Studies on wilt disease of Guava (Psidium guajava L.)

Pathogenic fungus Fusarium oxysporum f. sp. psidii were isolated from different areas of Aligarh from diseased plants & rhizospheric soil. The max. radial growth of F. oxysporum f. sp. psidii was found at temp. 25 C. Among all biofungicides (T. harzianum, T. virens, T. viride A. niger & P. flourescens) used against pathogen in dual inoculation test, the maximum growth inhibition was recorded with T. viride 75%. Effects of volatile compounds produced by T. harzianum were seen on the growth of the pathogen & found that 2 days of incubation with T. harzianum gave a max. growth inhibition of 76.5% followed by 4, 6, 8 and 10 days of incubation with 63.6 %, 50.0% 36.4%, 23.6% of inhibition. Among ten plant extracts max. 56.46% growth inhibition of pathogen was recorded with Azadirachta indica. Highest increase in shoot length 20% & root length 28.5% were recorded with P. flourescens & dry weight of shoot 21% and root 24.5% with A. niger in comparison to uninoculated control pots, were as max. increase in shoot length 19%, root length 25%, dry weight of shoot 22% & dry weight of root 23% were recorded with T. viride in comparison to inoculated (Fusarium. oxysporum f. sp. psidii)control pots