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Cork spot-like physiological disorder (CSPD) is a newly identified issue in 'Kurenainoyume' apples, yet its mechanism remains unclear. To investigate CSPD, we conducted morphological observations on 'Kurenainoyume' apples with and without pre-harvest fruit-bagging treatment using light-impermeable paper bags. Non-bagged fruit developed CSPD in mid-August, while no CSPD symptoms were observed in bagged fruit. The bagging treatment significantly reduced the proportion of opened lenticels, with only 17.9% in bagged fruit compared to 52.0% in non-bagged fruits. In non-bagged fruit, CSPD spots tended to increase from the lenticels, growing in size during fruit development. The cuticular thickness and cross-sectional area of fresh cells in CSPD spots were approximately 16 µm and 1600 µm², respectively. Healthy non-bagged fruit reached these values around 100 to 115 days after full bloom from mid- to late August. Microscopic and computerized tomography scanning observations revealed that many CSPD spots developed at the tips of vascular bundles. Therefore, CSPD initiation between opened lenticels and vascular bundle tips may be influenced by water stress, which is potentially caused by water loss, leading to cell death and the formation of CSPD spots. [ABSTRACT FROM AUTHOR]

Cork spot-like physiological disorder (CSPD) is a newly identified issue in ‘Kurenainoyume’ apples, yet its mechanism remains unclear. To investigate CSPD, we conducted morphological observations on ‘Kurenainoyume’ apples with and without pre-harvest fruit-bagging treatment using light-impermeable paper bags. Non-bagged fruit developed CSPD in mid-August, while no CSPD symptoms were observed in bagged fruit. The bagging treatment significantly reduced the proportion of opened lenticels, with only 17.9% in bagged fruit compared to 52.0% in non-bagged fruits. In non-bagged fruit, CSPD spots tended to increase from the lenticels, growing in size during fruit development. The cuticular thickness and cross-sectional area of fresh cells in CSPD spots were approximately 16 µm and 1600 µm², respectively. Healthy non-bagged fruit reached these values around 100 to 115 days after full bloom from mid- to late August. Microscopic and computerized tomography scanning observations revealed that many CSPD spots developed at the tips of vascular bundles. Therefore, CSPD initiation between opened lenticels and vascular bundle tips may be influenced by water stress, which is potentially caused by water loss, leading to cell death and the formation of CSPD spots.

Calcium is a very poorly translocated nutrient in the flesh of apple fruits with the advancement of growth. Within the fruit, movement is further restricted toward distal portion relative to proximal. Even numerous foliar applications of calcium do not always achieve the desired effect. Thus, the objective of this study was to enhance the calcium allocation in distal parts of apple fruit in response to whole plant application of abscisic acid (ABA). Five-year-old apple plants of Super Chief Sandidge on M9 were treated with ABA at 400 ppm, calcium chloride at 0.4% and water (Control) at four stages (30, 65, 100, and 135 days after full bloom (DAFB)), and then analyzed for xylem functionality and calcium allocation in leaf and various fruit tissues at 10 days after each treatment, i.e., S1—40, S2—75, S3—110, and S4—45 DAFB. The results obtained showed that xylem functionality started impairing just after S2; consequently, the calcium allocation was also reduced in middle and calyx portions of fruit after that stage. However, xylem functionality was significantly retained (up to 30%) in ABA-treated fruits at S4 stage, which in other treatments was found to be nil at the calyx end of the fruit. This retention of xylem tissue functionality enhanced allocation of calcium from roots in middle and calyx end of the apple fruit. Leaf calcium was reduced with ABA applications. With the enhancement of calcium in the fruits, increases in soluble solid content and titratable acidity were observed at maturity. Le calcium est un oligoélément qui se déplace très mal dans la chair des pommes, quand elles grossissent. Ces déplacements se limitent de surcroît à la partie distale du fruit plutôt qu'à sa partie proximale. Enfin, les applications foliaires de calcium, même nombreuses, ne donnent pas toujours l'effet escompté. Les auteurs voulaient améliorer la part de calcium acheminée jusqu'aux parties distales du fruit après application d'acide abscissique (AA) à la plante entière. Pour cela, ils ont appliqué de l'AA à 400 ppm, du chlorure de calcium à 0,4 % et de l'eau (témoin) à des pommiers Super Chief Sandidge sur M9 de cinq ans, à quatre stades (30, 65, 100 et 135 jours après la floraison - JAF). Ensuite, ils ont analysé la fonctionnalité du xylème et la répartition du calcium dans les feuilles ainsi que divers tissus du fruit, dix jours après chaque traitement, soit S1-40, S2-75, S3-110 et S4-145 JAF. Les résultats obtenus indiquent que le xylème commence à perdre sa fonctionnalité immédiatement après le deuxième stade (S2), avec la diminution subséquente de la quantité de calcium acheminée au centre du fruit et au niveau du calice. Le xylème des fruits traités à l'AA avait néanmoins gardé passablement sa fonctionnalité (jusqu'à 30 %) au stade S4, alors qu'elle était inexistante au niveau du calice dans les autres cas. Le fait que le xylème demeure fonctionnel signifie une meilleure répartition du calcium venant des racines dans le cœur du fruit et au niveau du calice. L'application d'AA réduit la concentration de calcium dans les feuilles. La plus forte teneur en calcium du fruit s'accompagne d'une augmentation de la concentration de solides solubles et de l'acidité totale à maturité. [Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

In apples, a bottleneck effect in calcium (Ca) transport within fruit stalk has been observed. To elucidate that how auxin affects Ca forms and distribution in the apple fruit stalk, we investigated the effects of different concentrations of auxin treatment (0, 10, 20, and 30 mg·L -1 ) on Ca content, forms, distribution, and fruit quality during later stages of fruit expansion. The results showed that auxin treatment led to a dramatic reduction in total Ca content in stalk, while an approximately 30 % increase in fruit. Furthermore, auxin treatment effectively enhanced the functionality of xylem vessels in vascular bundles of the stalk in bagged apples. Finally, TOPSIS method was used to assess fruit quality, with treatments ranked as follows: IAA20 > NAA20 > IAA30 > IAA10 > CK > NPA. The findings lay a foundation for further studies on the bottleneck in Ca transport within stalk, uneven distribution of Ca in fruit, and provide insights into Ca utilization efficiency in bagged apples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

‘Honeycrisp’ apple is susceptible to bitter pit, which is associated with fruit mineral nutrient composition. Rootstock genotypes can affect nutrient acquisition, distribution, and fruit yields, which all affect fruit nutrient composition and bitter pit susceptibility. However, the changes of these traits among different rootstock genotypes in response to abiotic stress under semiarid conditions are relatively unknown. The objective of this study was to evaluate the influence of different rootstocks and irrigation on nutrient uptake and partitioning with ‘Honeycrisp’ apple grown in an irrigated, semiarid environment. ‘Honeycrisp’ apple trees were grafted on four different rootstocks, Geneva 41 (‘G.41’), Geneva 890 (‘G.890’), M.9-T337 (‘M.9’), and Budagovsky 9 (‘B.9’), and these were planted at high density (3000 trees/ha). Irrigation was applied as either a water-limited treatment where volumetric soil water content was maintained near 50% field capacity (FC) and a well-watered control where soil water content was maintained near 100% FC. ‘G.890’, the most vigorous rootstock, had lower nitrogen and higher potassium content in leaves, while ‘B.9’, the least vigorous rootstock, had lower potassium and higher nitrogen content. Rootstock genotype did not affect calcium uptake. Interestingly, water-limited conditions increased the nutrient content in root and stems but not in leaves. Water-limited trees partitioned more nitrogen and calcium to roots, while well-watered trees in the control partitioned more nutrients to the stems. Fruit size was the largest for ‘G.890’ and smallest for ‘B.9’. Both ‘G.41’ and ‘G.890’ had higher bitter pit incidence, which was associated with higher potassium content in leaves and fruit. These results suggest that rootstock-induced vigor and irrigation can both contribute to nutrient imbalances in leaves and fruit that could affect the development of physiological disorders in ‘Honeycrisp’ apple.

We evaluated regional variation in the Delta Absorbance Meter® index of absorbance difference (IAD) as a measure of harvest maturity and for predicting the occurrence of storage disorders in ‘McIntosh’ apples [Malus ×sylvestris (L.) var. domestica (Borkh.) Mansf.] in 2016 and ‘Honeycrisp’ apples in 2016 and 2017. Apples were grown in Maine (ME), Minnesota (MN), and Ontario (ON), and they were harvested from one orchard in each region, and two to three times each year, followed by cold storage at 0.5 °C for 2 months in 2016 and 4 months in 2017. In 2016, ‘Honeycrisp’ IAD values were similar in ME and ON, but lower than in MN. In 2017, IAD was greater in ME than in the other two regions during the first harvest, and it similar to MN in the latter two harvests and lower in ON than in the other regions. In ‘Honeycrisp’ apples, IAD was more strongly related to starch pattern index (SPI), internal ethylene concentration, and fruit peel blush than to chlorophyll or soluble solids concentration. Soft scald incidence (SSI) of ‘Honeycrisp’ fruit was greater in ME than in MN and ON in both years. In ME, SSI was related to IAD at harvest in both years, but with an inverse relationship with the first harvest and a positive relationship in the second harvest. A positive relationship also occurred in ON in 2017. SSI was not related to IAD at harvest in MN in both years and ON in 2016. Regional similarities in patterns of change in ‘Honeycrisp’ fruit IAD were not consistent from year to year, and this indicates that a single IAD standard should not be used to assess fruit maturity in different regions. In ‘McIntosh’, IAD values were variable among the three regions and were not related to other maturity indicators. IAD was not useful for measuring maturity in ‘McIntosh’ apples, but it was weakly related to core browning incidence.

‘Honeycrisp’ is among the most widely grown apple cultivars in the United States and ‘WA 38’ is a new apple cultivar released in Washington State. ‘Honeycrisp’ is highly susceptible to bitter pit and other physiological disorders; however, ‘WA 38’ is not susceptible to bitter pit but little is known about its susceptibility to other disorders. Bitter pit is a calcium-related disorder that has been associated with localized calcium deficiencies in fruit in addition to the proportions of calcium relative to the presence of other nutrients like potassium and magnesium. The objective of this study was to compare physiological differences and fruit quality between ‘Honeycrisp’ and ‘WA 38’ to determine how these differences might correspond to differences in mineral nutrient composition and bitter pit susceptibility. Here, ‘Honeycrisp’ and ‘WA 38’ elemental composition in leaves, fruit, and xylem sap was measured every 20 days starting 30 days after full bloom and compared with leaf gas exchange and stem water potential. ‘Honeycrisp’ had greater foliar transpiration rates that corresponded with greater calcium in the leaves and lower leaf K+Mg/Ca ratio, when compared with ‘WA 38’. In contrast, fruit calcium concentrations were higher for ‘WA 38’ with lower K+Mg/Ca ratios. Xylem conductance was higher during late summer in ‘WA 38’ compared with ‘Honeycrisp’. ‘WA 38’ fruit was denser than ‘Honeycrisp’ and more research is needed to determine whether differences in fruit structure may affect susceptibility to bitter pit in apple.

The high-value apple cultivar ‘Honeycrisp’ is prone to bitter pit, a physiological disorder characterized by the development of dark, sunken lesions on fruit particularly towards the calyx-end. Identifying the genetic basis of bitter pit is critical for mitigation of the disorder and development of bitter pit-free varieties. To this end, we performed an RNA sequencing experiment to compare the peel and flesh transcriptomes of healthy and bitter pit-affected ‘Honeycrisp’ fruit, with the objective of identifying bitter pit candidate genes. A similar number of genes were expressed in flesh and peel (~ 27,000), and we detected flesh- and peel-specific expression. Within the flesh and peel datasets, 2.6% and 1% of genes were differentially expressed between healthy and bitter pit apples, respectively. We identified over 1000 differentially expressed genes in both flesh and peel datasets that are distributed throughout the genome, sixteen of which are within a previously identified bitter pit QTL, making them potential candidate genes. Both MdMADS5 and MdIDL1, the orthologs of Arabidopsis APETALA1 and INFLORESCENCE DEFICIENT IN ABSCISSION-LIKE 1, respectively, which are possibly involved in fruit development and organ abscission, stand out as candidate genes for bitter pit, based on their proposed function, differential expression, and location within a bitter pit QTL. The RNA-seq data also revealed that many genes involved with defense response and stress are upregulated in bitter pit-affected tissues. We discuss how these differentially expressed genes could provide important information about the physiology, development, and progression of bitter pit. [ABSTRACT FROM AUTHOR]

The present research intents to study skin fatty acids and physiological disorders developed during cold storage in ‘Golden Delicious’ apples treated with 1-MCP and calcium. Harvested fruits were treated with calcium chloride (Ca), 1-MCP (MCP), Ca + MCP or no treatment (control) and then subjected to cold storage at 0.5 °C for 6 months. Fatty acids’ composition, malondialdehyde (MDA) and the physiological disorders bitter pit (BP), superficial scald and diffuse skin browning (DSB) were measured at harvest and after storage plus 7 days of shelf-life at room temperature ≈22 °C. Palmitic acid decreased and linoleic acid increased over time, while oleic and stearic acids had few changes. Generally, unsaturated/saturated fatty acids and MDA increased over the storage period. Treatment with Ca showed that, at the end of the experiment, the lowest MDA values and the highest unsaturated/saturated fatty acids ratio were mainly due to higher linoleic and lower palmitic acids concentrations, which are coincident with less severe BP. There was no clear correlation between the measured fatty acids (palmitic, linoleic, oleic and stearic), unsaturated-to-saturated fatty acids ratio or MDA with chilling skin physiological disorders. Further research is needed to clarify the changes in membrane properties and the effect of some treatments in response to chilling injury during storage.

Consumers are more disposed towards paying price premiums for sustainable food products. This fact is especially important for products with a PDO (Protected Designation of Origin) label, such as the high-acidity apple cultivar ‘Reinette du Canada’. However, ‘Reinette du Canada’ apple fruit is affected by two of the main post-harvest disorders in apple cultivars, bitter pit and senescent breakdown. As a means to achieve sustainable production of this high-quality apple cultivar, the effect of a sustainable preharvest technique, summer pruning, in combination with a zero-residue postharvest treatment allowed in organic farming on calcium-related disorders and quality in global terms in this PDO-labelled apple cultivar was assessed during storage. The combination of the two sustainable practices was an effective tool in diminishing senescent breakdown from 43% to 17% and to decrease bitter pit incidence by up to 21% (from 36% to 15%) throughout storage, especially in fruit with high susceptibility to this disorder during storage. Moreover, the overall acceptability was kept high (values of more than 3 on a 5-point scale) when applying this environment-friendly sustainable horticulture practice, which will not only reduce the synthetic pesticide input in the apple agroecosystem, but also contribute to producing fruit with zero residues.

Shade cloth is commonly used to reduce incident light in apple (Malus domestica [Suckow] Borkh.) orchards. Nevertheless, this technology can generate changes in plant physiology that affect tissue nutritional composition and cause fruit nutritional disorders. The effect of shade cloth on the nutritional concentration of six macroelements and six microelements on leaves, six macronutrients in the fruits of 'Fuji' apples, and bitter pit incidence was assessed in a study conducted in a commercial orchard in south-central Chile for three seasons. Two treatments (control without shade cloth and 30% shade cloth cover) were evaluated with five replicates in a split plot design. Averaged results for the three seasons showed that shade cloth increased Mg, Mn, and Zn concentrations in leaves by 0.02%, 40 mg kg-1, and 5.5 mg kg-1, respectively, and decreased K, Mg, and S concentrations in fruits by 12, 0.35, and 0.38 mg 100 g-1 fresh fruit, respectively. Bitter pit incidence was not affected by shade cloth (values between 0.3% and 6.6%), but seasonal conditions did affect this abiotic disorder. In conclusion, the use of shade cloth in apples did not affect bitter pit incidence, but it caused some changes in leaf and fruit nutritional concentration. [ABSTRACT FROM AUTHOR]

We evaluated regional variation in the Delta Absorbance Meter® index of absorbance difference (IAD) as a measure of harvest maturity and for predicting the occurrence of storage disorders in 'McIntosh' apples [Malus ×sylvestris (L.) var. domestica (Borkh.) Mansf.] in 2016 and 'Honeycrisp' apples in 2016 and 2017. Apples were grown in Maine (ME), Minnesota (MN), and Ontario (ON), and they were harvested from one orchard in each region, and two to three times each year, followed by cold storage at 0.5 °C for 2 months in 2016 and 4 months in 2017. In 2016, 'Honeycrisp' IAD values were similar in ME and ON, but lower than in MN. In 2017, IAD was greater in ME than in the other two regions during the first harvest, and it similar to MN in the latter two harvests and lower in ON than in the other regions. In 'Honeycrisp' apples, IAD was more strongly related to starch pattern index (SPI), internal ethylene concentration, and fruit peel blush than to chlorophyll or soluble solids concentration. Soft scald incidence (SSI) of 'Honeycrisp' fruit was greater in ME than in MN and ON in both years. In ME, SSI was related to IAD at harvest in both years, but with an inverse relationship with the first harvest and a positive relationship in the second harvest. A positive relationship also occurred in ON in 2017. SSI was not related to IAD at harvest in MN in both years and ON in 2016. Regional similarities in patterns of change in 'Honeycrisp' fruit IAD were not consistent from year to year, and this indicates that a single IAD standard should not be used to assess fruit maturity in different regions. In 'McIntosh', IAD values were variable among the three regions and were not related to other maturity indicators. IAD was not useful for measuring maturity in 'McIntosh' apples, but it was weakly related to core browning incidence. [ABSTRACT FROM AUTHOR]

'Honeycrisp' is among the most widely grown apple cultivars in the United States and 'WA 38' is a new apple cultivar released in Washington State. 'Honeycrisp' is highly susceptible to bitter pit and other physiological disorders; however, 'WA 38' is not susceptible to bitter pit but little is known about its susceptibility to other disorders. Bitter pit is a calcium-related disorder that has been associated with localized calcium deficiencies in fruit in addition to the proportions of calcium relative to the presence of other nutrients like potassium and magnesium. The objective of this study was to compare physiological differences and fruit quality between 'Honeycrisp' and 'WA 38' to determine how these differences might correspond to differences in mineral nutrient composition and bitter pit susceptibility. Here, 'Honeycrisp' and 'WA 38' elemental composition in leaves, fruit, and xylem sap was measured every 20 days starting 30 days after full bloom and compared with leaf gas exchange and stem water potential. 'Honeycrisp' had greater foliar transpiration rates that corresponded with greater calcium in the leaves and lower leaf K+Mg/Ca ratio, when compared with 'WA 38'. In contrast, fruit calcium concentrations were higher for 'WA 38' with lower K+Mg/Ca ratios. Xylem conductance was higher during late summer in 'WA 38' compared with 'Honeycrisp'. 'WA 38' fruit was denser than 'Honeycrisp' and more research is needed to determine whether differences in fruit structure may affect susceptibility to bitter pit in apple. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Frequent pesticide treatments in fruit orchards increase hazards for workers, consumers and the environment. Moreover, the indiscriminate and excessive use of pesticides often induces resistance in pests. In the past few years, physical exclusion strategies have been proposed as an alternative for the control of insect pests. The goal of this study was to evaluate the effectiveness of anti‐hail photoselective netting in protecting apples against key and emerging pests, as well as the impact on beneficial arthropods, fungal diseases and fruit quality. RESULTS: In netted plots, a significant reduction in pest populations, i.e. fruit moths, Halyomorpha halys (Stål) and Drosophila suzukii (Matsumura), was recorded in comparison with un‐netted controls. Moreover, the damage on fruits caused by H. halys was reduced up to 62% compared with insecticidal treatments. The net did not negatively affect the abundance of predators and the incidence of post‐harvest rot. In addition, the incidence of bitter pit on apple was reduced up to 52%. Furthermore, fruit quality was unaffected by the net coverage (both at harvest and after 4 months of storage). CONCLUSION: Anti‐hail photoselective pearl netting proved a promising exclusion system that can prevent attack by more than one insect pest at a time, allowing for a strong reduction in insecticide treatments and relative costs. At the same time, the netting did not negatively influence the presence of predators, the incidence of fungal disease or fruit quality. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

‘Honeycrisp’ (Malus domestica Borkh.), a premium applecultivar, is highly susceptible to bitter pit and decline in quality during long-term storage. In order to enhance the quality, an aqueous composition containing hexanal was applied as a preharvest spray. The effects of hexanal were assessed on the treated fruit and compared with HarvistaTM (a sprayable 1-Methylcyclopropene based commercial formulation) applied and control fruit under both cold (2.5 °C; four months) and cold after room temperature storage (20 °C; 14 days) conditions. Color, firmness, and total soluble solids (TSS) did not show a significant change in response to any treatment at harvest, while abscisic acid (ABA) significantly reduced and tryptophan increased in response to hexanal, compared to HarvistaTM and control. The treatment effects on quality traits were observed during storage. Both hexanal and HarvistaTM sprayed apples had higher TSS under both cold and room temperature storage. In addition, both sprays enhanced firmness at room temperature storage. However, the effects of sprays on other quality traits showed a different pattern. Apples sprayed with hexanal had lower phospholipase D enzyme (PLD) activity, lower incidence of bitter pit, and decreased expression of MdPLDα1 compared to HarvistaTM and control. On the other hand, HarvistaTM treated fruit produced lower ethylene. Both sprays decreased the expression of MdPLDα4, MdCaM2, MdCaM4 and MdCML18 genes. Generally, PLD alpha has a direct role in promoting fruit senescence, whereas the calcium senor proteins (CaM/CMLs) may involve in fruit ripening process via calcium and ethylene interactions. Therefore, improved postharvest qualities, including the lower incidence of bitter pit in hexanal treated ‘Honeycrisp’, may be associated with lower membrane damage due to lower PLD enzyme activity and decreased expression of MdPLDα1 and MdPLDα4 genes throughout the storage period.

Soil catena concept is a sequence of soils extends across relief positions and is developed from similar parent material. This study highlighted on the important aspects and properties of soil catena of Daher El-Jabal in Jabal Al-Arab mountainous area South eastern of Syria, by implementing pedologic study in 2010-2012. Six soil profiles have been studied along pedo-genetic transect in order to highlight the soil catena prevailing properties. The results reveal that the soil has formed from igneous basaltic parent casts, related to Neogen era, where reliefs had the key role in the developing of soil solum. Consequently, Entisols were dominated on eroded summits, Inceptisols on back slops and mountain flanks, Mollisols on depressions. Both water erosion of soil surface and leaching inside soil solum processes were responsible for variation of soil texture, as such soils showed evident of changing in particles size distribution as well as in clay content. Cation exchange capacity (CEC) was less than moderate with domination of Magnesium cation. Soil trace elements were poor to somewhat poor. Soil pH values in general were low; which reflect the pedo-genic character of igneous parent material in which soil drifted from. In some cases, where soil body subjected to continuous leaching of soil bases, in particular calcium cation; soil profiles became totally freed from calcium carbonates. Accordingly soil problems related to downing of soil reaction (pH) are more expected to be increasing by time. This is main reason for some physical diseases, which beginning arise on pomes fruits, particularly bitter pit.INTERNATIONAL JOURNAL OF ENVIRONMENT Volume-6, Issue-1, Dec-Feb 2016/17, page: 87-107

Penicillium expansum infection of apples and mycotoxin patulin (PAT) production has previously been associated with many pre- and postharvest factors other than physiological disorders. In the current study, 'Antei' and 'Krameri tuviõun' apples with and without bitter pit (BP) symptoms and 'Talvenauding' apples with and without superficial scald (SS) symptoms were used in order to determine if the named physiological disorders may influence susceptibility to P. expansum infection and PAT production. Apples were inoculated with 10 μL P. expansum spore suspension with the concentration of 1x105 conidia mL-1 and stored at 24 °C with relative humidity (RH) 80%. After 7 and 11 days, lesion diameters were measured, and apples were pressed into juice. PAT content was determined in pasteurized juice. Two cultivars out of three showed that in fruit with physiological disorders, Penicilllium infection and PAT production proceeded significantly faster compared to apples, which did not have physiological disorders. SS increased the risk for PAT occurrence in juice more than BP: while the juice pressed from BP--affected apples with no visual signs of fungal diseases did not contain PAT, juice pressed from apples with SS contained PAT three times above legislative limits defined by the World Health Organization (50 μg L-1). [ABSTRACT FROM AUTHOR]

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• Passive, ethylene and magnesium induction of bitter pit investigated. • These methods showed good correlation with actual bitter pit. • The passive method showed consistent results and easiest to apply. • Correlations for non-chemical methods as good or better than for minerals. • The non-chemical method eliminates the need to carry out mineral analyses. Bitter pit is a physiological disorder that can develop during storage and result in major economic losses of susceptible apple cultivars such as 'Honeycrisp'. Prediction methods to determine the risk of disorder development have focused primarily on mineral composition of the fruit, but there has also been interest in non-mineral based methods. In this study, we have compared non-mineral methods with mineral analyses for bitter pit prediction. Fruit of 'Honeycrisp' were harvested three weeks before anticipated commercial harvest and at commercial harvest. Mineral contents in peel from the calyx-end were measured in fruit at both harvest times. In year 1, fruit were kept at 20 °C (passive method), dipped in 2000 mg L−1 2-chloroethylphosphonic acid (ethylene method) or 0.8 M MgCl 2 (Mg method). Treated fruit were then kept at 20 °C for three weeks. At commercial harvest, fruit were stored at 0.5 or 3 °C with and without 1 week of conditioning at 10 °C. The Mg method showed toxicity on the fruit, which was hard to distinguish from bitter pit. Therefore, in year 2, only the passive and ethylene methods were used, and fruit from the commercial harvest were stored at 3 °C with or without conditioning. In year 3, only the passive method was used because of its simplicity and lack of registration of ethephon for this purpose. Fruit from the commercial harvest of 38 orchards in three growing regions were stored at 3 °C after conditioning. Fruit were stored for two months in year 1 and four months in years 2 and 3, and assessed after 4 d at 20 °C. Multivariate analysis shows that the passive and ethylene methods for fruit harvested three weeks before the anticipated harvest had higher or similar correlations with the actual bitter pit after cold storage than those from minerals. Although actual bitter pit incidence was higher than that predicted from the passive method, the method results in predictions that are similar to mineral-based predictions, and also is more straightforward for commercial application. [ABSTRACT FROM AUTHOR]

High temperatures, wind, and excessive sunlight can negatively impact yield and fruit quality in semi-arid apple production regions. Netting was originally designed for hail protection, but it can modify the light spectrum and affect fruit quality. Here, pearl, blue, and red photoselective netting (≈20% shading factor) was installed in 2015 over a commercial “Cameron Select® Honeycrisp” orchard. Our research objectives were to (1) describe the light quantity and quality under the colored nets compared to an uncovered control and (2) investigate the effect of Photoselective nets on “Honeycrisp” apple quality for two growing seasons. Light transmittance and scattering for each treatment were measured with a spectroradiometer, and samples for fruit quality analyses were collected at harvest. PAR (photosynthetic active radiation), UV, blue, red, and far-red light were lower underneath all netting treatments compared to an uncovered control. The scattered light was higher under the pearl net compared to other colors, while red and far-red light were lower under the blue net. For two consecutive years, trees grown under the photoselective nets intercepted more incoming light than the uncovered trees with no differences among the three colors. In both years, trees under red and blue nets had more sunburn-free (clean) apples than pearl and control. Red color development for fruit was lower when nets were used. Interestingly, bitter pit incidence was lower underneath red nets for both years. Other than red color development, “Honeycrisp” fruit quality was not appreciably affected by the use of netting. These results highlight the beneficial effect of nets in improving light quality in orchards and mitigating physiological disorders such as bitter pit in “Honeycrisp” apple.

‘Fuji’ is among the most cultivated apples worldwide but affected by the disorder bitter pit (BP). Calcium deficiency plays an important role on fruit susceptibility to BP. The objectives of this study were to determine nutritional relationships in BP-affected fruit and to verify if Vis-NIR models can predict Ca concentration in ‘Fuji’ apples. Fruit was harvested during 2018 season from two different orchards with historical high BP incidence. Seven hundred and fifty apples were stored at 0 °C for 150 days plus 10 days at 20 °C for BP assessments. After storage, 20 fruit with BP symptoms (BP+) and 20 healthy fruit (BP−) were assessed individually for mineral concentration. Vis-NIR evaluation involved a spectra range from 285 to 1200 nm to predict Ca concentration from ‘Fuji’ powder enriched Ca solutions. In each orchard, healthy apples had significantly higher Ca concentration than apples with BP. The K/Ca and Mg/Ca ratios were significantly lower in healthy fruit compared with BP− affected fruit. The relationship B/Ca proved to be significant in BP fruit. Although Ca interaction with organic substances and/or cellular structures could influence NIR spectra in fresh fruit, our results showed that Vis-NIR models could not be used to direct prediction of fruit Ca concentration.

The physiological disorders superficial scald, bitter pit, and lenticel blotch pit severely compromise the commercial value of 'Granny Smith' apples. A number of chemical treatments are available to alleviate these disorders but they are unacceptable in the expanding organic market. The objective of this research was to study the effectiveness of prestorage treatments--delayed cooling and elevated temperature under ultra-low oxygen (ULO) atmospheres--as organic-friendly strategies to control these disorders. 'Granny Smith' apples were exposed to four different treatments: 1) conditioning temperature treatments (CTemp): 10 days at 3 °C or 30 days at 3 °C or 10 days at 20 °C, in air; 2) the same conditioning temperature treatments combined with an ultra-low oxygen (ULO) conditioning treatment of 0.2-0.5 kPa O2 and <0.5 kPa CO2; 3) 1-methylcyclopropene (1-MCP) treatment as a commercial control; and 4) untreated control fruit. After the prestorage treatment, fruit were stored for 90 or 150 days at 0 °C, and then held poststorage for 8 days at 20 °C before quality analysis. A combination treatment of temperature conditioning and ULO for 30 days at 3 °C achieved the best control of superficial scald, bitter pit, and lenticel blotch pit. The use of ULO with CTemp for 10 days at 20 °C offered the same control but induced high concentrations of ethanol and acetaldehyde that affected the organoleptic acceptability of the fruit and reduced its commercial value. The use of 1-MCP offered 100% control of superficial scald but bitter pit and lenticel blotch pit disorder incidences were similar or higher than in the control fruit. All ULO conditioning treatments resulted in high ethanol and acetaldehyde concentrations during the first 90 days of storage, but fruit exposed to ULO conditioning treatment for 30 days at 3 °C showed similar organoleptic acceptability to control fruit after 150 days. Therefore, ULO conditioning is a potentially useful treatment for the organic apple industry. [ABSTRACT FROM AUTHOR]

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Calcium (Ca) sprays are commonly used to control Ca-related disorders such as bitter pit in apple. Increases in the frequency and the amount of Ca applied directly to the fruit have increased fruit Ca levels and are associated with a reduction in bitter pit incidence. However, the absorption efficiency at different fruit developmental stages is poorly understood. Here, the absorption efficiency was measured using 44Ca stable isotope applied to 30 individual fruit at five different times every 2 weeks between June drop and 2 weeks before harvest in a medium-density 'Honeycrisp' orchard. Fruit size, spray adhesion, and Ca and potassium (K) content were monitored weekly for 12 weeks between 26 May and 13 Aug. 2015. At harvest, the 44Ca-labeled fruit was picked and separated into peel and inner fruit for mass balance analysis of 44Ca absorption to regions of the fruit that are important to prevent Ca-related disorders. As expected, 44Ca was greater in the peel than the interior of the fruit. However, there was a significant amount of 44Ca present in the inner fruit at harvest for all five applications applied during the growing season. Using a stable isotope tracer approach, we present evidence that Ca is absorbed throughout fruit development. These findings support current recommendations for frequent Ca applications in low concentrations throughout fruit development to increase fruit Ca levels and reduce the incidence of bitter pit in 'Honeycrisp' apple. [ABSTRACT FROM AUTHOR]

Calcium deficiency disorders in fruit, such as bitter pit (BP), have puzzled researchers for years, and little is known regarding the mechanisms involved in the development of these physiophaties. Previous studies have suggested abscisic acid (ABA) as an alternative treatment to influence calcium allocation to the fruit, by regulating stomatal conductance and transpiration in leaves. We explored the feasibility of this approach in ‘Super chief’, an apple cultivar susceptible to BP, with the specific purpose to elucidate the mechanisms underpinning calcium partitioning and its resulting availability in the fruit cells through field trials and molecular analysis. Our findings reveal that foliar spraying with ABA, carried out four times during the season (starting from 66 DAFB) can be effective in apple bitter pit prevention, via a preferential supply of Ca 2+ to fruit. Higher amounts of Ca 2+ have been detected in treated apples at harvest and, consistently, the transcriptional analysis evidenced, in the same samples, the down-regulation of three genes involved in Ca 2+ partitioning ( MdACA8 , MdCAX and MdCDPK ). These data are in agreement with the hypothesis that BP prevention could be associated to the increased Ca 2+ concentration in the apoplast and a coordinated regulation of specific Ca 2+ -related genes. [ABSTRACT FROM AUTHOR]

Bitter pit and healthy ‘Honeycrisp’, ‘Golden Delicious’, and ‘Granny Smith’ apples were collected from three commercial orchards. Apples were scanned using Fourier transform infrared (FTIR) and X-ray fluorescence (XRF) spectrometers to associate the elemental profile with bitter pit occurrence in apples. The FTIR spectra were acquired from apple peel and flesh; while XRF spectra were acquired from the apple surface (peel). Destructive elemental analysis was also performed to estimate calcium, magnesium, and potassium concentrations in the apples. There were significant differences between healthy and bitter pit affected apples in calcium, magnesium, and potassium concentrations, in addition to magnesium/calcium and potassium/calcium ratios (5% level of significance). Peak analysis of FTIR spectra of prepared standards indicated the possible spectral regions associated with calcium content as 1150–1450 cm −1 . Two different classification models (support vector machine, SVM and soft independent modeling of class analogy, SIMCA) were used to classify healthy and bitter pit affected apples using FTIR spectral signatures. FTIR spectra were able to predict bitter pit incidence in apples with higher classification accuracy using peel tissue (92%) than using flesh tissue with SVM model. The XRF technique could determine bitter pit incidence in apples and semi-quantitative analysis using XRF data was in agreement with the elemental analysis. FTIR and XRF spectrometric techniques are rapid methods that can be used for elemental profile analysis in apples. These techniques can serve as potential prediction tools for elemental profile analysis to detect bitter pit in apples. [ABSTRACT FROM AUTHOR]

Fruit mineral analysis at harvest is recommended as a predictive method to assess the risk of bitter pit (BP) in apple orchards, although it only provides valuable information if conducted just before harvest. To gain more time to implement corrective action, some studies proposed early season analysis of fruitlets. However, neither results were reported for analysis accuracy, nor the best time to perform it. The objective of this study was to evaluate the accuracy of early season fruitlet analyses at different stages — 40, 60 and 80 days after full bloom (DAFB) — to predict BP in ‘Golden Smoothee’ apples. Multivariate models for each early stage were developed and compared to a linear model using the calcium (Ca) content alone. Both the multivariate analyses and linear correlations suggested 60 DAFB as the best time to perform early mineral analysis. The Ca concentration in the fruit contributed greatly to BP incidence either at an early stage or at harvest. The boron concentration showed a negative correlation with Ca concentration and a positive correlation with BP incidence. The other tested nutrients (magnesium, nitrogen, potassium) showed little effect on the prediction models and/or an irregular pattern. The accuracy of the multivariate model (R 2 = 0.580) was not significantly better than the analysis of Ca alone (R 2 = 0.504) when the occurrence of BP was high. Finally, a Ca threshold at 60 DAFB equal to or greater than 11.0 mg 100 g −1 fresh weight (f. w.) indicated a low risk of BP (<10% of incidence). This early season threshold value was a better indicator of the BP risk than the traditional threshold value at harvest (5–6 mg Ca 100 g −1 f. w.). [ABSTRACT FROM AUTHOR]

Calcium (Ca) sprays and Ca applications to soil throughout the growing season or Ca solution dips at post-harvest are widespread practices to supply Ca and decrease bitter pit in apples. However, published results conflict, and there is no information about the effectiveness of combining all these treatments. In the present study, the following treatments were assessed during four growing seasons: early-season (April) Ca soil applications applied 4 times, mid-season (May) CaCl 2 sprays applied 7 or 13 times, late-season (June) CaCl 2 sprays applied 7 times, and the combination of late-season sprays and soil applications. In addition, post-harvest dips were evaluated in the latter two growing seasons. Notably high bitter pit incidences were monitored for the first and fourth year of study (>20%), while the second and third year were almost without incidence. Post-harvest dips mitigated bitter pit incidence to a greater extent than pre-harvest treatments, and the sprays mitigated bitter pit to a greater extent than Ca soil applications. The combination of sprays and soil applications did not improve the results relative to Ca sprays alone. No detectable advantage for starting spray programmes earlier than June was observed. Our results showed a trend towards reduced bitter pit with an increasing number of CaCl 2 sprays, but this was not clearly an effect of maximizing fruit Ca. Finally, applying 13 CaCl 2 sprays in combination with a Ca solution dip at post-harvest appeared to be the most effective practice for minimizing the risk of bitter pit development. [ABSTRACT FROM AUTHOR]

Orchard performance is influenced by weed competition. In this study, the effects of weed competition on nutrient contents, chemical and physical fruit quality properties were sought. The study was carried out in a high-density apple orchard ('Golden Delicious'/M.9) over two consecutive growing seasons. The effect of weed competition was studied at three different levels: weak, moderate and strong. Fruit firmness, soluble solids content, macronutrients (such as nitrogen, potassium and calcium) and potassium+magnesium/calcium ratio in fruit were significantly affected by weed competition. Strong weed competition negatively affected soluble solids content and potassium+magnesium/calcium ratio. In both trial years, soluble solids content was significantly higher in weak weed competition. In the first year of the study, soluble solids content ranged between 13.77±0.06% (strong weed competition) and 15.20±0.10% (weak weed competition). In the following year, soluble solids content values were determined as 13.13±0.23% in strong weed competition and 13.83±0.21% in weak weed competition. Weak weed competition showed superiority for fruit weight and potassium+magnesium/calcium ratio. As a whole, this study indicates that insufficient weed control in tree rows might be a limiting factor for fruit quality in high-density apple orchards. [ABSTRACT FROM AUTHOR]

Bitter pit is an economically important physiological disorder in apples resulting in serious economic losses. Current visual assessment techniques are not completely useful in evaluating the extent of bitter pit development as they are limited to external symptoms. An X-ray computer tomography (CT) based imaging and associated image processing algorithm was used to assess the number of bitter pits inside the fruit and on the surface of apples. Samples of 40 healthy and 40 bitter pit affected ‘Honeycrisp’ apples were selected from two different field sites, and scanned with CT equipment on 0, 21 and 63 days after harvest. The results showed that the average number of bitter pits increased both on the surface and inside the fruits with increasing storage period. An average of 42–66% pits was present inside the apple fruits in bitter pit-affected apples. In addition, most of the newly developed bitter pits in healthy apples appeared within the fruit. Therefore, the usefulness of X-ray CT imaging as an effective phenotyping tool in identifying internal bitter pit and on the surface in the automated manner was demonstrated in this study. [ABSTRACT FROM AUTHOR]

Calcium (Ca 2+ ) and 1-methylcyclopropene (1-MCP) appear to have opposite effects on the development of bitter pit. However, both post-harvest treatments seem capable of influencing fruit ripening, reducing superficial scald and improving post-storage quality. The objective of this work was to investigate the effect of calcium chloride and 1-MCP alone or combined on the incidence and development of physiological disorders and the delay of ripening of apples during storage (at 0.5 °C in air) and subsequent shelf-life at room temperature ≈22 °C. ‘Golden Delicious’ apples were harvested in 10 orchards and treated with calcium chloride (1.5%, w/v), 1-MCP (625 nL L −1 ), calcium chloride plus 1-MCP, and without any treatment (control). Physiological disorders and quality parameters were evaluated at harvest and after 6 months storage as well as after 7 d shelf-life. The 1-MCP treatment was effective to prevent superficial scald, slow softening, increase soluble solids content and reduce electrolyte leakage and color changes associated with ripening, during storage and shelf-life. However, this treatment also enhanced the development of bitter pit, especially the moderate and severe symptoms in some orchards, which may be attributable to orchard cultivation techniques. CaCl 2 alone and CaCl 2 plus 1-MCP reduced bitter pit intensity by reducing moderate and severe incidence, maintained higher lightness and had firmer fruit than control. Postharvest dips of ‘Golden Delicious’ apples in CaCl 2 before 1-MCP application (CA + MCP), may be a good solution to prevent scald, and reducing the bitter pit which is enhanced by 1-MCP alone. [ABSTRACT FROM AUTHOR]

Research was carried out during the 1999-2007 growing and storage season using ‘Ligol’ apples from trees grafted on M.26, and fertilised in accordance with recommendations for commercial orchards. The approximate optimum harvest date was determined mainly on the basis of starch index measurements and Streif index calculations, evaluated 7-8 times every 4-5 days each year. In addition to samples collected to determine OHD each year, there were four harvests of fruit intended for storage. The apples were stored in a cold storage room at 1-2°C and RH of around 90% for about five months. Following a storage period lasting the same number of days for each harvest, the quality of fruits was examined and the correlation between the concentration of minerals in apples and all fungal diseases and physiological disorders was calculated. In years with high precipitation in the period preceding the harvest, the share of fruits affected by fungal diseases and physiological disorders after storage depended more on weather conditions prevailing in the growing season than on the harvest date. The incidence of bitter pit increased with the number of days preceding OHD. Other recorded losses were caused by internal breakdown and superficial scald, but they were small and did not seem significant for ‘Ligol’ apples. Each characteristic mineral concentration in the fruit at harvest (N, P, K, Ca and Mg) was correlated with the incidence of physiological disorders and/or fungal diseases. The incidence of bitter pit and lenticel blotch pit and the sum of physiological disorders increased along with the increase in nitrogen concentration. The feature that best predicted the storability of ‘Ligol’ was the K/Ca ratio.

The effects of calcium fertilizers on cv. Ligol apples were studied in the experiment conducted at the Lithuanian Institute of Horticulture in 2007-2009. Fertilizers were applied four or eight times from June to September on the 8th-9th leaf of apple trees on P 22 rootstock. Calcium nitrate or liquid calcium fertilizers were used. The results differed over the years of experiment. During the first year, four applications of liquid calcium fertilizers significantly reduced the Mg/Ca ratio in fruit, whereas in 2008 the tendency of decrease in the ratios of K/Ca and Mg/Ca at both fertilizers was observed. The bitter pit incidence rate on stored apples of the 2007 yield was 1.5-3.0%. The eight applications of liquid calcium fertilizers significantly reduced the incidence of bitter pit after storage. In 2008, higher fruit calcium content and lower ratios of N/Ca, K/Ca, and Mg/Ca were detected. Moreover, these apples were not affected by bitter pit. The worse fruit quality of the 2007 yield could be linked to the abundant rainfall during 2007 vegetation season. However, the application of fertilizers had a positive effect on natural weight loss and fruit flesh firmness after storage.

O objetivo deste trabalho foi avaliar os efeitos da pulverização pré-colheita de macieiras 'Gala' e 'Fuji' com aminoetoxivinilglicina (AVG) sobre a qualidade dos frutos e a ocorrência de distúrbios fisiológicos e doenças. O experimento foi conduzido nos anos de 2005 e 2006, com pulverização de AVG (30 dias antes do início da colheita comercial dos frutos) nas doses de 0; 125 e 250 mg L-1, sendo que, na segunda safra, também foi utilizada a dose de 62,5 mg L-1. Em maçãs 'Gala', o aumento na dose de AVG reduziu o desenvolvimento de coloração vermelha e a permeância à perda de água na casca. Nesta mesma cultivar, em frutos avaliados após armazenamento refrigerado (três meses a 0±0,5ºC/90-95% UR), seguido de uma semana de vida de prateleira (20±4ºC/60-70% UR), o tratamento pré-colheita com AVG aumentou a incidência de "bitter pit", porém reduziu a incidência de escaldadura, rachadura peduncular e podridões. Em maçãs 'Fuji', o aumento na dose de AVG reduziu a incidência e a severidade de pingo-de-mel em frutos colhidos tardiamente. A pulverização com AVG aumentou a severidade de mancha foliar de 'Gala' (Glomerella cingulata).The objective of this work was to study the effects of preharvest spraying of 'Gala' and 'Fuji' apple trees with aminoethoxyvinylglycine (AVG) in fruit quality and incidence of physiological disorders and diseases. The experiments were carried out in 2005 and 2006, with AVG sprayed (30 days before anticipated fruit harvest) at the doses of 0, 125 and 250 mg L-1, and also at the dose of 62.5 mg L-1 in 2006. In 'Gala' apples, the increase of AVG dose delayed red color development and reduced the water loss permanence of the skin. For this cultivar, the preharvest treatment with AVG increased the incidence of bitter pit, and reduced the incidence of scald, stem-end splitting and decay on fruits assessed after cold storage (three months at 0±0.5ºC/90-95% RH), followed by one week of shelf life (20±4ºC/60-70% RH). The increase in AVG dose reduced the incidence and severity of watercore in late harvested 'Fuji' apples. The product increased the severity of 'Gala' leaf spot (Glomerella cingulata).

Calcium sprays have normally improved both the quality and the storage life of apples throughout the world because Ca helps to prevent many fruit disorders and that taken up from the soil does not often reach the fruit in adequate amounts. Since the efficacy of Ca sprays varies according to soil, apple cultivar, and weather conditions, this study was carried out from 1998 to 2004, in the Southern of Brazil, in order to assess the effect of Ca sprays on the quality and storability of 'Gala' fruits. The experiment was set up in an orchard planted in 1988, on a density of 1234 trees/ha. Treatments consisted of 0, 4, 8, and 12 annual sprays of 0.5% CaCl2 regularly distributed 30 days after petal fall until one week before harvest. Fruits of the same size and maturity level were annually analyzed at harvest and after five months of conventional cold storage (-1ºC and 90-95% of RH). In five out of six seasons, fruits from all treatments were free of any physiological disorder, and Ca sprays had no effect on leaf composition and on any fruit attribute (soluble solids, titratable acidity, starch pattern index, flesh firmness, and concentrations of N, K, Ca and Mg). In the season of 2000/2001, however, when yield was 18 t ha-1 and fruits had an average weight of 175 g, the incidence of bitter pit plus lenticel blotch pit on stored fruits was 24% in the treatment with no calcium sprays and it decreased up to 2% in that with 12 sprays. Two seasons later, yield was also low (25 t ha-1) and fruits were large (168 g each), but they did not show any physiological disorder regardless of the number of Ca sprays. It seems that the incidence of Ca related disorders in 'Gala' apples grown on limed soils in Brazil with no excess of any nutrient only occurs on seasons with low crop yield, as a result of large fruits and a high leaf/fruit ratio, associated with some unknown environmental conditions.Pulverizações com cálcio normalmente melhoram a qualidade e a capacidade de armazenamento de maçãs porque este nutriente ajuda a prevenir muitos distúrbios fisiológicos, associado ao fato de que a absorção de Ca, a partir do solo, às vezes não chega aos frutos em quantidades adequadas. Como a eficiência das pulverizações com Ca varia com o tipo de solo, com a cultivar e com as condições climáticas, conduziu-se o presente trabalho com o objetivo de avaliar o efeito das mesmas na qualidade e na capacidade de armazenamento de maçãs da cultivar Gala. O experimento foi conduzido de 1998 até 2004, em Vacaria-RS, sobre um pomar plantado em 1988, numa densidade de 1.234 árvores por hectare. Os tratamentos consistiram em 0; 4; 8 e 12 pulverizações anuais com solução de CaCl2 0,5%, regularmente distribuídas desde 30 dias após a queda de pétalas até uma semana antes da colheita. Frutos de mesmo tamanho e com mesmo nível de maturação foram analisados na colheita e após 5 meses de armazenamento em câmaras frigoríficas convencionais (-1ºC e 90-95% UR). Em cinco das seis safras, não houve incidência de distúrbios fisiológicos nos frutos em nenhum tratamento, e as pulverizações com Ca não afetaram a composição química das folhas e nenhum atributo dos frutos (sólidos solúveis, acidez titulável, índice de iodo-amido, firmeza e concentração de N, K, Ca e Mg). Na safra de 2000/2001, entretanto, quando a produtividade foi baixa (18 t ha-1) e os frutos apresentavam um peso médio de 175 g, a incidência de "bitter pit" e a depressão lenticelar atingiram 24% das maçãs que não foram pulverizadas com Ca, tendo diminuído para 2% nas que receberam 12 pulverizações. Dois anos mais tarde, a produtividade foi novamente baixa (25 t ha-1), e os frutos foram grandes (168 g), mas não houve incidência de nenhum distúrbio fisiológico, independentemente do número de pulverizações com Ca. Verifica-se, portanto, que o aparecimento de distúrbios fisiológicos em maçãs 'Gala', produzidas em pomares da região Sul do Brasil com acidez adequadamente corrigida e sem excesso de nutrientes, somente ocorre em áreas com baixa produtividade, em função da existência de frutos grandes e da alta relação entre folhas e frutos, associada com alguns fatores climáticos predisponentes ainda desconhecidos.

Bitter pit is a serious disorder in apples. The current technique involves manual inspection of fruits prior to packaging for fresh market. Therefore, the main objective of this study was to evaluate the near infrared (NIR) spectroscopy for bitter pit detection in apples. The spectral reflectance data were collected from healthy and bitter pitted honeycrisp apples from two different locations. Apples were stored in cold storage and spectra were acquired at 0, 35 and 63 days after harvest (DAH). On each of the DAH, each of the 40 apples (20 healthy and 20 bitter pitted) were analyzed to acquire three spectra per location with three marked locations per fruit. Suitable spectral features were selected using stepwise multilinear regression and rank feature technique. The spectral bands of 971.2, 978.0, 986.1, 987.3, 995.4, 1131.5, 1135.3, 1139.1 and 1142.8 nm were identified as the bands thought to be associated with bitter pit in honeycrisp apples. Feature datasets were evaluated using quadratic discriminant analysis and support vector machine classifiers to evaluate robustness of these features in bitter pit detection. Overall, classifiers performance comparison revealed that bitter pitted honeycrisp apples can be distinguished with average accuracy in the range of 78–87%. Based on spectral features of this study, spectra related to cell membrane water-soaked regions that contribute to spectral variation might have been identified. Our on-going studies are further validating those bands on Honeycrisp and other apple cultivars and using different spectral band selection methods towards developing a portable sensing module for apple bitter pit detection. [ABSTRACT FROM AUTHOR]

Bitter pit is a physiological disorder that is defined as brown, corky and roundish lesions, which can develop in apples before and after harvest. This disorder greatly reduces the product utilization value of the fruit, and can result in several million dollar economic loss to the apple industry. Computed Tomography (CT) imaging is a non-destructive and rapid sensing technique that can be applied to packaged apples. In this study, healthy and bitter pit Honeycrisp apples were harvested from two field sites and stored for 63 days. CT images of the sampled apples were collected on 0, 7, 14, 21, 35 and 63 days after harvest. Images were analyzed to estimate the total pit area in each of the individual apples and were related to pit incidence and progression in different stages of storage. Results showed pit development during the storage period in bitter pitted apples. The rate of progression differed in samples collected from different field sites. Further analysis for pit distribution along each of the bitter pit affected apples showed 54% of pits located at the calyx-end of apples in comparison with middle and stem-end. Classification of healthy and bitter pitted apples using logistic regression based method resulted in false negative of 7–21%. [ABSTRACT FROM AUTHOR]