| Summary: | 碩士 === 國立臺灣大學 === 植物病蟲害學系 === 84 === A total of 5220 bacteria isolated from rhizosphere of tomato
and sweet pepper were screened by dual cultures. Concomitant
cultures on 5 kinds of media for ability to control
Phytophthora blight of sweet pepper caused by Phytophthora
capsici. Seven isolates exhibited antagonism not only to P.
capsici but also to other plant pathogenic fungi and were
brought to bioassy in the screenhouse. Isolate #294 among seven
isolates was more consistency in their control efficacy and
reduced the amount of propagule survived in the potting media
of P. capsici. The combination of#294 antagonist and various
ingredients which were molasses, glutamate, calcium hydroide,
peptone, and ammonium oxalate to constitute C5 and A10
formulation. The maintenance of #294 antagonist in C5 and A10
formulation lasted for 3 months with population density of 10
cfu/ml. While the population with N.B. declined rapidly in 7
days. Compare the populationmaintenance of C5, N.B., and 0.1M
magnesium sulfate solution on #294 antagonist survival. The
results showed that the hightest recovery freguencies of #294
antagonist labelled with antibiotic resistance markers were
potting medium incorporated with C5 formulation. The amount
wuth C5 was 5.9 times higher than N.B. in 7 days. By means of
adding detergent diluted to 1000ppm,the modified formulation
was effective to inhibit the sporangia germination of P.
capsici than C5. A10 and other liquid fertilizers tested which
included fish extract, sea algae extract, humic acid, Garmu,
Condola, complex of amino acids and complicated liquid fertil-
izers. In greenhouse experiment, modified formulation reduced
the disease index in average by 50% and better than previously
formulations, even though with antagonists involved in them.
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