1.
Cucumber
is susceptible to attack by the following pest and disease.
2.
Flea
beetle: in the early stages of growth a cucumber plant is susceptible to the
flea beetle that greatly decreases leaf
mass and inhibit photosynthesis.
3.
Aphids:
aphids can kill young plants and they also carry mosaic disease.
4.
Cucumber
beetle: this is one of the main threat to the crop. The adult lay eggs at the
base of the plant , the larvae hatch and feed on the roots for 2-4weeks ,
then emerge as adults.
The cucumber beetle chew the leaves ,
blossoms and fruits . As the adults feed on the crop they may spread bacterial
wilt and mosaic which are two serious diseases.
Diseases of Cucumber
1.
Angular
leaf spot: This is bacterial disease
that develop on leaves and fruits. The fruits have small sunken water soaked
lesion that become susceptible to secondary rots.
2.
Downy
mildew : this is high in pickling cucumbers because they are planted at such
high densities. Yellow and brown spots
appears on the upper leaf surface, with a purplish mold on the underside. It is
win+d born disease and the use of resistance variety will reduce the incidence
of downy mildew.
3.
Cucumber
mosaic virus: the plant is stunted and foliage is mottled followed by
occasional wilt and death of leaves. It is vectored by aphids and the cucumber
beetles.
4.
Powdery
mildew: this is an air borne fungus that is serious in warm areas and in the
green house. First, white powdery spots appears on the leaves then the plants
wither and die.
5.
Scab:
this is a fungal growth that appears as dry corky lesions on the fruits.
Production
Limitation of Cucumber
Adverse
environmental factors such as high humidity, high temperature and low soil
fertility are major constraint to increasing the output of the cucumber. High
temperature and high humidity of the rainy season encourages pest and disease
attack.
The crop is often planted at wide spacing
(1m×1m or 1.5m) when inter planted with other vegetables. In many cases the
present crop spacing appear to be a waste of land. Under low fertility
condition, wide spacing may appear to be reasonable but closer spacing supported
by optimum nutrients supply may be more profitable to both the crop and the
farmer, Bamidele (2000).
Origin And
Distribution of Cucumber
Cucumber
is believe to have originated in Northern India. It was known to ancient
Egyptians, Greeks and Romans and was available in China in the 6th
Century AD. It has now spread throughout the world , its areas of cultivation
includes Northern and southern India ,South east Asia, China, Africa, Central
and south America, the Caribbean and most tropical areas (Beaker,1969).
Climatic and
Soil Requirement of Cucumber
Cucumber is the thermophilic and frost susceptible crop. it is essentially
a warm –season crop grown mainly in tropical and sub tropical region, cucumber
prefer slightly low temperature compare to melon and hence it is grown
extensively in sub tropical regions. Light intensity and time of the day
influences anthesis more than temperature in cucumber but temperature has
greater influence on another dehiscence and pollen fertility. The optimum
temperature favoring anthesis and dehiscence is 13 degree centigrade to 18 degree centigrade. never the less, for
optimum vegetative growth and yield, the temperature requirement is 18 degree
centigrade to 24 degree centigrade .A well drained loamy soil is preferred by
cucumber. It is necessary that soil should be fertile and well provided with
organic manure, cucumber prefers a PH of 5.5—6.8(Hand book of Horticulture ,
Indian council of Agricultural r Reseach new Dechi 5th july, 2001).