The common nitrogen -fixer in paddy field is
Rhizobium
Azopirillum
Oscillatoria
Oscillatoria
B.
Azopirillum
Azopirillum is a nitrogen-fixing bacterium in paddy fields. It is very useful soil and root bacterium. It is an associative symbiotic N2 -fixing bacteria. When it is added to the soil, it multiplies in millions and can supply 20-40 kg of nitrogen per hectare per season. It also produces growth promoting substance like Indole Acetic acid (IAA). Gibberellins and promotes root proliferation. These substances improve the plant growth and yield.
Biochemical Oxygen Demand (BOD) in a river water
remains unchanged when algal bloom occurs
has no relationship with the concentration of oxygen in the water
gives a measure of Salmonella in the water
gives a measure of Salmonella in the water
A person likely to develop tetanus is immunised by administering
dead germs
preformed antibodies
wide spectrum antibiotics
wide spectrum antibiotics
A common biocontrol agent for the control of plant diseases is
Baculovirus
Bacillius thuringiensis
Glomus
Glomus
Which of the following is not used as a biopesticide?
Trichoderma harzianum
Nuclear Polyhedrosis virus (NPV)
Nuclear Polyhedrosis virus (NPV)
