Phosphonate (PO3-) effectiveness against Phytophthora cinnamomi Rands on Thryptomene calycina, Banksia grandis and Banksia spinulosa

Plant Pathology Journal 3(1) 2004 : 19-25
I Nyoman Pugeg Aryantha1* and David I. Guest2
1) Dept. of Biology and Research Development Group on Life Sciences, Institut Teknologi Bandung (ITB), Jalan Ganesha 10, Bandung 40132, Indonesia
Tlp./Fax. +62-22-2509165, Email : nyoman@bi.itb.ac.id
*) Corresponding author should be addressed
2) School of Botany, The University of Melbourne, Victoria-Australia


ABSTRACT

Our study shows that Potassium phosphonate has been proven to slow down the growth rate of P. cinnamomi in in vitro. Phosphonate drench as low as one gram per litre was effective in protecting Thryptomene calycina, Banksia grandis, and B. spinulosa in pot and field trials. In glass house trials, concentrations as low as one gram per litre (drench) significantly suppressed the P. cinnamomi population. Concentrations over two and a half gram per litre were phytotoxic to all plant species tested. The most sensitive species was B. spinulosa. Phosphonate [5 gL-1] killed all B. spinulosa plants in seven weeks, therefore it must be used with a great care. Phosphonate treatment alone was effective protecting plants from disease in the field, but did not result in high plant health. Despite new root growth in pot trials after seven weeks, poor growth was commonly observed on T. calycina after 14 months in field trials. This suggests that phosphonate is not suitable as sole application particularly for the long term. A combination of phosphonate with compost as well as antagonist as an integrated management will be a good alternative for P. cinnamomi management in the future.
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Keywords : Phosphonate, Phytophthora cinnamomi, Thryptomene calycina, Banksia grandis, Banksia spinulosa, phytotoxic, Integrated control

Suppression of Phytophthora cinnamomi Rands by mycoprasitic and antagonistic microorganisms

Plant Pathology Journal : 5(3) 2006, 291-298
Suppression of Phytophthora cinnamomi Rands by mycoprasitic and antagonistic microorganisms

I Nyoman P. Aryantha [1] and David I. Guest2
1) Dept. of Biology and Research Development Group on Life Sciences, Institut Teknologi Bandung (ITB), Jalan Ganesha 10, Bandung 40132, Indonesia
Tlp./Fax. +62-22-2509165
Email : nyoman@bi.itb.ac.id
2) School of Botany, The University of Melbourne, Victoria Australia
Running title: Antagonists from composted manuresSuppression of Phytophthora cinnamomi Rands by mycoprasitic and antagonistic microorganisms

ABSTRACT

We have isolated bacteria and fungi from composted chicken, sheep, cow and horse manure and screened each isolate for its ability to suppress P. cinnamomi in dual-culture in vitro plate and slide assays. Of the 180 isolates, including 31 actinomycetes, 64 fungi, 44 fluorescent pseudomonads and 41 endospore-forming bacteria, 45 isolates significantly inhibited the growth of P. cinnamomi. The inhibitory microbes were identified based on morphological and biochemical characters including 24 fungi (including Trichoderma spp., Gliocladium penicillioides and Fusarium spp.), 10 actinomycetes (all Streptomyces sp.), 7 fluorescent pseudomonads (Pseudomonas sp.) and 4 endospore-forming bacteria (Bacillus sp.). The most common mode of action observed was antibiosis, although mycoparasitism, indicated by parallel hyphal growth, hyphal coiling, appressorium formation and direct penetration, was also observed with one isolate of Trichoderma. These results help to explain the role of microbes in the suppression and biological control of P. cinnamomi by composted manures.
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Keywords : Antagonism, Antibiosis, Mycoparasitism, Biocontrol, Phytophthora cinnamomi,
Bacillus, Pseudomonas, Actinomycete.
[1] Corresponding author should be addressed to