Mikania weed, Mikania micrantha H.B.K., a perennial plant of neotropical origin, is a major threat to natural and plantation forests and agricultural systems in Asia and the Pacific. In India, it is a serious weed in the south-eastern and north-eastern states. The efficacy of herbicides to control mikania weed is short lived, and manual weeding is labour intensive and expensive. In this context, the rust fungus Puccinia spegazzinii de Toni, from Trinidad, shown to be highly specific and damaging to Mikania, was assessed for its control. Following a consultation process with the Ministry of Agriculture, Government of India and other local stakeholders, the rust was imported in 2004 into the quarantine facility at the National Bureau of Plant Genetic Resources in New Delhi. After additional host-specificity testing, field release was permitted by the Government of India in 2005. The rust was first released in tea gardens in Assam (north-east India) in October 2005 but did not establish, most likely due to the presence of a biotype of the weed that was partially resistant to the rust pathotype used. In Kerala (south-west India), releases of the rust were initially made in agricultural systems in August 2006, followed by forest sites. These releases are now considered to be successful; the rust has spread and is persisting. This is the first instance where a fungal pathogen has been used as a biocontrol agent against an invasive alien plant in continental Asia. An awareness-raising campaign on the merits of biological control of invasive alien weeds, targeting the general public, farmers, policy makers, forest officials and the scientific community, was undertaken. The range of methods, including engaging the media, publications and demonstrations are discussed.
Sankaran, K.V.; Puzari, K.C.; Ellison, C.A.; Kumar, P.S.; Dev, U. Field release of the rust fungus Puccinia spegazzinii to control Mikania micrantha in India: protocols and awareness raising. In: Julien, M.H., Sforza, R., Bon, M.C., Evans, H.C., Hatcher, P.E., Hinz, H.L. and Rector, B.G. (Eds), Proceedings of the XII International Symposium on Biological Control of Weeds. CAB International, Wallingford, UK (2008) 384-389. ISBN 9781845935023