Abstract
The trend in glasshouse horticulture has always been to start culture systems as aseptic as possible. However, several root diseases still cause problems under these conditions. The present paper shows the importance of the microflora to suppress Pythium aphanidermatum, a fungal root pathogen which is a serious threat in cucumber. Introduced single antagonists as well as the indigenous microflora suppressed pythium root and crown rot. Pseudomonas fluorescens, Streptomyces griseoviridis, Pythium oligandrum, and 2 isolates of Trichoderma harzianum reduced the disease occurrence by 60 ␘r more in several, but not all, of the experiments. The indigenous microflora showed a very constant disease suppression of 50 to 100 &Eth;This was tested in experiments where P. aphanidermatum was added to sterilised and non-sterilised rockwool, and to sterilised rockwool that had been recolonised with the original microflora. Suppressiveness correlated with the number of filamentous actinomycetes present in the nutrient solution in the rockwool slabs. If a beneficial microflora is present in the cropping system, it should not be disturbed or eradicated by treatments such as disinfection of the recirculated nutrient solution. Therefore, the effects of different disinfection procedures on the composition of the microflora were compared. Numbers of filamentous actinomycetes in the nutrient solution in the tank after the disinfection treatment were highest without disinfection, intermediate after slow filtration, and lowest after UV treatment. Numbers of actinomycetes in the slabs, i.e. around the roots, were not distinctly different between the treatments. The implication of potential shifts in the microbial populations due to certain treatments for the disease development is not known. Increased knowledge on the beneficial microflora and the treatments that influence the composition of such a microflora, will stimulate the exploitation of microbially balanced and optimised soilless culture systems.
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Claims 9
Claim · model-written summary
Pseudomonas fluorescens reduced cucumber disease occurrence by 60 or more in several experiments.
- Taxon
- cucumber
Cucumis sativuse1 - Treatment
- Pseudomonas fluorescense0
- Interactor
- Pseudomonas fluorescens
.JPG?width=60)
Pseudomonas fluorescense0biocontrol_agent - Outcome
- disease occurrencee0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.JPG?width=500)
Verbatim
e0“Pseudomonas fluorescens, Streptomyces griseoviridis, Pythium oligandrum, and 2 isolates of Trichoderma harzianum reduced the disease occurrence by 60 ␘r more in several, but not all, of the experiments”
e1“a serious threat in cucumber”
Claim · model-written summary
Streptomyces griseoviridis reduced disease occurrence by 60 or more in several experiments.
- Taxon
- cucumberCucumis sativuse1
- Treatment
- Streptomyces griseoviridise0
- Interactor
- Streptomyces griseoviridisStreptomyces griseoviridise0biocontrol_agent
- Outcome
- disease occurrencee0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pseudomonas fluorescens, Streptomyces griseoviridis, Pythium oligandrum, and 2 isolates of Trichoderma harzianum reduced the disease occurrence by 60 ␘r more in several, but not all, of the experiments”
e1“a serious threat in cucumber”
Claim · model-written summary
Pythium oligandrum reduced disease occurrence by 60 or more in several experiments.
- Taxon
- cucumberCucumis sativuse1
- Treatment
- Pythium oligandrume0
- Interactor
- Pythium oligandrum
Pythium oligandrume0biocontrol_agent - Outcome
- disease occurrencee0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pseudomonas fluorescens, Streptomyces griseoviridis, Pythium oligandrum, and 2 isolates of Trichoderma harzianum reduced the disease occurrence by 60 ␘r more in several, but not all, of the experiments”
e1“a serious threat in cucumber”
Claim · model-written summary
Two Trichoderma harzianum isolates reduced disease occurrence by 60 or more in several experiments.
- Taxon
- cucumberCucumis sativuse1
- Treatment
- 2 isolates of Trichoderma harzianume0
- Interactor
- Trichoderma harzianum
Trichoderma harzianume0biocontrol_agent - Outcome
- disease occurrencee0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pseudomonas fluorescens, Streptomyces griseoviridis, Pythium oligandrum, and 2 isolates of Trichoderma harzianum reduced the disease occurrence by 60 ␘r more in several, but not all, of the experiments”
e1“a serious threat in cucumber”
Claim · model-written summary
Indigenous microflora consistently suppressed cucumber disease by 50 to 100.
- Taxon
- cucumberCucumis sativuse1
- Treatment
- indigenous microflorae0
- Interactor
- indigenous microflorae0biocontrol_agent
- Outcome
- disease suppressione0
- Direction
- suppressione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The indigenous microflora showed a very constant disease suppression of 50 to 100 &Eth;”
e1“a serious threat in cucumber”
Claim · model-written summary
Suppressiveness correlated with filamentous actinomycete numbers in rockwool nutrient solution.
- Taxon
- cucumberCucumis sativuse1
- Interactor
- filamentous actinomycetese0biocontrol_agent
- Outcome
- Suppressivenesse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Suppressiveness correlated with the number of filamentous actinomycetes present in the nutrient solution in the rockwool slabs”
e1“a serious threat in cucumber”
Claim · model-written summary
Disinfection treatments ranked tank actinomycete numbers highest with no disinfection, intermediate after slow filtration and lowest after UV treatment.
- Taxon
- cucumberCucumis sativuse1
- Treatment
- disinfection treatmente0
- Interactor
- filamentous actinomycetese0biocontrol_agent
- Outcome
- Numbers of filamentous actinomycetese0
- Direction
- higheste0
- Comparator
- without disinfectione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Numbers of filamentous actinomycetes in the nutrient solution in the tank after the disinfection treatment were highest without disinfection, intermediate after slow filtration, and lowest after UV treatment”
e1“a serious threat in cucumber”
Claim · model-written summary
Actinomycete numbers around roots were not distinctly different among disinfection treatments.
- Taxon
- cucumberCucumis sativuse1
- Treatment
- treatmentse0
- Interactor
- actinomycetesActinomycetese0biocontrol_agent
- Outcome
- Numbers of actinomycetes in the slabse0
- Direction
- not distinctly differente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Numbers of actinomycetes in the slabs, i.e. around the roots, were not distinctly different between the treatments”
e1“a serious threat in cucumber”
Claim · model-written summary
Beneficial microflora should not be disturbed or eradicated by disinfection.
- Taxon
- cucumberCucumis sativuse1
- Interactor
- beneficial microflorae0biocontrol_agent
- Outcome
- it should not be disturbed or eradicated by treatments such as disinfectione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“If a beneficial microflora is present in the cropping system, it should not be disturbed or eradicated by treatments such as disinfection of the recirculated nutrient solution”
e1“a serious threat in cucumber”
The same questions in other papers
Pythium oligandrum · disease · Cucumis sativus (cucumber)Results agree
2 papers in the same direction as this paper
- positive
- positive
Pseudomonas fluorescens · disease · Cucumis sativus (cucumber)Results agree
5 papers in the same direction as this paper
- positive
- positive
- positive
2 papers more in this group
See all 6 papers →Trichoderma harzianum · disease · Cucumis sativus (cucumber)Results agree
7 papers in the same direction as this paper
- positive
- positive
- positive
4 papers more in this group
See all 8 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.