Proceedings of the 21st Asian Pacific Weed Science Society Conference (Editors: B. Marambe, U.R. Sangakkara, W.A.J.M. De Costa, and A.S.K. Abeysekara), 2-6 October 2007, Colombo, Sri Lanka. EFFECT OF SEEDLING EMERGENCE TIME ON THE PERFORMANCE OF MAYWEED (Anthemis cotula L.): AN ALIEN INVASIVE SPECIES IN KASHMIR HIMALAYA I. Rashid, Z. Reshi and B.A. Wafai Department of Botany, University of Kashmir, Srinagar, J&K, India
[email protected] Abstract: Biological invasions, caused by non-native invasive species are a major factor contributing to ecosystem perturbations and hence are being actively pursued worldwide. Mayweed (Anthemis cotula L.), a native of southern Europe-West Siberia is an aggressive invasive species in Kashmir Himalaya, India. Among the myriad of attributes, seedling emergence time is critical to its successful colonization of habitats with varying levels of soil disturbance. Field studies revealed that the species recruits individuals over an extended period of time from September to May. This recruitment period is interspersed by harsh snowy winter (December-February) and hence the established plants of the species are constituted of pre-winter and post-winter populations, with former contributing to the fitness component of its life history and latter to the survival component. Except for number of achenes per capitulum and achene weight, all other investigated parameters such as stem height, number of primary branches per plant and number of capitula per plant were significantly higher in individuals belonging to pre-winter population in than the individuals constituting the post-winter plants. Fecundity of pre-winter individuals was further enhanced if decapitated by a specific herbivore that results in over-compensatory growth.