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The production of cauliflower and other brassicas has been impacted worldwide due to the occurrence of the disease clubroot,caused by Plasmodiophora brassicae (Wor.). Therefore, it is necessary to search for disease management strategies that may contribute to reducing the losses caused. The objective of this work was to evaluate the effects ofdoses of castor bean cake(CK) on the severityof the disease and on the growth of cauliflower plants. Two experiments were carried out in a greenhouse where, in tubes and pots, respectively. In the first one, the effects of CK doses (0, 10, 20 and 40 Mg ha-1) on the disease incidence and dry mass of the aerial part of plants (DMAP) were evaluated.In the second, theeffects of thedoses of CK (0, 10, 20, 30 and 40 Mg ha-1) on disease severity, root attributes and biomass accumulation in plants were evaluated. Significant differences were observed in incidence, which decreased, and DMAP, that increased,as a function of doses. There were decreases in the severity of the disease and increasesin the growth of healthy roots. In addition, positive effects on plant height, number of leaves and dry mass of leaves, stemsand roots were observed. It is concluded that the use of castor bean cake was promising and further studies should be performed under field conditions and with longer cycle times

Clubroot, caused by Plasmodiophora brassicae, is a disease that limits the cauliflower cultivation and is difficult to control. This study aimed to evaluate the efficiency of liming combined with the use of Trichoderma harzianum-based biofungicide for the control of clubroot in cauliflower. In a field experiment, the use of the biofungicide in combination with the application of calcined limestone doses (0 Mg ha-1, 1.0 Mg ha-1, 2.0 Mg ha-1 and 4.0 Mg ha-1) was evaluated. Subsequently, in a greenhouse, the biofungicide combined with liming with quicklime (2.54 Mg ha-1) was tested, and cyazofamid and water were tested as controls. The disease severity and attributes related to root and plant development were analyzed. In the field experiment, the healthy root volume and fresh weight, total root dry weight and inflorescence fresh weight and diameter were all significantly increased, while the diseased root volume, in response to the limestone doses, was reduced. The biofungicide reduced the root growth and inflorescence fresh weight. In the greenhouse, liming increased the healthy root volume and fresh weight, as well as total root dry weight, and reduced the disease severity. No significant difference was observed between the biofungicide and the control (water), which were inferior to cyazofamid. The biofungicide was not efficient in controlling the disease and did not favour the growth of cauliflower plants, either alone or combined with liming. Liming reduced the disease severity and increased the cauliflower root growth and yield.

Objetivo do presente trabalho foi avaliar o desempenho de cinco híbridos de couve-flor (Brassica oleracea var. botrytis), em condições de campo em Seropédica, Baixada Fluminense do Rio de Janeiro. Realizou-se ensaio no período de junho a setembro de 2017. Avaliaram-se os híbridos Sharon (Sakata), Bonus (Tecnoseed), Barcelona (Seminis), caracterizados como de meia estação; e Desert (Tecnoseed) e Verona (Seminis), recomendados para cultivo de verão. O delineamento experimental adotado foi de blocos casualizados com cinco tratamentos, quatro repetições e quatro plantas úteis por parcela. As plantas foram colhidas aos 64, 69 e 73 dias após o transplantio quando se avaliaram a produtividade comercial estimada (PE); precocidade média (PM); número (NF), massa fresca (MFF) e seca (MSF) de folhas; diâmetro horizontal (DI), massa fresca (MFI), seca (MSI) de inflorescências. Todas as plantas avaliadas apresentaram inflorescências, porém com variações de características em função do cultivar. Não houve diferença entre as cultivares quanto à precocidade. A cultivar Sharon apresentou maiores valores de MFI, MSI, DI e maior produtividade (17,90 Mg ha1), seguida por Bonus (13,68 Mg ha1). As demais cultivares apresentaram produtividade de 7,88 a 9,56 Mg ha1, não diferindo entre si. Conclui-se que a produção de couve-flor de meia-estação e verão nas condições de inverno da Baixada Fluminense foi possível e satisfatória e que as cultivares Sharon e Bonus se destacaram por maior produtividade e crescimento de folhas e inflorescências.