Farm level grain storage pest management in Nepal

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1.1 Introduction

Nepal is situated on the Southern slopes of the mid-Himalayas bounded on the North by the Tibetian region of China and on the South-West and East by indict. It is located between 26 22' and 30 27' North latitudes and 80 40' and 88 12, East longitude. It has an area of 147,181 Sq. Km. (14.72 million hectares). Out of this total land, about 3.24 million hectares are arable area. Agroecologically, the country is broadly divided into three parallel zones viz. Mountains, Hills and Terai (indo-gangetic alluvial plain). About 35% of the total area lies in Mountain/zone, 43% in Hill zone and rest 22% in Terai zone. The total/cultivated area is about 2.9 million hectares. The average land holding is less than 0.5 ha. in Hills/Mountains and 1.5 ha. in Terai. Temperature ranges from 15C - 40C in Terai, about 5 - 25C in Hills and below 0C - 10C in Mountains.

The precipitation occurs mostly (80%) in summer (June September) and the annual rainfall ranges approximately from 300 mm to 3500 mm with an average of about 1600 mm. The average annual rainfall received in dry seasons (October May) is 300 - 500 mm. About 14% of the total cultivated land is under irrigation (seasonal/annual and gravitational/underground).

The population growth rate is 2.66% and about 33% of the total population is literate. Population density is about 120 persons/sq. km and 6 persons per hectare of cultivated land. Administratively the whole country is divided into 5 Development Regions, 14 Zones and 75 Districts.

Agriculture is the main stay of the national economy, which contributes about 60% of GDP and 60% of national export. Nore than 90% population directly derives their livelihood from it. Mainly because of topographic features, it has been widely conceptualized to encourage livestock farming in Mountains (at an altitude of 3000 m) above MSL) and horticulture is Hills (at an altitude range of 1000 M-3000 m MSL) and cereal and cash crops (sugarcane, jute, cotton, tobacco etc.) with altitude range between a hundred to 1000 meter MSL.

Farming in Hills in concentrated in valleys and around small plateaus, river banks and terraced slopes. Hill farming is mostly of subsistence and/or subsubsistence nature. The productivities of the crops are also low with an average yield of 2.016 mt/ha. for Paddy, 1.55 mt for Wheat and 1.446 mt/ha. for Maize and 0.922 mt/ha. for Millets.


2.1 HMG/N is committed to fulfil the basic needs of the people by the year 2000 A.D. Based on the results of different studies on food requirement, the minimum average per capita daily calorie requirement of Nepalese people has been fixed at 2250. Rice, Wheat, Maize and Millets, Barley (cereals) pulses and potato have been identified as major food sources to supply the 1964 calorie of the total minimum calorie requirement of the people. The rest of the calorie requirement will be supplied from vegetable, root crops, fruits, milk and milk products, meat, eggs and fish etc.

To cope with the food demand by 2000 A.D. the present production levels of cereals, pulses and potato (4,312,000 mt, 95,000 mt and 387,000 mt) need to be raised to 8,651,000 mt of cereals, 27,000 mt of pulses and 86,900 mt of potato. The projected production of the increased cereals and grain legumes (approx 8.618 million mts) will demand a corresponding increase in the postharvest loss reduction activities/facilities, as the increased food production will naturally exert tremendous strain on and manifest problems in existing methods of handling, storing and processing. This will lead to unwarranted increase in post-harvest food losses, and will decrease enormously overall food availability. Establishment and maintenance of adequate facilities for harvesting, storage, processing and other post-harvest operations at different levels wil be essential as it is estimated that 70-80% of produce in Terai and about 100% in the Hills and the Mountains is retained by the farmers in Nepal for needs of the family, lalour seed and cattle. Balance quantity which constitutes the marketable surplus passes through the hands of grain stockists, private traders and retailers.

2.2 The reduction of post-harvest losses at the level of stockists and private trade (2-3%) becomes more difficult because of their unmindful attitude and behaviour in view of the fact that their profits are not significantly affected by wastage/losses and therefore, contributes to general apathy towards improvements. The cooperative societies have also not gone much beyond the traditional method of handling and storage. However the Nepal Food Corporation and Agricultural Inputs Corporation have attempted to modernise the techniques of handling and storage of foodgrains and seeds.

Considering the fact that more than 70% of the production is retained on farm and this is where the larger part of losses (7-10%) occurs, the farm level storage clearly emerges as an area of priority for implementing the loss reduction activities.

2.3 In view of the need of development and diffusion of post-harvest loss reduction technology (LRT) to improve the availability and quality of foodgrains, this was established in 1980 under the Ministry of Agriculture (MOA) with the assistance of FAO. At present the various agencies involved in postharvest sector in Nepal are as follows :

(i) Rural Save Grain Project.

(ii) Nepal Food Corporation - Ministry of Supply (MoS).

(iii) Sajha Cooperative.

(iv) Salt Trading Limited - Pvt. (STL).

(v) Private Millers and Traders.

(vi) Bi and Multi lateral projects- MOA/MPLD. (Ministry of Panchayat and Local Development)


Besides losses in storage, losses also occurs in harvesting, threshing, processing and milling of various foodgrains both in quantity and quality. The details are given below:

3.1 Harvesting

All three crops (Paddy, Wheat and Maize) are harvested manually. Paddy and wheat are harvested by cutting at the base of plants. In some parts of the country wheat is harvested by picking up the ear heads only. Maize is harvested by lashing the cobs from the stalk. The average harvest losses in paddy, maize and wheat have been found 1.63%,3.33% and 1.76% respectively. The harvesting loss includes mainly the shattered grains, leftover panicles and cobs.

3.2 Threshing/Shelling

In Mountains/Hills paddy and wheat are threshed by beating the plants on the floor or stones kepy on the threshing floor, whereas in Terai the threshing is done by trampling with ox or by tractors or with rare exception by the power thresher. Un warranted delay occurs in paddy threshing particularly with big and medium farmers due mainly to lack of efficient means of threshing. They often stack paddy for 1-3 months after reaping, depending upon the sizes of their holdings and the resources they possess. This delay in threshing causes consider ble lossos due to rodents, birds, animals and pilferages. These stacks also allow the rodents to survive the lean period.

Maize is generally stored unthreshed/ unshelled. It is shelled as and when the farmer requies it. Maize is shelled either by beating the cobs with stick or stripping in paddy, maize and wheat have been found to the extent of 2.19%, 2.85% and 3.70% respectively. The losses includes the shattered grains and ungleaned grains.

3.3 Transportation

Grains are transported from threshing yards to storage either on the human back after packing it in the bags or baskets or carried as head load or by bullock-carts or mules. The transportation losses have been found to be 0.32% in paddy 1.04% in maize and 0.34% in wheat. This loss occurs due to grain dropping/shattering and spoilage.

3.4 Drying

Sun drying is the most prevailent method of drying crops. Hence the extent of drying depends on the season and temperature. Farmers generally dry the threshed grains on rice-straw wooven mats or on the ground especially prepared for it. Farmers who have access to metalled road, also dry the grains on the road. The drying loss has been observed 1.5% in paddy and 2.07% in wheat.

3.5 Storage

The farmers store the major portion of their production (70-80%) for their consumption. Storage practices vary with the types of crops grown, climatic conditions and local customs. Paddy and wheat are commonly stored in structures made of bamboo splits and strippings (Bhakari), Dhukuti, mud Dehari and wooden granary (Kothi) and recently the metal bins of different sizes are in use. In general management of stores is traditional.

Maize is usually stored on Thangro (made on vertical-pole) or stacked on floors or wooden platforms. Hanging of Maize cobs in bundles under the eaves is also common. Insects, rodents and birds are important storage pests. The average storage period of paddy, maize and wheat are 7 months, 8 months and 4.5 months respectively. The loss due to insects/rodents are respectively 6.22%, 7.3% and 5.92% (by weight) of paddy, wheat and maize.

3.6 Processing/Milling

Quern, leg pounder, hand pounder, water mills, Engleberg steel huller and modern sheller/ plate mills, all are found for food processing. The traditional technologies are simple, and labour intensive.

The out-turn of brown rice in pounder ranges from 50-60%. Recovery rate in Quern/water mills ranges from 95-97% but flour is coarse compared to flour obtained from modern flour mills. Results of loss assessment study done in huller mills showed that 4.4 Kg. of milled rice is lost for every 100 Kg. of Paddy milled.


Various types and sizes of storage structures and containers are traditionally in use. They are being made with different types of locally available materials and skills. These structures are mainly for the storage of different grains in various forms in different ecological conditions and socio-economic situations. They also differ in sizes, shapes and construction materials. A summary of these structures are:

(a) Traditional Out-Door Storage Structures

Bery/Bhakari (Made of bamboo splits and timber).
Muja-ko Bhakari (made of straw/reed.)
Suliout-door raised platform with proper roofing for maize storage.
Thungki (wooder-granary with roofing).
Thangro (timber/bamboo drying/storage rack).
Dhansar (a separate house made of timber and planks for storage, few big farmers are only using it).

(b) Traditional In-Door Storage Structures/ Containers

Kath-ko Bhakari (made of wooden planks and plat form).
Gundari-ko Bhakari (made of straw/ bamboo mats).
Chitra/Choya-ko Bhakari (make of bamboo splits and strippings).
Kotho -(made of bamboo splits and strippings).
Doko -(made of bamboo stripping and splits).
Dalo/Bamboo basket (made of bamboo strippings and splits as well as reeds).
Dehari and Kothi (Mud-bins-respectively smaller and bigger in sizes).
Gagro and Ghyampo (clay pots-respectively smaller and bigger in sizes
Dhukuti -(mansonary structure-brick wall Bhakari).
Eaves of the houses (mostly for drying and storage of maize, garlic, chillies, etc.).


The existing structures do not provide sufficient safety to stored grains against insects, rodents and birds. Therefore, some efforts have been made to improve these structures. These improvements need further in-depth studies. They are as follows:

Proper plastering of mud-cowdung-straw mix from both the sides - inner and outer - of structures made of bamboo splits/strippings/bamboo and straw mats/reeds and regular sanitary measures for their disinfection.

Results obtained from these demonstrated improvements are greatly gratifying and their management is also comparatively easier and cheaper.

Any successful and manageable improvements in Mud-bin will bring revolution change in the saving of grains in storage particularly in Terai.


Efforts were also made to demonstrate the efficiency and effectiveness of metal bins and Pucca Kothi/Dhukuti (Bhakari made of brick and cement mortar) and Ferro-cement bins of different capacities. These structures have proved completely effective against rodents and birds. If handled and managed properly, foodgrains could safely be stored against insects and molds without the use of any chemicals. Among these structures Ferrocement bins have not been liked by farmers because of handling problem and Pucca-Kothi is costlier. But, metal bins are getting popular and wider acceptance by the farmers. The major problem associated with metal bin was of transportation both by truck and porter. To overcome this problem, this project was be able to develop packable kits of metal bins. These packable kits have increased 4-6 times transportation efficiency by truck and 3-4 times by porters.


Much of the post-harvest foodgrains losses can be attributed to rodent and insect pest. So it is necessary to workout appropriate rural storage technology which will reduce the harm caused by these pests. Among the most destructive are:

(1) Rodents:

(a) Rattus Sp
(b) Mus museulus
(c) Bendicota bengalensis

(2) Insects:

(a) Sitophilus Sp
(b) Rhizopertha dominica
(c) Oryzaephilus Surinamensits
(d) Tribolium castaneum
(e) Sitotroga cerealelia
(f) Plodlia interpunctella

(3) Molds:

(a) Aspergillus Sp
(b) Penicillium Sp

(4) Birds:

(a) Passar Sp and

(5) Mites etc.

The common grain storage pest management methods exercized in the country includes (i) Inspection (ii) Sanitation (iii) Physical and mechanical (iv) Chemical. Much of the emphasis has been placed on sanitation and inspection. However the use of chemical is gaining popularity rapidly among the farmers, and so the principle of prevention first and the employment of both prevention and treatment at the same time is also recommended. Some of the safe, economical and effective means to be taken include maintaining proper storage hygiene, physical and mechanical and chemical control methods, as all these methods are closely related to and supplement each other. The aim of the sanitation is to create an unfavourable environment for the growth and breeding of insects.

Suggestions are made to farmers on giving a thorough cleaning of bins to keep free of holes, cracks, and also litters around the stores to be removed to eliminate the hiding places for insects and rodents.

Further, as the proper utilization of chemical. play an important role in IPC, farmers are given training on the judicious use of chemical, in order to ensure good results and avoid contaminating the grain.

As large scale or collective farms are rare in Nepal, the economics of large-scale operations at farmlevel may not be possible. It is, therefore, imperative that whatever technologies are adopted or recommended, these should be simple, low cost and continuous type.

The storage structures, drying and aeration play a very important tole in on-farm storage of foodgrains. Effects have been made by Rural Save Grain Project to develop new designs as well as improvement of existing storage structures. Some of the designs and metal silos have been well accepted by the farmers in Nepal. The metal bins of variable capacities ranging from 100 to 300 kgs. are being supplied to the farmers through District Agricultural Officers at 25% subsidy.

The moisture in foodgrains at the time of harvesting vary from region to region and season to season. The farmers generally are aware of the important of drying and they do undertake drying before storage. The maize cobs are tied with rope for hanging around the house under the roofs for drying. Control measures recommended by RSGP for safe storage of grains at farm-level include:

(i) Discourage accumulation of grain and/or grain product residue in and around all farm structures.

(ii) Use of sound structures for storage of grains.

(iii) Clean and remove residues of grains from storage structures 4-6 weeks prior to placing new harvest for storage.

(iv) Spray storage structures/surroundings (with recommended residual insecticides) after cleaning 4-6 weeks before arrival of new harvest.

(v) Storage of clean and dry grains.

(vi) Aeration (if possible) to cool grain and maintain temperatures.

(vii) Inspection of grains regularly, (at least monthly) to see.

a. temperature increase,

b. insect activity,

(viii) If insects are detected, grain should be fumigated. Fumigation of bags can be undertaken with polythene sheets under on-farm conditions.

(ix) Rodent control measures:

(a) Use of traps,
(b) Use of chemical.

However, in Nepal, the selection of appropriate storage technology and management of grain storage are influenced by various factors such as:



8.1 The existing post-harvest loss reduction activities of RSGP which is implemented in 17 districts, will be extended to all 75 districts on priorities basis. Staff of this central unit will assist the technical divisions and extension unit for basic research and subsequent field testings.

8.2 Dessimination of technical message on loss reduction through the model village approach will be continued in addition to existing extension units of DOA.

8.3 Training of farmers SMS, JT/JTA will be carried out in cooperation with regional training centres of DOA.

8.4 The research activities will be concentrated on the following areas of PHS.

8.4.1 Storage structures development and improvement on existing structures.

8.4.2 Testing and evaluation of small scale thresher, driers, reapers designed and developed in the country or in neighbouring countries.

8.5 Stimulation of local manufacturing base will be continued. Small scale entrepreneurs at local level will be encouraged to multiply technological improvements developed by government agencies. Government support for research, credit and creating demand for their product will be continued.

8.6 The loss assessment and survey of major crops will be conducted as per need.

8.7 External assistance for the establishment of Post-Harvest Field Stations, exchange of technological achievements and development of local manufacturing units will be sought in future for efficient management of post-production losses.

8.8 Preliminary studies on storage feasibility of perishable food at farm levels will be initiated and on the basis of the result of the study appropriate programmes will be formulated for implementation.

8.9 Demonstration and distribution of improved post-harvest equipment (thresher, bins, driers etc.) and other extension materials like pamphlets, bulletings/brochures etc. will be carried out as per need.

8.10 Women in the rural household are to a large extent responsible for many of the postharvest operations, including harvesting, threshing and safe storage of foodgrains and seeds and so the training to the women on the post-harvest loss reduction technology is provided in close coordination with Women's Training Centre WTC) under Ministry of Panchayat and Local Development (MPLD) will be continued.


Nepal would like to share experience and expertise on the following areas on PHS with regional network member countries:

9.1 Development of information systems for sharing experience on PHS and loss reduction technology (LRT).

9.2 Development of appropriate post-harvest equipment and machines suitable for small farmers.

9.3 Collaborative establishment of local manufacturing units for PH equipment and machines.

9.4 Development and implementation of community rodent rodent control programme.

9.5 Development of suitable package of message for extension workers on loss reduction activities.

9.6 Development of programmes on perishable food materials.

9.7 Trainings of subject matter specialists on PHS.

9.8 Farm level potato seed storage.

9.9 Exchange visits amongst NMC countries by PH/LR Technologists to identify areas for collaborative programmes.


20.30% of the total produced foodgrains enters the trade channel (off-farm) for internal distribution to urban consumers, food deficit areas, export and retention with various marketting agents. NFC under Ministry of Civil Suppies (MOS) is one of the major public institution handling the food at off-farm level. At present NFC deals mainly with Paddy, Rice, wheat, Maize and Oil Seeds. Its one of the main activity is to purchase the grains from the surplus areas and distribute them to the deficit districts in the country. NFC at present has a storage capacity of about 86,O00 MT.


Cooperative is a multi-purpose organization at the grass root level for the promotion of rural developmental activities. It is managed by locally elected board of directors and supervised, guided and assisted by Department of Cooperative Development (DCD). Cooperatives in Terai districts act as procurement agents for NFC and salt Trading Limited. They have about 50,000 MT capacity godowns which are mostly located in Terai and a few in Hills. They are mostly engaged in procurement of Paddy. They store only for a short period.


STL is also involved in foodgrain business. But it handles only wheat grain. The capacities possessed by STL is about 28,000 MT.


Private millers and traders are major agents involved in the post-harvest foodgrain operations. They procure from farmers and middlemen, to supply to NFC of Sajha for local distribution and exports. Almost all big traders/millers have their wn godowns/storage facilities. They do not have any trained technician but have well experienced administrative staff, who handle the grain at all levels. It is estimated that presently the private traders and millers have about 463,O00.


Method Recommended Recommended Dosage % Ratio & Time of Application
Protective method      
1. Chemical Spraying of 50 EC 0.5 3 Lit. per 100 M
  Malathion   before storing the
  50 EC and Nuvan   grains.
  (DDVP) 0.5  
2. Sanitation Cleaning/drying Pre Storage  
1. Mixing Malathion 5% dust 29 m/Kg of Seed  
2. -Fumigation      
(a) Bulk   3 gms tablet of  
(b) Bag   Almunium phosphide  
    per ton of orain As necessary

In addition farmers use the local herbs and plant products to protect their seeds grains, commonly used plants are as follows:

(a) Neem leaf (Azadirchta Indica) mixing the grinded leaf in the grain.
(b) Timur (Xanthoxylum armatum) mixing leaf as well as seeds in the stored grains at the rate of 10 gms/Kg of seeds.
(c) Similarly Titepati (Artemisia vulgaris) is also used in different parts of the country.

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