Bradbrook - 2012 - Rice Farming complete with methods to increase ric

anywhere from 25 to 40 days depending on the variety. The grains are considered
to have reached maturity and be ready for harvest when they have turned golden
brown and are hard and opaque. At this stage, the leaves start to decay and lose
their color.
The developing grains are susceptible to attack from sucking insects in the early
stages and birds and rats in the later stages. They are also sensitive to changes in
environmental conditions. Grain filling (during milk and dough stages) is the
process whereby starch and protein accumulate in the grain. This process is greatly
hastened when the ambient temperature increases, resulting in partially filled
grains containing undeveloped starch granules. On the other hand, low
temperatures will lengthen the grain filling period; a significant incidence of frost
will cause the entire ripening process to stop altogether.
Light intensity is another factor that affects grain filling. Carbohydrates are
synthesized during photosynthesis in the leaves and delivered to the grains. During
periods of cloudy or rainy weather, the rate of photosynthesis decreases resulting
in lower carbohydrate production and grain filling.
Part 11: Cultural Management Practices
1. Water management
a. Upland rice culture
In developing countries, rice plants grown under upland conditions are completely
dependent on rainfall for water. In developed countries, irrigation water may be
made available to the field. In both cases, it is important to ensure that the soil is
moist but not flooded; therefore, a good drainage system must be constructed to
ensure good plant growth. Flooding during the vegetative stage results in poor
tillering; during the ripening stage, grain filling is affected resulting in poor grain
quality.
b. Lowland rice culture
The largest amount of water usage during lowland rice production occurs during
land preparation when the soil is flooded to facilitate easy plowing and harrowing.
The action of breaking the soil surface results in significant water loss through
percolation and seepage. It is therefore vital that land preparation be done as
quickly as possible after flooding.
Once the seeds have been sown or the seedlings transplanted, continuous supply of
water on the field ensures good plant growth resulting in high yields. At the early