The successful discovery of DDT in 1939 opened the floodgates worldwide for more pesticide synthesis and their use, especially for the control of agricultural pests and vector-borne diseases. In 1950, DDT and pyrethrum brought from the US were used exclusively for Malaria control in Gandaki Hydropower Project. Subsequently, in 1952, the Ministry of Health introduced DDT pesticides in Nepal, marking the introduction of pesticides in the country. Also in 1955, Paris green, Gammexene and nicotine sulfates were imported to eradicate malaria. These pesticides were mostly provided by USAID, which sponsored programmes through grant assistance, primarily for the control of vector-borne diseases. 

Since then, the use of pesticides for plant protection has steadily increased with the introduction of high yielding varieties of rice, maize, wheat and vegetables which led to the formation of the Agriculture Inputs Corporation in 1967 to deal with agricultural inputs including pesticides. Nepal has a history of more than 40 years of using chemical fertilizers and pesticides. However, the search of biopesticides and novel compounds is a recent practice—generally after 2000. 

Most pesticides that are used in Nepal are broad spectrum in nature, which affect both target and non-target organisms. The general tendency to choose chemical pesticides is based on their knockdown effects, since a higher kill rate improves their value. The majority of Nepali farmers are unaware of pesticide types, doses, frequencies, waiting periods and safer disposals. The resultant effects on human health include cancer, birth defects, reproductive problems, tumours and damage to liver, kidneys and neural organs. To prevent such hazards, 16 types of pesticides have been banned. However, because of an open and porous border with India, there is a considerable but unknown quantity of pesticide trade between farmers close to the border. Hence, this issue has to be addressed with a multilateral approach.

Injudicious use 

The government of Nepal considers agricultural sector development a priority, but the export situation is discouraging. Looking at the agro-ecological potential, Nepal can pursue agricultural development through the adoption of organic agriculture, especially given the readily available markets in neighbouring countries, China and India. Organic agriculture systems promote the environmentally, socially and economically sound production of crops with respect to the natural capacity of plants and local conditions. It aims to optimise quality production and is an emerging area. So this is the right time to begin organic agriculture in Nepal. 

A lack of good transportation facilities still keeps various places in the country beyond the reach of chemical inputs. Production of niche agricultural products in such areas has high potential. Many places in the country are far from all the negative environmental effects of the inorganic method of farming. There is still time to make them aware of the situation and prevent the future use of chemical inputs in those areas. For a country bestowed with tremendous organic agricultural potential, this is the right choice. But it has to be harnessed judiciously. Use of chemical pesticide and fertiliser is very low in Nepal compared to the neighbouring countries, which indicates that the effects of chemical compounds are  due not only to the high dose of application but also to injudicious use. Some of the places in Nepal like Panchkhal are living examples of the consequences of overuse and mishandling of chemical pesticides, where the people are suffering from skin irritation, headache, nausea, and even skin cancer. 

The strategies Organic agriculture is more suited to Nepal where a majority of farmers own less than a hectare of land. Organic production will not only contribute to GDP but will also help in poverty reduction through secured income. Organic agriculture is often inexpensive and easier for small farmers because of price premiums and lower production costs. The technologies adopted in organic agriculture can decrease the costs of production as chemical inputs are substituted by locally available cheaper organic inputs. 

In order to promote organic farming, capacity building and availability of organic inputs such as biopesticides are important. Biopesticides are certain types of pesticides derived from animals, plants, bacteria and some minerals. They are based on microorganism as the active ingredients. They can control many different kinds of pest insects and diseases. Biopesticides are usually inherently less toxic than conventional pesticides. Biopesticides generally affect only the target pest and closely related organisms, and no other organisms. They often are effective in very small quantities and decompose quickly, thereby resulting in lower exposure and largely avoiding the pollution problem caused by conventional pesticides. In short, biopesticides can greatly reduce the use of conventional pesticides, while the crop yields remain high and organic.

Some government laboratories and private industry have started biopesticide production. For example, there is an insect pathogenic fungus, popularly known as Green Muscle, which is effective on a range of insects. Its production has been initiated with the local strains of Nepal. More of such undertakings need to be encouraged by the government. 

GC is Director General of Department of Agriculture