Pink Lady Apples Research Articles

First Report of Apple Rot Caused by Neofabraea alba in Chile.

A new rot of stored apples was observed in local and export markets on apples that were grown in the south-central region of Chile during 2004. Circular, pale brown spots with a darker outer ring were observed at least 3 months after harvest in cvs. Braeburn, Fuji, Granny Smith, Pink Lady, and Royal Gala. Lesions developed from lenticel cavities or wounds and reached 2 to 3 cm in diameter after 1 week at room temperature. Symptoms resembled those produced by the bull's eye rot pathogens on apple that occur in other parts of the world. Acervuli developed in the rotted areas, and microscopic examination revealed the presence of the fungus Neofabraea alba (Guthrie) (anamorph Phlyctema vagabunda Desm.) characterized by production of curved macroconidia and absence of microconidia (1). Pure culture on potato dextrose agar (PDA) yielded a characteristic white sterile mycelium. Four cv. Pink Lady apples were wound inoculated with mycelium of the pathogen and four apples were wound inoculated with a 5 × 104 CFU/ml conidial suspension. Four apples were wounded and inoculated with sterile water as a negative control. The fruit was held at 20°C. Symptoms appeared after 4 and 5 days in the mycelium and conidial inoculated apples, respectively. Resulting symptoms were similar to those originally observed. Abundant macroconidia were produced at the inoculation sites, and a sterile, white mycelium was recovered after isolation on PDA. To our knowledge, this is the first report of apple fruit rot caused by N. alba in Chile. Reference: (1) J. L. Henriquez et al. Plant Dis. 88:1134, 2004.

FLESH BROWNING IN PINK LADY™ APPLES: RESEARCH RESULTS HAVE HELPED TO CHANGE MARKET SPECIFICATIONS FOR BLUSH COLOUR WHICH IS AN ADDED BONUS FOR GROWERS

ISHS International Conference Postharvest Unlimited Downunder 2004 FLESH BROWNING IN PINK LADY™ APPLES: RESEARCH RESULTS HAVE HELPED TO CHANGE MARKET SPECIFICATIONS FOR BLUSH COLOUR WHICH IS AN ADDED BONUS FOR GROWERS

RETAIN® MAINTAINS ´PINK LADY´™ FRUIT QUALITY DURING LONG TERM STORAGE

'Pink Lady' apples were harvested from two growing regions (South Australia and Victoria) and at two harvest maturities (early and late). Fruit were treated with aminoethoxyvinylglycine (AVG, ReTain®) at two different times in the orchard (7 and 21 days before harvest). Fruit were harvested according to maturity and stored at 0°C in controlled atmosphere (CA) storage (2% O 2 and 1% CO 2 ) or regular air storage. Fruit quality (internal ethylene concentration, firmness, background colour, starch, soluble solids content) were assessed at two monthly intervals for up 10 months storage. Fruit were subject to a two week shelf life at 20°C after six months storage. All air stored fruit were removed at six months storage. The ReTain® treatment significantly reduced ethylene production across all treatment and storage regimes, compared to the untreated control. Ethylene production was also lower in the ReTain® treatments during the 14 days shelf life at 20°C after six months storage. Flesh firmness (measured by penetrometer) was generally higher in the fruit stored in CA and in the ReTain® treated fruit. This effect was maintained during the entire storage period. The results show that the preharvest application of ReTain® on 'Pink Lady apples can be a useful tool for managing harvest and ensuring postharvest fruit quality after both air and CA storage.

MODELLING FRUIT QUALITY IN VARIABLE TEMPERATURE SCENARIOS: CAN WE ASSUME HISTORY INDEPENDENCE?

ISHS III International Symposium on Applications of Modelling as an Innovative Technology in the Agri-Food Chain; MODEL-IT MODELLING FRUIT QUALITY IN VARIABLE TEMPERATURE SCENARIOS: CAN WE ASSUME HISTORY INDEPENDENCE?

Identifying defects in images of rotating apples

An experimental machine vision system was used to identify surface defects on apples, including bruises. Images were captured through two optical filters at 740 and 950 nm, respectively. In the ensuing grey scale images, defects appeared as dark areas, however, so did shadows and parts of the stem/calyx area. This paper reports a novel approach to locate the defects and eliminate other dark areas. The method is based on rotating the apples in front of the camera while multiple images are acquired. Dark areas, which are found at the same position, relative to the apple, during the rotation, represent defects, while other dark areas, which change shape and/or position from one frame to the next, are not classified as defects. In a test using 54 Pink Lady apples with 56 defects, the system successfully detected 52, or 92% while providing two false positive. In another test with Ginger Gold Apples, where the rotation technique was combined with images of the stem and calyx regions, 90% of the defects were detected with no false positives.

Delay in ripening of Gala and Pink Lady apples in commercial orchards following pre-harvest applications of aminoethoxyvinylglycine

Aminoethoxyvinylglycine (AVG) was applied to Gala and Pink Lady apple trees on commercial orchards at label rates (830 g/ha ReTain with 0.1% v/v organosilicone surfactant) 21–28 days before anticipated first harvest. Fruit from treated and untreated trees in each orchard were sampled weekly during the commercial harvest period (2–6 times) and assessed for starch pattern index, background colour, soluble solids and flesh firmness. Ripening of AVG-treated Gala apples was delayed by 9–12 days based on starch pattern index and background colour whereas fruit softening was delayed by 5 days. Ripening of AVG-treated Pink Lady apples was delayed by 5 days based on SPI and fruit softening was delayed by 7 days. These differential delays for starch pattern index and fruit softening did not adversely affect the fruit quality of either apple variety, as there was no difference between the flesh firmness of treated and untreated fruit when fruit of the same starch pattern index were compared. Regardless of treatment, Gala apples grew an average 1.16 g per day during the harvest period whereas Pink Lady apples grew an average 0.22 g per day. These results suggest AVG has major benefits as a harvest management tool, as it allows growers to regulate fruit ripening.

Correlation between electronic nose signals and fruit quality indicators on shelf-life measurements with pinklady apples

In this work, an electronic nose is used to assess the ripeness state of pinklady apples through their shelf-life. In order to evaluate the electronic nose performance, fruit quality indicators are also obtained to compare results from both techniques. Pinklady apples were harvested at their optimal date so that electronic nose measurements and fruit quality measurements could be performed on the fruit samples during their ripening process. A PCA analysis, a well-known linear classification technique, does not show any clustering behaviour that might be attributed to ripening. On the other hand, Fuzzy art, an unsupervised neural network classification algorithm, shows a tendency to classify measurements regarding to their shelf-life period. Finally, electronic nose signals are correlated with classical fruit quality parameters such as firmness, starch index and acidity. Good correlation coefficients are obtained, a clear indication that electronic nose signals are related to the ripening process of apples.

Evaluation of a non-chemical disinfestation treatment on quality of pome fruit and mortality of lepidopterous pests

Australian pome fruit exports to northern America and Japan are rejected if they contain lightbrown apple moth (Epiphyas postvittana Walker) or codling moth (Cydia pomonella Linnaeus) respectively. A warm controlled atmosphere (CA) disinfestation treatment (72 h at 28˚C at 0, 1 or 2 kPa O2 ), followed by varying lengths of cold storage (5 weeks, 10 weeks or 6 months), is described. Four cultivars were studied: Packham’s Triumph pears (Pyrus communis Linnaeus); Royal Gala; Fuji and Pink Lady apples (Malus domestica Borkh.). Consumer panels found that fruit subjected to the 2 kPa O2 warm CA treatment and cold storage were as acceptable as control fruit. This is an important finding as previously published results for a harsher treatment described treated fruit (especially Pink Lady) as being less acceptable than controls. Some advanced ripening was observed for treated Packham’s Triumph pears. After 5 and 10 weeks cold storage, treated Royal Gala apples were generally firmer than the controls. Insects were also subjected to the 2 kPa O2 warm CA treatment. The most tolerant life stage (MTS) of lightbrown apple moth was the sixth instar with an LT95 of 37 days cold storage (0.5˚C) after the 2 kPa O2 warm CA treatment. Comparison with previous research suggests that the 2 kPa O2 warm CA treatment approximately halves the time required in cold storage for effective control of late instar lightbrown apple moth. A LT95 of 81 days was achieved for fifth instar codling moths (considered to be the MTS) and this may need to be reduced for export to Japan. Preliminary observations suggested that there may not be substantial difference between the resistance of non-diapausing and pre-diapausing codling moth larvae to the warm CA followed by cold treatment.