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Trends
And Descriptions (Cotton)
Cotton is an oil
crop, though grown mainly for its fiber. The fiber
consists of long, fine, flattened and convoluted hairs
called ‘lint’, which can be detached easily from the
seed. The value and quality of the cotton variety
depends on the fineness of the fiber as well as its
length. The longer and finer the staple the better its
quality, since it can be used to produce thinner and
lighter textiles without knots or uneven surfaces. A
single fiber is a little less in diameter than a human
hair, and is measured in micronaires. Five different
staple lengths are distinguished: short (less than 21
mm), medium (21-25 mm), medium long (26-28 mm), long
(28-34 mm), and extra long (more than 35 mm). The
majority of the world production (about 60 per cent)
consists of medium long staple. Medium staple is around
18 per cent, and short staple a mere 3 per cent,
produced almost exclusively in South Asia. Longer staple
lengths (long and extra long), comprise around 18 per
cent of the world production of cotton (during 1977-78
to 1981-82), and can only be grown in more or less ideal
conditions regarding soil, water, temperature, and
light.13 Slightly more than half of the increase in
total output is accounted for by yield expansion. Yield
trends can be divided into five different phases.
1950s
Constant yields: In the 1950s, yields remained
more or less constant for the entire decade, from
1949-50 to 1959-60, at around 200 kilogram per hectare.
1960s
steady growth: the first spurt of growth took
place in the 1960s, when yields rose steadily from 200
to 300 kilograms per hectare in 1970-71, and to 361
kilograms in 1971-72.
1970s
The first cotton crisis: A severe and persistent
attack of the American bollworm devastated the crop
during the 1970s, resulting in wildly fluctuating yields
between a high of 377 and a low of 233 kilograms,
re-attaining the 1971-72 figure only in 1979-82.
1980s
Rapid growth: The 1980s saw a dramatic growth in
yields, from 364 kilograms per hectare in 1982-83 to 769
kilograms in 1991-92. This was also a period when the
major expansion in pesticide use took place.
1990s
The second cotton crisis: Repeating the
experience of 20 years earlier, the peak achieved in
1991-92 was followed by another severe and persistent
pest attack, this time of the leaf curl virus and its
disease vector, the whitefly. Yields dropped
dramatically from 769 to between 500 and 600 kilograms
per hectare.
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