A Field Guide for Identification and Scoring Methods of Diseases in the Mountain Crops of Nepal

Authors: Hira Kaji Manandhar, Ram Devi Timila, Sarala Sharma, Sharada Joshi, Shrinkhala Manandhar, Suk Bahadur Gurung, Sajal Sthapit, Epsha Palikhey, Anju Pandey, Bal Krishna Joshi, Gyanu Manandhar, Devendra Gauchan, Devra I. Jarvis, Bhuwon Ratna Sthapit
Year: 2016
Description: This guide is a compilation of published information for the identification and scoring of diseases of selected mountain crops (amaranth, barley, beans, buckwheat, finger millet, foxtail millet, proso millet and rice) in Nepal. As this guide is intended for the crops grown in the mountain region, it does not cover all the diseases known to occur in the country. Also, disease information on some of the crops, especially proso millet, foxtail millet, buckwheat and grain amaranth, is very limited. As a result, the disease information of these crops might not have been sufficiently covered in this guide. Some of the diseases included in this guide have not been reported in Nepal, but they are included because of their likely occurrence in the mountain climates.

For identification purposes, pictures of pathogens and disease symptoms have been derived from different sources. Also, several pictures, especially of disease symptoms, taken during field visits to the project sites in Jumla, Humla, Lamjung and Dolakha have been used. Several diseases were diagnosed at the Plant Pathology Division of Nepal Agricultural Research Council, Khumaltar, Lalitpur.

The scoring scales for various diseases have been taken from different sources; for example, the IRRI scale for rice diseases, the CIMMYT scale for barley, the CIAT scale for beans, and other scales published by various researchers for other crops. Scoring scales for disease assessment vary a lot. Specic disease scoring scales are not available for some crops. In such cases, scoring scales describing similar diseases were adopted from other crops.

One can note that some scales start with ‘0’ while others begin with ‘1’. In this guide, the starting value for most of the bean diseases is ‘1’ for no disease, and for most of the other crops it is ‘0’. Generally, ‘0’ values are disregarded for statistical analysis, but it depends how the value is used for analysis. While it was proposed to simply change all the values of ‘0’ to ‘1’, this was not done, as it would be inappropriate to modify the widely adopted international scales.

This guide is primarily based on one season of field verification of the crops. It is hoped that the Guide will be revised and updated following the identification of more diseases and the completion of additional field verification.