Some Observations on the Root System of some Tropical Dicotyledonous Weeds¹

Studies were conducted to understand the rooting patterns of some major dicotyledonous weeds, which play an important part in the competition for nutrients, moisture, and space with the crops. Observations indicated that the weeds had wide range of variations in their rooting patterns like depth of tap root, frequency, distribution, and angular diversions of lateral roots at different zones of the tap root. On the basis of the distribution of the lateral roots, the dicotyledonous weeds were grouped under seven major categories. The distribution of lateral roots at different zones indicated their efficiency in competition with the associated crops. It is suggested that the efficacy of a weed control method on a particular weed depends considerably on the pattern and distribution of its root system. The results are interpreted as supporting evidence to the belief that the study of root syslems of weeds and the associated crops can be an important field of research in weed ecology and crop-weed association.