley, mint, basil and chive.
clubroot of crucifers; rudbeckia; alternative control
