Soil Factors Related to the Severity of Clubroot in Rio de Janeiro, Brazil

Abstract

Soil pH and calcium levels are determining factors in the success or failure of managing clubroot during the cultivation of Brassica spp. The aim of the present study was to evaluate the influence of soil attributes in tropical regions on the development of roots and clubroot and the accumulation of biomass and nutrients in cauliflower. One hundred and fifty-one samples of soil and plants were collected from 16 family farms that have a history of more than 50 years of regular cauliflower cultivation in Nova Friburgo, Rio de Janeiro, Brazil. Chemical and physical analyses were performed on the soil samples, and the severity of clubroot and the accumulation of biomass and

Liming and biofungicide for the control of clubroot in cauliflower1

“…The effect of liming probably derives from both its beneficial action on the neutralization of Al +3 and its phytotoxic effect on root development (Sousa et al 2007, Bhering et al 2017, as well as from its positive effect on the increase in pH and Ca +2 levels, which negatively affect the germination of P. brassicae spores and root infection by the * For each variable, means followed by the same uppercase letter in the row and lowercase letter in the column do not differ significantly according to the Tukey test (p ≤ 0.05). 1 Data transformed using √ x + 1.…”

“…Liming, besides helping to reduce losses caused by clubroot (Donald & Porter 2009), can increase cauliflower yield, as cauliflower is highly demanding of soil fertility and poorly tolerant to acidity and toxic Al +3 (May et al 2007, Bhering et al 2017. Moreover, the elevation of pH with liming may favour an increase in soil biological activity (Campos et al 2013), which may be important in suppressing clubroot (Penalber 2009).…”

“…This molecule was registered recently and acts on resting spore germination (Agrofit 2017). Thus, cauliflower producers, such as those in Serra Fluminense, a region with serious problems with clubroot (Bhering et al 2017), have been using biofungicide based on Trichoderma spp., together with other control measures, and obtaining variable results.…”

“…A calagem reduziu a severidade da doença e aumentou o crescimento radicular e a produtividade de couve-flor. (Bhering et al 2017) and in the world (Diederichsen et al 2016).…”

Identification of Plasmodiophora brassicae effectors — A challenging goal

“…Brassica crops are widely cultivated and economically important for many countries around the world, with economic losses exceeding billions of dollars per year [1,2]. Clubroot disease, although it appears to have been first identified in Western Europe, today has been reported in countries as widely distributed as Brazil, South Africa, Australia, New Zealand, China, and Russia, across six of the seven continents [2,3]. Clubroot is caused by Plasmodiophora brassicae , a soil-borne pathogen member of the Order Plasmodiophorales, which are obligate intracellular parasites of fungi, algae, or higher plants [4].…”