Negative impact of chemical pesticide

a. Development of resistancy in insect: Pests have innate capacity of enduring pesticide and escaping the lethality. The moment of a certain insect should this capacity which is called pesticide resistant. Continual exposure and intensity of pesticide induce the target pest to develop a resistance generation.

b. Outbreak of pest: Mass destruction of the natural enemies due to pesticide influence

also creates a congenial environment for major and minor pest.

c. Hazard of pesticide residue: Depending on the inherent nature of the chemical build-up of a pesticide it depletes its toxicity in time. Before they given up their toxicity due to environmental weathering factors, these chemical left over persist becoming a potential hazard.

d. Environment Pollution: Hardly one half of the treated pesticide deposits itself on the treated surface the rest is disseminated to uncharged areas. This make the environment polluted. They remain in water, soil, air and mammal adipose tissues for a long time and may cause long lasting time.

e. Phytotoxicity: Depending on the nature of pesticides plants may be harmed because of chemical interactions among plants and pesticide. Burning spot on leaves, distorted leaves, restricted growth and other undesirable symptoms are seen in plants.

f. Adverse effect on non-target organism: Use of pesticide against target pests affects insect parasitoids and predators, honeybee, other pollinators and wildlife also, which cause the loss biodiversity. Repeated use of pesticides on crop has disruptive effects on beneficial insects like pollinators, bio-control agents, soil wild and aquatic life. Many invertebrates take up pesticide from soil into their bodies and may concentrate pesticides several times greater in their tissues than those in the surrounding soil. Soil microorganisms which cause breakdown of cellulose, nitrification, turn-over of organic matter and other biological materials may also be adversely influenced by pesticides. Indiscriminate use of insecticides on the field crops has resulted in widespread mortality of honeybees and wild bees which are essential for pollination.

g. Resurgence of pest: Resurgence refers to an abnormal increase in pest population

following insecticide application. Use of broad spectrum and persistent insecticide kill the natural enemies resulting into resurgence of insect pests. Sometimes, pesticides kill the key pests and under such condition secondary pests become the primary pests. Resurgence may also develop due to increase in feeding and reproductive rates of insects due to application of sub-lethal dose of pesticide. Resurgence is a dosage-dependent phenomenon and hence emphasis should be placed on correct dose of effective and recommended pesticide.

Way for reducing negative impact of pesticide:

 Pesticide should be used only when it is absolutely essential. The non-chemical method of pest control should be encouraged.

 Only recommended pesticide should be applied at the right time and at the prescribed dose.

 Preference should be given to the use of less persistent pesticide. Never use banded pesticide.

 Ripe fruit and vegetable should be picked before pesticide application and waiting period should follow.

 Should follow the waiting period, residual effect etc.