Development Of Red Blush Research Articles

Generative and Vegetative Traits of the 'Granny Smith' Apple Grown under an Anti-Insect Photoselective Red Net

Anti-insect photoselective nets present a new technology that combines light manipulation and pest protection in orchards. In this study, the effect of the anti-insect photoselective red net on the generative and vegetative traits was studied in an apple orchard near the city of Zadar, Croatia. 'Granny Smith' apples were grown on M9 rootstock and raised as slender spindles. The experiment consisted of two treatments: the trees covered with the red photoselective anti-insect nets (AGRITECH S. r. l., Eboli, Italy; mesh size of 2.4 × 4.8 mm) and uncovered trees as control. Yield, percentage of fruit with diameter >70 mm and fruit mass were not significantly different between treatments. L* color value was higher on fruit skin grown under the red net, and there was no significant difference in other color values (a*, b*, C* and h°). Soluble solids concentration (SSC) and total flavonoid content were significantly lower in fruit grown under red net than in control, and there was no significant difference in titratable acidity (TA), SSC/TA ratio, starch degradation and Streif maturity index. Red net proved to be effective against fruit red blush development (undesirable trait for 'Granny Smith' apple) and sunburn damage occurrence.

The effects of plant growth regulators on red blush development on peel of mango ‘Mahachanok’

'Mahachanok' mango is accounted as one of the most important Thai mango cultivars for export. 'Mahachanok' mango has an attractive red blush peel preferred by consumers. The development of red blush on the mango peel is related to many factors such as sunlight, temperature and some kinds of plant growth regulators (PGRs). In this study, the application of 100-2,000 mg L(‑1) jasmonic acid or 14 mg L(‑1) salicylic acid on 'Mahachanok' mango at 55-60 days after flowering and also the sunlight exposure which affected to the red blush development was investigated. The results showed that the fruit at outside of the canopy had more intense red blush compared to the fruit at inside of the canopy. The application of 300 mg L(‑1) jasmonic acid to the fruit at outside of the canopy and bagged showed the most intense red blush with the anthocyanin of 0.09-0.53 mg 100 g(‑1) FW and more red blush peel fruit than the other PGR treatments. Moreover, this treatment had no effect on fruit quality after ripening. The smell and taste were normal with soluble solids of 14.1-14.4% and titratable acidity of 0.21-0.26%. However, the control group for which the fruits were applied by water at the outside of the canopy, and had no bagging, also showed intense red blush and were sometimes better than those fruits applied with 300 mg L(‑1) jasmonic acid and bagging. This revealed that the sunlight exposure has more impact to the red blush development than with PGR application. Therefore, the most effective way to promote red blush development on the bagged mango is to use the effective PGR together with orchard management (shrub pruning) that lets the fruits expose to sunlight.

Biochemical and Gene Expression Involved in Red Blush Color Development in ‘Ambrosia’ Apple

The market value of the apple (Malus ×domestica Borkh.) cultivar Ambrosia is closely linked to the characteristic blush on the skin surface. For ‘Ambrosia’ orchards that produce consistently low levels of surface blush, the implementation of reflective rowcovering has improved surface coloration, but the reflected wavebands responsible for this enhanced color production have not been confirmed. This study consisted of two separate experiments: one conducted in the field to confirm reflective rowcovering efficacy and the other in a controlled environment cabinet to determine which waveband was enhancing red blush production. The red blush production in orchards with and without reflective rowcovering was then directly compared with the red blush produced on the surface of apples that were poorly colored at harvest and then exposed to visible, fluorescent, ultraviolet A (UVA), or ultraviolet B (UVB) light sources within the controlled environment chamber. Consequent analysis of the red blush color within the Commission Internationale de l’Eclairage a* and b* color space was conducted to evaluate the quality of the red blush pigment under each treatment in the field and the controlled environment chamber. The analysis revealed that the red blush that developed on apples from the reflective rowcover treatment most closely matched the red blush that developed in response to UVB exposure in the controlled environment cabinet. Further analysis of gene expression and anthocyanin contents in the ‘Ambrosia’ apples support the hypothesis that the primary driver for the characteristic red blush development, when reflective rowcovers are used, is increased exposure to UVB light.

Pre-harvest spray application of phenylpropanoids influences accumulation of anthocyanin and flavonoids in ‘Cripps Pink’ apple skin

Abstract Poor colour development on ‘Cripps Pink’ apple fruit causes serious economic losses to the growers in the warmer regions of the world. Effects of pre-harvest spray application of different concentrations (0, 50, 100, or 200 mg L−1) of cinnamic acid, p-coumaric acid, d -phenylalanine, l -phenylalanine, and naringenin, on red blush development on the fruit surface and accumulation of anthocyanins, dihydrochalcones, hydroxycinnamic acid, flavanols, and flavonols, in the skin of ‘Cripps Pink’ apple at commercial fruit maturity were investigated. Skin of apple fruit harvested from the trees sprayed with l -phenylalanine or cinnamic acid contained significantly higher concentrations of total anthocyanins, cyanidin 3-galactoside, and flavonols, compared to control and to those treated with other phenylpropanoids, in a dose- independent pattern. Based on tristimulus system of colour perception {i.e. chromaticity values such as L*, a*, b*, chroma (C*), and hue angle (h°)}, a similar trend of red blush development was observed on fruit’s exterior at commercial maturity, in response to pre-harvest spray application of phenylpropanoids. The apple fruit harvested from the trees sprayed with l -phenylalanine or cinnamic acid had the highest values of a* and the lowest values of h° for colour perception on the exposed side of apple fruit, irrespective of their doses applied, indicating a substantial trend of red blush intensification on the fruit surface. In conclusion, a single pre-harvest spray application of l -phenylalanine (100 mg L−1), applied 3–4 weeks prior to the anticipated commercial fruit maturity was most effective in improving red blush development, increased production of export-grade fruit, accumulation of total anthocyanins, cyanidin 3-galactoside, flavanols, chlorogenic acid and flavonols in the fruit skin, without adversely affecting the fruit quality.

Time of methyl jasmonate application influences the development of ‘Cripps Pink’ apple fruit colour

The effects of time and numbers of pre-harvest sprays of methyl jasmonate (MJ) on the development of red blush, export-grade fruit, accumulation of flavonoids in fruit skin and quality of 'Cripps Pink' apple were investigated in 2005 and 2006. In the first experiment during 2005, whole trees were sprayed once with 10 mmol L(-1) MJ at weekly intervals from 155 to 183 days after full bloom (DAFB). In second experiment during 2006, different numbers of sprays (0, 1, 2, 3, 4, 5 or 6) of 5 mmol L(-1) MJ were applied from 151 to 179 DAFB. A single spray of MJ (10 mmol L(-1)) at 169 DAFB resulted in the highest increase in the red blush, export-grade fruit, accumulation of anthocyanins, cyanidin 3-galactosides, chlorogenic acid, phloridzin, flavanols and flavonols in fruit skin as compared to all other treatments without affecting fruit quality. A single spray of 5 mmol L(-1) MJ at 186 DAFB was more effective in improving red blush, export-grade fruit and accumulation of anthocyanins in fruit skin as compared to its multiple applications. The exposed sides of fruit developed better colour than the shaded sides, regardless of time and numbers of MJ sprays. Time of a single spray of MJ is more effective than its multiple applications. A single pre-harvest spray of MJ (10 mmol L(-1)) at 169 DAFB or MJ (5 mmol L(-1)) at 186 DAFB was effective in improving the red blush and export grade fruit through accumulation of flavonoids in fruit skin without adversely affecting quality at harvest.

Delayed harvest improves red blush development and quality of ‘Cripps Pink’ apple

The poor red blush development on ‘Cripps Pink’ ( Malus x domestica Borkh.) apple fruit at commercial maturity (CM) reduces the economic return to apple growers in warmer regions of the world. The effects of delayed harvest maturity up to 6 weeks following CM on the development of red blush and fruit quality of ‘Cripps Pink’ apple were investigated at two locations in Western Australia during 2003 and 2004. The red blush, export-grade fruit, total anthocyanin, cyanidin 3-galactoside, chlorogenic acid, catechin, and epicatechin of apple fruit skin tissues increased with advancement of harvest maturity at both locations in both years, whereas hue angle, concentration of phloridzin, fruit firmness, and titratable acidity (TA) of apple fruit tissues decreased with delayed harvest. The internal ethylene concentration was elevated with the delayed harvest. The concentrations of quercetin 3-galactoside, quercetin 3-arabinoside, quercetin 3-rutinoside, quercetin 3-rhamnoside, and quercetin 3-glucoside increased up to 2 weeks following CM, and then declined in 2003 at both locations and at Perth Hills in 2004. Delayed harvest resulted in improved development of red blush on the fruit surface, accumulation of total anthocyanin, cyanidin 3-galactoside, chlorogenic acid, catechin, epicatechin, and quercetin glycosides in fruit skin, SSC:TA ratio and reduced fruit firmness possibly due to the increased ethylene production.

Pre-harvest spray application of methyl jasmonate improves red blush and flavonoid content in ‘Cripps Pink’ apple

SummaryPoor and erratic red blush development in ‘Cripps Pink’ apple causes serious economic losses to growers. The effects of a single pre-harvest spray application of various methyl jasmonate (MJ) emulsions on the development of red blush and fruit quality in ‘Cripps Pink’ apple were investigated at three locations. In the first and second experiments, during 2005, apple trees were sprayed separately with 0.0, 1.0, 5.0, 10.0, or 15.0 mM MJ at Perth Hills (PH) and at Manjimup (MM). In the third and fourth experiments, during 2006, 0.0, 1.25, 2.5, 5.0, or 10.0 mM MJ was sprayed separately at PH and at Donnybrook (DB). In 2005, at PH and MM, fruit treated with 1.0 mM or 5.0 mM MJ exhibited the greatest increases in red blush, in the percentage of export-grade fruit, and in the levels of total anthocyanins, cyanidin 3-galactoside, chlorogenic acid, phloridzin, flavanols, and flavonols. In 2006, at PH, the maximum improvement in red blush, in the percentage of export-grade fruit, and in the accumulation of total anthocyanins and colour parameters (lower CIE L* and hº values, and higher a* and C* values) were achieved with a 1.25 mM MJ spray application. In contrast, at DB, the same results were achieved with 5.0 mM MJ. In both years, fruit quality (i.e., firmness, and the soluble solids concentration: titratable acidity ratio) was not significantly influenced by the application of MJ. In conclusion, a single pre-harvest application of 1.0 – 5.0 mM MJ emulsion improved the development of red blush, the accumulation of total anythocyanins, and the level of flavonoids in fruit skin, without affecting fruit quality at commercial harvest. Orchard location also had a significant influence on the efficacy of the application of MJ on the development of red blush and on the level of flavonoids in ‘Cripps Pink’ apple.

TRAINING SYSTEMS AND PRE-HARVEST ETHREL APPLICATION AFFECT FRUIT COLOUR DEVELOPMENT AND QUALITY OF 'PINK LADY™' APPLE AT HARVEST AND IN CONTROLLED ATMOSPHERE STORAGE

Development of poor red blush on the surface of apple (Malus × domestica Borkh.) fruit at commercial harvest is one of the major limiting factors for theirexport. Ethylene has been reported to directly affect accumulation of red pigments and development of red blush in many fruit crops including apple. The efficacy of an ethylene releasing compound – ethrel (ethephon) for the improvement of red blush of ‘Pink Lady’ apple fruit from the trees trained as vase (VS), central leader (CL), spindle bush (SB) and double row (DR) systems, was investigated at harvest in 2005. The influence of ethrel treatment on important quality parameters such as fruit firmness, soluble solids content (SSC) and titratable acidity (TA) was also studied at harvest and following 190 days controlled atmosphere (CA) storage. Pre-harvest ethrel spray significantly increased the concentrations of total anthocyanin and cyanidin 3-galactoside in the fruit skin and improved red blush and chromaticity values a*, C* and h° of the fruit colour at commercial harvest, irrespective of the training systems. Ethrel treatment increased the concentration of total anthocyanin nearly two fold in the skin of the exposed side (ES) of the fruit from the trees trainedas SB, compared to control. There were no significant differences in fruit firmness, SSC or TA of the fruit harvested from ethrel-treated and control trees trained on any of the systems, at commercial harvest. Following 190 days CA storage, ethrel treatment slightly increased SSC and TA of the fruit compared to control, whereas fruit firmness was not consistently influenced by ethrel treatment. In conclusion, preharvest ethrel spray application improves the development of red blush in ‘Pink Lady’ apple fruit at commercial harvest irrespective of training system without adversely affecting fruit quality at harvest or following 190 days CA storage.

Ethylene Biosynthesis and Fruit Color Development in `Pink Lady' Apples during Growth and Maturation

Growth and maturation of `Pink Lady' (Malus domestica Borkh.) apples with special emphasis on ethylene biosynthesis and color development were monitored in Western Australia during 2002-2003. Changes in fruit growth, respiration rate, ethylene production, anthocyanin accumulation and development of red blush were evaluated between 60 days after full bloom (DAFB) and commercial harvest (191DAFB). Fruit diameter, length and fresh weight showed the typical single sigmoid growth curve, with linear increases until 158 DAFB. High respiration rate and ethylene production were recorded 60 DAFB followed by rapid decrease until 144 DAFB and then a steady increase, which peaked between 172 and 179 DAFB. Red blush on the fruit surface showed steady increase from 167 DAFB and corresponded to concomitant decrease in hue angle. Total anthocyanin increased from 167 DAFB till harvest and synchronized with increasing ethylene and maturity of apples. There were significant (P ≤ 0.001), direct linear relationships between ethylene production and total anthocyanin (r = 0.63, y = 7.6032x + 2.4756), total anthocyanin and red blush (r = 0.74, y = 0.5082x -1.54). Significant (P ≤ 0.001) negative direct linear relationships between total anthocyanin and hue angle (r = -0.89, y = -0.5973x + 110.14), and ethylene and hue angle (r = -0.69, y = -5.37x + 109.60) were recorded. Increasing anthocyanin content and red blush also coincided with decreasing daily temperatures in the orchard. Reduction in fruit firmness and acidity and increase in TSS from 167DAFB were good indicators of advancing maturity of apples. Our experimental results indicate that red blush in `Pink Lady' apples develops a few weeks before harvest and is regulated by ethylene biosynthesis and temperature.

THE AUSTRALIAN NATIONAL MANGO BREEDING PROGRAM - IN SEARCH OF IMPROVED CULTIVARS FOR THE NEW MILLENNIUM

The Australian mango industry is predominantly based on a single cultivar Kensington Pride. Although this cultivar is popular in the domestic market, it has a number of limitations, which impact greatly on the economics of production. Problems such as excessive tree vigour, unreliable flowering and poor fruit-set result in low and irregular cropping. Fruit quality of Kensington Pride also suffers from short shelf life, susceptibility to sap burn, inconsistency in development of red blush and internal physiological disorders. Although chemical means aimed at overcoming some of these limitations have been useful, cultivar research and breeding are being looked at for more sustainable and long term solutions. The Australian National Mango Breeding Program was initiated in year 1994 as a joint project between four Australian state and federal agricultural organisations to develop superior genotypes. In most crosses, Kensington Pride was used as one of the parents and crossed with a range of Floridian, Indian and Asian cultivars. Emasculation and hand pollination was used to evolve over 1800 crosses involving 33 parental combinations with 40 to 50 each in most of the crosses. These hybrids are being evaluated in two different environmental conditions, one in the humid tropical climate of Darwin and the other in the dry milder tropical conditions of Mareeba district in Queensland. Results from the early phases of the program are presented together with some promising early outcomes and plans for the future. Over 300 progenies fruited by year 2000, of which six outstanding crosses have been selected for regional testing. The project will also generate valuable information on inheritance of various traits for future breeding work.

Postharvest Irradiation Enhances Anthocyanin Synthesis in Apples But Not in Pears

`Cripps' Pink' apples (Malus ×domestica Borkh.) subjected to 72 hours of postharvest irradiation developed a better red blush with high pressure sodium (HPS) (hue angle 56.5°) than with UV-B plus incandescent (UVB+I) lamps (hue angle 70.7°). Only HPS lamps were used in subsequent experiments. The increase in red color (hue angle decrease of 14.9°) in `Braeburn' apples held at -0.5 °C for 8 weeks prior to treatment was smaller than in fruit stored for 4 weeks (hue angle decrease of 23°). No increase in color or anthocyanin concentration was observed in `Forelle' pears (Pyrus communis L.) that were similarly treated. `Forelle' pears were harvested with or without attached stem and leaves to determine whether precursor availability restricted postharvest color development. Fruit were irradiated with HPS at 20/20 °C and 20/6 °C (day/night) for 168 hours. The absence of leaves hastened the decrease in hue angle, but this was due to yellowing and not to development of red blush. Since `Forelle' pears showed no response to light after harvest, two fully red cultivars, Bon Rouge and Red Anjou, were irradiated with HPS lamps for 72 hours. Hue angle was not affected by irradiation. Thus, anthocyanin synthesis was stimulated by postharvest irradiation with HPS lights in apples, but not in pears.

574 Nitrogen, Trunk Scoring, and AVG Treatments Influence Fruit Color and Quality of `Jonagold' Apple

`Jonagold' apple often has problems of inadequate red blush development at harvest, and loss of firmness and skin “greasiness” after refrigerated storage. During two growing seasons we tested factorial combinations of three preharvest treatments for managing these problems: 1) N fertilization (no applied N, 34 kg N/ha in May, or 1% (w/w) foliar urea sprays in May and June); 2) mid-summer trunk scoring (girdling); and 3) aminoethoxyvinylglycine (AVG) applications 3 weeks prior to harvest. Fruit were harvested at four weekly intervals each year, and evaluated for size, blush, firmness, soluble solids, ethylene, and starch hydrolysis. Nitrogen delayed blush development in 1998, but not 1999, and there was no difference in fruit surface blush coverage between foliar urea and soil applied N. Nitrogen applications increased fruit size, decreased fruit firmness, and increased post-storage flesh breakdown in 1999. Trunk scoring increased blush coverage and intensity both years, and improved market-grade packouts. Blush increase after trunk scoring was not caused by advanced fruit maturity (based on ethylene and starch indices) in either year, although it did increase skin greasiness slightly. AVG treatments delayed maturity and blush development of `Jonagold' by 7 to 10 days both years, relative to untreated fruit. Flesh firmness increased and greasiness decreased in AVG treated fruit harvested on the same dates as controls. However, in AVG fruit harvested at comparable stages of maturity 7 to 10 days later, firmness and greasiness were equivalent to untreated fruit on the previous harvest date. Trunk scoring and no N fertilizer were effective for improving fruit blush coloration, and AVG for delaying harvest maturity.

355 Effect of UV-C on Ripening and Postharvest Quality of Peaches

Brown rot of peaches is one of the most devastating diseases that can occur before and after harvest. There has been extensive research that has shown that ultraviolet light (UV-C) kills the fungus that causes brown rot. However, it is has not been determined whether UV-C will also change ripening and fruit quality. We applied UV-C to `Loring' peaches that were harvested 10 days before normal harvest. We intentionally picked the fruit early because we wanted to make sure the fruit had not entered the climacteric. The fruit were treated with UV-C and ethylene, skin color, firmness, and soluble solids were measured. We also held fruit at three storage temperatures to determine whether there may be an interaction between UV-C treatment and storage temperature. Ethylene was slightly higher for UV-C treated fruit at 70 °F (20 °C) and 55 °F (12 °C), but not at 40 °F (4 °C). However, there was very little effect on firmness and soluble solids. There was a slight delay in development of red blush. UV-C had little effect on ripening and peach fruit quality.

Light Transmission, Yield Distribution, and Fruit Quality in Six Tree Canopy Forms of 'Granny Smith' Apple

Six different orchard canopy forms with 'Granny Smith' apple (Malus domestica Borkh) were evaluated for yield and fruit quality attributes over three years. The canopies studies were young, established, and top-dominant central-leader, vertical axis, multi-leader, and tiered trellis planted in either N-S or E-W rows. Mean fruit weight, soluble solids concentration, and specific leaf weight were all positively related to light transmission within a canopy and, for each factor, a common linear regression described all canopy forms. The greatest proportions of total fruit yield occurred in those canopy regions with the highest light transmission values. Greenest and firmest fruit occurred in inner canopy regions, whereas red blush development on the skin surface occurred wherever light transmission exceeded 40% of above-canopy values. Quadrant position had little influence on fruit quality factors, but mean fruit size was greater on the north than on the south side of each canopy.