Articles
INTEGRATION OF CHEMICALS AND BIOCONTROL AGENTS FOR MANAGING WHITE ROOT ROT OF APPLE
Article number
635_18
Pages
141 – 149
Language
English
Abstract
White root rot (Dematophora necatrix) is a pernicious soil borne disease of apple in India and is highly damaging in nurseries, as well as to mature trees.
Currently, the only approach to control the disease is the use of chemicals, which in addition to being costly, disturb the soil ecology.
Therefore, an experiment was conducted to determine the compatibility of biocontrol agents with commercially effective chemicals.
Carbendazim fungicide (Bavistin) and biocontrol agents, such as Trichoderma viride, T. harzianum, Gliocladium virens and Enterobacter aerogenes, which were found effective under in vitro conditions and in pots during the previous studies, were further evaluated in different combinations.
Of the various chemicals tested under in vitro conditions, Bavistin was inhibitory to all the fungal antagonists whereas, Mancozeb and Phorate were least inhibitory at 200 ppm.
However, E. aerogenes was insensitive to all these chemicals.
The pot evaluation of Bavistin in combination with different antagonists revealed that application of E. aerogenes + Bavistin (0.1 or 0.05%) showed more than 92 % disease control when applied as pre-inoculation to the pathogen.
In simultaneous inoculation, 0.1 % Bavistin in combination, completely prevented the appearance of the disease, however, 0.05 % in combination with E. aerogenes, T. viride and G. virens gave 90.4, 86.9 and 81.0 % disease control, respectively.
The post inoculation application of these was less effective.
These treatments not only delayed appearance of the disease but also increased the root weight as compared to control.
Currently, the only approach to control the disease is the use of chemicals, which in addition to being costly, disturb the soil ecology.
Therefore, an experiment was conducted to determine the compatibility of biocontrol agents with commercially effective chemicals.
Carbendazim fungicide (Bavistin) and biocontrol agents, such as Trichoderma viride, T. harzianum, Gliocladium virens and Enterobacter aerogenes, which were found effective under in vitro conditions and in pots during the previous studies, were further evaluated in different combinations.
Of the various chemicals tested under in vitro conditions, Bavistin was inhibitory to all the fungal antagonists whereas, Mancozeb and Phorate were least inhibitory at 200 ppm.
However, E. aerogenes was insensitive to all these chemicals.
The pot evaluation of Bavistin in combination with different antagonists revealed that application of E. aerogenes + Bavistin (0.1 or 0.05%) showed more than 92 % disease control when applied as pre-inoculation to the pathogen.
In simultaneous inoculation, 0.1 % Bavistin in combination, completely prevented the appearance of the disease, however, 0.05 % in combination with E. aerogenes, T. viride and G. virens gave 90.4, 86.9 and 81.0 % disease control, respectively.
The post inoculation application of these was less effective.
These treatments not only delayed appearance of the disease but also increased the root weight as compared to control.
Authors
V.K. Gupta, K. Sharma
Keywords
Dematophora necatrix, Rosellinia necatrix, antagonists, integrated disease management
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