WHAT ARE PEST
Any organism that is noxious ,destructive,troublesome,dangerous for human society and interfere directly or indirectly with humans or their social and economic endeavours known as pest.
PESTICIDES
The chemicals used to kill ,eradicate and destruction of pests known as pesticides -may be chemical or organic pesticides
CLASSIFICATION AND THEIR PROPERTIES
1.Insecticides-Which kills insects
2.Rodenticides-Which kills mice and rat
3.Fungicides-Which kills fungi
4.Nematicides-Kills nematodes
5.Herbicides-Which kills herbs
Use of pesticides pose hazard to other organism including humans are also called Biocides
TYPES OF PESTICIDES
Natural Pesticides
These are non-persistent organic compound like nicotine ,tobacco,pyrethrum,rotten debris are used to kill pest earlier
FIRST GENERATION PESTICIDES
Include all inorganic pesticides -due to their high toxicity and accumulation in soil ,these restrict the growth of plant and are toxic in nature for other organisms
SECOND GENERATION PESTICIDES
It include synthetic organic chemicals like -DDT(dichlorodiphynyl trichloroethane)
-Organo chlorine- it contains -DDT ,Endosolphan,aldrine ,chlorodrane and merix.
Crop production is increased by application of DDT and it is highly capable to kill pests-its negative point is it is accumulated in soil ,crop animal tissue ,including human-it directly enters to food chain and go for biomagnification.
ORGANOPHOSPHATE
Chemical pesticide include parathion ,azodrin,phosphodrin,malathion,with persistance of one week to one month in the environment.These pesticides are are toxic and hazardous to human ,bird and animals
ORGANOCHLORINE
It include toxafin ,diazinon etc.
Demerits of these organochlorine pesticides are -1.It developes pest resisistance characters in pest-which lead to use of more pesticides latter .
2.Resourgence and secondary pest outbreak
3.Adverse environmental and human health impact
CARBAMATES
These are chemical pesticides such as-zectrain and carbyl having resistance two week or less.
PEST RESISTANCE
When a pesticides applied on an area -few organisms,especially insects,survive because they have specific genes that make them resistance to a specific pesticides .these few resistance reproduce in a huge number within a certain time period and weaken the effect of pesticides
RESURGENCE AND SECONDARY PEST OUTBREAK
Sometimes pest completely eliminated because of pesticide use ,return at higher and more severe level .This is known as resurgence.Even some population of insects that were previously no concern because of their low numbers suddenly start multiplying and creating new problems -These phenomena is called secondary pest outbreak
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