Gardening the Bhutanese Way

Wednesday, October 24, 2012

Food Safety & Security

 As the indiscriminate use of synthetic chemicals is at the rage of augmentation, the concern of food security and ecological balance has become a major issue. Besides sustainable production, it is equally important to maintain food hygiene and safety both at the time of consumption as well as production.

Pesticides are not only the solution to pest problems but often they are the causes of the problems themselves. The incessant use of chemicals would not only lead to chemical residue problems in soils and deteriorate soil health, but also lead to the development of resistant strains of pests.

Not only that, insect resurgence, the sudden or abnormal increase in pest population is a common phenomenon often following a pesticide application.  Secondary pest outbreak is also a notable ill-effect. More than anything, it kills the natural enemies and thereby disrupts the ecological balance.

In addition to that, certain chemicals being highly liposoluble can accumulate in the adipose tissues of animals. Human beings are not an exception as there are several incidences of casualties. The Minimata disease of Mercuric poisoning in Japan, the hydrogen cyanide poisoning in Bihar case, the Arsenical poisonings are so evidential. The biomaccumulation and biomagnification of toxic chemical residues would prove highly lethal to living organisms.

The book entitled, “Silent Spring”, by Rachel Carson depicts the extent of harm the use of pesticides have inflicted. The lethal effect of the large scale application of DDT pesticide in pest control has deprived the valley of its usual cacophony and the blissful tunes of the spring birds and has made it as silent as a dead valley.

Nevertheless, nature has in store its own set of natural enemies of every pest or pathogen. It is equipped with its self- regulatory or its own balance mechanism to maintain the natural ecosystem. The so called predators and parasitoids has been identified, mass multiplied, and released on inoculative or inundative basis. This is a recent development in the field of horticulture.

For example, the beautiful ladybird beetles that we often spot strolling up and down the leaves are nothing but in keen search of their prey. They are predaceous on almost all Lepidpteran insects, the most destructive order infesting a number of horticultural crops. Befriend them, carry them to the laboratory, mass multiply and release them into the infested field or gift them to farmers in need for they are none but farmer’s friends.

They would be more than happy to carry out the task entrusted to them. I can assure you that they will perform their task so efficiently and host specifically without demanding for wages in return. In fact, the expenses incurred on the purchase of pesticides and labor charges can also be curtailed.

Another set of organisms called parasitoids can also be employed for the same task. They depend on their hosts for completing only a certain stages of their life cycle. For instance, Trichogramma brasiliensis, an egg parasitoid, deposits its eggs on the host and its progeny emerge from the host egg. A larval parasitoid, Bracon hebator, deposits eggs on host larva and its later instars emerge from host larva.  Pupal parasitoid, Brachymeria nosotoi, is yet another such example.

In addition to that, entomopathogenic fungi, Trichoderma viride, can be formulated with talc powder and carboxy methyl. The formulation can be dried in the sun, grinded and the resultant powder is packed and supplied to farmers. This affords effective biological control against a number of fungal pathogens.

All these are a few classical examples of biological control amongst the existing innumerable list. The potentiality of these could be exploited by the horticulturists and agriculturists and subsequently employed in biocontrol. Indeed, they have a role to bridge the gap between research findings and the practical utility in the field for farmers. If this is done, our sole objective of ensuring a safer and healthier food, and the globe in which we dwell a happier and a better place to live in is achieved.

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