Effect of environmental conditions and inoculum density on infection of guava fruits by Colletotrichum glososporioides.

Autor: Pandey, R.R., Arora, D.K., Dubey, R.C.
Zdroj: Mycopathologia; Mar1997, Vol. 137 Issue 3, p165-172, 8p
Abstrakt: 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 °C, whereas the disease incidence was less at 20 and 35 °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. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index