Rice development programme in Nepal

T.P. Pokhrel
Rice Coordinator, Nepal Agricultural Research Council, Nepal

INTRODUCTION

Rice is by far the most important crop in Nepal and accounts for about 50 percent of the total agricultural area and production in the country. It is grown on about 1.45 million ha, and total production since 1988/89 has hovered between 3.2 million and 3.5 million tonnes. Rice contributes approximately one-fourth of GDP and more than 75 percent of the working population is engaged in rice farming for at least six months of the year. Furthermore, rice in Nepal provides nearly 50 percent of the calorie requirements supplied by cereals. Table 1 presents details of the production, exports and imports of rice between 1975/76 and 1993/94. Total production shows an upward trend, with an annual growth rate of 1.65 percent over the 18-year period. The year 1993 was favourable for the paddy crop and, despite some flood damage, the crop harvest was generally good. The production figure was 3.4 million tonnes of paddy, based on preliminary estimates.

Data on the import of rice were published in Foreign Trade Statistics, issued by the Nepalese Ministry of Finance. Although Nepal exported substantial quantities of rice in the 1970s and mid-1980s, the country stopped exporting it from 1987/88 onwards (Government of Nepal, 1992), and in times of drought imports are required. It seems that population growth has outstripped rice production, and rice imports will be necessary unless total production is significantly increased. Table 2 presents daily food supply per caput. While in 1961 the percentage contribution of rice to daily human calorie intake in Nepal was 36.7, this increased to 41.3 in 1985. Cereals contribute about 90 percent of the total calorie intake, and 50 percent of this comes from rice.

Table 1

Rice production, exports and imports

Fiscal year

Production1

('000 tonnes)

Exports2

(million rupees)

Imports3

(tonnes)

1975/76

2 605

495.4

-

1976/77

2 386

343.0

-

1977/78

2 282

185.0

-

1978/79

2 339

257.2

-

1979/80

2 060

 42.3

-

1980/81

2 464

117.6

-

1981/82

2 560

222.6

-

1982/83

1 833

 11.3

34 147

1983/84

2 757

 75.4

13 119

1984/85

2 709

250.0

 8 592

1985/86

2 804

 93.2

 6 166

1986/87

2 372

 14.4

34 602

1987/88

2 982

-

19 981

1988/89

3 283

-

 8 375

1989/90

3 390

-

12 967

1990/91

3 502

-

NA

1991/92

3 223

-

NA

1992/93

2 584

-

NA

1993/94

3 496

-

-

Sources: 1Government of Nepal.
2 Government of Nepal, 1992.
3 Ministry of Finance, Government of Nepal. Foreign Trade Statistics (various issues).

Table 2

Daily per caput food supply

Year

Total calories

Calories from cereals

Percentage of intake from cereals

1981/82

1 765

1 628

92

1982/83

1 608

1 461

90

1983/84

1 755

1 615

92

1984/85

1 815

1 667

92

1985/86

1 852

1 704

92

1986/87

1 923

1 772

92

1987/88

2 000

1 849

92

1988/89

2 077

1 920

92

1989/90

2 125

1 949

92

1990/91

2 288

2 131

93

Source: Food and Price Unit, Marketing Services Union, Government of Nepal.

NATIONAL RICE POLICIES AND DEVELOPMENT STRATEGIES

The many structural changes which occurred in the agricultural research institutions of Nepal between 1924 and 1992 are presented in detail (see Box), while the current status of research and development in the country is summarized in the following sections.

BOX

Structural changes in agricultural research institutions, 1924-1992

1924

The Department of Agriculture was created and two trial and demonstration farms (one each for crops and horticulture) were established in the Kathmandu Valley.

1947

The Parwanipur Agriculture Station, Bara (Terai) was established, focusing on the Terai environment for the production of cereal crops in Nepal.

1950s

Additional research stations and farms were established (e.g. at Janakpur, Chitwan, Pokhara) and various disciplinary divisions (e.g. agronomy, pathology and soils) were created to test and modify exotic technologies for application in Nepalese conditions.

1966

The existing Department of Agriculture was dissolved and five new departments were created (Agricultural Education and Research, Agricultural Extension, Horticulture, Livestock and Animal Health and Fisheries). The Department of Agricultural Education and Research was made responsible for cereal crop research in Nepal.

1971

A separate commodity-specific research programme on some major crops was initiated by the Department of Agricultural Education and Research.

1972/73

A ten-year agricultural development plan was formulated; the existing five departments were merged into one Department of Agriculture within the Ministry of Food, Agriculture and Irrigation; and the commodity-specific research programmes were expanded to include rice, maize, wheat, citrus and potatoes. Thus, the national rice research programme (then called the Rice Improvement Programme) was created as the commodity-specific programme for rice to test and develop new high-yielding rice technologies in the country.

1985

The National Agricultural Research and Services Centre (NARSC) was created to strengthen and coordinate research activities of the Department of Agriculture.

1987

The services component of NARSC was omitted and NARSC became the central secretariat of the Research Coordination Committee (RCC) within the Ministry of Agriculture. The Member-Secretary of RCC served as the Executive Director of NARSC.

1990

NARSC became the Nepal Agricultural Research Council (NARC), an autonomous institution governed by a board, headed by the minister for agriculture.

1991

The Government of Nepal nominated NARC board members, representing, among others, agricultural research scientists, industrialists and farmers.

1992

By-laws were drafted (for approval by the NARC board members) to give greater flexibility and freedom to the executive director to achieve more effective research planning and administration.

The Coordinated Rice Research Programme

The Coordinated Rice Research Programme functions under the Nepal Agricultural Research Council (NARC). It was established in 1972 with its headquarters at Parwanipur Agriculture Station (260 km southwest of Kathmandu), which is on the flat plains of the Terai region. Since its inception, the programme has engaged in the identification of high-yielding and disease-resistant varieties. Headed by a coordinator, it conducts trials on soil fertility, agronomy, entomology and the pathology of rice. An important fact to note is that the production of breeder seeds of the released varieties is the sole responsibility of the Coordinated Rice Research Programme, which is also involved in foundation seed production.

Furthemore, the programme has the mandate of providing advanced yield trials and nurseries to regional agricultural stations as well as to agricultural research stations of the subtropical regions. The Division of Botany, stationed in the Kathmandu Valley, is responsible for rice varietal research for the "mid-hills". Limited research on varietal development is undertaken at Jumla, which lies in the "high hills" (mountains).

Extension network

The Department of Agricultural Development has the mandate for extension activities. There are 75 districts in Nepal, which each have a district development office with at least one graduate agricultural development officer at district headquarters. The district headquarters office has to carry out its extension activities in crops, horticulture, fisheries, veterinary and livestock under one "umbrella" policy. A strong linkage exists between research and extension, whereby on-farm trials are conducted by the regional and agricultural research stations in collaboration with the district agricultural development offices.

On-farm trials are designed mostly on prereleased varieties, pesticide/fungicides, soil fertility and crop management, depending on the need of the area. Extension personnel are involved immediately from the planning stage through to the execution of on-farm trials. Field days are organized to acquaint the neighbouring farmers with the latest rice technology, with the active participation of the district agricultural development office.

Inputs

In Nepal there is a price subsidy on urea and a transportation subsidy on chemical fertilizers. Farmers are using more fertilizer on rice than previously. There is no crop-specific policy on credit. In order to make it more productive and effective, it is felt that proper attention needs to be paid to integrating agricultural credit with farming needs. Currently, the government announces the support price prior to planting the rice crop; however, this is irregular and abrupt. Moreover, the prices in India affect Nepalese domestic prices.

THE RICE PRODUCTION PROGRAMME

As previously stated, rice is the major crop in Nepal. It is grown in three agro-ecological zones, namely the Terai, mid-hills and high hills. About three-quarters of the total rice area is located in the flat plains of Terai. The mid-hills and high hills occupy only about 23 and 2 percent, respectively, of the country's rice area (Table 3). There was an overall increase in area and production in the 1980s, with the Terai registering a growing trend in productivity since the mid-1980s.

Table 3

Average rice area and production by agro-ecological zone, 1975-1992

 

Mountains

Hills

Terai

Total

Area ('000 ha)

1975-79

26.26
(2.1)

199.71
(15.8)

1 033.71
(82.1)

1 259.68

1980-84

26.28
(2.0)

250.39
(19.1)

1 032.92
(78.9)

1 309.59

1985-89

39.91
(2.50)

326.96
(23.4)

1 036.65
(74.1)

1 399.54

1990-92

40.08
(2.91)

341.60
(24.82)

994.66
(72.27)

1 376.30

Production ('000 tonnes)

1975-79

54.97
(2.3)

473.98
(20.3)

1 805.59
(77.3)

2 334.53

1980-84

48.21
(2.0)

53.75
(21.5)

1 885.72
(76.5)

2 464.68

1985-89

65.04
(2.3)

650.26
(22.7)

2 145.07
(75.0)

2 860.37

1990-92

78.96
(2.54)

753.18
(24.27)

2 271.06
(73.19)

3 103.20

Note: Figures in parentheses are percentages of the total.
Average yields: Mountains 1.97 tonnes/ha; hills 2.20 tonnes/ha; Terai 2.28 tonnes/ha; and Nepal 2.25 tonnes/ha.
Source: Government of Nepal, 1992.

There are 13 agricultural research stations around the country and six central disciplinary divisions responsible for carrying out research under NARC. The agricultural research stations have the mandate to conduct on-farm trials in the command areas. The trials are carried out by researchers, usually under irrigated conditions and with the active participation of farmers. The potential rice yields under Terai and mid-hill conditions are 4 and 4.5 tonnes/ha, respectively, although the actual yields of Terai and the mid-hills are 2.28 and 2.20 tonnes/ha (Table 3). These differences between potential farm yields and actual yields are attributable to biological constraints (e.g. varieties, weeds, diseases, insects and water supply) and socio-economic constraints (e.g. costs and returns, credit, input availability and institutions).

Popular rice varieties

The popular rice varieties grown in the three agro-ecological zones of Nepal are as follows:

Terai
Spring rice (February/March - June/July)
Chaite 2 (IR7151-1260-3-3)
Chaite 4 (IR9729-67-3)
Ch 45
Bindeswari (IET 1444)
Main season rice (June/July - October/November)
Mahsuri (called "Masuli" in Nepal)
Savitri (IR2071-124-6-4)
Makawanpur-1 (BG400-1)
Janaki (BG90-2)
IR8423 (prereleased variety)
Upland rice
Ghaiya-2 (MW10)

Hills
Taichung 176
Khumal 4
Pokhareli Masino

Ch 45 is a popular spring rice variety in the Terai, the lower river basins and valleys of up to an altitude of 900 m. Chaite 2 and Chaite 4 are replacing Ch 45 in the Terai. Bindeswari is grown more as a rainfed variety in the main season, although it was released as an early-maturing variety for the spring season. Masuli was released in 1973 and is still popular despite its susceptibility to blast and bacterial leaf blight. It is slowly being replaced by Savitri in the central and western Terai regions. The use of Makawanpur-1, originally released for the gall midge-infested area of Makawanpur district, is spreading in central Terai and the river valleys. Janaki, which was previously released for the whole of Terai, has become extremely popular in the Banke district of midwestern Terai. Ghaiya-2, an upland variety, is also grown under irrigated conditions in the spring season as its yields are extremely high, more than 5 tonnes/ha for beaten rice. Meanwhile in the mid-hills, Pokhareli Masino, Taichung 176 (especially in Kathmandu Valley) and Khumal 4 are extremely popular. However, plenty of local varieties are also grown in remote areas.

Rice-wheat-fallow is the predominant cropping pattern in Nepal, although other cropping patterns prevailing in the country include: rice-rice-wheat, rice-rice-fallow, rice/lentil-fallow, rice-wheat-mung bean, rice-winter maize-fallow, rice-chickpea-fallow and rice-mustard-maize.

Biological constraints

Diseases, insects and weeds are the major biological constraints to high rice yields in Nepal. More than 19 fungi, five nematodes, four bacteria and two viruses are reported to affect rice plants in the country. Blast and bacterial leaf blight are the major production hazards among the diseases. The insects causing significant losses are: the Gundhi bug (Leptocorisa acuta); hispa (Dicladispa armigera); mealybug (Ripersia oryzae); planthoppers (Nephotettix apicalis, Sogatella fercifera and Ceeadela spectra); yellow stem borer; striped borer; and armyworm (Mythimna seprata). There are also some isolated cases of significant losses caused by seed-bed beetle, caseworm and leaffolder. A population dynamics study (1988-1990) has shown that the peak of many rice insects is usually followed by the peak of predators and parasite populations in nature. Weeds are particularly serious in direct seeded and upland rice. In these cases, yields may be virtually non-existant unless weeding is carried out. Small farmers keep their fields free of weeds by removing them manually. Larger-scale farmers have started using herbicide because of a lack of labour. In transplanted conditions, weeds are a minor problem in the Terai.

Physical constraints

About 79 percent of the rice area is rainfed, of which about 70 percent is lowland and 9 percent is upland. The crop either suffers from prolonged drought or is submerged as a result of excess rain for a long period (owing to the absence of drainage) under rainfed lowland conditions. This results in poor rice yields, yet farmers are reluctant to grow modern varieties of rice under these conditions. The availability of assured irrigation is imperative for increased rice production, but in Nepal only about 20 percent of the area is irrigated. Adverse topography and soils also seem to be significant constraints to high rice yields. Zinc deficiency has been increasingly common, and this adversely affects rice yields. Isolated cases of soil acidity, poor drainage and siltation problems have also been reported, but their severity at the national level is yet to be assessed.

Socio-economic constraints

About 50 percent of the rice area comes under modern varieties and the estimated annual demand of seed is more than 35 000 tonnes. However, the Agricultural Input Corporation has been able to supply only a small part of this quantity. The remainder is met through farmer-to-farmer seed exchange practices. Therefore, the lack of quality improved seed is one of the major constraints to rice production (Table 4).

The yields of rice are highest in the regions where the use of chemical fertilizer is also highest. For example, the average farm yields in the Kathmandu Valley, which has the highest application of chemical fertilizers in the country, are in the order of 5 tonnes/ha. The national level of fertilizer application to rice is nearly 26 kg/ha. Available results of fertilizer experiments over time clearly indicate that rice varieties respond profitably to fertilizer applications of up to 90 kg/ha of nitrogen. The low level of fertilizer application in Nepal can be attributed largely to its unavailability at the right time and the poor purchasing power of Nepalese farmers (Table 5).

Table 4

Improved paddy seed consumption, 1982/83-1991/92

Year

Consumption ('000 tonnes)

1982/83

691

1983/84

318

1984/85

238

1985/86

154

1986/87

141

1987/88

212

1988/89

213

1989/90

146

1990/91

156

1991/92

277

Table 5

Consumption of chemical fertilizers, 1982/83-1991/92

Year

Nitrogen

Phosphorus

Potash

Total

 

('000 tonnes)

1982/83

22 882

7 459

938

31 279

1983/84

28 058

8 463

779

37 300

1984/85

31 656

10 623

550

42 829

1985/86

31 698

11 053

657

43 408

1986/87

32 900

11 940

210

45 050

1987/88

38 113

15 210

858

54 181

1988/89

39 801

15 268

1 770

56 839

1989/90

49 206

16 742

1 338

67 286

1990/91

51 929

19 256

1 533

72 718

1991/92

6 008

22 833

1 602

84 443

CURRENT STATUS OF THE COORDINATED RICE RESEARCH PROGRAMME

Human resources

The situation regarding personnel for the Coordinated Rice Research Programme is gloomy. From the mid-1970s to the mid-1980s there were sufficient human resources. However, most of the trained research scientists have either left the programme for the private sector or have been transferred to administrative posts within NARC. Both the programme and the Parwanipur Agricultural Station combined once had 25 vacancies for research scientists of various disciplines, but these positions were filled more than a decade ago. Now the actual total of research staff working for the programme does not even make up half the number of planned posts. NARC is currently filling up the vacant positions with mostly B.Sc. graduates. The programme currently consists of one technician with a Ph.D., three with an M.Sc. and five with a B.Sc. as well as five junior technicians. Two research scientists on the programme are undertaking M.Sc. degrees in rice improvement, while the rice research unit for the mid-hills stationed at the Division of Botany, Kathmandu, is headed by an M.Sc. technician. In addition, the regional agricultural research stations do not have adequately trained and experienced personnel. As a result, rice research has suffered.

Facilities

The programme has laboratories for the study of soil, pathology, entomology, and quality, and also possesses a greenhouse and irrigation and housing facilities. It also has its own administration building. The experimental plots are well laid out, and there is enough land for seed multiplication. A seed processing plant was installed in the early 1980s. However, renovation is required for houses, offices, irrigation and stores.

Funding

At present, the programme is funded by the government. Support from the United States Agency for International Development (USAID) is also provided for research management and on-farm trials.

Research and production

A total of 38 rice varieties have been released so far, of which 10 to 12 varieties have been widely adopted by farmers. These varieties have helped increase the yield by over 1 tonne/ha compared with local varieties. Most of these modern varieties fit into the cropping pattern and, as a result, farmers have been able to produce two rice crops a year as well as a third crop. Harvesting main season rice by the end of October allows farmers to plant winter crops in time and, furthermore, higher yields of winter crops are being obtained.

Previously, varieties were released without a good understanding of the ecosystems or of the farmers' circumstances and needs. Nowadays this is no longer true. The rapid rural appraisal survey has provided information on research priority areas. A study on returns to wheat research in Nepal, for example, showed a rate of return of 75 percent from 1960 to 1990 and an annual gain in yield potential of 1.3 percent. The relationship is yet to be established in rice, but it is believed that more than half a million tonnes of rice production is attributable to modern varieties.

FUTURE ACTIVITIES

Through NARC, the Coordinated Rice Research Programme will maintain linkages with the Department of Agricultural Development and, most important, district extension offices, regional research stations and agricultural research stations. Since about 50 percent of the rice area is covered by improved varieties, an effort will be made to cover the remaining areas with the new modern varieties.

CONCLUSIONS

Rice is the foremost food in Nepal. The increase in rice production has mainly resulted from area expansion. As there is no further scope for bringing more area under rice cultivation, the only viable strategy is to increase the productivity of rice. Resource-rich farmers have been obtaining 4 to 5 tonnes/ha in the main season rice crop. These yields are realized in irrigated and well-fertilized areas with adequate plant protection. Modern varieties yield well under these conditions. About 79 percent of the rice area is rainfed when the coverage by the improved varieties is not substantial. It is mainly in the irrigated and favourable rainfed areas, where the rainwater is retained longer, that the HYVs are grown. The development of drought-tolerant varieties is the top priority of Nepal's Coordinated Rice Research Programme: Bindeswari, Makawanpur-1, Ghaiya-2, TCA 80-4 (prereleased) and IR8423 (prereleased) are currently being popularized.

There is scope for increasing basmati rice production in the country with new modern varieties. Work in varietal identification has been initiated and the hybridization of basmati rice is also planned. Hybrid rice research will begin in collaboration with the International Rice Research Institute (IRRI).

The rice programme carried out under the Department of Agriculture received declining shares of the state agricultural budget: in the 1970s maize had a higher budget allocation than rice and, at the beginning of 1980, rice received an even lower proportion of the agricultural budget than the disciplinary divisions. This situation is likely to improve with the NARC system, and it is widely believed that NARC will also give proper attention to the development of human resources.

The seed multiplication of rice needs to be strengthened. The Agricultural Input Corporation should multiply certified seed through contract seed growers, as there is enough foundation seed produced in different agricultural research stations. However, this will need careful planning to be both productive and effective.

The training of extension personnel in rice production technology should be regular. The district extension offices should take the initiative in the dissemination of rice technologies. Improved seeds should be made available to farmers. Zinc deficiency is widespread in Terai and causes substantial yield losses. Blast usually becomes very severe in the inner areas of Terai. Insect pests cause significant losses in certain pockets. Moreover, extension personnel need to be alert and able to continue their work when the rural road network is disrupted by landslides and floods.

REFERENCES

FAO. 1992. Selected indicators of food and agricultural development in the Asia-Pacific region, 1981-91. Bangkok, FAO, Regional Office for Asia and the Pacific.

Government of Nepal. 1992. Economics survey. Kathmandu, Ministry of Finance.

NARC. 1994. Research planning and programme development process. Lalitpur, Nepal.

NRIP. 1986. Rice improvement programme reports from the 13th Summer Crops Workshop 1986, Parwanipur, Nepal. Kathmandu, Ministry of Agriculture.

Singh, R.B. 1992. In Res. Dev., 1992(17).

Upadhayaya, H. 1994. Rice production constraints and drought loss in East and South Asia. Paper presented at the Seventh Annual Meeting of the Rockefeller Foundation International Programme on Rice Biotechnology, 16-21 May 1994, Bali, Indonesia.

Upadhayaya, H. & Ojha, G.P. 1992. Trends in Terai foodgrain productivity: lessons from the past. Kathmandu, Winrock International.

Upadhayaya, H., Pokhrel, T.P., Sivakoti, G.P. & Vaidya, S.N. 1991. Current state of Nepal's rice research: implications for research priority settings. Workshop on Rice Research Prioritization, 13-15 August 1991, Los Baños, the Philippines. Los Baños, the Philippines, IRRI.

PROGRAMME DE DÉVELOPPEMENT DE LA RIZICULTURE AU NÉPAL

Le riz est de loin la culture la plus importante au Népal où il entre pour environ 50 pour cent dans la superficie et la production agricoles totales du pays. Il est cultivé sur quelque 1,45 million d'hectares et sa production totale oscille depuis

1988/89 entre 3,2 et 3,5 millions de tonnes. Le riz fournit approximativement un quart du produit intérieur brut (PIB).

Il est cultivé dans trois zones agroécologiques à savoir, le Teraï, les moyennes et les hautes montagnes. Les trois quarts environ de la production de riz proviennent des plaines du Teraï. Les moyennes et les hautes montagnes ne représentent respecti-vement que 23 pour cent et 2 pour cent environ de la superficie plantée en riz du pays. Les années 80 ont enregistré une augmentation générale de la superficie et de la production rizicoles, la productivité du Teraï marquant une tendance à la hausse depuis le milieu des années 80.

Il existe 13 stations de recherche agronomique dans le pays et six divisions centralisées par discipline chargées de mener la recherche sous la direction du Conseil de recherche agronomique du Népal (NARC). Les stations ont pour mandat d'effectuer des essais en plein champ dans les périmètres irrigués. Les essais sont effectués par des chercheurs, habituellement sur des cultures irriguées avec la participation active des cultivateurs. Les rendements potentiels de riz dans les conditions du Teraï et des moyennes montagnes sont de 4 et de 4,5 tonnes/ha respectivement, bien que les rendements effectifs y soient de 2,28 et de 2,20 tonnes/ha. Ces différences entre les rendements potentiels au niveau de l'exploitation et les rendements effectifs sont attribuables aux contraintes biologiques (variétés, adventices, maladies, insectes et eau) et socioéconomiques (rapport coût/rendement, crédit, disponibilité de facteurs de production et institutions).

Jusqu'ici, 38 variétés de riz ont été mises sur le marché, dont 10 à 12 ont été largement adoptées par les riziculteurs. Ces variétés ont contribué à accroître le rendement de plus d'une tonne/ha par rapport aux variétés locales. La plupart de ces variétés modernes s'insèrent dans le système de culture et il s'ensuit que les riziculteurs ont été à même de réaliser deux récoltes de riz par an voire une troisième. Par l'intermédiaire du NARC, le programme de recherche coordonnée sur le riz maintiendra des liens avec le Ministère du développement agricole et, chose plus importante, avec les bureaux de vulgarisation de district, les stations régionales de recherche et les stations de recherche agronomique. Etant donné que la moitié de la superficie plantée en riz est couverte de variétés améliorées, on s'efforcera de planter de nouvelles variétés modernes sur les superficies restantes. Le Programme de recherche sur le riz donne la priorité à la création de variétés résistant à la sécheresse: il distribue actuellement Bindeswari, Makawanpur-1, Ghaiya-2, TCA 80-4 et IR8423 (les deux dernières en prédissémination). Il reste possible d'accroître la production de riz basmati dans le pays au moyen des nouvelles variétés modernes. L'identification variétale a commencé et l'hybridation du riz basmati sera aussi entreprise. La recherche sur le riz hybride sera lancée en collaboration avec l'Institut international de recherche sur le riz (IRRI).

PROGRAMA DE FOMENTO DEL ARROZ EN EL NEPAL

El arroz es con mucho el cultivo más importante en el Nepal y ocupa el 50 por ciento aproximadamente de la superficie agrícola del país. Se cultiva en unos 1,45 millones de ha y su producción total varía entre 3,2 y 3,5 millones de t desde 1988/89. El arroz aporta un cuarto aproximadamente del producto interno bruto. Se produce en tres áreas agroecológicas principales: las llanuras del Terai, que cubren las tres cuartas partes de la superficie total sembrada de arroz, y las zonas montañosas medianas y altas que ocupan sólo el 23 y el 2 por ciento respectivamente de dicha superficie. En el decenio de 1980 hubo un incremento general de la superficie y de la producción, registrando la productividad en el Terai una tendencia creciente desde mediados de ese decenio.

Hay 13 estaciones de investigación agrícola en el país y seis direcciones centrales que se encargan de realizar investigaciones en el marco del Consejo de Investigación Agrícola del Nepal (NARC). Las estaciones de investigación llevan a cabo ensayos en las explotaciones agrícolas de la zona de su jurisdicción. Los ensayos son realizados habitualmente en sistemas de regadío y con la participación de los agricultores. Los rendimientos potenciales del arroz en el Terai y en las zonas montañosas de mediana altitud son de 4 y 4,5 t/ha respectivamente, pero los rendimientos efectivos son de 2,28 y 2,20 t/ha. Esta diferencia entre rendimientos potenciales y efectivos se explica por las limitaciones biológicas (variedades, malas hierbas, enfermedades, insectos y agua) y socioeconómicas (rentabilidad, crédito, disponibilidad de insumos e instituciones).

Hasta ahora se han distribuido en total 38 variedades de arroz, de las cuales entre 10 y 20 han sido ampliamente adoptadas por los agricultores. Estas variedades han contribuido a aumentar el rendimiento en más de 1 t/ha respecto de las variedades locales. Casi todas estas variedades modernas se ajustan a las modalidades de cultivo y gracias a ellas los agricultores han podido recoger dos o tres cosechas al año. El Programa coordinado de investigación sobre el arroz, a través del NARC, mantendrá contactos con el Departamento de Desarrollo Agrícola y, lo que es más importante, con las oficinas de extensión de los distritos, las estaciones de investigación regionales y las estaciones de investigación agrícola. Dado que el 50 por ciento de la superficie está sembrada de arroz de variedades mejoradas, se intentará plantar nuevas variedades modernas en las zonas restantes. El desarrollo de variedades resistentes a la sequía es el objetivo prioritario del programa. Actualmente se están popularizando las variedades Bindeswari, Makawanpur-1, Ghaiya-2 y TCA 80-4 e IR8423, éstas dos últimas distribuidas previamente. Hay posibilidades de aumentar la producción de arroz basmati en el país con las nuevas variedades modernas. Se ha iniciado la labor de identificación varietal y en breve se comenzará la hibridación del arroz basmati y se podrán en marcha investigaciones sobre el arroz híbrido en colaboración con el IRRI.