The decay setting: Some structural, chemical, and moisture features of wood features of wood in relation to decay development

During a survey of postharvest diseases in Red Delicious apples (Malus domestica) conducted in 2003, a previously undescribed postharvest fruit rot was discovered in Washington State. The causal agent has been described as a new species, Phacidiopycnis washingtonensis. In this study, we described the symptomatology of this disease, determined its occurrence and prevalence in Washington State, tested pathogenicity, and determined infection courts on fruit of three apple varieties. Decayed fruit were sampled from 26, 72, and 81 grower lots during March to August in 2003, 2004, and 2005, respectively, during packing operations from commercial packinghouses. Symptoms of decayed fruit were recorded and isolations were made from decayed fruit to correlate causal agents with the disease symptoms observed. Fruit of Red Delicious, Golden Delicious, and Fuji apples were inoculated in the orchards with conidial suspensions of the fungus at 1 and 2 weeks before harvest. All fruit were harvested and stored at 0°C, and decay development on the fruit was monitored monthly for up to 9 months. The symptoms were primarily stem-end rot and calyx-end rot. Infection also occurred at lenticels on fruit skin, particularly on Golden Delicious. The decayed area was spongy to firm and appeared light brown to brown. On Red Delicious, brown to black specks at lenticels often appeared at the decayed area as the disease advanced. This disease occurred in 23, 26, and 17% of the total grower lots, accounting for approximately 1, 4, and 3% of the total decay in 2003, 2004, and 2005, respectively. In 2004 and 2005, severe losses of fruit were observed in three grower lots of Red Delicious, and their losses were as high as 24%. After 9 months in storage, 48, 48, and 24% of Red Delicious, Golden Delicious, and Fuji that were inoculated in the orchards, respectively, developed symptoms of this disease, and the fungus was reisolated from decayed fruit. Stem-end rot was common on Red Delicious and Golden Delicious, whereas calyx-end rot was common on Fuji. We propose “speck rot” as the name of this disease.

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The effect of ambient pH modulation on ochratoxin A accumulation by Aspergillus carbonarius

World Mycotoxin Journal ◽

10.3920/wmj2017.2200 ◽

2017 ◽

Vol 10 (4) ◽

pp. 339-348 ◽

Cited By ~ 8

Author(s):

U. Maor ◽

S. Sadhasivam ◽

V. Zakin ◽

D. Prusky ◽

E. Sionov

Keyword(s):

Ochratoxin A ◽

Molecular Mechanisms ◽

Growth Conditions ◽

Aspergillus Carbonarius ◽

High Accumulation ◽

Host Environment ◽

Expression Of Genes ◽

Regulatory Signal ◽

Concomitant Reduction ◽

Decay Development

Aspergillus carbonarius, the main cause of severe post-harvest decay of vine fruit, is considered the major source of ochratoxin A (OTA) contamination of grapes and derived products. The factors inducing OTA accumulation by A. carbonarius and its contribution to pathogenicity remain unclear. Present findings indicate that the production of organic acids, such as D-gluconic acid (GLA) and citric acid, by A. carbonarius in the growth medium or in the decayed fruit tissue was directly related to ambient pH reduction. Under these conditions, induced transcript expression of genes involved in OTA biosynthesis occurred concurrently with mycotoxin accumulation. The high accumulation of OTA during acidification process raised the question of its importance in host-pathogen interactions during the fungal colonisation. Treatment of colonised grapes with sodium bicarbonate reduced accumulation of organic acid and OTA with a concomitant reduction in decay development, suggesting that tissue acidification is a significant factor in A. carbonarius pathogenicity. The present findings suggest that ambient pH is a regulatory signal for induction of mycotoxin production by A. carbonarius under the dynamic nutritional growth conditions occurring in culture. Yet the molecular mechanisms of OTA biosynthesis induction during colonisation of the acidic host environment are still unclear and should be further investigated.

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Fruit Maturity and Storage Temperature Influence Response of Strawberries to Controlled Atmospheres

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.127.5.836 ◽

2002 ◽

Vol 127 (5) ◽

pp. 836-842 ◽

Cited By ~ 29

Author(s):

M.C.N. Nunes ◽

A.M.M.B. Morais ◽

J.K. Brecht ◽

S.A. Sargent

Keyword(s):

Storage Temperature ◽

Soluble Solids ◽

Temperature Influence ◽

Total Anthocyanin ◽

Controlled Atmospheres ◽

C Storage ◽

Fruit Maturity ◽

Lower Temperature ◽

And Storage ◽

Decay Development

`Chandler' strawberries (Fragaria ×ananassa Duch.) harvested three-quarter colored or fully red were stored in air or a controlled atmosphere (CA) of 5% O2 + 15% CO2 at 4 or 10 °C to evaluate the influence of fruit maturity and storage temperature on the response to CA. Quality evaluations were made after 1 and 2 weeks in air or CA, and also after 1 and 2 weeks in air or CA plus 1 day in air at 20 °C. By 2 weeks, strawberries of both maturities stored in air at 10 °C were decayed, however, strawberries stored in CA at 4 or 10 °C or air at 4 °C had no decay even after 2 weeks plus 1 day at 20 °C. Three-quarter colored fruit stored in either air or CA remained firmer, lighter (higher L* value) and purer red (higher hue and chroma values) than fully red fruit, with the most pronounced effect being on CA-stored fruit at 4 °C. CA was more effective than air storage in maintaining initial anthocyanin and soluble solids contents (SSC) of three-quarter colored fruit and fruit stored at 10 °C. Strawberries harvested three-quarter colored maintained initial hue and chroma values for 2 weeks in CA at 4 °C, becoming fully red only when transferred to air at 20 °C. Although three-quarter colored fruit darkened and softened in 10 °C storage, the CA-stored fruit remained lighter colored and as firm as the at-harvest values of fully red fruit. After 1 or 2 weeks in CA at either 4 or 10 °C plus 1 day at 20 °C, three-quarter colored fruit also had similar SSC levels but lower total anthocyanin contents than the initial levels in fully red fruit. CA maintained better strawberry quality than air storage even at an above optimum storage temperature of 10 °C, but CA was more effective at the lower temperature of 4 °C. Three-quarter colored fruit responded better to CA than fully red fruit, maintaining better appearance, firmness, and color over 2 weeks storage, while achieving similar acidity and SSC with minimal decay development.

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The Management of Tree Root Systems in Urban and Suburban Settings II: A Review of Strategies to Mitigate Human Impacts

Arboriculture & Urban Forestry ◽

10.48044/jauf.2014.025 ◽

2014 ◽

Vol 40 (5) ◽

Author(s):

Gary Watson ◽

Angela Hewitt ◽

Melissa Custic ◽

Marvin Lo

Keyword(s):

Urban Areas ◽

Human Impacts ◽

Natural Infection ◽

Root Systems ◽

Sewer Pipe ◽

Root Space ◽

Tree Roots ◽

Tree Health ◽

Urban Tree ◽

Decay Development

Root systems of nearly all trees in the built environment are subject to impacts of human activities that can affect tree health and reduce longevity. These influences are present from early stages of nursery development and throughout the life of the tree. Reduced root systems from root loss or constriction can reduce stability and increase stress. Natural infection of urban tree roots after severing has not been shown to lead to extensive decay development. Roots often conflict with infrastructure in urban areas because of proximity. Strategies to provide root space under pavements and to reduce pavement heaving have been developed, but strategies for prevention of foundation and sewer pipe damage are limited to increasing separation or improved construction.

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