Department of Botany and Forestry. Vidyasagar University, Midnapore-721 102. West Bengal, India.
National Seminar of Plant Physiology ‘Physiological Basis for Improving Productivity of Agricultural, Horticultural and Medicinal Plants’. December 27–29, 2004. University of Pune, Pune, India. Abstract No. 317. (2004)
The interference in the growth of one plant by another can result either from competition which involves the removal of some factors (nutrient, water and light) from the environment/habitat or through chemical(s) released from one plant (donor) that effect to other (receiver) sharing the habitat. The latter phenomenon known as “allelopathy” is now considered as important as competition for influencing plant growth both in natural and agricultural ecosystem. The purpose of this investigation is to screen out the phytotoxicity of leaf extracts and leaf leachates of Lantana camara on mungbean (Vigna radiata L.cv.K.851), measured in terms of seed germination, speed of germination, TTC stainability. T50 (time required for 50% germination), field emergence capacity, seedling growth and some reliable biochemical indices.
This study showed that seed pretreatment of mungbean with various concentrations [1:1and 1:2 (w/v)] of Lantana leaf extracts and leaf leachates for 24 h reduced the percent germination and speed of seed germination, TTC-stainability and field emergence capacity alongwith increase of the T50. Levels of protein and activities of catalase and dehydrogenase enzymes were significantly reduced with concomitant increase of soluble carbohydrates and amino acids and activity of amylase enzyme in seed samples pretreated with leaf extracts and leaf leachates of Lantana. Seedling performance was very poor when they were raised from seeds pretreated with plant extracts and leachates. This was measured in terms of root length, shoot length, internodal length, number of leaves per plant, fresh weight and dry weight of seedlings. Decreased seedling potential in the plant extract pretreated samples was evident from the low content of cholorophyll and protein and activity of catalase enzyme. Leaf extract and leaf leachate retarded germinability and suppressed the activities of catalase and dehydrogenase enzymes being the important allelopathic indices. It was concluded that Lantana has allolepathic effect on mungbean. Hence the fast growing exotic invasive weeds like Lantana having inhibiting property should be treated as a potential threat to plant diversity in a natural ecosystem. Therefore, this study calls for the proper management of Lantana and other invasive weeds showing similar behaviour.
