|
Main Page
|
 |
|
News Channel |
|
Spread of cotton pink bollworm
April 05: Cotton is the single largest cash crop
of Pakistan. In Sindh cultivation of cotton
started before the opening of the Sukkur barrage.
During the pre-barrage period up to the year 1932
the cultivation of Sindh's desi cotton [Gossypium
arborium] covered nearly 0.13 million hectare
whereas area under American cotton was only 0.01
million hectare.
With the advent of perennial irrigation of Lloyd
Barrage at Sukkur, the area under American cotton
[upland cotton] increased rapidly. In the year
1950-51 the area under desi and American cotton
was 0.32 and 0.364 acres respectively. During
1961-62 the area and production of cotton was
0.421 million hectares and 0.545 million bales
respectively. Presently the area and production of
cotton in Sindh is more than 397,000 hectares and
2,200,000 bales respectively.
With the inception of the Pakistan Central Cotton
Committee in 1948 a large number of promising
varieties and strains were developed. Among the
new upland varieties M-100, H- 59-1 [Qalandry],
S-59-1 [Sarmast] and K-68 -9 were released in
Sindh besides several varieties in Punjab.
The Punjab cotton varieties were introduced in
Sindh in mid 80's.Among the Punjab varieties Niab
-78 occupied almost 80 per cent of the area in
Sindh by 1987-88.Main reasons behind fast adoption
of Niab -78 in Sind were its high yielding and
about two weeks early harvesting than the Sindh's
varieties of cotton enabling growers to undertake
timely sowing of cotton.
Here it would be proper to mention that prior to
introduction of Punjab cotton varieties in Sindh,
Pink bollworm was not a problem either in lower or
upper Sindh, whereas it was a serious pest of
cotton in Punjab.
Review of fortnightly survey report of the Federal
Plant Protection Department, Karachi, for the
period covering 1980's has indicated that
following introduction of Niab-78 variety in to
Sindh, sporadic insurgence of pink bollworm was
observed in lower Sindh.
Fortunately early termination of crop probably did
not allow this deadly pest to establish properly.
But, unfortunately this very comfortable situation
did not last long. Introduction of cotton leaf
curl virus disease [CLCV] factor first in Punjab
in early 1990's then in Sindh by mid-1990's
particularly in upper Sindh turned the very
comfortable situation, earned through Niab -78 of
Punjab, upside down.
This was because of the fact that on the one hand
Sindh had no CLCV resistant varieties of its own,
on the other hand Niab-78 domiciled in Sindh fell
victim of CLCV disease having no tolerance against
the very deadly virus [geminy]. Having no
alternative, corruption ridden Sindh Seed
Corporation was allowed to purchase some quantity
of CLCV tolerant varieties from Punjab by the
department of agriculture, Government of Sind.
The varieties purchased from Punjab were CIM- 443,
CIM-446, and CIM-448. Besides seed companies were
also allowed to sell CLCV tolerant varieties in
Sindh. However under the cover of this very
facility many unscrupulous seed companies and
ginning factories also known as seed mafia pumped
a number of cotton varieties of unknown pedigree
in to Sindh, particularly in upper Sind, where the
CLCV problem had become widespread.
Unfortunately, this free-for-all like situation
led to the introduction of many cotton varieties
which have been found susceptible to both army
worm as well as pink bollworm. For example
FH-1000, developed at Faisalabad, no doubt is high
yielding but has been found highly susceptible to
armyworm during 2003 cotton season in upper Sindh,
as observed by this scribe during surveys.
Similarly some new varieties of Punjab, not known
to the growers, were found highly susceptible to
pink bollworms during surveys in the districts of
Khairpur, Sukkur and Ghotki.No doubt late sown
cotton crops in general are vulnerable to pink
bollworms attack but the presence of this pest in
August and September at many places in upper Sindh
was a haunting threat.
In the backdrop of these apprehensions, with a
view to ascertaining the present status of pink
bollworm in upper Sindh, a survey was conducted by
this scribe covering the leftover bolls on cotton
plants still in the fields, harvested cotton
plants lying on the edge or bunds of the field
under wheat cultivation as well as discarded seeds
and cotton refuge in the ginning factories.
A survey was conducted from 20-24 January 2004
covering district Khairpur and Sukkur including
Kachho area of district Khairpur. Surprisingly
about 30 per cent leftover dried cotton bolls were
found with live hibernating pink boll worm larvae.
Similarly cotton refuge were found heavily
infested with larvae of the said worm. Pink
bollworm is a serious pest of cotton.
Its population starts building up in the cotton
field in August -September and reaches its peak in
November particularly on late fruiting, as
observed during the survey in upper Sindh region
last year. The larvae, which are pink in colour,
enter into seed and feed on its content and also
deplete the quality of lint.
CONTROL: Its control by chemical means is not only
expensive but also not very much satisfactory. In
USA, China and Africa, where this was a serious
pest, it has been brought under control not by
chemical means but by cultural practices. To clear
the fields early defoliate or desiccate the mature
crop using defoliator or concentrated urea
solution.
Since the removal of crop residues such as cotton
sticks and bolls from the field soon after the
harvest, check the carryover of pink bollworm
infestation; it must be rigidly adopted. The
cotton fields should be deeply ploughed. The
grazing of cotton by cattle also minimizes the
chances of carryover of pink bollworm larvae. The
task of removal of cotton must be completed by the
end of December in lower Sindh and end of January
in upper Sindh.
Early maturing cotton varieties are very much
important in this programme, since the development
of most of the potential over wintering population
of pink bollworms can be virtually prevented if
the cotton plants are removed from the field prior
to cultivation of wheat crop in November/December.
Moreover, at the time of sowing seed free of pink
bollworm infestation should be selected. The seed
may be fumigated or be spread in the mid-day sun
in the end of February for about 4 -5 hours to
kill lurking larvae of pink bollworm.
Besides, with a view to stopping emergence of pink
bollworm moths from the infested seeds/refuge its
burning should be made mandatory prior to January
in all the ginning factories of Upper Sindh.
Growers should also be advised to burn all the
cotton sticks prior to this period.
The DAWN |
|
|
|
|
Pakissan.com; Advisory Point
|
|
