Environmental and Health costs Assessment of Pesticide use in Potato Farming in Nepal

Potato is one of the most important vegetable of Nepal. It is used as a major crop in Terai and mid-hills and as a staple food in the high hills and mountains. According to the recent statistics, potato ranks fifth in area (185,342 ha), second in production (25,17,696 tons) and first in productivity (13.58 t/ha) among the major food crops grown in Nepal. The potato is considered as the king of vegetables. The market demand of the potato and the area under cultivation is increasing day by day. Three major potato growing seasons in Nepal are:

  • Rainy season, with planting in July-August
  • Winter season with planting in October
  • Spring season with planting in December-January

Insect pests are important biotic constraints affecting and limiting potato production in Nepal. Depending on the level of infestation, losses in terms of quality and quantity can easily reach upto 60% which seriously affects the income of subsistence farmers. According to some studies the insect pest attacking potato foliage and tubers are Red ant, white grubscut worm, wire worm, green peach aphid, potato tuber moth, black beetle, semi-looper, cotton ball worm, epilachna beetle, flee beetle and leafminer fly.
Pesticide use in Nepal started in the early 1950's, especially with the use of DDT for malaria eradication. A pesticide is any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest including insecticide, herbicide, fungicide, and various other substances used to control pests. Farmers use pesticides to kill the pest in crops with subsequent yield increase, which is essential both during growth and their storage and transport. It is difficult to draw inferences about pesticide use from a simple comparison of overall usage in two time periods. Pesticide use depends on a number of factors and fluctuates heavily over time due to factors such as weather and pest pressures. In addition to this, management practices such as the adoption of new technologies also plays a big role. The massive use of pesticides leads also to the environmental pollution in many different forms inflicting global warming and depletion of the ozone layer, pest migration and expansion that affects productivity, profitability and safety of food products. The national mean pesticide consumption of Nepal was 142g /ha in the recent data, which seems low compared to pesticide consumption of other Asian countries. However the use of pesticides is not uniform in Nepal. Most pesticides are used in rice (40-50%), pulses (14-20%), cotton (13-15%) and vegetables and fruits (10-15%). Moreover, pesticides are used by vegetable farmers in the periphery of urban and sub-urban areas where they have access to vegetable markets.
A number of 306 commercial products grouped under 71 common names of pesticides have been registered in Nepal: insecticides (40); fungicides (18); herbicides (5); rodenticides (3); acaricides (1) and others (4). Illegal trade and use of pesticide has been an issue for journalists and highlighted by the media now and then. Till now, 14 type of pesticides (POPs) have been banned in Nepal including DDT, BHC, aldrine, dialdrin, endrin, chlordane, lindane, heptachlor, toxaphene, mirex, phosphamidon, organomercury compounds, monocrotophos and methyl parathion. At present, commonly found pesticides in markets are organophosphates, synthetic pyrethroids and one organochlorine i.e. Thiodan.
The use of chemical pesticides in potato farming is increasing day by day in developing countries as farmers intensify production and expand cultivation into areas and planting seasons beyond the crop's traditional range. The chemicals used are highly toxic and applied with little or no protective equipment. Most commercial potato farmers rely largely on herbicides, fungicides and insecticides to control this pest.
The main objective of my thesis is to investigate the impacts of commonly used pesticides in vegetable farming esp. potato in selected areas of Kathmandu Valley, Nepal This will be achieved by investigating the awareness level of the farmers regarding pesticide use and health safety through a questionnaire survey.
After the preparation of survey questionnaire, I would be travelling to Kathmandu, Nepal for the field visit. I would be visiting some places like Panchkhal, Sankhu, Lalitpur, Bhaktapur, Dhading and Kathmandu where vegetables like potato, tomato, chilli, cucumber, cauliflower and cabbage are cultivated. I would also be talking about awareness level of pesticides use and their health safety methods with the locals and the farmers. Some agricultural organisation such as NARC (Nepal Agricultural Research Council), have already been in contact with local districts farmers, where they have already informed farmers about my field visit and the questionnaire samples. After the full filled questionnaire survey, I would be using those data for pesticides use in Nepal, to compare it with other developing countries. Also, I would be looking into effects of pesticides use in environment and health. The main focus would be in observing if there are any dead aquatic animals, mammals near the farm or if any unusual behaviour has been noticed near farms such as dead birds or lizards. If there is any unusual behaviour then I would be questioning about the type of pesticides used in certain areas and reasons behind it.
The scope of the study is to analyse the levels of pesticides in different vegetables of Kathmandu valley as well as to assess the awareness level of farmers regarding pesticide use and safety.