Incidence of Red Rot Disease of Sugarcane in Thakurgaon and Rajshahi Areas with Especial Reference to Ecological Factors

Abstract

A set of biotic and abiotic habitat factors that determine the distribution, growth and reproduction of species. Physiochemical I. e. abiotic factors are fundamentally important. They vary from place to place. For each abiotic factor, a species possesses an amount of tolerance within which it can grow and reproduce. Different sugarcane varieties display different sets of tolerance ranges and these are reflected in their forms and functions i.e., in their vegetative organs. That is why ecologists pay greater attention to the vegetative parts of plants than to their floral ones, as the floral parts remain unchanged even under diverse habitat conditions. According to Moore et al. (1986) any adaptation of sugarcane to any environment induces morphological, anatomical, pathological and physiological changes. According to Stocker (1960) the structural modifications occur in nature due to the scarcity of water. Water and light greatly influence the external and internal structure of sugarcane as well as their physiological process. Sugarcane varieties that prefer wet/or moist habitats are hygrophytes and those that can adjust 1.0 drier habitats are xerophytes. Most of the xerophyte’s arc· sun loving and are known as helophytes, while most of the hygrophytes are shade loving and are known as schizophytes. Species without any Eco phenic and/or ecotype variations are adapted only to a fixed combination of environmental factors and have very narrow ecological amplitude, while those with much variation can fit into a wide range of habitat conditions and hence have wide ecological amplitude (Daubenmire, 1959). Wild uncultivated-sugarcane appears to have broad ecological amplitude. About 300000 species of plants have so far been identified in our planet, while tens of thousands more remain undiscovered. Of these only 1500 species (about 0.5%) are nurtured for food, fodder, fiber, timber, medicine, sugar, beverage and flowers.