Clubroot (Plasmodiophora Brassicae) - A Threat for Oilseed Rape

Abstract

Clubroot presents a serious threat to cultures of oilseed rape, especially if the share of this plant species in sowing structure is high. This is related to a long-lasting survival of pathogens resting spores in soil. The casual disease agent is Plasmodiophora brassicae Woronin -an obligatory, internal pathogen of Brassicae family which causes the formation of tumors on roots and hypocotyls. Plants with disease symptoms have a confined ability of nutrients' and water uptake and this may cause considerable losses in quantity and quality of potential yield. Monitoring performed in cultivation areas and the information obtained from farmers allowed to confirm a threat of disease occurrence in several voivodeships. At the same time there is a serious danger of the infection spread to other regions of oilseed rape crops.Confining plant infection by clubroot pathogen may be obtained mainly by applying a correct crop rotation, and also by providing resistant varieties for cultivation. In the performed greenhouse experiment, reaction to the infection caused by P. brassicae of chosen winter oilseed rape cultivars was studied. The degree of plant infection was assessed at the growth phase of green bud. It was stated that cv. Mendel revealed significantly the lowest degree of infection, as compared to the other studied cultivars. The other tested varieties were infested in a differentiated degree, however these differences were mostly not confirmed statistically. The infection level was mainly dependent on places of soil derivation.

Chinese cabbage (Brassica rapa ssp. pekinensis) – a valuable source of resistance to clubroot (Plasmodiophora brassicae)

“…Host resistance should be used rationally to avoid development of new virulent pathotypes of the disease causal agent (Korbas et al 2009). In clubroot, the stewardship of resistance genes is complicated by a lack of knowledge on the nature of, and relationship among, sources of resistance in commercial hybrids.…”

“…For the last few years the disease has been an increasing concern for farmers in Poland (Korbas et al 2009). Clubroot occurs in large areas of rapeseed cultivation, although the disease severity greatly differs between regions of the country.…”

Advances of Fungicide Application for Winter Oilseed Rape

“…Gray mould (caused by Botrytis cinerea) and wilt (caused by Verticillium dahliae) have been observed very sporadically (Sadowski et al, 2002). Clubrot (caused by Plasmodiophora brassicae) as an important disease and serious threat to oilseed rape production is recognized in many regions of Poland, especially if rape and other crucifers occupy a large part of the sowing structure (Korbas et al, 2009;Jedrycka et al, 2002). Snow mould (caused by Typhula spp.…”

Pathotypes of Plasmodiophora brassicae causing damage to oilseed rape in the Czech Republic and Poland

“…For years, clubroot was observed in vegetable crops, but was noticed only incidentally in oilseed rape. However, clubroot has been found with increased frequency on oilseed rape, causing concern among growers (Korbas et al 2009). Currently, the disease occurs in large areas cultivated to oilseed rape, primarily in the northern and south-western regions of the country; however, clubroot infestations extend to the borders with Belarus and the Ukraine Korbas et al 2014).…”