Threat to wheat crop
By Shaukat Ali Bhambhro
The province of Sindh has three distinct physiographic
regions - rive rine and irrigated alluvial region, sandi
eastern region (Thar desert), and rocky western region (Khirthar
range).
The land use in the rive rine and irrigated region is
related to agriculture and forestry. According to the Sindh
forest department statistics, the riverine belt of the
province comprises riverine forest spread over an area of
241,217 hectares.
The rive rine forest lies within the protective embankments
on either side of the River Indus. Reportedly, rive rine
forest are managed on clear felling silvi culture system
which is rational, economical and sustainable in flood
plains of lower Indus. Clear felled areas of rive rine
forest were fully regenerated and restocked a year later
with natural inundation.
But contrary to the facts mentioned above, a survey of the
rive rine forest area in District Ghotki, Sukkur and
Khairpur undertaken by this scribe has indicated that the
existing system of riverine forest management is not
sustainable and likely to crumble with the passage of time
if almost total absence of the forest department and
free-for-all like situation continues further for longer
period.
No doubt one of the important reasons of deterioration of
forest wealth in the riverine belt is absence of inundation
water since about a decade, however, the main reason is
practice of illegal island crop cultivation (wheat and
cotton) removing long established forest vegetations and
trees in the riverine belt.
Among the dominant plant species in this tropical forest
area are Acacia nilotica and Prosopis spicigera. Other plant
species prevalent in the forest are Populas eupharatica,
Tamarix articulate, Moringa and numerous herbs and shrubs.
However, among the weed flora of riverine belt one dominant
weed species is Phyla Nodiflora, as identified by Professor
Dr Raza Bhatti of the Botany Department, Shah Latif
University, Khairpur. This weed is locally known as "Buccan."
Phyla nodifolia weed serves as an alternate host of White
Rice Plant Hopper (Cofana spectra). During rice growing
season migration of this hopper has been observed by this
scribe from wed flora to its host plant (rice crop).
Hitherto, white plant hopper has been found or considered as
a minor pest of rice crop. The major one is known as
Whitebacked Plant hopper (Sogatella sp.) which often assumes
serious proportion causing severe damage to rice crop,
especially Irri varieties in the upper Sindh region.
Unfortunately wheat crop as island crop in the riverine belt
has provided another host to the white plant hopper which is
not a good omen. This is because its severe infestation may
invite insecticidal spray for its control allowing
resurgence of secondary pest problem.
Presently wheat is the only major cereal crop where
pesticide use is almost nil. During survey counting of plant
hopper revealed 15 to 20 adult hoppers per square feet which
was of course a very high population. Despite heavy
population however damage to the young 2 to 4 stage wheat
crop was not apparent except on few leaves showing whit is
patches following suction of saps by this sucking pest
(white plant hopper).
Its reason may be fresh migration of adult population of the
hoppers from the vegetation in the vicinity of the very crop
island. Here it would be proper to mention that such a
phenomenon had been experienced during the early settlement
of North America by the European colonist when agricultural
crops were grown in small patches surrounded by large tract
of uncultivated land, crops were like small island in a vast
matrix of natural vegetation.
However, as agriculture developed this matrix of forest
vegetation dwindled fast with the passage of time. Thus from
the very fact it may be inferred that with the dwindling of
riverine forest, problem of white plant hopper will
automatically dwindled. Hence no need to worry. What a pity?
SUGGESTION: Growers of riverine belt who have undertaken
cultivation of wheat crop adjoining forest vegetation should
be advised not to be panicky with white plant hopper, tip
burning of wheat crop could be addressed with fertilizer
application.
Courtesy: The DAWN
|
Pakissan.com;
|