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produced by Sr18 has low toxicity and harmless to animals eyes and skin. The bio-nematicide
produced by fungus Sr.18 were used for the control of tomato and cucumber root-knot
nematode (Meloidogyne incognita) in greenhouse and got good control effects. The result of
control cucumber root-knot nematode showed that it could reduce the number of second stage
juvennil(J 2 ) by94.68% ,and the control effect investigated at the harvest season was up to
80.27%, which is significantly higher than that of chemical and biological control
nematicides. Moreover, It also could promote the growth and yield of the plant. The average
height and the weight of each cucumber plant which was treated with the Sr.18 bionematicide
were higher than that of control groups, increasing by16.32% and 20.43%
respectively. The cucumber yield also increased by 28.28% which was significant higher than
contrast groups with chemical and biological nematicide.
Influence of Fungicides on a Nematode-Suppressive Soil
Timper, P. (1) & A.K. Culbreath (2)
(1) USDA ARS Crop Protection & Management Unit, P.O. Box 748, Tifton, GA, 31793; (2) Department of
Plant Pathology, University of Georgia, P.O. Box 748, Tifton, GA 31793, USA.
We identified a field in Georgia, USA that was moderately suppressive to Meloidogyne spp.
In the greenhouse, reproduction of both M. incognita on cotton and M. arenaria on peanut
was greater in microwave-heated soil than in natural soil from this field suggesting that
nematode suppression was caused by a heat-sensitive organism. Because fungi antagonistic
to nematodes are common in soils and are frequently associated with suppressive soils, we
hypothesized that fungicides would reduce the activity of these fungi and allow greater
nematode reproduction. To test this hypothesis, we collected soil from the suppressive field
and placed it in 6 liter pots. Peanut was planted and 2 weeks later inoculated with 3,000 eggs
of M. arenaria. Starting 5 weeks after planting (WAP), the peanuts were sprayed with one of
four fungicide treatments: 1) five applications of chlorothalonil, 2) four applications of
tebuconazole, and 3) two applications each of flutolanil, and 4) azoxystrobin. These
fungicides are commonly sprayed on peanut at the rates and frequencies used. There were
eight replications of each treatment and control (no fungicide). The number of eggs/g root
was determined 15 WAP. In both trials of the experiment, azoxystrobin was the only
fungicide that led to an increase (P = 0.0004) in nematode densities relative to the control;
nematode densities in the other fungicide treatments were not different from the control. The
number of eggs/g root was 20,391 in control pots and 44,315 in azoxystrobin-treated pots, a
two-fold increase in nematode reproduction. Further research is underway to determine
whether azoxystrobin has a similar effect on nematode densities in heat-treated soil.
5 th International Congress of Nematology, 2008 302