Identification of Accelerated Aging Conditions for Seed Vigor Test in Rice (Oryza sativa L.)

AUTHOR: Suraj Chhetri and Thawatchai Teekachunhatean 

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Participatory Variety Selection: Increasing Rice Varietal Diversity

AUTHOR: Sangay Tshewang and Mahesh Ghimiray Read more

Morphological and molecular characterization of Colletotrichum capsici

AUTHOR: Kinlay Tshering

ABSTRACTS

The taxonomy and diversity of Colletotrichum capsici was validated by morphological characters (conidia shape & size, colony characteristics, appressoria size) and molecular analysis using ISSR (Intersimple sequence repeats) markers with the objectives to adopt ISSR technique to assess the level of genetic variation among C. capsici isolates, to determine if the genetic variation among isolates corresponded with variation in morphological traits, and to determine if differentiation among C. capsici isolates based on morphological or ISSR variation was related to the host from which the isolates were collected. Morphological characters were quite variable within the species. Molecular analysis revealed that there was a genetic diversity with Thai isolates from Capsicum annuum being more similar than the other isolates from Queensland collected from other hosts like sugar apple, soy bean, etc. The phylogenetic groupings of C. capsici based on ISSR polymorphism did not appear to be congruent with morphological pattern and the rate of growth of isolates in culture. Further molecular analysis with a larger samples from a range of countries are required to determine if the clustering based on geographic origin and host plant is occurring. A high degree of molecular variability indicated that ISSR markers can be well utilized for the intraspecific characterization of C. capsici.

KEYWORDS:

Colletotrichum capsici, ISSR, Morphology, Molecular variability, Capsicum annuum

REFERENCES

Bernstein, B., Zehr, E. I. & Dean, R. A. (1995). Characteristics of Colletotrichum from peach, apple, pecan and other hosts. Plant Disease 79(5) : 478-482.

Blair, M. W., Panaud, O. & McCouch, S. R.(1999). Inter-simple sequence repeats (ISSR) amplification for analysis of microsatellite motif frequency and fingerprinting in rice (Oryza sativa L.). Theoretical and Applied Genetics 98: 780-792.
Chacko, R. J., Weidemann, G. J., TeBeest, D. O. & Correl, J. C. (1994): The use of compatibility and heterokaryosis to determine potential asexual gene exchange in Colletotrichum gloeosporioides. Biological Control 4 : 382–389.

Ciser, R., Spiegel, F. W., TeBeest, D. O. & Trout, C. (1994). Evidence of mating between isolates of Colletotrichum gloeosporioides with different host specificities. Current Genetics 25 : 330-335.

Fabre, J. V., Julien, J., Parisot, D. & Dron, M. (1995). Analysis of diverse isolates of Colletotrichum lindemuthianum infecting common bean using molecular markers. Mycological Research 99 : 429-435.

Hawksworth, D. L. (1974). Mycologist’s Handbook. Commonwealth Mycological Institute, Kew, Surrey, England. 231 pp.

Holiday, P. (1980). Fungus diseases of tropical crops. Cambridge University Press, Cambridge.

Katan, T. (2000). Vegetative compatibility in Colletotrichum. In: Prusky, D., Freeman, S. & Dickman, M. B. (eds.). Colletotrichum: Host specificity, pathology and host-pathogen interaction. pp. 145-179. The American Phytopathological Society, St. Paul, MN.

Lu, G., Cannon, P. F., Reid, A & Simmons, C. M. (2004). Diversity and molecular relationships of endophytic Colletotrichum isolates from the Iwokrama Forest Reserve, Guyana. Mycological Research 108 : 53–63.

Maclean, D. J., Braithwaite, K. S., Manners, J. M. & Irwin, J. A. G. (1993). How do we identify and classify fungal plant pathogens in the era of DNA analysis? Advances in Plant Pathology 10 : 208-244.

Nagaoka, T & Ogihara, Y.(1997). Applicability of inter-simple sequence repeat polymorphisms in wheat for use as DNA markers in comparison to RFLP and RAPD markers. Theoretical and Applied Genetics 94 (5) : 597 – 602.

O’Neill, N. R., van Berkum, P, Lin, J. J., Kuo, J., Ude, G. N., Kenworthy, W. & Saunders, J. A.(1997). Application of amplified restriction fragment length polymorphism for genetic characterization of Colletotrichum pathogens of alfalfa. Phytopathology 87 : 745-750.

Photita, W., Taylor, P.W.J., Ford, R., Lumyong, P., McKenzie, E. H. C., Hyde, K. & Lumyong, S.(2005). Morphological and molecular characterization of Colletotrichum species from herbaceous plants in Thailand. Fungal Diversity 18 : 117-133.

Pring, R. J., Nash, C., Zakaria, M. & Bailey, J. A. (1995). Infection process and host range of Colletotrichum capsici. Physiological and Molecular Plant Pathology 46 : 137-152.

Sharma, P. N., Kaur, M., Sharma, O. P., Sharma, P. & Pathanja, A.(2005). Morphological, pathological and molecular variability in Colletotrichum capsici, the cause of fruit rot of chillies in the subtropical region of North-western India. Phytopathology 153 : 232-237.

Smith, B. J. & Black, L. L. (1990). Morphological, cultural and pathogenic variation among Colletotrichum species isolated from strawberry. Plant Disease 74 : 69-76.

Sutton, B. C., (1992). The genus Glomerella and its anamorph Colletotrichum. In: Bailey, J. A. & Jeger, M. J. (eds.). Colletotrichum: Biology, pathology and control. CAB International, Wallingford. pp. 128.

Performance of Rice under System of Rice Intensification (SRI) at CNR, Lobesa

AUTHOR: Karma Lhendup  Ugyen Wangchuk, Jitshen Wangchuk, Tika R. Bhandari, and Sangay Chophel Read more

Effect of different rates and combinations of Farm Yard Manure and inorganic fertilizers on chilli (Capsicum annum) yield

AUTHOR: Karma Dema Dorji, Yeshey Dema and Tashi Uden Read more

Comparative Study of Broiler Feeds in Bhutan

AUTHOR: Karma Nidup and Pema Wangchuk  Read more

Fodder quality of in Bhutanese Environments

AUTHOR: Kelzang Wangchuk , Karma Dorji ,Ugyen Lhendup and Tsering Gyeltsen

ABSTRACT

Ficus auriculat, a species of fig tree is widely used to augment winter fodder shortage in subtropical environments. Very limited studies were carried out to establish its nutritional qualities in Bhutanese environments. A study was conducted in 2004 with the objectives to quantify nutritional qualities and evaluate the effect of elevation and rainfall. 15 random samples were collected from 15 different sites under subtropical environment. Samples were collected from homogeneous trees in winter. Representative samples were analyzed for crude protein, acid detergent fiber, neutral detergent fiber, and dry matter digestibility.

The nutritional properties were diverse and varied between sites. The nutritional quality was superior for trees at higher elevations and vice versa for the trees at lower elevations. It is concluded that there is diverse nutritional quality amongst populations of Ficus auriculata along environmental gradient.

KEYWORDS:

Ficus auriculata, nutritional quality, CP, NDF, ADF, elevation, rainfall.

REFERENCES

AOAC (1990). Official Methods of Chemical Analysis 16th edition, Association of Official Agricultural Chemists, Washington DC.

Amatya, D.B. (1991). Forest Development, Utilization and Management, Background Paper to the NationalConservation StrategyforNepal,VolII,IUCN,Kathmandu,Nepal.

Jackson, J.K. (1987). Manual of Afforestation in Nepal. Nepal/UK, Forestry Research Project, Kathmandu, Nepal.

Mahato, S.N. and Subba, D.B. (1988). Nutrient Evaluation of Fodder at Pakhribas Agricultural Centre, Dhankuta, Paper Presented at the Second Meeting of the Working Groupon Fodder Trees, Forest Fodder and leaf litter, FRIC, Kathmandu, Nepal.

McLeod, M.N., and Minson, J.D. (1982). Accuracy of predicting digestibility by the cell&se technique; the effect of pre treatment of forage samples with neutral detergent or acid pepsin, Animal Feed Science Technology,7:pp.83-92

Pearson, R.A. (1990). A Note on Live Weight and Intake and Digestibility of food by draught cattle after supplementation of rice straw with the fodder tree Ficus auriculata,Animal Production, 51, pp. 635-638.

Rajhan, S.K. (1977).Animal Nutrition and Feeding Practices in India (2nd Edition), Vikas Publishing House Pvt. Ltd., Gaziabad, Uttar Pradesh,India,pp.162.

Roder, W., Wangdi, K., Gyamtso, P. and Dorji, K. (2001). Feeding the Herds-Improving Fodder Resources in Bhutan, ICIMOD, Kathmandu, Nepal, pp. 124.

Roder, W., Rinzin, and Gyaltsen, T. (2003). Ficus auriculata – Its Relative Importance in Bhutan, Farmers’ Preference and Fodder Quality, Agroforestry Systems, 57, pp. 11-17.

Shrestha, R.K. and Tiwari, B.N. (1991). Nutritive Value and Tannin Content of Some Common Tree Fodder Species of the Western Hills of Nepal, LAC Seminar Paper 31/91, Lumle Agricultural Centre, Kaski, Nepal.

Tamang, D.B. (1987). Nutrient Composition of Feed Resources in Bhutan (Bulletin I and II), Bhutan Journal ofAnimal Husbandry, 10, pp. 20-33.

Thorne, P.J., Subba, D.B., Walker, D.H. Thapa, B, Wood, C.D. and Sinclair, F.L. (1999). The basis of Indigeneous Knowledge of Tree Fodder Quality and its Implications for Improving the Use of Tee Fodder in Developing Countries, Animal Feed Science and Technology, 81, pp. 119-131.

Van Soest, P. J., Robertson, J. B. and Lewis, B. A. (1991). Methods for dietary fiber, neutral fiber and non-starch polysaccharides in relation to animal nutrition, Journal of Dairy Science, 74: pp. 473–481.

 

Demonstration of Integrated Rice-Fish Culture under Bajo Research Conditions

AUTHOR: Dawa L Sherpa

ABSTRACT

Rice and fish go together as food in many parts of the world and so is in Bhutan. The synchronous system of fish cum rice culture is adopted for productive utilisation of land both for crop and fish production to supplement the income to the farmers. Pursuant to this view, two years experiment was carried out at Bajo, Wangdue to validate the information generated by fishery researchers afresh. The plots were renovated by excavating canals, pools or trenches to retain water. This would provide shelter to fish and stored water could be used for the irrigating crops. ‘I” shaped trenches were dug with depth of 80cm and width of 60 cm on top on both sides of the plots.

The two years experiment indicated that the growth rate of Common carp (Cyprinus carpio) was found to be much higher compared to Grass carp (Ctenopharyngondon idella). The first year results revealed that Common carp weight ranged between 170-410 gm compared to 30-80 gm only from that of Grass carp within a period of 90 days. In total, Common carp yielded 11.2 kg and 3.5 kg Grass carp. During the second year of experiment, the yearlings were reared instead of fingerlings. About 200 Common Carp and Grass Carp were released in the field. The fish were harvested at 110 days of growth period in the rice field. On the day of harvest 190 out of 200 Common Carp were counted which yielded 15 kg in total. Out of a total of 200 Grass Carp yearlings released only 60 were found available on the day of harvest. The total yield from Grass Carp was only 3 kg. Further it was noted that their growth rate was optimal and overall survivability was found to be quite good amongst the species. Some degree of predation was noticed by aquatic birds which was unavoidable. The fingerlings might have also escaped through the holes of the bunds made by insects and rodents especially during night time that ultimately contributed to over loss. However during the entire trial period no major mortality and diseases occurrences were observed.To validate existing information and draw suitable future recommendation, more research needs to be conducted on-farm.

KEYWORDS:

Rice fish culture, integrated, grass carp, common carp, feeding, yield, comparative

REFERENCES

Pradhan B.B. (1979). Fish culture in Rice Field, Nepal, Fisheries Development Division, Harihar Bhawan, Lalitpur, Nepal.

Thingh B, (1998). Carp Culture at National Warm Water Fish Culture Centre National Livestock Research Coordination Workshop Proceedings, 1998, RNRRC Jakar, Bumthang.

S. C. Agarwal, (1994). A Hand Book of Fish Farming, Narendra Publishing House, Maliwara, Delhi, India.

Parker Chris, 1992, Weeds of Bhutan, NPPC Simtokha, Royal Government of Bhutan.

Current Status of the Odonata of Bhutan: A Checklist with Four New Records

AUTHOR: Amit Mitra

ABSTRACT

Specimens of dragonflies were collected from Trashiyangtse and Pemagatshel districts of eastern Bhutan during the months of July and September 2003. One specimen of Neurothemis fulvia was collected on 5thSeptember2004 SamdrupJongkhar district. Altogether 61 specimens of Odonata belonging to 16 species and subspecies under 13 genera and four families were listed during the present study, which revealed four new records of odonates for Bhutan viz., Orthetrum s. sabina, Acisoma p. panorpoides, Brachythemis contaminata and Neurothemis fulvia. An up-to-date checklist of 31 species and subspecies of odonates known till date from Bhutan had also been made. However, since the collection period was too short and didn’t spread over the whole year, the above list of odonata from the concerned localities remained incomplete. The survey did not cover the southern, western and central districts of Bhutan and thus does not represent a complete checklist of Odonates of Bhutan. An extensive Odonatological survey needs to be carried out to explore the rich diversity of these elegant insects and come up with a representative checklist of Odonates for Bhutan.

KEY WORDS:

Bhutan, checklist, dragonfly, new record, Odonata, Pemagatsel, Samdrup Jongkhar, Tashiyangtse

REFERENCES

Fraser, F.C. (1933). The Fauna of British- India including Ceylon and Burma, Odonata. Vol. I. Taylor and Francis Ltd., London.

Fraser, F.C. (1934). The Fauna of British- India including Ceylon and Burma, Odonata. Vol. II. Taylor and Francis Ltd., London.

Fraser, F.C. (1936). The fauna of British- India including Ceylon and Burma, Odonata. Vol. III. Taylor and Francis Ltd., London.

Lieftinck, M.A. (1977). Ergebnisse der Bhutan-expedition 1972 des naturhistorischen museums in Basel: Odonata. Entomologica Basiliensia 2: 11-37. Mitra, A. (2002). Dragonfly (Odonata: Insecta) Fauna of Trashigang Dzongkhag, Eastern Bhutan. In: Gyeltshen, T. & Sadruddin (ed.) “Environment and Life Support Systems of the Bhutan Himalaya, Vol. I”, Sherubtse College, Kanglung, Bhutan: 40-70.

Prasad, M. & Varshney R.K. (1995). A checklist of the Odonata of India including Data on larval studies. Oriental Insects 29: 385-428.

Silsby, J. (2001). Dragonflies of the world. Natural History Museum in association with CSIRO Publishing, UK and Europe.

Tsuda, S. (1991). A distributional list of world Odonata. Tsuda, Osaka.

Physico-Chemical Assessment of Water in Diverse Lentic Habitats of Bhutan

AUTHOR: Shivaraj Bhattarai

ABSTRACT

Water samples collected from diverse habitats in Bhutan, mainly from the eastern Dzongkhags, were analysed for basic water qualities during the period from February 2000 to January 2002. Most of the sampled water bodies depicted their sub-tropical nature with their waters ranging from typically acidic to circum-neutral to slightly alkaline and with poor to moderate mineral contents. They are mostly well oxygenated and moderately hard to soft confirmed by methyl orange alkalinity, total hardness as well as by low calcium, magnesium and chloride contents, thereby also suggesting a need to supplement the water bodies with essential mineral nutrients in case of any future plans to harness them for biological productivity. Comparisons in water quality are also made with available reports from the Himalayan Region.

KEY WORDS:

Bhutan, Himalayas, Freshwater, Water bodies, Water quality

REFERENCES

Anon, (1992). Bhutan towards sustainable development in a unique environment. National Environment Secretariat, Planning Commission Thimphu. 71 pp.

A.P.H.A. (1992). Standard Methods for Examination of water and wastewater (18th Ed.). American water Works Association and Water Pollution Control

Federation, New York. 1198 pp. (Eds. Arnold E. Greenberg, Lenore S. Clesceti and Andrew D. Eaton.).

Arora, R. K. (1990). Water pollution: studies on nitrite in Kanglung waters. In: Bhutan and Its Natural resources, Vikas Publishing House Pvt Ltd., New Delhi.

Barbosa, F.A.R. (1981). Variacos diuarnas (24 horas) de Parametros limnologicose da Productividae Primaria do fitoplancton na Lagos Carioca-Parque Florestral do Rio Doce-MG-Brasil. Ph.D. Thesis. Univ. Fed. S. Carlos.

Chandler, D.C. (1942). Limnological studies of western lake Erie. III. Phytoplankton and physical chemical data from November 1939 to1940. Ohio Journal of Scence, 42: 24-44.

Dhendup, T. and Boyd, C. E. (1994). Chemical features of water and soil farming areas in Bhutan. Journal of Aquaculture in the Tropics, 9: 35-41.

Gyeltshen, T. (2001). Bhutan Water Partnership launched. In: Kuensel, Bhutan’s National Newspaper. Vol.XVI. No.34.

Horne, Alexander J. and Goldman, Charles R. (1994). Limnology (2nd ed). McGraw-Hill Inc., New York. 576 pp.
Jain, A, Rai, S.C., Pal, J. and Sharma, E. (1999). Hydrology and nutrient dynamics of a sacred lake of Sikkim Himalaya. Hydrobiologia, 416: 13-22.

Kaushik, S. and Saksena, D.N. (1999). Physico-chemical Limnology of certain In: water bodies of central India. Freshwater Ecosystems of India. (Ed. K. Vijayakumar), Daya Publishing House, Delhi. 2-58.

Pandit, A.K. (1999). Trophic Structure of Plankton Community in some Typical Wetlands of Kashmir, India. In: Limnological Research in India (Ed. S.R. Mishra), Daya Publishing House, Delhi. 190-224.

Payne, A.R. (1986). The ecology of tropical lakes and rivers. John Wiley & Sons. New York. 301 pp.

Quadri, M.Y. and Yousuf, A.R. (1988). A comparative study of the Limnology of three typical water bodies of Kashmir. In: Recent Advances in Fish Ecology, Limnology and Eco-conservation (Ed. Surendra Nath), Creative Publishers, New Delhi, pp 176.

Sarwar, S.G. (1999). Water Quality and Periphytic Algal Component of Anchar Lake in Kashmir. In: Freshwater Ecosystem of India (ed. K. Vijayakumar). Daya Publishing House, Delhi. 237-250 pp.

Sharma, B.K. (2001). Water Quality of Subtropical lentic biotopes of Meghalaya. In: Water Quality Assessment, Biomonitoring and Zooplankton Diversity.

(Ed. Prof. B.K Sharma), Department of Zoology, North Eastern Hill University, Shillong, Meghalaya. 10-22 pp.

Sharma, B.K. and Bhattarai, S. (2005). Hydro-biological analysis of a peat bog with emphasis on its planktonic diversity and population dynamics in Bumdeling Wildlife Sanctuary: eastern Bhutan. Limnology 6: 183-187.

Singh, S.P., Pant, M.C., Sharma, P.C. and Purohit Rekha. (1982). Limnology of Shallow Water zones of lakes in Kumaon Himalaya (India). In: Proc. First International Wetlands Conference (Eds. B. Gopal, R.K. Turner, R.G. Wetzel and D.F. Whigham), Jaipur, India. 39-49.

Swar, D.B. and Fernando, C.H. (1979). Cladocera from Pokhara valley, Nepal with notes on distribution. Hydrobiologia 66:113-128.

Venkateswarlu, V. (1983). Taxonomy and ecology of algae in the river Moosi, Hyderabad, India. II. Bacillariophyceae. Bibliotheca Phycologica (Ed. J. Cramer). 66: 1-44.

Wetzel, R.G. (1983). Limnology. W.B. Saunders, Philadelphia,767pp.

Webber, W.J.Jr. and Stumm. (1963). Mechanism of hydrogen ion buffering in natural waters. Journal of American Water Works Association, 155: 1553.

Existing Resources, Practices and Potentials of the Arecanut within the East-Central Region (Sarpang Dzongkhag)

AUTHOR: Ms. Pema Yuden, Mr. Sangay Dorji

ABSTRACT

Arecanut (Areca catechu L) commonly known as betelnut is a tropical palm cultivated for its nuts. It is cultivated in the lower humid sub-tropical areas (below 600m) of Bhutan. A survey conducted in Sarpang Dzongkhag found that the crop was introduced by the farmers themselves about 70 years ago from neighbouring Assam, India. The crop agronomy and management practices are self acquired. There are 4 unknown varieties or types known by the shape of the fruits. Majority of the farmers raise their own planting material. Major pests and diseases are shoot rot or bud rot, fruit drop, ants, and stem borer or stem rot. Yield per hectare varied greatly. Some of the constraints are reported to be irrigation, pests and diseases and fruit drop.

KEYWORDS:

Arecanut, resources, management practices, intercropping, pest, diseases

REFERENCES

Dorji, Sangay. (2000). Arecanut survey summary report: Research and extension recommendations. Proceedings of the fourth Regional Review and Planning Workshop, Trongsa

LUPP (1995).Dzongkhag data sheets for Sarpang, Ministry of Agriculture, Thimphu, Bhutan

Vossen, H.A.M van der. and Wessel, M. (2000). Prosea. Plant Resources of South East Asia 16, Stimulants, p 51-55.

Rainfed Lowland Rice Cultivation in Bhutan: A Survey Report

AUTHOR: Karma, Mahesh Ghimiray

ABSTRACT

This study reports on the rice cultivation practices under rainfed environment in Bhutan based on a rapid farm survey conducted in 2003. Although rainfed lowland rice system accounts for major portion of rice growing area, it contributes least in terms of production due to uncertainty of irrigation water, soil fertility and pest problems. About 33 traditional or introduced local varieties are cultivated by farmers. Traditional varieties are characteristically white preferred for their taste but are susceptible to diseases. About 17 local varieties are reported to be lost. Mean yield of rough rice is estimated at 680 kg/acre. The rate of adoption of improved varieties is about 44%. Use of chemical fertilizers is limited to 13.2% and tethering is the common practice of manure application. Adoption of the use of herbcides and pesticides is low. Weed, diseases and pests are major problem in rainfed rice ecosystem and estimated to reduce 2-50% of total yield. Vertebrate pest, especially elephant, is a nuisance in rice crop, often destroying the crop completely. Storage losses due to rodents, weevils and grain moth are estimated at 2-50% of total production. Approximately, 97 men-days of labor are required to carry out various cultural operations. An additional labor of 60 men-days per season is spent in guarding the crop against vertebrate pest. Recommendations include evaluation of suitable varieties for the rainfed ecosystem together with component technologies, better soil and pest management and the use of labour-saving technologies.

KEYWORDS:

Rainfed rice, rainfed rice environments, local varieties, pests, storage losses

REFERENCES

RNRRC Bajo, (2001). National Field Crops Research Strategy and Program Ninth Five Year Plan (2002-2007). DRDS, MoA.

Kouffman et al. (1994). Improving Rainfed lowland rice. International Rice Research Institute. Philippines.

Mackhill et al. (1996). Rainfed lowland Rice System. International Rice Research Institute. Philippines.

Shrestra et al, (2003). An Economic Impact Assessment of Rice Research Program in Bhutan. International Rice Research Institute. Philippines.

Minor Cereals and Food Security in the Marginal Areas of Bhutan

AUTHOR: Wangda Dukpa

ABSTRACT

A random household survey was conducted in 2002-2003 in seven districts with a sample size of 10%, covering 250 households, to document the farming practices of minor cereals (buckwheat, barley and finger millet), their roles in household food security and to assess future potential. The study revealed that barley and buckwheat are predominantly grown in high AEZ and finger millet in mid AEZ respectively. Minor cereals are cultivated under subsistence farming for home consumption. Farmers have mixed perceptions on the cultivation trend and the cultivation practices vary between AEZs. An estimated net return of Nu.2258, Nu.1982 and Nu.156 are obtained per hectare from barley, buckwheat and finger millet respectively. Results revealed that 61% of buckwheat, 37% of barley and 47% of finger millet are consumed as food. Minor cereals supplement rice and maize, and substitute other cereals during the lean period (March-June). The importance of minor cereals in food security at different AEZ and their future potential in the farming systems in the marginal areas are discussed.

KEYWORDS:

Minor cereals, food security, marginal areas, Agroecological zones (AEZ), cropping pattern

REFERENCES

Bonafaccia, G & Fabjan, N.(2003). Nutritional Comparison of Tartary Buckwheat with Common Buckwheat and Minor Cereals. Zb. Bioteh. Fak. 81,349-355.

BSSP. (2000). Physical Land Evaluation System for Bhutan. RGOB, MoA Edwardson, S. (1996). Buckwheat: Pseudocereal and Nutraceutical. In: Progress in NewCrops. (J. Janick, ed.). Alexandria, ASHS Press.

Fischbeck, G. (2002). Contribution of Barley to Agriculture: A brief Overview. In: Barley Science: Recent Advances from Molecular Biology to Agronomy of Yield & Quality. (G.A. Slafer, J.L. Molina-Cano, R. Savin, J.L. Arans & I. Romagosa, eds.). USA, The Hawthorn Press Inc.

Hulse, J.H, Laing, E.M & Pearson, O.E. (1980). Sorghum and the Millets: Their Composition and Nutritive Value. New York, Academic Press Inc.

Joshi, B.D & Rana, R.S. (1995). Buckwheat (Fagopyrum esculentum). In: Cereals and Pseudocereals. (J.T. Williams, ed.). USA, Chapman & Hall

Konishi, T. (1992). Isozyme Variation of Barley Populations Collected from Bhutan Barley Genetics Newsletter. 21, 38-47.

Lal, R & Stewart, B.A. (1995). Soil Management: Experimental Basis for Sustainability & Environmental Quality. USA, CRC Press.

McNeill, P. (1990). Research Methods. (2nd ed.). New York, Routledge.

MoA. (2001). Wild Boar Management: Action Long Overdue. Report of the Task Force. RGOB, Thimphu.

MoA. (2002a). Renewable Natural Resources Statistics 2000 (Vol. 1). Phuntsholing, KMT Press.

MoA. (2005). Agricultural Area and Land Holdings. Available from, http://www.moa.gov.bt/census_land.php, (accessed on 25 May 2005).

MTI. (2001). Malting Barley Production and Agro-processing inBhutan: A Feasibility Study. RGOB, Thimphu.
Myers, R.L. (2002). Buckwheat: A Versatile Short-Season Crop. Columbia, Jefferson Institute.

Nilan, R.A. & Ullrich, S.E. (1993). Barley: Taxonomy, Origin,Distribution, Production

Genetics and Breeding. In: Barley: Chemistry & Technology. (A.W. MacGregor & R.S. Bhatty, eds.).USA, American Association of Cereal Chemists, Inc.

Norbu, S. & Roder, W. (2000). Nutrient Management Systems in the Temperate Regions of Bhutan, in Proceedings of 13th International IFOAM Scientific Conference, August 28-31, 2000. Convention Centre, Basel.

Ohnishi, O & Murai, M. (1996). Population Genetics of Cultivated Common Buckwheat Fagopyrum esculentum Moench. X. Diffusion Routes Revealed by RAPD Markers. Genes Genet. Syst. 71, 211-218.

Oppenheim, A.N. (1992). Questionnaire Design, Interviewing and Attitude Measurement. London, Pinter Publishers.
Pradhan, P, Katwal, T.B & Adhikari, N.B. (2002). Technical Series on Field Crops. MoA, DRDS, RNRRC-Khangma.
Purseglove, J.W. (1976). Tropical Crops: Monocotyledons. London, Longman Group Limited.

Rachie, K.O & Peters, L.V. (1977). The Eleusines: A Review of the World Literature. India, ICRISAT.
Roder, W & Gurung, P.R. (1990). Mountain Crop Resources of Bhutan in Retrospect and Prospect. RNRRC Yusipang.
Scheiere, J.B, Joshi, A.L, Seetharam, A, Oosting, S.J, Goodchilds, A.V, Deinum, B & Keulen, H.V. (2004). Grain and Straw for Whole Plant Value: Implications for Crop Management and Genetic Improvement Strategies.Experimental Agriculture. 40, 277-294.
Stevenson, F.C, Lègére, A, Simard, R.R, Angers, D.A, Pageau, D & Lafond, J.(1998). Manure, Tillage, and Crop Rotation: Effects on Residual Weed Interference in Spring Barley Cropping Systems. Agronomy Journal. 90, 496-504.
Sthapit, B.R, Pradhanang, P.M, Khadka, R.J & Subedi, K.D. (1994). Maize and Finger Millet Relay Intercropping System in the Hills of Nepal: Its Constraints, Research Findings and Prospects. In: Advances in Small Millets. (K.W. Riley, S.C. Gupta, A.Seetharam, J.N. Mushonga, eds.). New York, International Science Publisher.

Wang, Y, Scarth, R & Campbell, G.C. (2005). Inheritance of Seed Shattering in Interspecific Hybrids between Fagopyrum esculentum and F. homotropicum. Crop Science. 45, 693-697.

Wolfe, T.K & Kipps, M.S. (1953). Production of Field Crops: A Textbook of Agronomy (4th ed). USA, McGraw Hill Book Company Inc.

Incidence and Distribution of the Apple Fruit Borer Argyresthia Conjugella Zeller (Yponomeutidae: Lepidoptera) and Its Chemical Control in Western Bhutan.

AUTHOR: Chencho Dorji, Phuntsho Loday

ABSTRACT

The apple fruit borer Argyresthia conjugella Zeller (Yponomeutidae:Lepidoptera) is found to be a serious pest of apple (Malus domestica Borkh.) in the high altitude apple growing areas in Bhutan. More than 80% of fruits can be infested in a particular season. Adult moths were caught by first week of May and infestation on fruits was first detected by mid week of July when the average size of fruits was between 30 to 45 mm in diameter. Two timed cover sprays with Chlorpyrifos 20% EC, at two week interval has been found to give effective control of the fruit borer. Three wild host plants (Malus baccata, Malus sikkimensis, and Pyrus pashia) all belonging to the Rosaceae family are confirmed to be the hosts of the fruit borer.

KEYWORDS:

Apple fruit borer, pests, wild host plants, chemical efficacy

REFERENCES

Belosel’s Kaya, Z.C. (1963).The mountain-ash moth Argyresthia conjugella Zell. (Lep. Yponomeutidae) as a pests of the fruits of apples and mountain-ash. Ent. Obozr., 4: 720-29.

Edland, T. (1965). Apple fruit moth, Argyresthia conjugella Zell. Binomica and control, a preliminary report. Gartneryrket 55: 430-436.

Edland, T. (1969). Apple fruit moth (Argyresthia conjugella Zell.). Factors affecting attacks upon apples, and an evaluation of control recommendations. Gartneryrket 59(21): 482-490.

Grierson A.J.C. & Long D.G. (1987). Flora of Bhutan, (Volume 1, Part 3), Royal Botanic Garden, Edinburgh.
Khajuria, D.R., Sharma, J.P., Dogra, G.S. (1992). Biology of apple fruit moth, Argyresthia conjugella Zell. In Himachal Pradesh. J. Insect Sci. 5 (1): 93-94.

Khajuria, D.R., Sharma, J.P., Dogra, G.S. (1989). Seasonal incidence of apple fruit moth in relation to temperature and humidity in Himachal Pradesh. Indian J. Ecol. 16-(1): 56-59.

Khajuria, D.R., Sharma, J.P., Dogra, G.S. (1987). Studies on varietal preferences of apple fruit moth, Argyresthia conjugella Zell. (Yponomeutidae: Lepidoptera). Indian Journal of Horticulture 44(3-4): 289-293.

Khajuria, D.R., Sharma, J.P., Dogra, G.S. (1986). Incidence of apple fruit moth (Argyresthia conjugella Zell.) in Himachal Pradesh, India. Tropical Pest Management 32 (4): 350.

Sharma, J.P., Khajuria, D.R., Dogra, G.S. (1988). Chemical control of apple fruit moth, Argyresthia conjugella Zell. (Lepidoptera: Yponomeutidae). Indian Journal of Agricultural Sciences 58 (5): 378-81.

Assessment of Calf Mortality in Trongsa and Bumthang

AUTHOR: R.B Gurung

ABSTRACT

Study on calf mortality was conducted in two districts of Bumthang and Trongsa covering nine blocks and 191 households. Data was collected using semistructured questionnaire. Results revealed that the average calf mortality rates were 28.5% and 38.5% in Bumthang and Trongsa, respectively with mean of 33.5%±14.2. Maximum calf mortality was recorded in Jersey cross (36.4%) and Siri (Thrabum) (35.1%) followed by Brown Swiss cross (21.8%). Over period of one year mortality was similar except for the month of June and July, which experienced higher calf mortality rate of 17.7% and 13.2%, respectively. The study also found that maximum numbers of calf died at the age of one to twelve months. General weakness, Calf scour, Black Quarter and wild animal predation were main causes of calf mortality. Need to improve calf management skills of the farmers and review of the existing vaccination schedule was recommended.

KEYWORDS:

Calf mortality, farmers, breeds, management, black quarter.

REFERENCES

Cameron, A (1991). Survey Toolbox for Livestock disease, ACIAR publication Dorji, K (2003). Annual report. Brown Swiss Farm, Bumthang

Fraser, C.M; Bergeron, J.A; Mays, A and Aiello, S.E (1991) Merck Veterinary Manual, 7th edn, p-181

Wangchuk, N (2004). Annual report. National Jersey Breeding Centre, Samtse

Williamson, G & Payne, W.J.A (1975). Introduction to Animal Husbandry

Tamang, N.B., Denzler, T., and Sharma B (1993). Calf Mortality investigation in Bumthang Dzongkhag, (1991-1993).National Horse and Brown Swiss Cross Breeding Program, Bumthang

Tamang, N.B and Perkins J.M (2005). Milk yield of Mithun-Siri Cross and Siri cattle managed on village farms in Bhutan. In press, SARRC Journal of Agriculture.

In Search of Species Suitable For Temperate Pasture Mixtures in Bhutan

AUTHOR: Wangchuk K, Roder W, Gyeltshen

ABSTRACT

Farmers in temperate areas were recommended to use mixtures containing white clover, Italian ryegrass, tall fescue and cocksfoot. Strong dominance of white clover in fields seeded with these mixtures induced the search for alternative species or establishment methods. Two experiments were conducted across a range of temperate environments from 1996-2002 to evaluate grass-legume mixtures for species composition and dry matter yield and the effect of seed rates on contribution of species to the total species composition. Except for Khangkhu the dry matter yield was not affected by the mixture components and the seed rates of tall fescue, cocksfoot and Italian ryegrass. The dry matter yield of lotus mixture was comparatively lower than white clover and lucerne mixtures. Lucerne mixture yielded higher at Khangkhu. Seed rates of grass species did not affect the frequencies of individual species. Cocksfoot frequency increased consistently over 6 years and cocksfoot affected the frequency of tall fescue. The frequency of lucerne, Prairie grass and Dallis grass increased at Khangkhu while the persistence of these species was poor in grass-legume mixtures at Bathpalathang.

The current extension recommendations need to be revised taking into consideration the strong competition by cocksfoot and variations in dry matter yield and species composition of mixtures between locations. It is proposed that specific mixtures should be identified for specific locations.

KEYWORDS:

Mixture, dry matter yield, frequency, seed rate, cocksfoot, tall fescue, white clover.

REFERENCES

Droslom, P.N., and Smith, D. (1976). Adapting species for mixtures, In: Papendick, R.I., Sanchez, P.A., and Triplett, G.B. (eds.) Multiple Cropping, Madison, Wisconsin, American Society of Agronomy, Crop Science Society of America, Soil Science Society of America: 223-234.

Grant, S.A. (1981). Swards components, In: J. Hodgson, R.D. Baker, A. Davies, A.S. Laidlaw, J.D. Leaver (eds.) Sward Measurement Handbook, British Grassland Society: 71-91.

Kemp, P.D., Condron, L.M., and Mathew, C. (1999). Pasture and soil fertility, In: J. White, and J. Hodgson, (eds.) New Zealand Pasture and Crop Science, Oxford University Press, Auckland, New Zealand: 67-82.

McKenzie Jr, J.D. and Goldman, R. (2005). The Student Guide to Minitab Release 14, Pearson education Inc., Sydney, Australia.

Norris, I.B. and Thomas, H. (1982). Recovery of ryegrass species from drought, Journal of Agricultural Science, Cambridge 98: 623-28. Pearson, C.J. and Ison, R.L. (1997). Agronomy of Grassland System, 2nd edn. Cambridge University Press, Cambridge, UK.

Roder, W. (1996). White Clover a dangerous weed? In Proceedings of the 1st Annual National Feed and Fodder Research Workshop: 53-56, RNR-RC Jakar, Bathpalathang, Bumthang.

Roder, W, Thinley, P., Wangdi, K. (1997). Experiences with temperate mixtures – review, Proceedings of the 2nd Annual National Livestock Research Workshop: 6978

Roder, W., Wangdi, K., Gyamtsho, P. and Dorji, K. (2001). Feeding the Herds: Improving Fodder Resources in Bhutan, ICIMOD, Kathmandu, Nepal.

Physical Characterization of Bhutanese Yak

AUTHOR: Tashi Dorji and Gyem Tshering

ABSTRACT

The aim of this study was to compare biometrical measurements, describe coat colour and horning pattern of yak population from three regions of Bhutan (west, central and east). The measurements including heart girth, body length, wither height and estimated body weights are larger for yak from western Bhutan. The eastern Bhutan yaks are the smallest. Black coat colour yak was most frequent with 60 to 73% occurrence. The differences in body dimension, coat colour, horning pattern and woolliness suggest that eastern Bhutan yaks are distinct to those from other two populations. These results are important for designing yak breeding and conservation programmes.

KEY WORDS:

yak, phenotype, colour, body size, Bhutan.

REFERENCES

Bat-Erdene, T (1996). Performance and appearance of Mongolian yak. International Yak Newsletter 2: 35-43.

FAO (1997). Primary guidelines document for development of national farm animal genetic resources management plans. In ‘Proceedings of the 2nd regional training workshop on the conservation of domestic animal diversity and the 3rd national coordinators meeting’. Manila, Philippines, pp. 119-180. (FAO Regional Project: Bangkok)

Gupta, S.C and Kumar, P (1994). Technical report on livestock genetic resources of Ladakh. National Bureau of Animal Genetic Resources, Karnal, India.

Gyamtsho, P (1996). Assessment of the condition and potential for improvement of high altitude rangelands of Bhutan. Ph.D. Thesis. Swiss Federal Institute of Technology, Zurich, Switzerland.

Hansen, P.J (1990). Effects of coat colour on physiological responses to solar radiation in Holsteins. Veterinary Record 127: 333.

Joshi, D.D (1982). Yak and Chauri husbandry in Nepal. His Majesty’s Government Press, Kathmandu, Nepal.

Li, C and Wiener, G (1995). ‘The Yak.’ (RAP/FAO 1995/25: Bangkok.)

Namikawa, T., Amano, T and Hasanath, M.A (1988). Geographical distribution of coat color variations and body confirmation of the native cattle of Bangladesh. Report of the Society for Researches on Native Livestock 12: 69-75.

Namikawa, T., Amano, T., Yamamoto, Y., Tsunoda, K., Shotake, T., Nishida, T. and Rajbhandary, H.B (1992). Genetic differentiation in blood groups and blood protein variants of Nepalese cattle, yak and zoopa. Report of the Society for Researches on Native Livestock 14: 36-37.

Nivsarker, A. E., Gupta, S.C and Gupta, N (1997). ‘Yak Production.’ (Indian Council of Agricultural Research: New Delhi.).

Olson, T. A (1999). Genetics of color variation. In “The Genetics of Cattle” (Eds R. Fries and A. Ruvinsky.) pp 33-53. (CAB International:Wallingford.).

Pal, R.N (1993). Yak (Poephagus grunneins L) of India. FAO Animal Genetics Resources Information 12: 63-71.

Pal, R.N., Barari, S.K and Biswas, D (1994a). Yak (Poephagus grunniens) husbandry in India. In ‘Proceedings of the 1st International Congress on Yak’. Lanzhou, P.R China, (Eds Z. Rongchang, H. Jianlin and W. Jianping.) pp. 16-21. (Gansu Agricultural University: Lanzhou.)

Pal, R.N., Barari, S.K and Basu, A (1994b). Colour pattern in yaks (Poephagus grunniens.L). Indian Journal of Animal Sciences 64: 890-92.

Peilieu, C (1984). Livestock breeds of China. In ‘FAO Animal Production and Health Paper’ No 46, Rome, pp. 96-108.

Phillips, R.W., Tolstoy, I.A and Jhonson, R.G (1946). Yak and yak hybrids in Asia. Journal of Heredity 37, 162-70, 206-15.

Sarbagishev, B.S., Rabochev, K.V and Terebaev, A.L (1989). Animal Genetic Resources of the USSR-Yak. In ‘FAO Animal Production and Health Paper’. No 65:357-364.

Tshering, L and Acharaya, T.N (1996). Bhutan: Country Report. In ‘Proceedings of the 1st regional training workshop on the conservation of domestic animal diversity and the 2nd national coordinators meeting’. Bangkok, Thailand, pp. 3-26. (FAO Regional Project: Bangkok).

Tshering, L and Dorji, T (1997). Bhutan: country reports. In ‘Proceedings of the 2nd regional training workshop on the conservation of domestic animal diversity and the 3rd national coordinators meeting’. Manila, Philippines, pp. 3-10. (FAO Regional Project: Bangkok).

Migratory Cattle Grazing: An Ecosystem Approach To Livelihood

AUTHOR: M.R. Moktan, L. Norbu, H. Nirola , D.B.Chhetri, T.B.Rai, Rinchen

ABSTRACT

This paper consolidates impact of traditional migratory system of cattle management on their household economy, and describes the interaction between sustainable livestock, forest and pasture resources development. Livestock remain as main livelihood source contributing 71% and 84% of the gross household incomes of herders from Haa and Merak respectively. Seasonal movement of livestock is in direct response to cold temperatures, acute shortage of green forages and income opportunities. In dry valleys, transhumance often makes best sustained use of grassland resources. Mutual understanding regulates grazing between the upstream and downstream cattle owners. The sustained use of grazing resource requires accommodation of traditional rights and clarity on ownership and management of rangeland in the existing legislations. Temperate and subtropical rangelands and forest along migratory cattle routes exhibit signs and symptoms of over-grazing. Rangeland management should be based on availability of forage resources, ecosystems stability and an ability to control livestock numbers. Rest periods and rotational grazing are essential particularly in severely depleted ranges to suppress the growth of unpalatable species.

KEY WORDS:

Migratory herders, rangeland, ecosystem approach, livestock, pasture development.

REFERENCES

Dorji, P and Wangdi, R (2001). Migration. In proceedings of the National Grazing Policy Workshop Bumthang, (21-24 August 2001). Ministry of Agriculture, Royal Government of Bhutan supported by Forestry Institutional Development Initiative.

Davidson, J. Moktan, M.R, Gyeltshen, J. Pradhan, R. and Wangdi, T (1999). Observations on the regeneration of the broadleaved forests of eastern Bhutan. Paper presented to IUFRO 1.07 Workshop on Silviculture and Sustainable Management of Mixed Broadleaved Forests in the Himalayas, (15-23 November 1999), Lobesa, Bhutan. Page 38.

DALS (2002). Livestock Sub-Sector 9th Five Year Plan Document (2002-2007) Department of Agriculture and Livestock Support Services, Ministry of Agriculture, Thimphu.

Gyaltshen, T and Bhattarai, B. N. (2003). Bhutan Case study 2: Transhumant Cattle rising in Western Bhutan. In proceeding on Transhumant Grazing Systems in Temperate Asia, Food and Agriculture Organizations of the United Nations, Rome Chapter XV, and pp 267-275.

Gyaltshen, T and Dorji, S (1998). Observations on Alpine Grazing in Bhutan. In proceeding of the Third Temperate Asia Pasture and Fodder Network (TAFON) Pokhara, (9-13 March 1998), Nepal. Food and Agricultural Organization of the United Nations, Rome.

Gyamtsho, P (1996). Assessment of the Condition and Potential for Improvement of High Altitude Rangelands of Bhutan. Doctoral thesis for the Degree of Natural Sciences, Swiss Federal Institute of Technology, Zurich.

Kuensel (2004). Bhutan’s National Newsletter. (January 10, 2004), Kuensel Corporation, Thimphu, Bhutan
Mongar, T.B and Gyeltshen, T (2001). High Altitude Tsamdrog. In proceedings of the National Grazing Policy Workshop Bumthang, (21-24 August 2001). Ministry of Agriculture, Royal Government of Bhutan supported by Forestry Institutional Development Initiative.

MoA (2001). Proceedings of the National Grazing Policy Workshop Bumthang, (21-24 August 2001). Ministry of Agriculture, Royal Government of Bhutan supported by Forestry Institutional Development Initiative.

Norbu, L. Pradhan, N. K and Dukpa, D (2003). Rights and Benefits for poor people in the traditional cattle grazing system in Tobesa Geog in Western Bhutan. Paper presented in the Regional Workshop on Policy Advocacy for Enhancing Equity and Rights in the Common Property Resources in the Hindu Kush Himalayas, (48 August), ICIMOD, Kathmandu, Nepal.

NCD (2004). Bhutan Biological Conservation Complex. A Landscape Conservation Plan: a way forward. Department of Forest Services, Ministry of Agriculture with support from WWF Bhutan Programme, (February 2004), Thimphu.

Norbu, L and Dorji, S (2001). Sub-tropical Tsamdrog. In proceedings of the National Grazing Policy Workshop Bumthang, Group III, (21-24 August 2001). Ministry of Agriculture, Royal Government of Bhutan supported by Forestry Institutional Development Initiative.

Rinchen, D (2004). Study on Grazing, Cattle Migration and Tseree/Pangzhing in Thrumshingla National Park-Phase I, (April 2004). A Draft Report by R. C. Consultancy

Rinchen, D and Pushparajah (1994). Management Plan for Haa East Forest Management Unit, Haa Dzongkhag. Forest Resources Development Section, Forest Resources Management and Institutional Development Project FAO/UNDP BHU/ 91/002.

Ura, K (2001) Herdsmen’s Dilemma. In Proceedings of the National Grazing Policy Workshop Bumthang, (21-24 August 2001). Ministry of Agriculture, Royal Government of Bhutan supported by Forestry Institutional Development Initiative.

Ura, K (2002). The Herdsmen’s Dilemma. Journal of Bhutan Studies. Centre for Bhutan Studies, Thimphu. Volume 7 Wangchuck, S (2003). An Overview and analysis of conservation threats, issues and opportunities. A background paper presented during the workshop on Operational Planning for Bhutan Biological Conservation Complex, (13 October), River View Hotel, Thimphu.

Wangchuck, S (2001). Grazing Management in National Parks and Protected Areas. In proceedings of the National Grazing Policy Workshop Bumthang, 3.3 Technical session IVb, (21-24 August 2001). Ministry of Agriculture, Royal Government of Bhutan supported by Forestry Institutional Development Initiative.

Wangchuck, T (1995). Competition of forage between Blue Sheep and domestic Yak in Jigme Dorji National Park: Tsenden 5(1): 15-21, Thimphu.

Forest Pattern Analysis Along the Topographical and Climatic Gradient of the Dry West and Humid East Slopes of Dochula, Western Bhutan

Author: Wangda P, Ohsawa M

ABSTRACT

The contrasting vegetation and climatic conditions on east and west sides of Dochula pass is a unique characteristic of the dry valley ecosystem. Temperature declines faster on the west slope than on the east slope. Moisture condition is the determining factor for the contrasting vegetation. Floristically 66 tree species belonging to 29 families were recorded and these included 3 conifers, 37 evergreen broad-leaved and 26 deciduous broad-leaved species. The dry pine forest of Pinus wallichiana and mixed pine-oak forest of Quercus lanata occurred on the west slope of Dochula. Contrastingly humid evergreen broad-leaved forest of Quercus oxyodon, Q. lamellosa, Q. glauca and Castanopsis hystrix occurred on the east slope. Dochula pass at 3000 m asl under cloud zone dominated by Tsuga dumosa, Betula utilis, and Quercus semecarpifolia divide the two slopes. We conclude that west slope vegetation corresponds to dry west Himalayan type and east slope the humid east Himalayan type, however, this gradually transits to dry west Himalayan type of Pinus roxburghii forest towards the dry valley bottom. The diverse forest types found on the west and east slope of Dochula pass can represent as a miniature of whole Himalaya and are the valuable standard pattern of the Himalayan forest types, which needs careful conservation and management.

KEYWORDS:

aspect, evergreen broad-leaved, soil moisture content, lapse rate.

REFERENCES

Grierson AJC & Long DG (1983-2000). Flora of Bhutan Vol. I. Part 1, 2, 3. Vol. II. Part 1, 2, 3 & Vol. III. Part 1, 2. Edinburgh.

Hocking D & Wangdi, J (2000). Review of the literature in Bhutan on Agroforestry. Hunting Technical Services Ltd. Hemel Hempstead, UK

Leith et al. (1990). Climate Diagram World Atlas. Backhuys publishers, Leiden

McCune B & MJ Mefford (1999). PC-ORD. Multivariate Analysis of Ecological Data, Version 4. MjM Software Design, Gleneden Beach, Oregon, USA.

Ohsawa M (1987). Vegetation zones in the Bhutan Himalaya. In: Life Zone Ecology of Bhutan Himalaya I. (ed. M. Ohsawa) pp. 1-73. Chiba University, Chiba.

Ohsawa M (1990). An interpretation of latitudinal patterns of forest limits in South and East Asian mountains. Journal of ecology. 78:326-339.

Ohsawa M (1991). Montane evergreen broad-leaved forests of Bhutan Himalaya In: Life Zone Ecology of Bhutan Himalaya II. (ed. M. Ohsawa) pp. 89-156. Chiba University, Chiba.

Polunin O & Stainton A (1984). Flowers of the Himalaya. Oxford Univ. Press. New Delhi.

Sargent C et al. (1985). The forests of Bhutan: a vital resource for the Himalaya? Journal of Tropical Ecology 1:265-286.

Schweinfurth U (1992). Mapping Mountains: Vegetation in the Himalaya. GeoJournal. 27:1 73-83.

Stainton A (1988). Flowers of the Himalaya, A supplement. Oxford Univ. Press. New Delhi.

Stainton JDA (1972). Forests of Nepal. John Murray.

Statistical year book (2002). Central statistical office, planning commission. Royal Government of Bhutan, Thimphu.