title: Effect of environmental conditions and inoculum density on infection of guava fruits by Colletotrichum glososporioides.
abstract: The influence of environmental factors (temperature and humidity), inoculum density on infection by Colletotrichum glososporioides and development of anthracnose lesions were determined on uninjured, sand-injured and punctured fruits. The optical temperature for severe infection was 30 degrees C, whereas the disease incidence was less at 20 and 35 degrees C. Inoculated guavas that received 1-60 h of continuous free moisture developed lesions, but the disease was minimal (0-7%) after 1-6 h free moisture. Infection rates of uninjured, sand-injured and punctured fruits receiving 60 h of free moisture were 34, 70 and 100%, respectively. Disease incidence increased as inoculum density increased from 101 to 106 conidia/ml. In field conditions, the development of anthracnose lesions was greater on punctured guavas than on uninjured or sand-injured ones, in both rainy and winter seasons. In general, the number of lesions was highest in sand-injured fruits, followed by punctured and uninjured fruits. In rainy season the number of lesions on injured and uninjured fruits was greater than similarly treated guavas in winter.
authors.affiliation: Department of Life Science, Manipur University, Imphal, India.
authors.forename: R R
authors.initials: RR
authors.lastname: Pandey
authors.forename: D K
authors.initials: DK
authors.lastname: Arora
authors.forename: R C
authors.initials: RC
authors.lastname: Dubey