Plant Quarantine and Pesticide Regulation Centre is a sole government institution authorized for regulating plant quarantine related activities under the Ministry of Agriculture and Livestock Development. Quarantine offices and quarantine check posts are located at different land frontiers and international airport. Now, there are 5 regional plant quarantine offices in each development region, 8 check posts, and 2 sub-check posts in different customs points.  Out of them, three check posts are in Nepal-China border; one check post is at Tribhuwan International Airport, Kathmandu; and all others are along the Indo-Nepal border. Currently, this institution has to regulate its activities on several plant health dynamics to reduce the risk of entry, establishment, and spread of notorious plant pests within the national territory according to [2,3]. This institution has also been officiating its hold as a vital counterpart of NPPO Nepal.  

Quarantine Office, Tribhuwan International Airport (TIA), Kathmandu, under Plant Quarantine and pesticide Regulation Centre, has the main responsible in inspecting consignments, treatment of the consignments, issuance of the phytosanitary certificate, and entry permit of the agricultural commodity traded through Tribhuwan International Airport, Kathmandu.

Major Agricultural Commodities that are imported through TIA are Vegetable Seeds, Flower seeds, Ornamental plants, Cut flowers, Vegetables like Mushroom, Asparagus, Capsicum, etc. from different countries like Netherland, Thailand, China, India, Korea, Japan, Bangladesh, Uganda, etc. While major Agricultural Commodities that are exported through TIA are Tea, Coffee, Rudraksha, Buddhachitta, Fresh Vegetable, Wooden Handicrafts, Medicinal Herb, Fruits, etc. to different countries like China, India, Germany, Japan, United Kingdom, United State of America, Canada, Qatar, U.A.E, Hong Kong, Vietnam, etc.

With increasing global trade of agricultural commodities, among others, there has been an increasing threat of introduction, establishment, and spread of exotic pests as well as diseases in the country. Thus it is important to apply SPS measures, as and when required, during export and import at the border, and management of such risk is equally crucial to minimize the introduction of risk that can have a larger economic impact. Trade of agricultural commodity among others should check the import of deleterious pest and assure the export of healthy commodity as per requirement.

This paper documents different phytosanitary action taken against the pest and diseases intercepted in agricultural commodities traded through TIA, Kathmandu. Since this is the first attempt to document the phytosanitary measures taken against pest of Agricultural commodities in Nepal, which would help in further study of such topics.

The site of the study was selected at the quarantine office, TIA, Kathmandu, since major agricultural commodities are traded through TIA, Kathmandu, and it is feasible and appropriate for the inspection. The study was conducted from April 2018 to May 2019. The primary and secondary information was obtained from the quarantine office, TIA, Kathmandu. This study was done on a single consignment basis, where sample collection and inspection were done as described below [1].

Sample collection

There is the provision of sample collection for further testing or inspection of the agricultural commodities that are traded through TIA, Kathmandu.

In the case of seed, the primary sample was collected from the different depths of sacks or packets in which seed was carried. The samples were collected using the Nobbe Trier, Hand, etc. In the case of the consignment of less than 500 kg, at least five, and more than 500 and less than 3000 kg, the size of the primary sample of 50 was taken. Then the composite sample was prepared by mixing a primary sample of similar size and shape. The sample that could not be diagnosed was sent for further tests. The sample was submitted, and a working sample of about 1 kg was prepared with the information on the label in the sealed bag.

A sampling of fruits was based on the quantity of the consignment; if the sample was less than ten boxes, all the samples were selected for inspection. If the consignment was more than 10 and less than or equal to 100 boxes, then sampling was done from at most 10% of the consignment or at least 5 boxes as per the standard set in the [1].

As per [1], sampling of a potted plant was done based on the number of pieces traded, as if it were less than 500 pieces. A sample of all consignments was taken for inspection to assess the risk to the importer on their farm.

Inspection

The inspection of the seed was done on the working sample collected during sampling. While in other consignments like potted plants, seedlings, fruits, etc., inspection was done on the sample taken based on the quantity of consignment in the inspection chamber of Air Cargo and also in the field site where it was grown.

Inspection of the agricultural commodities traded through TIA is mainly done as per [1], which is described below.

1. Visual Observation

Stage of live insects, the seed of weed, gall of nematode, or resting spore of fungus, i.e., ear cockles, ergot, Sclerotia, smut, or bunt galls that may be mixed with seeds, discoloration or misshapen, fungal growth, etc., was inspected on the surface of seeds, fruits, propagating material, wooden handicraft, etc. using an illuminated magnifier.

2. Microscopic Observation

Inspection and characterization of microscopic pests like mites, nematodes, fungi, bacteria, etc. were done using stereo and compound microscopes.

3. Incubation Observation

Under this method, the seeds of the suspected samples were placed in the Petri dishes with blotting paper, which should be wet. Then Petri dishes were placed in the incubation chamber at 25–30 °C for 7 days. A morphological study of the fungus is observed using a compound microscope.

4. Special Observation

In case of failure in the detection of suspected infection using the above-mentioned method, samples were sent to the National Agriculture Research Center (NARC) for further detection and confirmation of infection.

5. Post-entry quarantine inspection

Inspection of actively growing plant material like bulbs, pot plants, seedlings, grafted plants, etc. was done on the field site of an importer at their risk within 15 days to one month at regular intervals, depending on the propagating plants and types of pests intended after clearing the consignment from the quarantine office.

Results show that a number of pests were incorporated into agricultural commodities in trade either during import or export. Table 1 shows that different pests like larvae of diamondback moth (DBM)/slug, borer, and mold fungus were found on the sample of agricultural commodities, i.e., cauliflower, brinjal, Rudraksha, etc., during export. A visual inspection of these commodities was done using a magnifier. The commodity that was found to be infected with pests was discarded, and as a result, a phytosanitary certificate was not issued.

Table 1: Commodity traded * Pests inspected (Cross tabulation).

Similarly, from Table 1, it was found that different pests like a weevil, a mealybug, and Fusarium species were incorporated in the sample taken of imported agricultural commodities like grass seed, dragon fruit, rambutan fruit, phalaenopsis hybrid flower, etc. Cocksfoot, grass seed, and potted flower plants were found to be infected with the Desiantha weevil and aphid, respectively, which was verified by the Entomology Division of NARC. The release of the grass seed was done after a week of inspection of the commodity after the pest was found dead, while the release of the potted plant was done after a week of treating it with Imidaclorprid @ 1 ml/10 liter of water and Cypermethrin @ 1.5 ml/liter of water for 2 days at a 7-day interval. Similarly, imported rambutan and dragon fruit were found to be infected with a mealy bug and disease caused by Fusarium sp., which was confirmed through visual inspection as well as the report of the Plant Pathology Division of NARC. Mealybug-infected dragon fruit was released after 5 days of treatment with Nimbecidiene (Neem based insecticide) @ 3 ml per liter of water, as the treated fruit was free from the incorporated pest while disease-infected dragon fruits were disposed of since the fruits were found severely damaged and unsafe for consumption. Similarly, rambutan fruits infected with both disease and pest were disposed of by burying in the soil since they were severely damaged and unsafe for consumption. The root of the Phalaenopsis hybrid flower was found to be infected with fungi, i.e., Fusarium sp., as reported by the Plant Pathology Division of NARC (Table 1). After drenching with Bavistin @ 3 gm/liter of water with a frequency of two times at the interval of 10 days, a post-entry quarantine inspection was carried out on the importer nursery, and based on its recovery after the application of fungicides, it was released. 

It was found that different types of inspection methods were applied to identify different types of pests intercepted on the traded commodity. Figure 1 shows that more visual inspection, i.e., on 7 commodities, was carried out, followed by microscopic inspection on four different types of commodities at NARC, as visual inspection was found dubious to verify the intercepted pest, like a weevil, Fusarium species.

Figure 1: Showing different methods of inspection on the commodity traded against the pest intercepted.

The result showed that four types of commodities, i.e., avocado, potted flower, Phaelonopsis flower, and grass seed, were carried out on post-entry quarantine inspection to confirm the presence of pests, i.e., mealybug, aphid, weevil, and Fusarium sp., after being inspected visually or microscopically. It was clear from the above figure that to confirm the pest-intercepted commodity, multiple inspections were done on some commodities like the potted flower, avocado, cocksfoot, and Phalaenopsis hybrid flower. Also, it could be interpreted from the above figure that post-entry quarantine inspection should be carried out for the confirmation of pests intercepted before the release of the commodity.

There are different sampling procedures and inspection methods for the agricultural commodities traded in Nepal [1]. Although different inspections were carried out for pest identification, there were still some cons to the inspection method. Lack of technical knowledge related to inspection, inadequate tools for inspection, a lack of a reference laboratory, a lack of a post-entry quarantine chamber, inadequate skilled manpower, a lack of coordination among stakeholders, and an inadequate area for sampling and inspection at customs could be the major constraints related to the inspection of traded agricultural commodities. Appropriate and scientific phytosanitary measures on traded agricultural commodities could be possible if and only if constraints related to sampling and inspection were addressed.

International Standard for Phytosanitary Measures (ISPM) [4] describes phytosanitary principles for the protection of plants and the application of phytosanitary measures in international trade, which are related to the protection of plants, including cultivated and non-cultivated/unmanaged plants, wild flora, and aquatic plants; those regarding the application of phytosanitary measures to the international movement of people, commodities, and conveyances; as well as those inherent in the objectives of the IPPC. The type of treatment required may be mechanical, chemical, irradiation, physical, or controlled-atmosphere treatments. Treatments result in the killing, inactivation, or removal of pests, render pests infertile, or devitalize pests. ISPM 28 (Phytosanitary Treatments for Regulated Pests) gives important guidelines regarding specific requirements for the treatment of regulated pests in international trade. ISPM 23 describes procedures for the inspection of consignments of plants, plant products, and other regulated articles at import and export. It is focused on the determination of compliance with phytosanitary regulations based on visual examination, documentary checks, and identity and integrity checks. The objective of a phytosanitary import regulatory system (ISPM, 20) is to prevent the introduction of quarantine pests or limit the entry of regulated non-quarantine pests into imported commodities and other regulated articles. ISPM 9, Guidelines for Pest Eradication Programs, focuses on an emergency measure to prevent the establishment or spread of a pest following its recent entry (re-establish a pest-free area). Plant Protection Act [2], Section 24, states that if any plants or plant products, biological control agents, beneficial organisms, or other articles to be imported or transported according to this Act are found infected in the course of inspection or examination, those that can be treated shall be released after treatment, and those that are found to be infected despite treatment shall be seized and destroyed.

The plant quarantine office has the main responsibility of inspecting consignments, treating the consignments, issuing the phytosanitary certificate and entry permit, and conducting pest surveillance. The trade of agricultural commodities across borders increases the chances of different pests and diseases being incorporated with the traded commodities. Thus, the assessment of pests during the trade of agricultural commodities helps in checking the pests that can be potentially threatening in Nepalese agriculture as well as ensuring quality trade. Although enhancing and strengthening the technical capacity of existing quarantine offices is still inadequate, therefore, it is important to enhance the capacity of existing infrastructure and technical knowledge to apply appropriate SPS measures during the trade of agricultural commodities, which results in minimizing the introduction of risk that can have a larger economic impact.

Acknowledgements

It’s my great pleasure to express my heartfelt gratitude and sincere appreciation to Dr. Ratna Kumar Jha, Ph.D., Senior Plant Protection Officer, for his persistent encouragement, constant supervision, excellent guidance, and invaluable suggestions throughout the course of this investigation and during the preparation of the manuscript. I also express my gratitude to Mrs. Sabitri Baral, former chief of the Plant Quarantine and Pesticide Regulation Center, for her prompt suggestions and constant supervision during the period of study. I am profoundly thankful to the quarantine office at Tribhuvan International Airport as well as the Plant Quarantine and Pesticide Management Centre and officials, especially Ram Krishna Subedi, Senior Plant Protection Officer, for his constructive suggestions and support throughout the entire course of research. I would like to express my thanks to the Plant Pathology and Entomology Division, National Agriculture Research Council, Lalitpur, for their suggestions and cooperation on the diagnosis process during the research period. I also extend my special appreciation to the Custom Office at Tribhuvan International Airport, Kathmandu, Nepal, for providing a conducive environment for sampling and observation procedures during the research period, as well as to all the traders who were directly or indirectly involved in their coordination during this study.

1. Plant Protection Process Manual, 2067/068. Government of Nepal, Ministry of Agriculture Development, National Plant Quarantine Program, Hariharbhawan, Lalitpur, Nepal.
2. Plant Protection Act. Government of Nepal, Ministry of Agriculture Development, National Plant Quarantine Program, Hariharbhawan, Lalitpur, Nepal. 2007.
3. Plant Protection Regulation. Government of Nepal, Ministry of Agriculture Development, National Plant Quarantine Program, Hariharbhawan, Lalitpur, Nepal. 2010.
4. International Plant Protection Convention (IPPC). International standards for phytosanitary measures (ISPM), Rome, Italy. 19.