Agriculture Reference
In-Depth Information
cold injuries, blast, drought spell, very short span of cropping
seasons. Because of the rolling topography in these areas bench
terracing is being followed which limits the use of fertilizers
and improved agronomical practices. In these areas the crop
is sometimes affected due to low temperature in early stage
and sometimes at the fl owering times which leads to sterility
problems.
The effects of cold in the hills cause:
1. Poor germination and extended germination period.
2. Slow seedling growth, low vigor, leaf discoloration and
mortality.
3. Inhibited root development, growth, and tillering and non
synchronous tiller production.
4. Delayed heading and poor panicle exsertion, irregular
panicle exsertion.
5. Spikelet sterility, low and irregular grain fi lling, and early
senescence.
According to climatic conditions the cold spell affects the rice
adversely in cold areas at varying growth and developmental
phases even for a prolonged period in some areas. Availability
of high yielding genotype is the solution no doubt, but as the
life cycle of a plant is quite complex and some damages are
irreversible, the solution is quite diffi cult. An understanding
of the injury effects at different phases of the life cycle and the
biological and molecular cascade of changes following the cold
sensation will be elucidated vividly. As at different stages of
growth and development different primordials are attained
to manifest with varying functional activities, the whole
system should be taken up to realize the dependent nature
of functions as a whole so that a complete understanding is
possible because of the fact that at a time a number of points
are affected subsequently.
