Anthracnose in bean crops (Phaseolus vulgaris L.)

Abstract

In Mexico, bean production is low because it is a mainly
seasonal crop, in addition to the lack of pest and disease
control. The objective of this study was to identify the
pathogen that causes leaf spots that affect bean crops in
Tixtla, Guerrero, as well as to evaluate its incidence and
severity in plants. The variables were determined in
three plots in which the review of one hundred plants
was carried out in each one, with a zig-zag sampling. For
the evaluation of the damage, a scale of severity of
injuries was elaborated. For the incidence, the number of
plants with each type of damage was counted. The
pathogen was isolated in the laboratory from darkspotted

leaves in culture media. The experimental
pathogenicity tests were made in bean plants, one month
old, developed in a nursery, covering Koch's Postulates.
The disease that caused severe damage to bean crops
was anthracnose, the morphological characteristics of the
microorganism isolated from these damages
corresponded to the pathogen Colletotrichum
lindemuthianum (Sacc. Et Magn.) Scrib. In the plots, on
average, 05% of the plants presented level 5 (100%
affected the leaf area), 08% to level 4 (75%), 14% level
3 (50%), 11% level 2