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Rice ratooning: a technology to increase production
By
Hafeez ur Rehman, Dr Muhammad Farooq and Dr Shahzad M.A.
Basra
RICE occupies a
conspicuous position in our agro-based economy. It has
emerged as a major export commodity contributing about
13 per cent to the total foreign exchange earnings of
the country, 6.1 per cent value-added in agriculture and
1.3 per cent in GDP in the country.
Rice
is grown here on an area of over 2.5 million hectares
with an average yield of 2,117kg per hectare. The
country ranks 9th with respect to area and 14th for
yield per hectare in the world. There is 50.42 per cent
gap between the actual and potential yield. The reason
for this gap in yield is the poor rice production
practices adopted by farmers and rice-growers of the
area.
Rice ratooning is one of the potential and attractive
alternative technologies to increase rice production.
Based on land and water management, rice ecosystem is
mainly divided into lowland, upland and deep water or
floating rice. Rice ratooning is mainly practiced on
lowland rice ecosystem.
Rice ratooning is not a new practice with farmers. It
has been successfully adopted in many countries
including India, Japan, USA, Philippines Brazil,
Thailand and Taiwan. In India, of the 40mha under rice,
about 18.9mha constitute the ratooning under lowland.
Rice ratooning can be practised as an alternative to
double cropping in areas of available water after the
main crop season, particularly it is suited to hilly,
tropical areas with heavy rainfall and under rain-fed
conditions to tide over moisture stress because no other
crops except rice can be grown under the climate and
moisture limitations.
Advantages: The main advantage of rice ratooning is that
in areas where rice is the main crop, double crop of
rice can be grown for additional returns. The ratoon
crop matures earlier, it has been reported that days to
maturity of the ratoon crops are 65 per cent less than
the main crop. It requires 50 to 60 per cent less
labour. Require less water inputs, water use efficiency
is high and crop uses 60 per cent less water than the
main crop. The production cost is lower due savings in
land preparation, transplanting or direct seeding and
crop maintenance during early growth. This system
requires short duration, creating possibility for
growing another crop in the same cropping year and
offers an opportunity to increase cropping intensity per
unit of cultivated areas. The yield is up to 50 per cent
of the main crop. Rice varieties differ in their
ratooning ability. In case of Ratoon crops from early
maturing varieties, better performance in temperate is
reported.
However, intermediate to late maturing cultivars are
required for raising a good crop. The general trend is
that intermediate to late maturing varieties produce
higher yields than early maturing varieties. Hence,
there are no set rules with regard to choice of cultivar
regarding ratooning. Good agronomist of the area can be
a good ratooner. Many factors like variation in soil,
water, light, and temperature greatly influences the
ratooning ability. These interactions are needed to be
studied properly for manipulating ratooning ability
agronomically.
Rice ratooning depends on the ability of dormant buds on
the stubbles of the crop to remain viable, the buds may
be at different stages of development or similar in
length. Auxiliary buds that developed at those bud nodes
grew into ratoon tillers. Tillers regenerated from
higher nodes formed more quickly, grew faster and mature
earlier. The panicles from ratoon coming from lower
nodes produced more grains per panicle than those from
upper nodes, but their fertility percentage decreases.
However panicles from upper nodes contribute more to
ratoon yields than those from lower nodes.
The best time to harvest the main crop for raising a
good ratoon crop is when its culms are still green;
stalks should be cut before the main crop is fully
matured. The better yield from ratoon crop is reported
if main crop stubble is left with 2-3 nodes. Sowing
time, temperature, day length and other factors have a
profound influence on main crop duration, harvest date
of the main crop and its effect on the rice ratooning
also vary. Very little work has been done on this
aspect. However, any delay in planting the main crop
will delay the harvest and effects ratoon crop yield as
well.
The success of a good ratoon crop depends on the care
with which the main crop is cultivated in the growing
season. Agronomic practices and the care with which the
main crop is protected against insect pests and diseases
determine the success of ratooning and crop yields in
ratoonable cultivars. Reduction in tilling ability and
yield of the ratoon significantly are reported by low
temperature at post maturity, similarly, blast incidence
on the main crop can carry over to the ratoon resulting
in total failures. Ratooning provides higher resource
use efficiency per unit time and per unit land area.
However, better yield of ratoon crop is possible by
adopting appropriate management practices for main crop
as well as for ratoon crop.
These management practices include land preparation,
adequate plant density and spacing, use of appropriate
cultivars, water management, application of adequate
rate of fertilisers, appropriate height of cutting, and
control of diseases, insects and weeds.
Following strategies should be followed for improvement
of rice ratooning crop:
The prospects of ratooning should be studied under
rain-fed conditions to over moisture stress during later
growing phases of the crop than irrigated rice.
Major emphasis and systematic breeding efforts should be
undertaken to synthesise cultivars especially for
rationing. Cultivars suitable for different climate,
altitude and purpose should be identified to optimise
ratoon rice yields.
Efforts should be made to screen for rationing ability
of rice resistance to insects, pests and diseases,
tolerance for low temperature especially during early
seedling stage and for drought during later stages of
the crop.
Post harvest technologies including seed viability and
milling quality should be studied. Development of
low-cost technology in terms of bio-fertilisers, weed
management to minimise cultivation cost is necessary to
make ratoon rice a profitable enterprise.
Courtesy: The DAWN |
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Pakissan.com;
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