Claim · model-written summary
Onion anthracnose appeared in the field when temperatures were 23° C- 30° C.
- Taxon
- onion
Allium cepat0 - Outcome
- the disease appearse0
- Qualifier
- during seasons when temperature is 23° C- 30° C.e0
- Setting
- In the fielde0
Not reportedMaterialGeneCompoundOrgan / stageInteractorInteractor roleSecond interactorSecond interactor roleTreatmentComparatorDirectionValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the field the disease appears during seasons when temperature is 23° C- 30° C.”
t0“onion”
Title
J. A. B. Nolla The Journal of Agriculture of the University of Puerto Rico 1926. doi:10.46429/jaupr.v10i3-4.15070
Other claims from this paper (19)
- Observation Onion leaves and bulb scales were affected by anthracnose.
- Observation Market onion was affected by anthracnose.
- Observation A multiplier variety of Allium cepa L. was affected by anthracnose.
- Observation Yellow, red and white onion varieties lacked resistance to anthracnose.
- Observation Tropical onion varieties were as susceptible as temperate-zone types.
- Observation Onion plants of all ages were equally susceptible.
- Observation Anthracnose lesions on onion leaves were elliptic or oval spots.
- Observation Young lesions on red onion varieties showed a red stain.
- Observation The onion anthracnose pathogen was described as the new species Colletotrichum Chardonianum.
- Observation The causal fungus grew excellently in carbohydrate media, especially starch-containing media.
- Observation Controlled infection experiments showed that C. Chardonianum produced onion disease.
- Mechanism Onion infection occurred primarily through stomata.
- Mechanism Pathogen germ tubes may penetrate onion cuticle.
- Observation C. Chardonianum conidia germinated in water at 21° C. in 3 1/2 to 4 1/2 hours.
- Observation Conidial germination produced primary, secondary and tertiary appresoria, as well as secondary conidia.
- Observation Temperatures of 18° C. and 33° C. seemed to inhibit pathogen conidial germination.
- Observation Pathogen conidia germinated readily at 25° C.
- Observation The onion pathogen grew best in synthetic culture media at 27° C.
- Observation The pathogen apparently survived between seasons as mycelium in soil debris; conidia seemed to resist sulphur fungicides, while copper fungicides were effective in laboratory experiments.