Upland cotton belong to family
Malvaceae, genus Gosypium and tetraploid hirsutum specie that contain
chromosomes 2n=52.
Cotton is very important and cash crop of Pakistan because all textile or fiber
industry based on cotton crop.87% cotton crop grown in Punjab province
(Pakistan) mainly Multan, Bahawalpur division and district Toba Tek singh,
jhangh, vehari etc.
Cotton is very sensitive crop response to insect pest and diseases. Insect pest
attach start from seedling stage and remain through out season which cause yield
reduction. There are different cotton insect pests and diseases that severely
reduce the yield i.e. Cut worms (Termite, Black headed cricket, Grass hopper.),
Sucking pest (Trips, White fly,Jassid,Aphid,Red spider mite, Broad green
mite.),Bollworms (Army bollworm, American bollworm, Spotted bollworm, Pink boll
worm.),Mely bug. Good crop production depends on high yielded, insect pest
tolerance variety and crop protection management according to environment and
field feasibilities.
Insect pests attach can be minimize by proper pest scooting and better crop
production technology on economic threshold level.
There are some morphological traits that partially or completely tolerate the
pest attack, i.e.
Variety life span – Plant life span directly relate to pest tolerance because
the plant speedily complete vegetative or reproductive cycle and because of less
time meet to pest attack.
Plant type – plant type majourlly play important role of insect pest attack on
plant i.e.
*Monopodial- plant has only one main branch, directly fruit bearing branch and
this type of plant have less space for insect bearing because of shorteng of
branches and leave. But the variety yield of this plant type depend on plant
height e.g. FH 114
*Sympodial- plants have one to three branches, sympodial branch mean indirectly
fruit bearing branches. Of bolls per plant due to big plant vigour, but this
complex nature of plant cause more production of insect pest e.g.
Bt-886,Bt-888,VH-259 etc.
Plant shape – Specific Plant shape effectively tolerate the insect pest attach
i.e. bushy type because of open type, Proper light pest living space not
available Leaf type- okra type leaf better as compare to round shape to
tolerant insect survival on leaf because of less space available for insect on
leaf.
Leaf stiffness- it is very difficult to suck or eat by insect (aphid, jassid,
thrips etc.) Because of leaf hardness.
Leaf area- large leaf index cause more insect survival, diseases and as well as
evaporation that cause weakness in plant because of plant can not tolerant
insect pest attack.
Leaf orientation- leaf angle specially play important role to insect pest
tolerance because of proper sunlight passing and aeration.
Hairiness on stem or leaf- hairiness is also called puiscence, it barrier to
restrict the insect pest survival and attack.
Red color on stem- this is the insect behavior under control by gene, insect
dislike the red color and don not attack on red color of plant but one of fault
of red color, it reduce the photosynthetic efficiency.
Gossypol gland- Black spot on stem or leaf are called gossypol gland, it is
enzyme that is control by gene, gossypol gland produce poison in plant because
of minimum insect pest attack on cotton.