Role of Nematode-Trapping Fungi for Crop Improvement under Adverse Conditions - Crop Improvement Under Adverse Conditions - page 269

Fig. 12.2 a, b Effect of mass culture of A. oligospora with dung of different animals on the
growth of brinjal and tomato plants in root knot-infested soil. c, d Effect of different amounts of
mass culture of A. oligospora on the growth of brinjal and tomato plants in root knot-infested soil.
e, f Effect of time of application of mass culture of A. oligospora on the growth of brinjal and
tomato plants in root knot infested soil
Among all the nematode-trapping fungi, the most extensively studied fungus
is Arthrobotrys oligospora due to its fast growth as well as good saprophytic and
colonization ability. We have also used A. oligospora to determine its biocontrol
potential in pot experiments with a view to understand the basic criteria for its
establishment and efficacy in soil. Our study was conducted to determine whether
organic substrates in any form improve its potential, to determine optimum level
of mass culture for application and to determine the consequence and efficacy of
A. oligospora when applied either prior to planting or same day of planting of the
seedlings. We have tested the same set of experiments on different crops like brinjal,
tomato and rice with mass cultures of A. oligospora prepared on sorghum grains
and applied in nematode-infested soil for 30 days and 60 days after transplanting.
In the first experiment when mass culture of A. oligospora was applied to fully
rotten animal dung, the biotic stress caused by Meloidogyne incongnita was altered,
and the effect was also visible on the growth parameters of brinjal and tomato plants
(Fig. 12.2a,b ) in terms of shoot and root biomass and chlorophyll content in the
plants. The increased growth of plants in response to mass culture of nematode-trap-
ping fungi combined with farm yard manure or other animal dung might be because
of reduction of infective juveniles due to capturing and killing by nematode-trapping
fungi. Effective control of root knot diseases of plants by application of nematode-
trapping fungi have been found, particularly when these fungi were applied in combi-
nation with organic substrates or compost (Jansson et al. 1980 ; Stirling et al. 1998b ;