Articles
Colletotrichum acutatum infection in ‘Arbequina’ olive fruits under severe drought stress
Article number
1446_37
Pages
275 – 284
Language
English
Abstract
Olive anthracnose caused by Colletotrichum spp. is the most widely spread and economically significant olive fruit disease.
The olive tree is a crop with high tolerance to water deficit.
However, the length and intensity of water deficit determine olive productive and phytosanitary responses.
Plants exposed to moderate drought stress activate basal defense responses allowing plants to react against pathogen infection.
Particularly in olive fruits, moderate drought contributed to increase tolerance to Colletotrichum acutatum infection.
However, the effect of severe drought on fruit parameters and disease progress is unknown.
To unravel these effects, an experiment in six drainage lysimeters under controlled irrigation conditions (rain-out shelter) with ‘Arbequina’ olive trees was established along two consecutive seasons.
Two treatments were imposed: fully irrigated and non-irrigated from the end of pit hardening until harvest.
At harvest olives were assessed for fruit quality and a subsample was inoculated with an isolate of C. acutatum to evaluate disease progress in vitro.
Fruit moisture was significantly different among treatments, in non-irrigated it was <43% and in fully irrigated >64%. Fruit yield (kg tree‑1) doubled and fresh fruit weight (g) tripled in the fully irrigated treatment compared to the non-irrigated one.
Also, oil yield content in dry bases showed higher values in fully irrigated treatment.
Disease severity progress was shown to be half in non-irrigated treatment samples at the 6th day after inoculation compared with fully irrigated samples.
Severe drought stress was found to significantly reduce olive oil yield, but the fruits showed increased tolerance to anthracnose fruit rot.
These results underscore the importance of studying how abiotic stress, such as drought, can elicit defense mechanisms in plants.
The olive tree is a crop with high tolerance to water deficit.
However, the length and intensity of water deficit determine olive productive and phytosanitary responses.
Plants exposed to moderate drought stress activate basal defense responses allowing plants to react against pathogen infection.
Particularly in olive fruits, moderate drought contributed to increase tolerance to Colletotrichum acutatum infection.
However, the effect of severe drought on fruit parameters and disease progress is unknown.
To unravel these effects, an experiment in six drainage lysimeters under controlled irrigation conditions (rain-out shelter) with ‘Arbequina’ olive trees was established along two consecutive seasons.
Two treatments were imposed: fully irrigated and non-irrigated from the end of pit hardening until harvest.
At harvest olives were assessed for fruit quality and a subsample was inoculated with an isolate of C. acutatum to evaluate disease progress in vitro.
Fruit moisture was significantly different among treatments, in non-irrigated it was <43% and in fully irrigated >64%. Fruit yield (kg tree‑1) doubled and fresh fruit weight (g) tripled in the fully irrigated treatment compared to the non-irrigated one.
Also, oil yield content in dry bases showed higher values in fully irrigated treatment.
Disease severity progress was shown to be half in non-irrigated treatment samples at the 6th day after inoculation compared with fully irrigated samples.
Severe drought stress was found to significantly reduce olive oil yield, but the fruits showed increased tolerance to anthracnose fruit rot.
These results underscore the importance of studying how abiotic stress, such as drought, can elicit defense mechanisms in plants.
Publication
Authors
P. Conde-Innamorato, O. Borsani, J.J. Villamil, C. García, J. Girona, C. Leoni, M. Arias-Sibillote, G.P. García-Inza
Keywords
anthracnose, disease severity, lysimeter, oil content, Olea europaea L.
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