Sensitise farmers to minimise pesticide residue

Pest management

SS Chahal

Rice is one of the major foodgrains and a dominant crop of India. With 120 million tonnes in the 2020-21 financial year, India accounts for 20 per cent of the rice production worldwide. Basmati and white rice are preferred the most for general consumption. The area under basmati generally falls in northern states/UTs such as Jammu and Kashmir, Himachal Pradesh, Punjab, Haryana, Delhi, Uttarakhand and western Uttar Pradesh. In 2019-20, India exported 44.55 lakh metric tonnes of basmati worth $4.25 billion. However, the export consignments have to undergo stringent quality checks before acceptance by the importing countries. According to data provided by the Agricultural and Processed Food Products Export Development Authority (APEDA), the export of basmati decreased consistently to countries such as UAE, Qatar, Belgium, Germany, Italy, Brazil, Croatia, France, Greece, Portugal, Spain and Switzerland between 2017-18 and 2019-20. In 2013, the export of basmati to the US suffered a setback after the United States Food and Drug Administration (USFDA) stopped all basmati consignments which were having tricyclazole level more than 0.1 parts per million (ppm).

The issue of pesticide residue has hit basmati export from India like never before. Around 10 per cent of the country’s annual export is to the member countries of the European Union (EU). The EU has reduced the maximum residue limit (MRL) from 1.0 ppm to 0.01 ppm for tricyclazole, a systemic fungicide applied against the blast disease of rice. This has reduced the export by more than 45 per cent to EU countries. To avoid such rejection, the Central Government has made testing compulsory before exports. The Export Inspection Agency (EIA) examines rice consignments for pre-shipment testing of 22 pesticides for their residue. The Ministry of Agriculture and Farmers’ Welfare has also taken the initiative to develop Standard Operating Procedures (SOPs), initially for tricyclazole and buprofezin, and Good Agricultural Practices (GAPs) for the farmers to follow, enabling them to eliminate residue of these pesticides in rice grains.

It is estimated that various insect pests and diseases cause 25-30 per cent yield losses every year under humid and warm weather conditions in almost all rice ecologies. Pesticides are used to reduce such huge losses caused by pests infecting the rice crop from the seedling to the panicle stage. About two dozen insect pests and mites cause biotic stresses in rice-growing areas, including rice stem borers, which are widespread under all conditions. Asian rice gall midge, leaf folder, brown plant hopper, white-backed plant hopper and green leaf hopper cause enormous losses. Gundhy bug mainly appears in irrigated and low land areas. The major diseases are sheath blight, bacterial leaf blight, brown leaf spot, pyricularia blast, false smut, kernel bunt, sheath rot and stem rot. Basmati rice also suffers from foot rot or bakanae.

Usually, factors like monoculturing, heavy fertilisation and an intensive cropping system create a favourable environment for insect pests and diseases. Hence, various contact and systemic pesticides are widely used as part of the control measures. Often, these prescriptions are not adhered to as per the specified procedure, dosage, economic threshold level (ETL), timings, time intervals and without following other SOPs and GAPs. Mostly, farmers are prone to using a higher quantity of chemicals and non-judicious and indiscriminate pesticide applications because of their foremost interest to get maximum returns for their produce and aim to get shiny and marketable grain free from pests, thus leading to pesticide residue in the grains of such crops. Systemic pesticides applied less than 25-30 days before ripening are almost sure to persist in the grains. Where there is a need to curb such practices, efforts should be made to develop SOPs and GAPs for all 22 pesticides identified for pre-shipment testing by the EIA for residue in export consignments of rice to the EU and other countries. It can only be achieved through sensitisation of farmers for their implementation as well as discouraging the use of harmful pesticides. It is equally important to come out of pesticide-dependant pest control and promote the adoption of alternative pest and disease management practices in an integrated fashion in paddy cultivation.

The adoption of pest-resistant varieties is a key component of Integrated Pest Management (IPM) strategies. Green manuring with Sesbania or mungben enhances soil health by increasing the percentage of organic matter and also supports the multiplication of plant growth promoting microflora. Sesbania cannabina, commonly known as dhaincha, grown as a pre-kharif crop and used as green manure, is reported to contribute almost 25-kg nitrogen/hectare. Rice seeds may be treated with a generic fungicide, carbendazim, or bioagent trichderma viride or T. harzianum against seed and soil-borne diseases. Seed treatment with chloropyriphos is useful in termite-endemic areas. Biological control is the basis for IPM strategies to exploit the potential of naturally occurring antagonistic fungi, bacteria, parasitoides, predators and entomopathogens. Other activities under IPM include planting of 2-3 seedling/hill, adequate spacing, judicious fertiliser application, use of straw bundles for augmentation and conservation of beneficial insects like spiders, application of fungicides and pesticides based on ETL and manual weed management. While carrying out validation and impact analysis of such IPM modules on basmati rice, the National Research Centre for Integrated Pest Management has found significant reduction in the incidence of bakanae, brown plant hopper, conservation of beneficial organisms under ETL-based application of pesticides and carbendazim residue below the detectable level with highly favourable yield benefit-to-cost ratio.

There is great scope for young innovators to set up startups employing modern digital technologies like artificial intelligence and drones for bringing precision to the application of pesticides to targeted sites only, which can reduce indiscriminate use of pesticides. Last year, Punjab, a major basmati-growing state, had banned the use of acephate, carbendazim, thiamethoxam, triazofos, tricyclazole, buprofezin, carbofuran, propiconazole and thiophanate methyl on basmati rice, necessitating the popularisation of IPM procedures for raising healthy crops, avoiding yield losses and improving quality of the produce.

Organic cultivation of basmati rice has the potential to supply world-class produce in the international market. However, it is yet to pick up to the desired level.

The author is former V-C of Maharana Pratap University of Agriculture and Technology, Udaipur

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