Six-spotted mite and its predators on sprayed and unsprayed ‘Hass’ avocado trees

The effect of storage temperature on the shelf life, weight loss, respiration rate and ethylene production of Hass avocado (Persea americana Mill) was studied. Two batches of green mature avocado fruits, classified as ‘‘super extra’’ were stored at 10 and 20 C (first batch) and at 7 and 25 C (second batch). The avocado shelf lives were 22, 8, 32 and 6 days at 10, 20, 7 and 25 C, respectively. Based on the data of the first assay Q10 was calculated as 2.75, with this value the predicted shelf life at 7 and 25 C were 29.8 and 4.8 days, respectively. That meant shelf life was underestimated 7 and 20% at 7 and 25 C, respectively. Weight loss was linear at both the storage temperatures, it was 4.3% in fruits at 20 C for 8 days and 3.0% at 10 C for 22 days. The maximum CO2 production at 20 C was reached during the second day of storage, while at 10 C it was reached at the 17th day (176.17 15.98 and 74.73 7.32 mL/kg h, respectively). The maximum ethylene production at 20 C was reached the second day of storage, and at 10 C the 6th day (239.06 54.55 and 28.00 8.12 mL/kg h, respectively).

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DYNAMIC CONTROLLED ATMOSPHERE STORAGE OF NEW ZEALAND-GROWN 'HASS' AVOCADO FRUIT

Acta Horticulturae ◽

10.17660/actahortic.2010.876.4 ◽

2010 ◽

pp. 47-54 ◽

Cited By ~ 2

Author(s):

J. Burdon ◽

N. Lallu ◽

G. Haynes ◽

P. Pidakala ◽

D. Billing ◽

...

Keyword(s):

New Zealand ◽

Controlled Atmosphere ◽

Controlled Atmosphere Storage ◽

Avocado Fruit ◽

Hass Avocado ◽

Atmosphere Storage

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Between-tree variation in fruit quality and fruit mineral concentrations of Hass avocados

Australian Journal of Experimental Agriculture ◽

10.1071/ea04051 ◽

2006 ◽

Vol 46 (9) ◽

pp. 1195 ◽

Cited By ~ 4

Author(s):

J. R. Marques ◽

P. J. Hofman ◽

A. H. Wearing

Keyword(s):

Fruit Quality ◽

Cold Storage ◽

Dry Matter ◽

Fruit Body ◽

Conclusive Evidence ◽

Skin Area ◽

Calcium Magnesium ◽

Hass Avocado ◽

Individual Trees ◽

Mineral Concentrations

Inconsistent internal fruit quality in Hass avocados affects consumer confidence. To determine the influence of individual trees on fruit quality, Hass avocado fruit were harvested from adjacent trees of similar external appearance in 3 commercial orchards in 1998 and 1 orchard in 1999. The trees in each orchard were grown with similar commercial practices and in similar soil types. Within each location, there were significant (P<0.05) differences in the mean ripe fruit quality between trees with respect to fruit body rot severity (mainly anthracnose) with and without cold storage, internal disorders severity due to diffuse discolouration and vascular browning (after cold storage), days to ripen, percentage dry matter, and the percentage of the skin area with purple-black colour when ripe. These effects were also noted in the same orchard in 1999. There were significant (P<0.05) differences in fruit flesh calcium, magnesium, potassium, boron and zinc concentrations between trees. Significant (P<0.05) correlations were observed between average fruit mineral concentrations in each tree (particularly calcium, magnesium and potassium) and body rot severity, percentage dry matter and fruit mass. There was little conclusive evidence that characteristics such as the growth of the non-suberised roots or the degree of scion under- or overgrowth was involved in these tree effects; however, differences between trees with respect to other rootstock characteristics may be involved. The inconsistency of the correlations across sites and years suggested that other factors apart from tree influences could also affect the relationship between fruit minerals and fruit quality.

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Characterization and Pathogenicity of Botryosphaeriaceae Species Obtained from Avocado Trees with Branch Canker and Dieback and from Avocado Fruit with Stem End Rot in Chile

Plant Disease ◽

10.1094/pdis-07-18-1131-re ◽

2019 ◽

Vol 103 (5) ◽

pp. 996-1005 ◽

Cited By ~ 8

Author(s):

Ana L. Valencia ◽

Pilar M. Gil ◽

Bernardo A. Latorre ◽

I. Marlene Rosales

Keyword(s):

Vascular System ◽

Persea Americana ◽

Effective Control ◽

Future Research ◽

Severe Drought ◽

Internal Transcribed Spacer Region ◽

Avocado Fruit ◽

Hass Avocado ◽

Botryosphaeriaceae Species ◽

Branch Canker

Several species of the Botryosphaeriaceae family have been associated with branch canker, dieback, and stem end rot in avocado (Persea americana Mill.). In Chile, the incidence of diseases affecting the avocado tree increased from 2011 to 2016, which coincided with a severe drought that affected avocado production. Moreover, distant countries importing avocados from Chile also reported an increase of stem end rot of ripe avocados. Therefore, the aims of this study were to identify the pathogen species associated with branch canker, dieback, and stem end rot of avocado in Chile and to study their pathogenicity. This study was conducted between 2015 and 2016 in ‘Hass’ avocado orchards located in the main avocado-producing regions in Chile. A diverse collection of fungal species was recovered from both necrotic woody tissue and necrotic tissue on harvested ripe fruit. On the basis of morphology and phylogenetic analyses of the internal transcribed spacer region (ITS1-5.8S-ITS2) and the translation elongation factor 1-α (TEF1-α) gene, eight species in the Botryosphaeriaceae family were identified: Diplodia mutila, D. pseudoseriata, D. seriata, Dothiorella iberica, Lasiodiplodia theobromae, Neofusicoccum australe, N. nonquaesitum, and N. parvum. For each of these species, pathogenicity studies were conducted on 1-year-old healthy Hass avocado plants. All isolates produced brown gum exudate and caused necrosis in the vascular system 3 weeks after inoculation. N. nonquaesitum, N. parvum, and D. pseudoseriata were the most virulent species. Necrotic lesions and cavities with white mycelia near the peduncle union were observed on Hass avocado fruit inoculated postharvest. L. theobromae, N. australe, and N. parvum were significantly more virulent than the other tested species in the Botryosphaeriaceae family. This study identified and characterized the pathogenicity of Botryosphaeriaceae species in Chile, which will prove useful to future research on these pathogens directed at establishing effective control strategies in avocado.

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