Elaboración y validación de diagramas de severidad para el daño causado por mildiu (Peronospora variabilis) en quinua (Chenopodium quinoa Will.)

Abstract

The present investigation aims to develop and validate severity diagrams to quantify downy mildew damage (Peronospora variabilis Gäum.) on quinoa leaves (Chenopodium quinoaWilld.). The descriptive, explanatory and quantitative methods were used to support this investigation. It is characterized because it is a field and non-experimental investigation since the study was carried out in Penipe and Colta cantons. The severity diagrams with linear and logarithmic increments were validated by two groups of evaluators (producers and technicians). In each group of evaluators. The validation was carried out with and without support of the respective set of diagrams. The minimum and maximum severity levels found in the different quinoa fields varied according to the fields, with the severity ranges found in MATUS 0.72-65.94%, RAYALOMA 0.59-88.41%, and COPROBICH 0.17-69%, however, in the three fields sampled, in the three fields sampled the severity ranges of 0-12% were found in approximately more than 50% of the leaves sampled, the minimum and maximum severities of the sets of Severity diagrams with linear increments were 2.5% and 67.6%, and for Severity with logarithmic increments were 0.7% and 88%. Thus, the linearly incremented severity diagrams significantly improved the accuracy, precision and reliability of severity estimates relative to the logarithmically incremented severity diagrams. The sets of diagrams helped to improve the accuracy and reliability of downy mildew severity estimates. It is recommended to validate the diagrams with a greater number of evaluators, in order to check the usefulness of this type of tools and that these validations are carried out in-person, so that the evaluators do not have any bias when performing this work.