Abstract
Abstract Alfalfa ( Medicago sativa L.) growth and development is known to be adversely affected by Phytophthora megasperma Drechs. f. sp. medicaginis (Pmm), a root rotting fungus most active under waterlogged soil conditions. The response of the plant to the pathogen under low levels of flooding stress is not well‐established, but that relationship is important during alfalfa establishment on soils flooded for short periods by rainfall. Our main objective was to determine if yield reductions caused by the disease occurred in the absence of yield reductions caused by flooding on seedling alfalfa plants. Controlled environment studies were conducted to quantify the effects of flooding or inoculation with Pmm, or both, on alfalfa yield and disease severity, and to examine the differential response of a susceptible (‘Iroquois’) and a resistant (‘Oneida’) cultivar. At 26°C, one or two 3‐day cycles of flooding with subsequent 4‐day drainage periods did not reduce dry matter yields of alfalfa shoots grown in either soil (mixed, mesic Typic Udipsamment) or vermiculite. Inoculation with Pmm significantly reduced the shoot yield of Iroquois, but not that of Oneida. The presence of an interaction between Pmm inoculation and cultivar in the absence of a flooding × cultivar interaction indicates true disease resistance and not simply increased flooding tolerance in Oneida. Oneida also showed fewer and less severe root lesions than Iroquois. Flooding increased both the incidence and severity of root lesions. The pathogen, Pmm, could be reisolated from root tissue in which disease symptoms were observed. Redox potentials indicated that anaerobic conditions developed quickly in both soil and vermiculite following flooding and that aerobic conditions were reestablished within one day in both media upon draining. Resistance to Phytophthora root rot is of value on new stands subjected to marginal flooding stress.
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Claims 11
Claim · model-written summary
One or two flooding cycles did not reduce alfalfa shoot dry matter yield.
- Taxon
- alfalfa
Medicago sativae0 - Treatment
- one or two 3‐day cycles of floodinge0
- Outcome
- dry matter yields of alfalfa shootse0
- Direction
- did not reducee0
- Qualifier
- At 26°Ce0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At 26°C, one or two 3‐day cycles of flooding with subsequent 4‐day drainage periods did not reduce dry matter yields of alfalfa shoots grown in either soil (mixed, mesic Typic Udipsamment) or vermiculite.”
Claim · model-written summary
Pmm inoculation significantly reduced Iroquois shoot yield.
- Taxon
- AlfalfaMedicago sativat0
- Material
- Iroquoise0
- Treatment
- Inoculation with Pmme0
- Interactor
- Pmme0pathogen
- Outcome
- shoot yield of Iroquoise0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Inoculation with Pmm significantly reduced the shoot yield of Iroquois, but not that of Oneida.”
t0“Alfalfa”
Claim · model-written summary
Pmm inoculation did not significantly reduce Oneida shoot yield.
- Taxon
- AlfalfaMedicago sativat0
- Material
- Oneidae0
- Treatment
- Inoculation with Pmme0
- Interactor
- Pmme0pathogen
- Outcome
- shoot yielde0
- Direction
- note0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Inoculation with Pmm significantly reduced the shoot yield of Iroquois, but not that of Oneida.”
t0“Alfalfa”
Claim · model-written summary
The inoculation by cultivar interaction indicated disease resistance in Oneida.
- Taxon
- AlfalfaMedicago sativat0
- Material
- Oneidae0
- Interactor
- Pmme0pathogen
- Outcome
- true disease resistancee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The presence of an interaction between Pmm inoculation and cultivar in the absence of a flooding × cultivar interaction indicates true disease resistance and not simply increased flooding tolerance in Oneida.”
t0“Alfalfa”
Claim · model-written summary
Oneida had fewer root lesions than Iroquois.
- Taxon
- AlfalfaMedicago sativat0
- Material
- Oneidae0
- Outcome
- root lesionse0
- Direction
- fewere0
- Comparator
- Iroquoise0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Oneida also showed fewer and less severe root lesions than Iroquois.”
t0“Alfalfa”
Claim · model-written summary
Oneida had less severe root lesions than Iroquois.
- Taxon
- AlfalfaMedicago sativat0
- Material
- Oneidae0
- Outcome
- root lesionse0
- Direction
- less severee0
- Comparator
- Iroquoise0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Oneida also showed fewer and less severe root lesions than Iroquois.”
t0“Alfalfa”
Claim · model-written summary
Flooding increased root lesion incidence and severity.
- Taxon
- AlfalfaMedicago sativat0
- Treatment
- Floodinge0
- Outcome
- incidence and severity of root lesionse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Flooding increased both the incidence and severity of root lesions.”
t0“Alfalfa”
Claim · model-written summary
Pmm was reisolated from symptomatic root tissue.
- Taxon
- AlfalfaMedicago sativat0
- Interactor
- Pmme0pathogen
- Outcome
- Pmm, could be reisolated from root tissuee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The pathogen, Pmm, could be reisolated from root tissue in which disease symptoms were observed.”
t0“Alfalfa”
Claim · model-written summary
Anaerobic conditions developed quickly after flooding in both growth media.
- Taxon
- AlfalfaMedicago sativat0
- Outcome
- anaerobic conditions developed quicklye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Redox potentials indicated that anaerobic conditions developed quickly in both soil and vermiculite following flooding”
t0“Alfalfa”
Claim · model-written summary
Aerobic conditions returned within one day of drainage in both media.
- Taxon
- AlfalfaMedicago sativat0
- Outcome
- aerobic conditions were reestablishede0
- Value
- one daye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“aerobic conditions were reestablished within one day in both media upon draining”
t0“Alfalfa”
Claim · model-written summary
Root rot resistance is valuable in new stands under marginal flooding.
- Taxon
- AlfalfaMedicago sativat0
- Outcome
- Resistance to Phytophthora root rote0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Resistance to Phytophthora root rot is of value on new stands subjected to marginal flooding stress.”
t0“Alfalfa”
The same questions in other papers
flooding · yield · Medicago sativa (alfalfa)Results differ
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See all 69 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.