For diagnosis of plant disease, it is essential to determine whether the disease is caused by a pathogen or an environmental factor i.e. abiotic factor. It is also important to know whether the disease is infectional or non-infectional. Diagnosis of a disease caused by either a virus, viroids, rickettsia or …

Plant diseases affect the existence, adequate growth and productivity of all kinds of plants. A diseased plant is a plant that cannot carry out all the physiological functions. So, the importance of plant diseases in the agriculture sector is very significant. In the developing countries, 50-80% of the population is …

Based on causal agents Infectious or biotic plant diseases. Non infectious or abiotic plant diseases or physiological disorder. A. Infectious diseases A disease that is caused by pathogens which can spread from a diseased to a healthy plant. They are caused by animate factors. Viral disease: Witches broom. Bacterial disease: …

This series includes the difference table between Habitat and Niche Autochthonous and Allochthonous Neuston and Pleuston Extremophile and Extremozyme Habitat Niche A habitat is an ecological or and environmental area that is inhabited by a particular animal, plant or other types of organisms. A niche is a term describing the …

The Winogradsky column is a simple device for culturing a large diversity of microorganisms. Invented in the 1880s by Sergei Winogradsky, the device is a column of pond mud and water mixed with a carbon source such as newspaper (containing cellulose), blackened marshmallows or egg-shells (containing calcium carbonate), and a …

Nitrogen fixation is a process by which molecular nitrogen in the air is converted into ammonia (NH3) or related nitrogenous compounds in soil. Atmospheric nitrogen is a relatively nonreactive molecule that is metabolically useless to all but a few microorganisms. Biological nitrogen fixation converts N2 into ammonia, which is metabolized by …

The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among the atmosphere, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification, …

Positive and negative interactions take place not only between microbes but also between microbes and plants. The rhizosphere is a zone of predominantly commensal and mutualistic interactions þetween microbes and plants. Plant roots provide such suitable habitats for the growth of microorganisms that high numbers of different microbial populations are …

Organisms living together in a community influence each other directly or indirectly under natural conditions. All vital process of living such as growth, nutrition, reproduction required interactions between individuals of same species, or between species which are inter and intra-related. Such relationships of individuals in a population of an ecosystem …

Polysaccharides are polymeric carbohydrate molecules composed of long chains of monosaccharide unit bound together by glycosidic linkage. Example: starch, glycogen, cellulose, chitin etc. Characteristics of polysaccharide On hydrolysis, they yield monosaccharide units which are usually similar. D glucose is the commonest component of polysaccharide. They have high molecular weight. They …