Miscellaneous

Azolla
Azolla is a fast growing aquatic plant often observed in many water bodies. It itself is not much useful, except that it can add organic matter on decomposition. But an algae called Anabaena AzolIae inhabits in the cavities of Azolla leaves and fix atmospheric nitrogen. Thus, AzolIa leaves acts as excellent source of nitrogen, besides their capacity to act as source of organic matter.
Use of Azolla is st"andardised and recommended in paddy cultivation mainly due to aquatic condition prevailing in paddy fields. Before paddy seedlings are transplanted, Azolla is grown for· 40 - 45 days in standing water and on full leaf growth, they are dried and incorporated in soil. Use of Azolla is reported to have increased the yields of paddy by 30 - 35%.
Blue Green Algae (BGA)
Blue green algae are autotrophic and nitrogen fixing organisms unlike heterotrophic and symbiotic nitrogen fixing microbes discussed above. They manufacture their food by photosynthesis, as they have chloroplasts. Hence, they can live independently. BGA like Anabaena and Nostoc are found to live on soil, rocks. They have potentiality to fix large atmospheric nitrogen (upto 20 - 25 kg/ha). On completion of their life cycle, they add large quantity of nitrogen to the soil. Conditions necessary to grow BGA (light, adequate moisture, 20-30°C temperature, 70-75% humidity) must be maintained in the soil, in order to grow BGA successfully.
Phosphate Solu balising Bacteria
Some bacteria like Aspergillus awamori have the capacity to solubalise the phosphates fixed in soil. It must be recalled here that most of applied phosphorus is fixed in soil, and a small part of it is available to plants every year as labile phosphorous. When such bacteria are grown in large quantity in soil during the plant growth they release large quantities of phosphorus from fixed sources and make it available to crop roots. Recently such bacterial fertilizers are also made available in the market. Phosphate solubalising bacteria have potentiality to solubalise 10 - 20kg phosphorus per hectare there by avoiding the necessity to apply phosphatic fertilizers.
Vesicular Arbuscular Mycorrhizae (VAM)
Mycorrhizae is a type of fungus living in association with plant roots. Hyphae of such fungi are found in between cortical cells of roots and protrude outside the roots also. The Mycorrhizae lives in close association with roots without disturbing their normal physiology. These hyphae form swollen vesicles or finely branched mass of hyohae called arbuscules. VAM is also known for release of fixed phosphorous in soils, as it can secrete special p-solubalising hormones. VAM culture is being commercially used in many crops to avoid use of phosphatic fertilizers.
Bio - war
Bio - war refers to biological war. It means that biological organisms are used as weapons to carry out the war. It is latest form of war. It is carried out by spreading the pathogens in specific part of geographical region to deliberately spread a deadly disease. The ,diseases spread through bio war may bring skin disorders, respiratory disorders, muscular disorders or digestive disorders.
An important feature of bio war is to ensure that pathogens load on society is so large that it brings about an epidemic - so that large part of population suffer from same disease and medical care becomes more difficult to manage such a menace.
The information about the use of pathogens as weapons is necessary because of many reasons.
(a) Bio weapons can be used as means of terrorism.
(b) Bio weapons produce diseases that one difficult to diagnose because they rarely occur naturally andfoften mimic other diseases.
(c) Public health ~orkers must be aware of the threat of bio war and terrorism to minimize the effects of the biological attack.
(d) Physicians have'to recognize the diseases resulting from bio weapons.
(e) Public has to adopt safety measures against bio war.
Realities of biological warfare and terrorism
1. They are more threatening than the conventional weapons.
2. They are easy to oJ;>tainand are inexpensive.
3. Their detection an? prohibition are very difficult.
Potential biological weapon agents
Disease Pathogen
Anthrax Bacillus anthracis
Small pox Variola virus
Plague Versinia pestis
Q. Fever Coxiella brunette
Tularemia Francisella tularensis
Viral hemorrhagic fever Variety of RNA viruses
Viral encephalitides Alpha virus
Botulism Clostridium botulism