The Role of Trichoderma, VA Mycorrhiza and Dry Yeast in the Control of Rhizoctonia Disease of Potato (Solanum tuberosum L.)

Abstract

Laboratory and pot experiments were conducted to evaluate the
efficacy of Trichoderma viride, VA mycorrhiza and dry yeast, separately
and in combination, as an integrated strategy of Rhizoctonia disease
management in potato crop. The challenge inoculation with T. viride
caused a significant reduction in vitro in the linear growth of Rhizoctonia
solani, particularly when it was performed closer to the time of pathogen
inoculation. With the exception of the number of stems, yield and growth
attributes of potato plants infected with R. solani were significantly
affected. T. viride application significantly increased the growth
components (i.e., plant height, shoot fresh and dry weights, root fresh and
dry weights) and tuber yield (i.e., number and weight of tubers) compared
to potato plants inoculated with R. solani alone. Moreover, the disease
incidence and severity, as stem canker or black scurf on progeny tubers,
were also significantly alleviated by T. viride inoculation. Similarly, VA
mycorrhiza enhanced both the growth and yield measurements of
Rhizoctonia-inoculated potato plants and significantly reduced the
harmful effects of the disease. The dry yeast appeared to be the least
efficacious biocontrol agent to Rhizoctonia compared to the other two
organisms; yet it also significantly improved the disease situation of the
infected plants. The combined effect of T. viride and VA mycorrhiza
with or without yeast excelled other treatments in alleviation of almost all
tested facets of the disease development.