Department of Plant Physiology, Indira Gandhi Agricultural University, Raipur - 492006, Chhatisgarh, 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. 328, (2004).
Allelopathy or the chemical influences of plants on each other in an ecosystem, is a new concept of plant-plant interaction other than competition, because allelopathy involves addition of material (chemicals) in to the environment while competition involves removal of resources. Therefore, the field experiment was undertaken in the wet season of rice crop during 2003–2004. Five long duration varieties (Mahamaya, Swarna, 1001, HMT, Dubraj, 1–9) in experiment I and three short duration varieties (1010, Poornima, IR-64) in experiment II were tested to identify the varietal impact on floristic composition of weed species in upland condition of transplanted rice. The quantitative evaluation of weed species and their composition were measured at different time intervals. Similar herbicidal treatment and doses were applied to both short and long and short duration varieties. There was significant variation in weed growth rate, weed frequency, weed density and weed dry weight within both groups of rice varieties. Therefore, the requirement of herbicide also differed as per the varieties response. Hence, the study highlights the possibility of the presence of allelopathic impact of these rice varieties on weeds. There are, however, methodological difficulties and challenges in the allelopathy research and appropriate methodology is crucial for integrating allelopathy into ecological theory. A combined approach coupling laboratory and field studies has helped us to understand better. Finally, concerted efforts must be made to analyse it more specifically.
