Biocontrol of five invasive weeds of Meghalaya - A case study
Keywords:Biocontrol, Fungi, invasive, meghalaya, weeds
The state of Meghalaya, in North East India is endowed with a dense cover of natural forest. A vast majority of the forests are owned by communities who traditionally practice shifting cultivation. This has resulted in significant reduction of the original forest area leading to a drastic change in the floristic composition of the state. This is evident by the ubiquitous presence of various invasive weeds such as Mikania micrantha, Chromolaena odorata, Ageratum conyzoides, Spilanthes paniculata and Spermacoce hispida. A survey for natural fungal enemies against these weeds was carried out in the state with the objective of identifying potential biocontrol agents. A total of six pathogenic fungi were isolated from infected leaves of these target weeds. Of these, two fungi isolated from leaf spot and leaf necrosis disease of Mikania micrantha were identified as Gliocladium roseum and Phomopsis sp., respectively. The fungus isolated from S. paniculata, C. odorata, and A. conyzoides was Fusarium solani and from Spermococe hispida it was F. acuminatum. Pathogenicity test carried out on target weeds and agricultural crops grown in Meghalaya (Maize, Chilli, Tomato, Rice and Ginger) showed that all the isolated fungi were found infecting the weeds from which they were isolated and also maize and tomato. They were found non non pathogenic to seedlings of some economically important tree species of Meghalaya, viz., Pinus kesiya, Magnolia champaca, Alnus nepalensis, Chukrasia tabularis, Exbucklandia populnea and Castanopsis indica. Hence, these fungi can be tested in field condition on pilot scale, in forest areas but not in agricultural areas where maize or tomato is grown.
Chetti MB, Hiremath SM, Prashanti SK, Mummigatti UV, Kulkarni. 2001. Survey and Screening of various Pathogens for Biological Control of Chromolaena odorata. Status of Mikania infestation in Northeastern India: Management options and Future Research Thrust, pp. 146-149. In: Sankaran KV, Murphy ST, Evans, HC (Eds.), Alien Weeds in Moist Tropical Zones: Benes and Benefits. Kerela Forest Research Institute, Peechi, Kerala, India.
Gogoi AK. 2001. Status of Mikania infestation in Northeastern India: Management options and Future Research Thrust, pp. 77-79. In: Sankaran KV, Murphy ST, Evans HC (eds.), Alien Weeds in Moist Tropical Zones: Benes and Benefits. Kerela Forest Research Institute, Peechi, Kerala, India.
Haridasan K, Rao RR. 1985. Forest Flora of Meghalaya. Bishen Singh and Mahendra Pal Singh, Dehradun, Vol. 1.
Kaur M, Aggarwal NK, Kumar V, Dhiman R. 2014. Fusarium solani as biocontrol agent against parthenium weed. Mycopathology 12: 83-86.
Pimentel D, Zuniga R and Morrison D, 2005. Update on the environmental and economic costs associated with alien-invasive species in the United States. Ecol Econom. 52(3): 273-288.
Rao RR, Sagar K. 2012. Invasive alien weeds in the tropics: the changing pattern in the herbaceous flora of Meghalaya in North East India, pp. 189-198. In: Bhatt JR, Singh JS, Singh SP, Tripathi RS, Kohli RK (Eds.).
Invasive Alien Plants: An Ecological Appraisal for the Indian Subcontinent. CABI International, CPI Group (UK) Ltd., Croydon, UK.
Richardson DM, Pysek P, Rejmanek M, Brbour MG, Panetta FD, West CJ. 2000. Naturalization and invasion of alien plants: Concepts and definitions. Divers Distrib. 6, 93-107. https://doi.org/10.1046/j.14724642.2000.00083.x
Rosskopf EN, Charudattan R, DeValerio JT, Stall WM. 2000. Field evaluation of Phomopsis amaranthicola, a biological control agent of Amaranthus spp. Plant Dis. 84: 1225-1230.
Vitousek PM, D'Antonio C, Loope LL, Rejmanek M, Westbrooks R. 1997. Introduced species: a significant component of human-caused global change. New Zealand J Ecol. 21: 1-16
Waghmare MB, Waghmare RM, Kamble SS. 2011.Bioefficacy of plant extracts on growth of Botrytis cinerea causing leaf blight of rose. Bioscan 6: 643.