Response of Ipomoea carnea Jacq. to the Organic Matter and Water Content of Soils

Ipomoea carnea, Jacq. is an exotic weed distributed in tropical countries of Asia and America. In India it is a common weed in field and has probably got introduced along with cultivation. The species is recognized well all over India, particularly along the bunds of agricultural fields. It is a localized weed and wherever it grows it dominates over the associate species. A general survey of vegetation showed that this species formed pure or mixed stands in practically all types of habitats common in an urban environment, revealing its wide ecological amplitude. The plant species, though of common distribution in countryside, shows luxuriant growth within the city, especially near slums or hutment, where deposition of undecomposed organic matter and domestic waste are rampant. Likewise, luxuriant plant growth is also observed on toxic waste, water logged ground and sometimes, even on dry soils. Its gregarious and cosmopolitan distribution reflects on its inherent ability to either circumvent or overcome the adversity itself. It appears, therefore, that urbanization has been a spent force in so far as Ipomoea carnea is concerned. The organic matter in soils originates from green plants, animals and microorganisms. The nature of organic matter is governed by inputs and soil metabolism. Chemically, the soil organic matter is a potential source of N, P and S for plant growth and it aids in rendering available soil Ca, Mg, Fe and P. Humic colloidal substances function for base-exchange capacity of soil. Organic matter also functions as a source of CO2 for the higher plants. Water content of soil exerts a profound effect upon the form and structure of a plant. It is well known that compaction of soil can greatly restrict ischolar_main proliferation particularly when the soil is low in water content. The yield of plant may also be affected by deficiency of water, even though the soil is not allowed to dry to permanent wilting point. Water stress also affects leaf area through hastening the senescence. Present paper deals with response of Ipomoea carnea to different levels of organic matter and water contents of soils.