Pesticides are toxic to human, animals: Report

KARACHI: Insect pests cause 14 percent losses to agriculture. The percentage of losses vary with type of crop. About 38 percent losses occur in cotton and 30 percent in mustard production, says a new research conducted by Aziz Ahmed, a PhD researcher at Agriculture and Agribusiness Management Department, University of Karachi.

The research conducted under the supervision of Chairman Agriculture and Agribusiness Management, University of Karachi, Prof Dr Saleem Shahzad, informs about agriculture crop losses and soil degradation.

The study said: “Dangers of non-judicial use of chemical pesticides is increasing very rapidly. “The hazardous severity has been reported on living systems and ultimately on the cunning creature of human because pesticides residues in food, water and environment are very common.”

The research said many insecticides are toxic to human and animals even in low dozes. Researchers and farmers are therefore looking for less hazardous and alternatives to hazardous pesticides. “Alternatives to chemical pesticides probed and tried for crop-insect pest control include microbial insecticides, botanical insecticides and soap insecticides, the research said.

It said world pesticide production shows a steeply increasing trend. In 1980, the value of world pesticide production was about US$ 11600 million of which 14 percent represented herbicides, 34.7 percent insecticides, 18.8 percent fungicides and bactericides, and 5.5 percent other pesticides.

In 25 years (1980-2005), application of pesticides has increased in terms of amount to US$ 31191 million, of which the herbicides contributed 48 percent, insecticides 25 percent, fungicides ad bactericides 24 percent and other shared 3 percent in total pesticides cost worldwide.

Referring to his research, Aziz said that pesticides use in crops generate light poison in food which goes to the bodies of human and animals. Resultantly, human health is affected by this poisonous food. He said that there is need to introduce organic farming in the country so as to save people from poisonous implications of pesticides.

Organic farming is being carried out in whole Europe, Canada, US, Australia, New Zealand and Malaysia while China has also initiated it at low level.

“Biological control techniques, which are beneficial for human health, are being used to kill insects and pests instead of using pesticides chemical in crops. Entomopathogenic fungi can kill insect pest species like Aphid,” he said.

He informed that Trichoderma, an organism, if used in crops, can eliminate diseases of crops like Rust and Smut. This will save crops from use of pesticides which is harmful for human. He said that organic farming could be carried out by using animal dung in place of fertilizer and using organisms to kill insects and pests. However, organic farming would reduce crops production but it is very beneficial for soil and human health. “Hence the government needs to introduce organic farming in the country which is limited in Pakistan at some research centers in Sindh Agriculture University Tando Jam, Agriculture University Faisalabad and some other centers.”

He said that study was conducted to utilize the insecticidal potential of entomopathogenic fungi for agriculture pests like cotton mealy bug and mustard aphid. The mycoinsecticides have acquired a tremendous fame due to their non-hazardous impact to environment.

“The present study was focused to isolate and avail the hypocreales entomopathogenic strains. There were 7 strains isolated from field conditions and various insect population of agriculture habitat, while other nine strains were acquired from mycological culture facilities,” Mr Aziz said.

Cotton mealybug and mustard aphid are major pests in cotton and mustard crops. Cotton mealybug and mustard aphid were exposed to spores inside bioassay chambers to screen out avirulent strains. A comprehensive laboratory bioassay revealed that there were seven virulent strains. Besides entomopathogenic strains the chemical pesticides were assessed for their toxicity against cotton mealybug and mustard aphid. The insecticides were found more toxic to mustard aphid than cotton mealybug.