Allelopathy in Agroecosystems

Allelopathy is new science, which indicates inhibitory or stimulatory biochemical interactions between the two plant spp. Prof. Hans Molisch, a German Plant Physiologist coined this term in 1937. The first English Book ‘Allelopathy’ written by Dr. E.L. Rice was published in 1974. Thereafter, worldwide, much allelopathic research had been conducted in various fields of Agricultural and Biological Sciences. Hence, International Allelopathy Society in 1996, broadened its definition to ‘Allelopathy refers to any process involving secondary metabolites produced by plants, microorganisms, viruses and fungi that influence the growth and development of Agricultural and Biological Systems’ . In future, worldwide there will be increase in demand for better quality food and in large quantity due to increased human population. Therefore for Sustainability of Agriculture, we need to minimise the use to present pesticides (weedicides, insecticides, nematicides, fungicides), to control pests (weeds, insects, nematodes, diseases) in field crops, through use of allelopathic strategies for pests management. The present pesticides used for control of agricultural pests have caused many problems, viz., development of resistance in organisms, environmental pollution, toxicity related health hazards in humans and livestock. Studies have shown a great potential of allelochemicals in pest control, thus, these may minimise or eliminate the use of present pesticides. In this new Century (2000-) role of allelopathy is also being studied in New areas viz., Auto-toxicity, Soil sickness and spread of Invasive plants. etc. The Allelopathy offers great potential to (a) increase agricultural production (food grains, vegetables, fruits, forestry), (b) to decrease harmful effects of modern agricultural practices [multiple cropping, leaching losses from N fertilizers, indiscriminate use of pesticides (weedicides, fungicides, insecticides, nematicides), tolerant/resistant biotypes in pest] on soil health/ productivity and environment and (c) to maintain soil productivity and pollution free environment for our future generations. It is likely that in the near future allelopathy will be used in crop production, crop protection, agroforestry and agro-horticultural practices in developed and developing countries. Besides, allelopathy has many other applications in agroecosystems and thus provides basis to Sustainable Agriculture. Hence, Allelopathy may become one of the strategic sciences to reduce the environmental pollution and to increase agricultural production in Sustainable Agriculture of the 21st Century. Thus, it is now receiving more attention from agricultural and bioscientists. Therefore, it is priority area of multidisciplinary research in developed Countries and currently allelopathy research is being done throughout the World. For clean environment, to avoid health hazards in human and livestock and for development and Sustainability of Organic/Ecological Agriculture, use of allelopathic strategies in farming are essential.


Prof. S.S. Narwal is Agronomist. In 1975, he was developing Multiple Cropping Systems with recently developed Short duration varieties of green gram (Vigna radiata). He observed the allelopathic inhibitory effects of preceding greengram crop (April-June) on next greengram crop (July-October), whose growth and yield were drastically reduced. However, the preceding greengram was not harmful to other succeeding crops (Sorghum, pearlmillet, cluster bean, cowpea). Similar results were reported from International Rice reseach Institute, Phillipines, and they confimed it was due to Allelopathy. He got interested in field of Allelopathy after Reading Prof. E.L. Rice Book 'Allelopathy (1974)'. He was Visiting Scientist to Department of Allelopathy, Ukrainian Academy of Sciences, Kiev for 3 -Months in 1989. This visit provided him following opportunities to know more about Allelopathy and its Applied Aspects.
(i). He joined the Multi-desciplinary Team (Agronomy, Soil Science, Plant protection, Genetics/ Plant Breeding, Horticulture, Botany/Plant Physiology, Organic Chemistry, Biochemistry, Soil Microbiology) working on both Basic and Applied aspects of Allelopathy.
(ii). Attended All USSR Allelopathy Conference, there were more than 150 presentations on various aspects of Allelopathy from different provinces of USSR. It provided intractions with most renowned Allelopathy Scientists like Prof. V.V. Roshchina, Moscow. She is still submitting Research papers to Allelopathy Journal.
(iii). Studied the Allelopathy Reprints, collected by Prof. A.M. Grodzinsky, most Eminent Allelopathy Scientist.
(iv). Read 30-Allelopathy Books written by Prof. A.M. Grodzinsky. It Prompted Prof. Narwal to write Allelopathy books.
This visit greatly broadened the understanding and vision of Prof. Narwal about Allelopathy and its applied aspects in Sustainable Agriculture. After return to India, he vigorously pursued for the Development of Allelopathy research in India.


The Allelopathy Books and its Subsidiary International Allelopathy Foundation is for professional advancement and dissemination of knowledge about the Basic and Applied aspects of Allelopathy both in Terrestrial and Aquatic Ecosystems and other related Disciplines.


The mission of The Allelopathy Books and its Subsidiary International Allelopathy Foundation is to advance the disciplines of Allelopathy to understand its role in Cropping Systems, Ecological Pests (Weeds, Insects, Pathogens) control, Forestry, Agroforestry Systems, for sustainable Agriculture and forestry.