Volume II Issue I February 2019 ISSN 2616-3926 Royal Government of Bhutan BHUTANESE JOURNAL OF AGRICULTURE Agriculture Research and Extension Division Department of Agriculture Agriculture Research and Extension Division Ministry of Agriculture & Forests Department of Agriculture Thimphu : Bhutan Tel# 02-322228/331316/336462/336186(F) Ministry of Agriculture and Forests Printed at United Printing Press Thimphu: Bhutan Volume II Issue I February 2019 ISSN 2616-3926 Bhutanese Journal of Agriculture is registered with the ISSN International Centre, Located in Paris 75003 (France), 45 rue de Turbigo. Editor -In-Chief Mr. Mahesh Ghimiray, Specialist II, Agriculture Research and Development Centre (ARDC), Bajo Associate Editor Mr. Lakey, Principal Agriculture Officer, Agriculture Research and Extension Division, DoA, Thimphu Editorial Board Mr. Tirtha Bdr. Katwal, Specialist III, ARDC-Yusipang, Thimphu, DoA Dr. Yadunath Bajgai, Principal Research Officer, ARDC-Yusipang, Thimphu, DoA Dr. Dorjee, Principal Plant Protection Officer, National Plant Protection Centre, DoA,Thimphu Mr. Lakey, Principal Agriculture Officer, Agriculture Research and Extension Division, DoA, Thimphu Member Secretary Mr. Wangda Dukpa, Chief, Agriculture Research and Extension Division, DoA, Thimphu Editorial Assistant and Correspondence Ngawang, Agriculture Officer, Agriculture Research and Extension Division, DoA, Thimphu Editorial The Bhutanese Journal of Agriculture welcomes the submission of research articles and short communications. Article may be submitted to [email protected]/[email protected] or [email protected]. Please follow the journal format provided in the author guidelines, accessible from www.doa.gov.bt or www.moaf.gov.bt Publisher Agriculture Research and Extension Division, Department of Agriculture, Ministry of Agriculture and Forests, Thimphu: Bhutan Post Box 113, Postal Code 11001 Contact no. +975-2-322228/331316 Copyright © Department of Agriculture, 2019 Ministry of Agriculture and Forests, Royal Government of Bhutan A part or whole of this publication may be reproduced or disseminated with proper acknowledgement to the above address. Readers are encouraged to send comments or feedback on articles in this journal for future improvement. Volume II Issue I February 2019 ISSN 2616-3926 Royal Government of Bhutan BHUTANESE JOURNAL OF AGRICULTURE Agriculture Research and Extension Division Department of Agriculture Ministry of Agriculture and Forests Thimphu: Bhutan FOREWORD The Department of Agriculture is delighted to bring out the second volume of the Bhutanese Journal of Agriculture (BJA). BJA is a print open access English language journal on agriculture and publishes research articles annually with the primary purpose of providing an additional mechanism to disseminate appropriate technologies, and knowledge and information in the agriculture sector. The BJA targets research findings that are innovative and relevant to sustainable agriculture development in Bhutan, and includes cross-cutting themes like postharvest, economics, agro- biodiversity, soil and water management, farming systems, pest and disease management and climate change. We are continuously working at improving the quality of the journal and just this past year’s single and maiden issue in itself has been a huge learning curve. Our editorial team, comprising members entirely from within the Department of Agriculture, is working hard to push a notch up with every issue. We are also looking at registering a DOI (digital object identifier) for the journal and launching its electronic version. It is indeed rewarding to note that the BJA has, up to a significant extent, succeeded in motivating our researchers and field colleagues in maintaining a vibrant culture of research and scientific communication – key to success in research for agriculture development. The department would like to thank the authors and the reviewers alike for their contribution. Above all, the BJA Editorial Board is commended for putting in extra effort in publishing this edition successfully. Kinlay Tshering (Ms) DIRECTOR i EDITORIAL After a successful launch in February 2018, we are pleased to publish the second volume of the Bhutanese Journal of Agriculture (BJA). We are in the process of conscientiously improving the BJA in terms of its technical content, professional outlook and scientific relevance for our agricultural scientists. As intended, the BJA provides a platform for our researchers and rural development workers to showcase their scientific work and build a career path that is competitive both nationally and globally. We are encouraged by article contributions from the non-RNR sector such as the Sherubtse College in Kanglung and Samdrup Jongkhar Initiative (SJI). We promote and value such contributions. In our second volume of the journal, we have a wide range of technical papers from crop production, economics, post harvest management, agro-biodiversity and morpho-agronomic analysis of new crop varieties. The paper on evaluation of chilli drying methods conclude that poly-tunnel drier is more efficient, economic and convenient compared to raised bamboo mat or bamboo mat with plastic roofing. The study on the analysis of SPAD value and chlorophyll content of organic vegetables under a protected system found a significant positive correlation between SPAD values, chlorophyll content and dry weight for spinach, fenugreek and amaranthus. Analysis of the status of on-farm diversity of field crops in two geogs of Samdrup Jongkhar revealed that on-farm agro-biodiversity plays a critical role in the food security and livelihood of farmers. Important insect pests, diseases and beneficial insects in fruits and vegetables in west central Bhutan were documented, which will form a scientific basis for appropriate crop protection interventions. Three separate but similar studies on post harvest damage and loss in apple, mandarin and rice provide information on losses incurred during harvest and post harvest operations. The reaction of Bhutanese wheat varieties to rust diseases in mid and low altitudes showed a disease incidence of 2.5-16% and that the disease severity was positively correlated with temperature and humidity. A morpho-agronomic analysis of new rice germplasm was carried out at ARDC Bajo based on both qualitative and quantitative parameters. The paper on adaptation study of a new crop, Quinoa, under the Bhutanese farming system provides insight into its agronomic performance in different altitude regimes and crop sequences while the article on the efficacy of Ageratina adenophora confirmed that 10% aqueous extract can effectively control white rusts of crucifers. The study on growth and yield of oyster mushroom under different substrates indicated that Quinoa stubble was superior to banana leaf or lemon grass. We wish you a happy reading of this rendition of the BJA! Mahesh Ghimiray EDITOR-IN-CHIEF ii TABLE OF CONTENTS FOREWORD ................................................................................................................................... i EDITORIAL ................................................................................................................................... ii Digital Soil Mapping of Soil Organic Carbon Stock in Bhutan ..................................................... 1 Morpho-agronomic Analysis of New Rice Germplasm at Agriculture Research and Development Centre, Bajo .................................................................................................................................. 13 Efficacy of Ageratina adenophora against White rust (Albugo candida): A laboratory and field study .............................................................................................................................................. 26 Comparative Study on Growth and Yield of Oyster mushroom (Pleurotus ostreatus) on Different Substrates ...................................................................................................................................... 35 Evaluation of Different Sun Drying Methods in Chilli ................................................................ 42 Analysis of SPAD Values and Chlorophyll Content of Organic Vegetables under Protected System ........................................................................................................................................... 53 Adaptation of Quinoa in Bhutanese Cropping Systems ............................................................... 71 Reaction of Wheat Varieties to Rust Diseases at Mid and LowAltitudes in Bhutan .................... 81 Postharvest Damage and Losses of Mandarin Fruits in Bhutan ................................................... 97 Status of Field Crops Diversity in Dewathang and Orong Geogs, Samdrupjongkhar................ 107 Post-harvest Losses of Rice in Paro Valley ................................................................................ 121 Effect of Harvesting Stages of Maize on Quality and Consumption Preferences of Tengma .... 131 Inventory of Important Insect Pests, Diseases and the Beneficial Insects in Fruits and Vegetables in West Central Bhutan ............................................................................................................... 143 Post- harvest Damage and Loss of Apples in Bhutan (Thimphu and Paro) ............................... 159 Guidelines for Bhutanese Journal of Agriculture, Department of Agriculture; MoAF .............. 167 iii Dorji et al. 2019