Optical density - a tool for the estimation of spore count of Trichoderma viride

Abstract

Spore count is an important parameter in mass multiplication of entomopathogens including Trichoderma viride for quality analysis. In the present investigation, it has been found that optical density (OD) is an easy and reliable method as compared to haemocytometer count (HC) reading. A positive correlation between T. viride concentration (0.05 to 0.5%) and OD had been found in proportional to HC count at seventh day and increased at 10th day after inoculation on sugarcane juice medium (SJM). The spore count of T. viride can be determined at 550nm with spectrophotometer in place of haemocytometer by measuring optical density.