Confirmed weed hosts of Sclerotinia sclerotiorum found in South Africa include the common blackjack (Bidens pilosa), common cosmos (Bidens formosum), pigweed (Amaranthus deflexus) and tall khakibos (Tagetes minuta; Phillips, 1992). These provide ‘shelter’ for the pathogen out of season and adding to the persistence of the pathogen during the season. Furthermore, ~40 weeds found in South Africa are reported to be susceptible when cross-referencing Botha (2001) with Boland and Hall (1994) and Saharan and Mehta (2007), however these are to be confirmed for pathogenicity in South Africa.
References
- Boland, G.J. and Hall, R. 1994. Index of plant hosts of Sclerotinia sclerotiorum. Canadian Journal of Plant Pathology 16: 93-108.
- Botha, C. 2001. Common weeds of crops and gardens in southern Africa/ Algemene onkruide in gewasse en tuine in Suidelike Afrika. Agricultural Research Council, Potchefstroom, South Africa.
- Phillips, A.J.L. 1992. Some common weed species as alternative hosts for Sclerotinia sclerotiorum. Phytophylactica 24: 207-210.
- Saharan, G.S. and Mehta, N. 2007. Sclerotinia diseases of crop plants: biology, ecology and disease management. Springer: Netherlands
Author: Lisa Rothmann
Universtiy of the Free State UFS
Department of Plant Science, Plant Pathology