Significant movements in cotton trends
over a 12 year period between 1979-81 and 1993 resulted in the area planted
dropping by 3.6 m/ha, or 10.4% globally. In country terms, the area is
dramatically down in the ex-USSR (7.5%), Sudan (69%), Brazil (which now plants
less than half the 3.6 m/ha under cotton in 1979-81) and Mexico, (which now
plants less than 9% of its plantings in that season). In contrast, Pakistan has
increased by 27% to become the country with the fifth largest area under cotton.
Among the smaller producers, dramatic increases of 54% took place in Paraguay
and 25% in Iran.
However, over the same period yields rose on average by
27%-an overall increase in annual harvests of about 14%. In some countries the
yield increases have been dramatic: up 74% in India, 40% in China, 46% in
Pakistan (there have since been severe problems with leaf curl virus there and
yields have plunged) and even US yields have risen by 19%. On a regional basis,
the general trend has been a fall in cotton production in Latin America, while
in Africa, with the exceptions of Sudan and Egypt, there has been an increase.
Asia has also increased production.
Cotton pesticides
The cotton crop is a major consumer of pesticides,
with generally around 10% of the end-user market value, which in 1994 amounted
to US$2,550 million. Eight agrochemical companies account for nearly half of
this market share (US$1,202 million)-the top eight companies are AgrEvo,
Ciba-Geigy, Bayer, Cyanamid, Zeneca, DowElanco, Du Pont and Rhône-Poulenc.
Cotton is also the single largest market for insecticides with sales of US$1,715
million in 1994, approximately 22.5% of all crop insecticide sales.
Until recently, the organophosphate (OP) group, one of the
most hazardous to workers' health, took the major part of the insecticide
market, but there has been a shift to pyrethroids in recent years, which had
about 42-43% of the market in 1994, just overtaking the 40% share of OPs.
The most important insecticides, those with a minimum 5%
share of the market, were deltamethrin, (12%), lambda-cyhalothrin (9%),
monocrotophos (9%), alpha-cypermethrin (8%), chlorpyriphos-ethyl (7%),
esfenvalerate (7%), methamidophos (6%) and dimethoate (5%). The other 46% of the
market is dispersed between insecticides such as azinphos-methyl, diazinon,
dimethoate, EPN, malathion, parathion, phosphamidon, quinalphos, bifenthrin,
beta-cyfluthrin, esfenvalerate, tralomethrin, aldicarb, carbaryl, carbofuran,
fenobucarb, methomyl and thiodicarb.
Given the hazards of some of these actives, particularly many
of the OPs, it is disappointing that the report makes no mention of the possible
health impact, particularly in developing countries. It does, however, point out
some problems, such as the undue hazard to beneficial insects posed by alpha-cypermethrin,
and the high toxicity of aldicarb, as well as groundwater concerns connected
with its use.
Although aware that the major factor affecting agrochemical
usage on cotton will be the problem of insect resistance to chemicals, the
report does not deal with herbicide resistance which is also becoming a problem.
Controversially, Rhone-Poulenc has been developing bromoxynil-tolerant cotton,
which has just received its first registration for this use in the US for trials
of the genetically engineered cotton seed. Bromoxynil is classified by the US
Environmental Protection Agency as a possible human carcinogen.
Why not more IPM?
The report points out that with the complexity of
pesticides used, detailed knowledge of the crop, the insects and the chemicals
are essential to arrive at a correct spraying regime. Without careful
application farmers risk big losses. Traditionally, an argument used against
greater application of IPM-a more knowledge-intensive approach to pest
control-has been that farmers need detailed knowledge of the crop and pest
environment. It appears that there may not be such a gap between the knowledge
farmers need to operate either regime.
... and other alternatives?
As the agrochemical market is the major thrust in this
study, it does not dwell on alternatives and good practice, but they are not
altogether omitted. It notes the effectiveness of pheromones and predicts more
will come onto the market; the use of resistant cultivars; control through
destroying all plant material and delaying sowing until the following season;
and crop rotations such as cotton/sorghum/groundnut widely practised in Africa.
A brief mention of organic cotton in the India profile cites
government attempts to encourage this in Rajasthan and Madhya Pradesh in an
effort to reduce pesticide use. No other mention is made of the organic
production, which, although expanding, remains still tiny compared to the
overall market (see PN28, the organic cotton supplement).
The bad news about this excellent report is that it has been
produced for an industry audience, and the price will therefore put it out of
the reach of many. It is, however, available for perusal by non-profit
groups in the Pesticides Trust [now PAN UK] library. (BD)
Cotton-the crop and its agrochemicals
market, Allan Woodburn Associates Ltd, 18 Newmills Crescent, Balerno, UK, Tel.
+44 (0)131 451 5173, Fax +44 (0)131 451 5172, £595, pp126.
[This
article first appeared in Pesticides News No. 30,
December 1995, page 11]