TABLE CONTENTS

TOPIC SEVENTEEN – NEMATODE BIOLOGICAL CONTROL AGENTS
Effects of Application of Compost and Cultivation of Antagonistic Plant on
Parasitic Fungi of Eggs of Soybean Cyst Nematode (Heterodera glycines)
Aiba, S.
Research Team for Detection of Plant Pathogens and Nematodes, National Agricultural Research Center, 3-1-1
Kannondai, Tsukuba, Ibaraki, Japan
Soybean cyst nematode (Heterodera glycines) is an important harmful nematode for soybean
and other legumes in East Asia, North and South America. The prevention of this nematode
is very difficult, therefore biological control using egg parasitic fungi is considered
particularly promising. To clarify a suitable soil environment for egg parasitic fungi,
multiplications of nematodes and ratio of abnormal eggs that were parasitic to the fungi was
investigated in different soil conditions, namely, continuous cropping, application of compost
and cultivation antagonistic plant.
Densities of nematode eggs were investigated at five fields, namely (a) continuous cropping
of soybean field, (b) application of compost after continuous cropping field, (c) cultivation
the crotalaria which is an antagonistic plant for soybean cyst nematode field, (d) antagonistic
plant mingle into soil field and (e) application of compost after cultivation antagonistic plant
field. It was observed that nematodes more decreased at (b) and (d).
Nematodes were inoculated into soils gathered from these five fields in the greenhouse and
were investigated densities and ratios of abnormal eggs after cultivation of soybeans.
Multiplications of eggs were higher in soils from (b) and (e). And ratios of abnormal eggs
were highest in soil from (b) next in (c). The fungus mainly isolated from abnormal eggs was
different in (b) and (c). The major fungus from (b) was Paecilomyces lilacinus. Furthermore,
P. lilacinus was inoculated into these soils in the greenhouse and multiplication of nematode
was examined. Nematode decreased most in the soil (b) and decreased least in the soil from
(e).
These results suggest that application of compost accelerate multiplication of soybean cyst
nematode, but compost activates egg parasite fungi such as Paecilomyces lilacinus, too.
Therefore, the density of nematode decreases. There are possibilities that crotalaria activate
other egg parasite fungi, but these effects offset each other.
5 th International Congress of Nematology, 2008 290