Plant Pathology (2011) 60, 661-670

J. Köhl, M. Vlaswinkel, B.H. Groenenboom-de Haas, P. Kastelein, R.A. van Hoof, J.M. van der Wolf and M. Krijger (2011)
Survival of pathogens of Brussels sprouts (Brassica oleracea Gemmifera Group) in crop residues
Plant Pathology 60 (4), 661-670
Abstract: Mycosphaerella brassicicola (ringspot), Alternaria brassicicola and A. brassicae (dark leaf spot) and Xanthomonas campestris pv. campestris (black spot) can infect leaves of Brussels sprouts resulting in yield losses. Infections of outer leaves of sprouts cause severe losses in quality. Crop residues can be a major primary inoculum source of the pathogens. Their population dynamics were followed in residues of leaves and stalks of crops of Brussels sprouts during 24 months using real-time PCR assays. Leaf residues on the soil surface or buried in soil decomposed within 4 months. However, residues of stalks were present in the field after 24 months. In such residues, M. brassicicola populations increased during the first 2 months, but decreased thereafter and the pathogen was found only occasionally in the second year. Alternaria brassicicola multiplied on stalks exposed on the surface of field soil and was present on such residues after 24 months. Survival was less on residues buried in soil. Alternaria brassicae population increased in stalks exposed on the soil surface during the first months but decreased thereafter under the detection limit. Xanthomonas campestris cv. campestris populations fluctuated in time but 1 × 10⁴ cells mg⁻¹ stalk residue were still found after 24 months. Additionally, the four pathogens were present in residues of 11 commercial rapeseed crops that were analysed. The observed variation in population sizes of the pathogens between individual pieces of crop residues indicates a stochastic spread of pathogens. Unravelling the underlying processes will support the development of novel methods for sustainable disease prevention.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Jürgen Köhl, Jan M. van der Wolf, Pieter Kastelein

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Alternaria brassicae	Cabbage (Brassica oleracea)
	Alternaria brassicicola	Cabbage (Brassica oleracea)
	Neopseudocercosporella brassicae	Cabbage (Brassica oleracea)
	Xanthomonas campestris pv. campestris	Cabbage (Brassica oleracea)
	Xanthomonas campestris