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Gray mold is the primary postharvest disease of ‘Hayward’ kiwifruit (Actinidia deliciosa) in Chile, with a prevalence of 33.1% in 2016 and 7.1% in 2017. Gray mold develops during postharvest storage, which is characterized by a soft, light to brown watery decay that is caused by Botrytis cinerea and B. prunorum. However, there is no information on the role of B. prunorum during the development and storage of kiwifruit in Chile. For this purpose, asymptomatic flowers and receptacles were collected throughout fruit development and harvest from five orchards over two seasons in the Central Valley of Chile. Additionally, diseased kiwifruits were selected after storage for 100 days at 0°C and 2 days at 20°C. Colonies of Botrytis sp. with high and low conidial production were consistently obtained from apparently healthy petals, sepals, receptacles, and styles and diseased kiwifruit. Morphological and phylogenetic analysis of three partial gene sequences encoding glyceraldehyde-3-phosphate dehydrogenase, heat shock protein 60, and DNA-dependent RNA polymerase subunit II were able to identify and separate B. cinerea and B. prunorum species. Consistently, B. cinerea was predominantly isolated from all floral parts and fruit in apparently healthy tissue and diseased kiwifruit. During full bloom, the highest colonization by B. cinerea and B. prunorum was obtained from petals, followed by sepals. In storage, both Botrytis species were isolated from the diseased fruit (n = 644), of which 6.8% (n = 44) were identified as B. prunorum. All Botrytis isolates grew from 0°C to 30°C in vitro and were pathogenic on kiwifruit leaves and fruit. Notably, B. cinerea isolates were always more virulent than B. prunorum isolates. This study confirms the presence of B. cinerea and B. prunorum colonizing apparently healthy flowers and floral parts in fruit and causing gray mold during kiwifruit storage in Chile. Therefore, B. prunorum plays a secondary role in the epidemiology of gray mold developing in kiwifruit during cold storage.

Raspberries (Rubus ideaus L.) are highly perishable and susceptible to rot during storage. An exploratory study of postharvest physiology associated with maturity was carried out for three new Chilean raspberry cultivars: Santa Catalina, Santa Clara and Santa Teresa. Fruit of these cultivars were harvested at three maturity stages based on color: pink (C3), bright red (commercial maturity) (C4) and dark red (C5). Two experiments were carried out to: i) determine postharvest quality and physiological parameters associated with maturity stages in comparison to those fruits of the main cv. Heritage, and ii) evaluate storage potential at 0 and 4 °C of ‘Santa Catalina’. In the first study, fruit quality parameters (such as weight, firmness, color, among others) of all the ‘Santa’ cultivars were assessed immediately after harvest, and the ethylene production and respiration rates (CO2) were recorded for 4 d at 20 °C. In the second experiment, ‘Santa Catalina’ was stored at 0 and 4 °C. According to the results of the first experiment, ‘Santa Teresa’ presented the largest fruit (7.9 g), followed by ‘Santa Clara’ (5.3 g), ‘Santa Catalina’ (4.9 g) and ‘Heritage’ (3.3 g). ‘Santa Clara’ (~ 6 ng kg-1 s-1) fruits had the highest levels of ethylene production, followed by ‘Santa Catalina’, and ‘Santa Teresa’ with the lowest production. Regardless the cultivar, the fruit at the C5 stage always showed the highest ethylene production. Overall, compared with ‘Heritage’, these three new cultivars presented better fruit quality at harvest. The 0 °C was an adequate storage temperature for ‘Santa Catalina’ reaching storage potential of 20 d without soft fruits; therefore, it is recommended for fresh markets.

Dieback symptoms associated with fungal trunk pathogens cause significant economic losses for farmers of kiwifruit and other woody fruit trees worldwide. This study represents the first attempt to identify and characterize the fungal trunk pathogens associated with cordon dieback disease of kiwifruit in central Chile. Field surveys were conducted throughout the main kiwifruit-growing regions in central Chile to determine the incidence and characterize the fungal trunk pathogens associated with cordon dieback of kiwifruit cultivar Hayward through morphological, molecular, and pathogenicity studies. A total of 250 cordon samples were collected and isolations were performed on 2% acidified potato dextrose agar (APDA) plus antibiotics and Igepal. The incidence of kiwifruit cordon dieback ranged between 5% and 85% in all surveyed areas in central Chile. A total of 246 isolates were isolated and identified using culture and morphological features belonging to three fungal taxa: Diaporthaceae spp. (Diaporthe ambigua and D. australafricana; n = 133 isolates); Botryosphaeriaceae spp. (Diplodia seriata and Neofusicoccum parvum; n = 89 isolates); and Ploettnerulaceae spp. (Cadophora luteo-olivacea and C. malorum; n = 24 isolates). These were identified using phylogenetics studies of the internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2) of the rDNA, part of the β-tubulin gene (tub2), and part of the translation elongation factor 1-α gene (tef1-α). Isolates of N. parvum and D. seriata were the most virulent, causing internal brown lesions and dieback symptoms in attached green shoots, attached lignified canes, and young inoculated kiwifruits. This report is the first to describe D. seriata and C. luteo-olivacea associated with kiwifruit cordon dieback in Chile. It presents the first description of N. parvum causing kiwifruit dieback worldwide.

Apple (Malus domestica Borkh) is a major fruit crop in Chile. Among apple diseases, moldy core (MC) in the fruit has a high prevalence (16 to 46%) in susceptible cultivars. Apparently healthy flowers and fruit were sampled at six growth stages, from the pink bud to the mature fruit, from the susceptible ‘Oregon Spur’ and from the resistant ‘Granny Smith’ apples during two growing seasons. At least seven fungal genera were detected colonizing flowers and the fruit of both cultivars. Small-spored Alternaria spp. were the primary species identified throughout all the growing stages. Independently of the growth stages, sepals, stamens and carpels of flowers were similarly colonized by Alternaria spp. in the susceptible (‘Oregon Spur’) and resistant (‘Granny Smith’) apple cultivars. However, in fruits of 4–6 cm in diameter, big differences in the frequency of Alternaria spp. in fruit carpels were observed between susceptible and resistant apples, with 55% and 1%, respectively. At least five Alternaria spp. were identified at the species level using plasma membrane ATPase, namely, A. alternata, A. arborescens, A. limoniasperae, A. tenuissima in sect Alternaria, A. kordkuyana in sect. Pseudoalternaria and Alternaria sp. in sect. Infectoriae. All Alternaria isolates, from sepals, stamens and carpels, from apparently healthy flowers and fruits were pathogenic, producing MC symptoms in apples. These results suggest that apparently healthy flowers and fruits may act as an important inoculum source of Alternaria spp. for MC infections and also suggest that control strategies against MC using fungicide applications should be carried at flowering, from pink bud onwards.

Use of high tunnels in sweet cherry production is a popular way to reduce rain-induced fruit cracking. However, little information is available for its effects on tree physiology and fruit quality in established sweet cherry orchards. The aim of this study was to evaluate changes in the physiological and production variables of sweet cherry under high tunnels in a Mediterranean type climate in the Central Valley of Chile (35o 1’ S, 71o 32’ W). In 2017, a trial was conducted in a commercial orchard with the early and highly - productive cultivar combination of ‘Royal Dawn’ on ‘MaxMa 14’. Trees were trained as a Y-trellis, spaced at 4.5 x 2.0 m and drip irrigated with four emitters (each emitter of 4 L h-1) per tree. Two treatments of five blocks per treatment were imposed. Treatments were ‘covered’ = trees under multi-bay Haygrove® high tunnels and ‘open’ = trees under open field conditions (control). The average value of gs increased during fruit development but the values under cover were generally 30% higher than in the open. Full bloom occurred 4 days earlier under cover and fruit was harvested 8 days earlier than that in the open and yields were similar (15 kg tree-1). Trees under high tunnels received 20% less amount of water than uncovered trees. There were no differences in fruit quality from different canopy layers. Significantly less cracking losses (3%) were observed in covered trees compared with open (19%). No differences in the ratio of leaf area to fruit number (193 cm2 fruit-1) were found between covered and open trees but fruit from covered trees were larger, less sweet and softer in firmness than that from trees in the open. These altered fruit quality attributes should be improved in relation to the target market and the associated requirements for transport and storage. Results indicate that the use of high tunnels for ‘Royal Dawn’ on ‘MaxMa 14’ sweet cherry production, in a Mediterranean type climate, reduces susceptibility to rain-induced cracking, advances the time of harvest and increases fruit size.

Moldy core (MC) of apple is an important disease in Chile, with prevalence observed between 4 and 46% in Fuji, Oregon Spur Red Chief, and Scarlet apple in the 2014–15 and 2015–16 growing seasons. However, there is no information on the identity of the causal agents associated with MC in Chile. The analysis of 653 MC fruit revealed the presence of several genera of filamentous fungi. However, species of Alternaria (67.7%) were by far the most frequently fungi isolated. In total, 41 Alternaria isolates were characterized morphologically and molecularly using Alternaria major allergen Alt a1, calmodulin, and plasma membrane ATPase gene regions. Six small-spored Alternaria spp. were identified; namely, in order of importance, Alternaria tenuissima, A. arborescens, A. alternata, and A. dumosa in sect. Alternaria; A. frumenti in sect. Infectoriae; and A. kordkuyana in sect. Pseudoalternaria. MC symptoms were reproducible and consisted of a light gray to dark olive-green mycelium over the carpel and seed of immature and mature fruit, confirming that the isolates of these Alternaria spp. were pathogenic. These isolates caused brown necrotic lesions with concentric rings on wounded detached apple leaves. This study demonstrated that at least six Alternaria spp. are the cause of MC of apple in Chile. These Alternaria spp. were isolated alone, or with two or more species coexisting in the same fruit. This is the first report of A. tenuissima, A. arborescens, A. frumenti, A. dumosa, and A. kordkuyana associated with MC of apple in Chile and the first report of A. frumenti, A. kordkuyana, and A. dumosa causing MC of apple worldwide.

Gray mold is the primary postharvest disease of 'Hayward' kiwifruit (

Rachis browning is a serious symptom of water loss affecting the quality of table grapes (Vitis vinifera L.) during storage. It has been evaluated subjectively based on a color scale or by image analysis, while water loss, which is considered as the main factor behind this problem, is mostly measured on basis of whole-cluster weight loss, with only few studies focusing on the rachis exclusively. Our main objective was to compare the sensitivity to water loss and rachis browning of ‘Krissy’ and ‘Thompson Seedless’ cultivars under different storage conditions and using different methods of evaluation (NIR spectrometry, image analysis, colorimeter, weight loss from initial weight and relative water content). The rachises were evaluated during 3 d subjected to a combination of temperatures (0 °C or 20 °C), relative humidity (Saturated or reduced RH), and previous storage at 0 °C for 0 (HT, Harvest Time) and 30 days (ST, Storage Time). NIR spectra (896−2500 nm) were collected, and Partial Least Squares regression (PLS) models were calculated to test the correlation between the spectra and the measurements from other evaluation techniques. Results showed that ‘Krissy’ is more sensitive to dehydration symptoms than ‘Thompson Seedless’. Saturated RH combined with low temperature (0 °C) are the most suitable to reduce rachis browning and water loss during the 3 d of storage at both HT and ST. The decrease in RWC (Relative Water Content) coincided with an increase in rachis browning throughout storage. Additionally, results provided six NIRS-based prediction models for browning severity (R2 = 0.82 and 0.84), hue color (R2 = 0.68 and 0.72) and water loss (R2 = 0.63 and 0.90) in rachises of ‘Krissy’ and ‘Thompson Seedless’, respectively. These results demonstrate that the NIRS can be a suitable non-destructive method to quantify a range of rachis browning severity produced under different storage conditions.

Dieback symptoms associated with fungal trunk pathogens cause significant economic losses for farmers of kiwifruit and other woody fruit trees worldwide. This study represents the first attempt to identify and characterize the fungal trunk pathogens associated with cordon dieback disease of kiwifruit in central Chile. Field surveys were conducted throughout the main kiwifruit-growing regions in central Chile to determine the incidence and characterize the fungal trunk pathogens associated with cordon dieback of kiwifruit cultivar Hayward through morphological, molecular, and pathogenicity studies. A total of 250 cordon samples were collected and isolations were performed on 2% acidified potato dextrose agar (APDA) plus antibiotics and Igepal. The incidence of kiwifruit cordon dieback ranged between 5% and 85% in all surveyed areas in central Chile. A total of 246 isolates were isolated and identified using culture and morphological features belonging to three fungal taxa: Diaporthaceae spp. (

Stem end rot (SER) caused by Botrytis cinerea is the primary postharvest disease in the Chilean kiwifruit industry. Relationships between the postharvest occurrence of SER in ‘Hayward’ kiwifruit and the temporal dynamics of earlier B. cinerea colonization of the floral parts (petals, sepals, receptacles, styles) was studied in five orchards over two consecutive seasons in Chile. Weather conditions in the first season favored B. cinerea infection with roughly constant colonization of floral parts up to about 120 days after full bloom, but colonization then increased up until harvest. In the second season, colonization was roughly constant throughout. Latent infections of the fruit occurred in both seasons but were high in the first season and low in the second. Incidence of latent infections at harvest were the best predictors (r > 0.8) of postharvest SER. The number of preharvest infection periods calculated using temperature, leaf wetness, and relative humidity satisfactorily predicted SER incidence by an exponential model, R2 = 0.90, P < 0.001. Results indicated environmental variables play key roles in the temporal dynamics of B. cinerea colonization. Quantification of latent B. cinerea infections in asymptomatic fruit close to harvest, is a practicable way to predict later incidence of SER during storage.

Stem end rot (SER) caused by

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 2; 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.

An herbaceous/grassy-like flavor has been reported by Chilean producers of Regina sweet cherry. There are no previous academic reports related to this flavor occurrence. Sweet cherries from five phenological stages were collected from six orchards with high herbaceous flavor incidence spanning Chilean production zones during the 2019/2020 season. Four experienced panelists tasted the fruit to identify the off-flavor incidence and intensity from four phenological stages, and the same cherries were analyzed for volatile compounds. Thirty-nine volatiles were identified and semi-quantified using solid-phase microextraction (SPME) and GC-MS. The highest off-flavor incidence was found at the bright red (stage 3) and mahogany colors (stage 4). No single volatile explained the herbaceous flavor consistently among orchards. However, it appeared that the off-flavor was related to delayed ripening in cherries, with more C6 aldehydes and less esters. Furthermore, rainfall and the elevation of the orchard had a significant effect on the incidence of off-flavor. Preharvest practices that promote fruit ripening along with avoiding early harvests are recommended to reduce the incidence of herbaceous flavor in Regina.

It is known that high tunnels modify sweet cherry physiological and agronomical response; however, horticultural practices such as irrigation have usually not been adapted to this cultivation system because there is no information about the effects of sweet cherry growing under this controlled environment on fruit tree water relations, water productivity and the possibility of saving water. The present work aims to assess the positive and negative impacts of irrigation regime and protective cultivation on tree water status, agronomical and physiological responses of the sweet cherry tree combination ‘Santina’/‘Colt’ in Mediterranean dry weather conditions of Central Valley of Chile. Two treatments were imposed, plastic covered trees under multi-bay high tunnels and uncovered trees under open field conditions. Within each environment, two irrigation treatments were assayed, a conventional treatment, which followed growers’ normal irrigation practices in the region, and a reduced irrigation treatment, which was irrigated the 75 % of the conventional treatment. High tunnel increased maximum air temperature, relative humidity and altered light radiation in relation to the environmental conditions in the open. Overall, trees under high tunnel showed higher values of soil matric potential, midday stem water potential (-0.8 MPa) and stomatal conductance (250 mmol m−2 s−1). In the open, trees under reduced irrigation showed soil matric potential values below -150 kPa. Thus, soil water deficit affected tree water status, decreased vegetative growth and fruit size. Covered trees blossomed 7 d earlier than those in the open and were harvested 10 d earlier. Total tree yield did not show significant differences among treatments (11.9 kg tree−1); however, when the tree was divided into bottom and top canopy layers, it was found that the top layer of covered trees resulted in significantly lower yield. The cherries from the covered trees were significantly larger (10.4 g) and less firm (75 Durofel units) than those from uncovered trees (8.4 g and 82 Durofel units). The reduced irrigation strategy did not negatively affect tree yield or fruit quality of covered trees and increased water productivity compared with those irrigated with the conventional irrigation. The results obtained highlighted the possibility of decreasing the irrigated water applied to sweet cherry trees under high tunnels by 25 % compared to conventional irrigation.

The rheological properties and structure of the flesh tissue at harvest-ripe fruit of the sweet cherry Prunus avium L. cultivars Bing, Lapins, Regina, Santina, Sweetheart and Van were measured using a textural analyzer equipment and described by light microscopy, respectively. The rheological measurements inflicted reproducible levels of mechanical damage (pitting). The structural and rheological properties of the mesocarp and epidermis correlate with their susceptibility to mechanical damage. Epidermal cell width and area of external mesocarp cells were negatively associated with susceptibility to mechanical damage while cell number, quantified in 1 mm 2 of external mesocarp, was positively associated. Fruit of Bing and Regina are the least susceptible to mechanical damage among the cultivars under study. The least sensitivity of Regina fruit was associated with its wide epidermal cells and high value of modulus of elasticity, while in Bing with its low number of cells as well as high values of stress and strain at bioyield point. The high susceptibility to mechanical damage of Sweetheart and Lapins fruit was associated with their large number of cells in the external mesocarp tissue and with the lowest values of strain at bioyield point, therefore with the lowest deformation capacity of the tissue.

In autumn 2013, fruit of Japanese plum (Prunus salicina) cvs. Angelino and Black Kat developed an unusual brown and soft rot after 2 months in cold storage (0°C) on nearly 1% of the fruit. Fruit showed small, circular, light brown spots that eventually destroyed the entire fruit. Small sporodochia appeared on the fruit surface. Fruit was harvested from orchards located near San Francisco de Mostazal (33°59′ S, 70°41′ W), Chile. Small pieces of diseased tissue were selected from margins of lesions of surface disinfected (96% ethanol) fruit (n = 7) and placed on acidified potato dextrose agar (PDA) plates for 5 days at 20°C. Light brown colonies with even margins and concentric rings of spores were obtained. The conidia of five isolates were one-celled, hyaline, lemon-shaped, (min. 10.7) 14.9 ± 1.5 (max. 18.6) × (min. 8.1) 9.4 ± 0.8 (max. 10.8) μm (n = 30), and borne in branched monilioid chains. This fungus was identified as Monilinia fructicola (G. Winter) Honey (1). Identification was confirmed by amplifying and sequencing the ribosomal ITS1-5.8S-ITS2 region using ITS1 and ITS4 primers (3). BLAST analysis of Chilean plum isolates (GenBank Accession Nos. KF148610 and KF148611) were 99 to 100% identical to isolates of M. fructicola originating from the United States (DQ314727 and HQ846966, respectively) and 100% identical to the first Chilean isolate (JN001480) found in nectarines originating from California at the supermarkets in Santiago in June 2009. Koch's postulates were fulfilled by reproducing brown rot symptoms on mature wounded Japanese plums cv. Angelino (n = 8) inoculated with 10 μl of a conidial suspension (105 conidia/ml) or with a mycelium plug (5-mm diameter). After 2 days in humid chambers (>80% relative humidity) at 25°C, all inoculated fruit developed brown rot symptoms with necrotic lesion means of 15.8 and 21.5 mm in diameter in fruit inoculated with conidia and mycelium, respectively. Non-inoculated control fruit remained healthy. Re-isolations were performed on PDA and the presence of M. fructicola was morphologically confirmed in 100% of the symptomatic fruits. To our knowledge, this is the first report demonstrating the presence of M. fructicola causing brown rot in stored Japanese plums in Chile after its first interception in 2009 in Chile, suggesting that this pathogen has been established in the field. Currently, M. fructicola is a quarantine organism under official control, restricted to Prunus orchards between Santiago and Nancagua in central Chile (2). References: (1) EPPO. EPPO Bull. 39:337, 2009. (2) Servicio Agrícola y Ganadero, SAG, Ministerio de Agricultura, Gobierno de Chile. www.sag.cl , accessed 15 November 2013. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, NY, 1990.

Chile is considered the third major exporter of kiwifruits (Actinidia deliciosa (A. Chev.) C. F. Liang & A. R. Ferguson) worldwide after Italy and New Zealand (1). The genus Diaporthe Nitschke (anamorph: genus Phomopsis) has been reported as causing postharvest rot in kiwifruit (4). During the current study, 1,400 fruits arbitrarily collected from seven controlled atmosphere (CA) rooms after 90 days of storage conditions (2% O2, 5% CO2) determined that 21.5% of the fruit were affected by decay and 0.86% developed symptoms different than those caused by Botrytis cinerea, the main postharvest pathogen associated to kiwifruit. Symptoms were soft rot with brown skin that started at the stem-end and in severe cases affected the entire fruit. Internally, affected fruit showed browning and watery tissues. Twelve affected fruits were surface disinfested (75% ethanol) and small pieces of internal rotten tissues were placed on acidified potato dextrose agar (APDA) for 7 days at 20°C. Twelve isolates were obtained, and four of them were identified morphologically and molecularly as Diaporthe ambigua, a species that has been previously described causing rot in stored kiwifruits in Chile (2). However, eight other flat, white to grayish colonies with sparse dirty-white aerial mycelium at the edge of the dish were obtained (3). Black pycnidia contained unicellular, hyaline, biguttulate, oval to cylindrical alpha conidia, with obtuse ends of (7.9) 6.7 (5.3) × (2.9) 2.5 (2.1) μm (n = 30). These isolates were tentatively identified as a Diaporthe sp. The species identification was determined by sequencing comparison of the internal transcribed spacer (ITS1-5.8S-ITS2) region of the rDNA (GenBank Accession Nos. KJ210020 to 24, KJ210027, and KJ210033) and a portion of beta-tubulin (BT) (KJ210034 to 38, KJ210041, and KJ210047) using primers ITS4-ITS5 and Bt2a-Bt2b, respectively. BLAST analyses showed 99 to 100% identity with D. novem J.M. Santos, Vrandecic & A.J.L Phillips reference ex-type (KC343156 and KC344124 for ITS and BT, respectively) (3). Eighteen mature kiwifruits cv. Hayward were inoculated using a sterile cork borer on the surface of the fruit and placing 5-mm agar plugs with mycelial of D. novem (DN-1-KF). An equal number of fruits treated with sterile agar plugs were used as negative controls. After 30 days at 0°C under CA, all inoculated fruit showed rot symptoms with lesions 7.8 to 16.4 mm in diameter. The same D. novem isolate was inoculated with 30 μl of a conidial suspension (106 conidia/ml) on the surface of 18 ripe kiwifruits that were previously wounded and non-wounded as described above. An equal number of wounded and non-wounded fruits, treated with 30 μl sterile water, were used as negative controls. All inoculated wounded fruits developed rot symptoms with necrotic lesions of 14.1 to 20.2 mm of diameter after 14 days at 25°C. Inoculated non-wounded and negative control fruits remained symptomless. Koch's postulates were fulfilled by re-isolating D. novem only from the symptomatic fruits. To our knowledge, this is the first report of rot caused by D. novem on kiwifruit during cold storage in Chile and worldwide. Therefore, both Diaporthe species appears to be associated to Diaporthe rot of kiwifruit in Chile. References: (1) Belrose, Inc. World Kiwifruit Review. Belrose, Inc. Publishers, Pullman, WA, 2012. (2) J. Auger et al. Plant Dis. 97:843, 2013. (3) R. Gomes et al. Persoonia 31:1, 2013. (4) L. Luongo et al. J. Plant Pathol. 93:205, 2011.

Diaporthe spp. are important plant pathogens causing wood cankers, blight, dieback, and fruit rot in a wide range of hosts. During surveys conducted during the 2013 and 2014 seasons, a postharvest rot in Hayward kiwifruit (Actinidia deliciosa) was observed in Chile. In order to identify the species of Diaporthe associated with this fruit rot, symptomatic fruit were collected from seven kiwifruit packinghouses located between San Francisco de Mostazal and Curicó (central Chile). Twenty-four isolates of Diaporthe spp. were identified from infected fruit based on morphological and cultural characters and analyses of nucleotides sequences of three loci, including the internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2), a partial sequences of the β-tubulin, and translation elongation factor 1-α genes. The Diaporthe spp. identified were Diaporthe ambigua, D. australafricana, D. novem, and D. rudis. Multilocus phylogenetic analysis revealed that Chilean isolates were grouped in separate clades with their correspondent ex-types species. All species of Diaporthe were pathogenic on wounded kiwifruit after 30 days at 0°C under normal and controlled-atmosphere (2% O2 and 5% CO2) storage and they were sensitive to benomyl, pyraclostrobin, and tebuconazole fungicides. D. ambigua isolates were the most virulent based on the lesion length measured in inoculated Hayward and Jintao kiwifruit. These findings confirm D. ambigua, D. australafricana, D. novem, and D. rudis as the causal agents of kiwifruit rot during cold storage in Chile. The specie D. actinidiae, a common of Diaporthe sp. found associated with kiwifruit rot, was not identified in the present study.

Bitter pit (BP) is a physiological disorder that develops in apples, mainly during storage. This study sought to develop NIR spectral models for prediction of future BP incidence and severity in ‘Fuji’ apples using spectral data collected at harvest and during storage. Partial Least Square classification models obtained from spectra reflectance between 950 and 1200 nm were compared, starting at harvest, at 10 days postharvest and every 20 days thereafter over 110 days at 0 °C in relation to BP severity (number of pits per fruit) after 150 days at 0 °C. The models used data from a total of 3000 fruit, collected over two seasons (2018 and 2019) from two orchards. All models were evaluated for Accuracy, Sensitivity, Specificity, Positive Predicted Value (PPV) and Negative Predicted Value (NPV). In the validation dataset, Accuracy, Specificity and NPV values varied between 60 and 80 % and were independent of the time of evaluation during storage. Sensitivity and PPV values did not exceed 60 % in the same dataset. Here, BP incidences in fruit with severities of

Sulfur dioxide and modified atmospheres were evaluated to find the optimal method to control decay and prolong the quality of blueberries after harvest. To determine the most suitable MAP system for highbush blueberry ( Vaccinium corymbosum , ‘Brigitta’), fruit were stored in controlled atmospheres (CO 2 /O 2 partial pressures in kPa: 5/1; 7/15, 15/5) or an atmosphere modified by varying the amount of fruit in two modified atmosphere packaging (MAP) systems. The MAP systems employed bags with 60 μm-thick low density polyethylene where the fruit were hermetically sealed in the bag: (1) without perforation (MAP 0); or (2) with two perforations of 3 mm 2 (MAP 2). ‘O’Neal’, ‘Duke’, ‘Legacy’, ‘Brigitta’, ‘Elliott’ and ‘Aurora’ were evaluated to reduce deterioration by the most suitable MAP system and, in a separate experiment, ‘Legacy’ fruit were fumigated with SO 2 and packed in the MAP and compared with perforated bag (PB). The effectiveness of reducing blueberry deterioration was evaluated after 30–45 days at 0 °C. CO 2 partial pressure higher than 8 kPa or O 2 partial pressure lower than 2 kPa induces ‘Brigitta’ fruit softening. Among the evaluated cultivars, MAP 2 attained CO 2 and O 2 partial pressures between 4.5–6.0 kPa and 13–15.0 kPa, respectively. Induction of fruit softening by CO 2 was dependent on the cultivar. ‘O’Neal’, ‘Duke’ and ‘Legacy’ were extremely sensitive, at CO 2 concentration of 6 kPa. The benefits of MAP 2 were mainly attributed to humid environment within the packages that allow reducing weight loss and symptoms of dehydration; effects that were mimicked by the perforated bag. ‘Legacy’ blueberry fruit were fumigated for 30 min at 20 °C with SO 2 at concentration time product of 100–150 (μL L −1 ) h, followed by packaging in MAP 2 or in a perforated (0.3% ventilation area) low density polyethylene bag and storage for 45 days at 0 °C. Decay, weight loss, and the percentage of dehydrated and soft fruit were reduced effectively when the SO 2 -fumigated fruit were stored in either MAP 2 or the perforated bag. Decay was particularly well controlled by SO 2 . SO 2 fumigated fruit, packed into a perforated bag was a better option than packaging the fruit into modified atmosphere bags, where the CO 2 steady state partial pressure that controlled decay was extremely close to the level that injured the fruit.

Mango (Mangifera indica L.) is a major tropical fruit that can develop internal physiological disorders at late ripening stages. These include jelly seed characterized by a transparent and jelly tissue around the seed that eventually becomes a brown ring enclosing the seed, and black flesh characterized by a diffuse brown discoloration that covers the seed. Both disorders can result in high postharvest losses due to the fact that little information is available about mechanisms involved and efficient control approaches. The objective of this study was to establish the feasibility of using a visible and near-infrared (Vis-NIR) portable spectrometer for predicting at harvest and detecting mangoes with internal disorders, such as jelly seed and black flesh after storage. A total of 141 'Keitt' mangoes from two commercial harvests were measured spectrally between 400–1100 nm on two opposite cheeks, at harvest and after 30 d at 12 °C. Spectra data and the incidence of jelly seed and black flesh after storage were used to develop classification models using logistic, linear discriminative analyses (LDA), supporting vector machine, functional data and random forest modeling approaches. The results show that wavelengths between 550 and 650 nm can be used to predict at harvest and detect after storage, fruit with internal physiological disorders, such as jelly seed and black flesh. However, it was not possible to differentiate internal disorders from each other. The spectral data show that healthy fruit have higher reflectance intensity than jelly seed and black flesh ones, both at harvest and after storage. The best classification models were obtained with Logistic and LDA model development approaches. In the validation process for internal disorder prediction at harvest, the Logistic model showed accuracy of 65 %, sensitivity of 78 % and specificity of 49 %, whereas the LDA model showed accuracy of 63 %, sensitivity of 76 % and specificity of 46 %. In the validation process for detecting internal disorders after storage, the Logistic model showed accuracy of 71 %, sensitivity of 75 % and specificity of 67 %, whereas the LDA model showed accuracy of 76 %, sensitivity of 78 % and specificity of 73 %. In conclusion, Vis-NIR technology associated with Logistic and LDA modeling approaches can be used to predict at harvest and detect after storage the incidence of jelly seed and black flesh in mangoes.

‘Cripps Pink’ apples are prone to develop internal browning disorder during cold storage rendering their commercialization particularly difficult after long-term storage. The purpose of this research was to predict internal browning defect quantitatively and qualitatively in apple, by a non-destructive equipment from spectra collected before the disorder develops. In order to obtain a broad expression of the disorder in severity and incidence, fruit treated and non-treated with 1-methylcyclopropene (1-MCP) were studied under three temperature regimes: T1) pre-cooled with forced air at −1 °C for 24 h and subsequently stored for 149 d at 0 °C; T2) placed directly at 0 °C and stored for 150 d; and T3) stored for 90 d at 5 °C then for 60 d at 0 °C. Every fruit was subjected to semi-transmittance spectral analysis between 100–1,100 nm at 0, 60, 90, 120 and 150 d of storage and matched with the presence and severity of internal browning. The disorder was quantified using image analysis in one half of cut fruit at the end of the 150 d plus 7 d at 20 °C (157 d) after verification that the damage was not evident in fruit stored before 120 d. Quantitative Support Vector Machine Regression (SVMR) model satisfactorily predicted the percentage of internal browning area per fruit shown after 157 d, as early as 90 d of storage with R2 ∼0.70, and a root mean square error for calibration (RMSEC) and prediction (RMSEP) datasets of ∼18% and ∼15% respectively. On the other hand, qualitative Partial Least Squares Discriminant Analysis (PLS-DA) model was able to predict the damaged fruit at the onset of storage (0 d) and to reach an accuracy values ∼87% in calibration and test datasets, and 12% of misclassified fruit at 90 d. Quantitative and qualitative neural network models were also evaluated, reaching similar correlation coefficients, in cross validation or accuracy rate as multivariable models did, offering a novel way for modelling biological processes. This study shows different models for predicting internal browning before the disorder appears in stored apple using semi-transmittance spectra.

Sweet cherry fruit is considered very sensitive to physical injury produced during harvest and postharvest handling. Surface depression (pitting and bruising) appears on the injured fruit area after a week of storage at 0°C. Two trials were conducted on ‘Van’, ‘Royal Dawn’, or ‘Sweetheart’ sweet cherry to test the hypothesis that fruit becomes more sensitive to physical injury at lower temperatures. In the laboratory trial, the incidence of impact damage was evaluated by dropping a steel ball at ten cm height on fruits with 2, 7, 10 or 15°C pulp temperature. A significant reduction in pitting incidence was obtained when the fruit temperature was increased from 2°C to 7°C or 10°C for ‘Van’ and ‘Royal Dawn’. In the packing line trial, ‘Sweetheart’ fruit were placed on a commercial packing line using cold water to achieve a 2.5-3.8°C or 5.3-6.3°C fruit temperature. The incidence of pitting and bruising from fruit handling at 5.3-6.3°C was 30.9% compared with 70.8% when the fruit temperature was in the range of 2.5-3.8°C. Evaluations comparing the different sectors of the packing line demonstrated that fruit at low temperature was more sensitive to develop small pit symptoms and these were mainly induced at the stem cutting sector. Therefore, water temperature management along the cherry processing line is required to reduce surface pitting symptoms after storage.

Highbush blueberries (Vaccinum spp.) are a major export fruit crop of Chile which is stored at 0 °C and transported to markets in Asia, Europe, and the USA, using more than 15 d of maritime transportation. Under these conditions, gray mold caused by Botrytis cinerea can produce important economic losses. The effectiveness of sulfur dioxide (SO2) concentration × time treatments on gray mold control was determined in the laboratory and validated prior to refrigerating the fruit, using pallet scale SO2 fumigation treatment on the following blueberry cultivars: ‘Brigitta’, ‘Legacy’, ‘Liberty’ and ‘O’Neal’. In inoculated ‘Brigitta’ and ‘Liberty’ blueberries, gray mold prevalence varied from 97.2% to 97.5% in non-treated fruit, and this value was reduced from 7.9% to 6.1% in blueberries that were exposed to a SO2 concentration × time (Ct) product of 400 (μL L−1) h. The relationship between SO2 Ct products and gray mold prevalence under laboratory conditions was best explained by exponential models, which had a determination coefficient (R2) that ranged from 0.88 to 0.96. The estimated EC90 values varied between 245 and 400 (μL L−1) h, and the SO2 Ct between 250 and 350 (μL L−1) h was validated using a pallet scale application treatment to obtain the best control and minimal variation. No visual phytotoxicity symptoms of SO2 were observed with the Ct that was tested in this study. Therefore, SO2 fumigation was demonstrated to be an effective and practical technology for reducing the risk of blueberry gray mold decay during storage, and further effort should be given to register the use of this product for blueberries in the main Chilean export markets.

Rivera, S. A., Zoffoli, J. P., and Latorre, B. A. 2013. Infection risk and critical period for the postharvest control of gray mold (Botrytis cinerea) on blueberry in Chile. Plant Dis. 97:1069-1074. Gray mold (Botrytis cinerea) is a major disease of blueberries (Vaccinium spp.), which require more than 15 days of shipment at 0°C to reach international markets. The aims of this study were (i) to determine the relative susceptibility of the flowering and fruiting stages, (ii) to determine the critical blueberry growth stages for postharvest gray mold control, and (iii) to determine the infection risks on the basis of weather conditions. The epiphytic colonization of B. cinerea of flowers and fruits was demonstrated in blueberry ‘Brigitta’ and ‘Duke’ in Antuco and Virquenco. In inoculated flowers and fruits in humid chambers at 20°C, full bloom and mature fruit stages were the most susceptible stages. Fungicide applications at the mature fruit stage appeared as the most critical period for gray mold control in stored fruits. The algorithm proposed, which was based on >6 h of wetness between 14 and 25°C, allowed the estimation of the periods of B. cinerea infection risk. A significant correlation between the B. cinerea infection risk and gray mold incidence in stored fruits was obtained (r = 0.96, P < 0.0001). Therefore, this algorithm has the potential to optimize fungicide applications under field conditions, but field validation of this algorithm remains to be determined. Highbush blueberry (Vaccinium spp.) is a high-value export crop cultivated on over 8,400 ha across a range of diverse soil conditions and climate zones in Chile (www.odepa.cl). The commercial plantings in Chile extend from latitude 29° to 42° south, with harvesting from October to April (1). The blueberries are exported mainly to the United States (3), but markets in Europe and Asia are increasing. Blueberry flowers and fruits can be affected by several fungal diseases (5,16,23,24), with the gray mold caused by Botrytis cinerea Pers. ex Fr. (teleomorph Botryotinia fuckeliana (de Bary) Whetzel) being one of the most frequent and severe diseases. Gray mold commonly occurs in blueberry plantings in Chile (31) when favorable weather conditions prevail during the growing season and causes blossom and twig blights and a soft decay in mature fruits at harvest time and during storage (2,5,29,30,32). Furthermore, although the blueberries are transported at near 0°C, the Chilean blueberry transport to market requires more than 15 days by sea, with severe losses often occurring (3). As proposed for other fruit crops (10,13,18,21), it is postulated that the postharvest gray mold decay of blueberry can be initiated at flowering or during the early stages of fruit development, remaining latent until harvest and postharvest. Therefore, to prevent severe losses due to gray mold during storage and transportation, fungicide treatments have been proposed between flowering and fruit maturity, and several fungicides have been registered in Chile, including anilinopyrimidines (e.g., cyprodinil) and anhydroxanilide (e.g., fenhexamid) (www.sag.gob.cl). Recently, sulfur dioxide (SO2) treatments applied to packed fruits just after harvest have been advocated to prevent gray mold decay during storage and transportation (8,27). However, further studies are needed to establish the critical growth stages for gray mold control in the current blueberry cultivars planted at a relatively high density in Chile. This information would be valuable for the timing of fungicide treatments. Although such weather conditions as the temperature and duration of free moisture have been previously related to B. cinerea infection in table grapes (6,20) and strawberries (7), the effect of such factors has yet to be studied with regard to gray mold in blueberries. Therefore, this study was conducted (i) to determine the relative susceptibility of the flowering and fruiting stages to B. cinerea, (ii) to determine the critical blueberry growth stages for postharvest gray mold control, and (iii) to determine the infection risks on the basis of weather conditions.

Maqui ( Aristotelia chilensis [Molina] Stuntz, Elaeocarpaceae) is a Chilean native species which produces small berries that are mainly collected from the wild. The health benefits of maqui fruit are attributed to their high polyphenol content as well as their wide variety of anthocyanins and flavonols. One of the main factors that affect the polyphenol content in fruit is the maturity stage at harvest. The objective of this study was to determine total phenol and total anthocyanin content and antioxidant activity (by ferric reducing ability of plasma [FRAP] assay) of maqui fruits harvested at different fruit maturity stages from two wild populations located in Central Chile. Each maturity stage was determined by days from fruit set, berry size, and soluble solids. Total phenol content declined while total anthocyanin content increased from the green to light red stage. Nevertheless, both total phenol and anthocyanin content increased from the light red to dark purple stage. The highest anthocyanin content and antioxidant activity was found in the late maturity stage (dark purple). The results show that ripening in maqui fruit can be expected with 1100 growing degree-days (91 d after fruit set) in Central Chile. At this moment of harvest, fruits with 18-19° Brix have the highest anthocyanin content and antioxidant activity (FRAP). This study constitutes the first advances in the understanding of maqui fruit ripening and corresponding antioxidant activity.

Maqui (Aristotelia chilensis Molina Stuntz, Elaeocarpaceae) is a Chilean native species which produces small berries that are mainly collected from the wild. The health benefits of maqui fruit are attributed to their high polyphenol content as well as their wide variety of anthocyanins and flavonols. One of the main factors that affect the polyphenol content in fruit is the maturity stage at harvest. The objective of this study was to determine total phenol and total anthocyanin content and antioxidant activity (by ferric reducing ability of plasma FRAP assay) of maqui fruits harvested at different fruit maturity stages from two wild populations located in Central Chile. Each maturity stage was determined by days from fruit set, berry size, and soluble solids. Total phenol content declined while total anthocyanin content increased from the green to light red stage. Nevertheless, both total phenol and anthocyanin content increased from the light red to dark purple stage. The highest anthocyanin content and antioxidant activity was found in the late maturity stage (dark purple). The results show that ripening in maqui fruit can be expected with 1100 growing degree-days (91 d after fruit set) in Central Chile. At this moment of harvest, fruits with 18-19 °Brix have the highest anthocyanin content and antioxidant activity (FRAP). This study constitutes the first advances in the understanding of maqui fruit ripening and corresponding antioxidant activity.El maqui (Aristotelia chilensis Molina Stuntz, Elaeocarpaceae) es una especie nativa de Chile que produce unas bayas pequeñas que se recolectan principalmente de individuos silvestres. Los beneficios para la salud atribuidos a los frutos de maqui se deben a sus altos contenidos de polifenoles, así como a la gran variedad de antocianos y flavonoles. Uno de los principales factores que afectan el contenido de polifenoles en frutos es el estado de madurez a la cosecha. El objetivo de este estudio fue determinar el contenido de fenoles totales, antocianos totales y la actividad antioxidante (método FRAP habilidad del plasma para reducir el hierro férrico) de frutos de maqui cosechados en diferentes estados de madurez de dos poblaciones silvestres ubicadas en Chile Central. Cada estado de madurez fue caracterizado de acuerdo a los días desde la cuaja de frutos, tamaño y sólidos solubles. El contenido de fenoles totales disminuyó mientras que el contenido de antocianos totales aumentó desde fruto verde hasta fruto en pinta; sin embargo, los valores de ambas variables aumentaron desde pinta hasta fruto purpura oscuro. La mayor capacidad antioxidante se observó en los frutos del Ultimo estado de maduez analizado (purpura oscuro). Los resultados demostraron que la madurez de consumo en frutos de maqui puede ser esperada con 1100 grados día de crecimiento (91 d después de cuaja) en Chile Central. En este momento de cosecha, frutos con sólidos solubles entre 18 y 19 °Brix tienen los mayores contenidos de antocianos y actividad antioxidante (FRAP). Este estudio constituye los primeros avances en el entendimiento de la maduración de frutos de maqui y su correspondiente actividad antioxidante.

M. Villasante, S. Godoy, J.P. Zoffoli, and M. Ayala. 2012. Pruning effects on growth and fruit quality of ‘Bing’/‘Gisela®5’ and ‘Bing’/‘Gisela®6’ sweet cherry trees ( Prunus avium ). Cien. Inv. Agr. 39(1): 117-126. Annual pruning is one of the most efficient ways to regulate crop load and renew fruiting wood in highly productive sweet cherry ( Prunus avium L.) combinations. Although Chilean growers did not previously prune cherry trees of more vigorous combinations, in recent years, the adoption of more dwarfing rootstocks and self-fertile cultivars has led to the inclusion of annual pruning as a practice in modern orchards. At first, this alteration in orchard management practices was not considered by growers, and thus, many of the initially established cherry orchards were not pruned as intensively as they should have been. As a consequence, many trees showed a reduction in fruit quality after 4 or 5 years of being planted, as they became overcropped and, consequently, registered reductions in their vegetative growth. There are only a few studies related to the effect of corrective pruning on dwarfing combinations that display an imbalance between reproductive and vegetative growth due to a reduction in the leaf area to fruit ratio of the tree. For this reason, the objective of this research was to study the effect of pruning in an orchard consisting of the dwarfing combinations ‘Bing’/‘Gisela®5’ (‘Bing’/‘GI®5’) and ‘Bing’/‘Gisela®6’ (‘Bing’/‘GI®6’), which shown a reduction in vigor, fruit quality and yield. Trees of both combinations were treated with a medium intensity pruning in late winter (early September). Several vegetative (shoot length, leaf area of spurs and shoots, trunk cross sectional area) and reproductive (total yield per tree, fruit growth and quality) parameters were evaluated after pruning. One of the most important effects of pruning for both combinations was an increase in the total current season shoot (CSS) growth, which was 112.5 and 125.6% for ‘Bing’/‘GI®5’ and ‘Bing’/‘GI®6’, respectively. Additionally, the average shoot length increased by 820.0 and 325.4% for ‘Bing’/‘GI®5’ and ‘Bing’/‘GI®6’, respectively. Furthermore, CSSs developed a higher leaf number in the pruned trees. There was no change in leaf number for reproductive spurs, but these had bigger leaves in the pruned trees, demonstrating increased total leaf area per spur. Additionally, pruning allowed crop load regulation and increased fruit size by 8.5 and 6.1% for ‘Bing’/‘GI®5’ and ‘Bing’/‘GI®6’, respectively. However, fruits from pruned trees showed a higher susceptibility to mechanical damage compared with unpruned trees of both combinations.

Over 54,600 ha of table grapes ( Vitis vinifera ), mainly cvs. ‘Thompson Seedless’, ‘Flame Seedless’ and ‘Redglobe’, are planted in Chile. Almost the entire production is exported to the USA, Europe, Asia, or one of several Latin American countries, which typically requires 15–40 d of maritime transportation. During this period, several physical, physiological, and pathological factors cause table grape deterioration. Because berry size is the main quality factor in international markets, farmers often overuse the growth regulators, gibberellic acid (GA 3 ) and forchlorfenuron (CPPU), in an effort to increase berry size. We examined the effect of preharvest growth regulators on seedless (‘Thompson Seedless’, and ‘Ruby Seedless’) and seeded (‘Redglobe’) table grape cultivars during cold (0 °C) storage plus a shelf life period of 3 d at 20 °C. The overuse of GA 3 , eight instead of two GA 3 applications on Thompson Seedless, and the use of one GA 3 application on Redglobe and ‘Ruby Seedless’, increased berry pedicel thickness and lowered cuticle content but induced shatter and predisposed grapes to gray mold caused by Botrytis cinerea . In contrast, CPPU increased berry pedicel thickness and cuticle content but did not increase shatter or gray mold incidence. Clusters that were subjected to overuse of combined GA 3 and CPPU were highly sensitive to shatter, had the thickest pedicel, and developed a high gray mold incidence during cold storage. Hairline, a fine cracking developed during cold storage, was induced on ‘Thompson Seedless’ and ‘Ruby Seedless’ by growth regulators, but no hairline occurred on ‘Redglobe’ table grapes. Therefore, berry quality during cold storage is greatly influenced by growth regulator management in the vineyard.

Hairline cracks, which developed after harvest among SO 2 -treated table grapes, were characterized by small, fine, longitudinal, cracking lines, almost undetectable with the naked eye. Juice exudation from the cracks resulted in a wet and sticky berry skin. Hairline cracks, which we propose to term ‘hairline’, were distinctively different from splitting observed before harvest. Hairline was only induced when table grapes were treated with gaseous SO 2 , commonly used to prevent decay of table grapes during cold storage in Chile. In practice, conditions that favored higher concentrations of SO 2 , such as the use of two SO 2 generating pads (one on top and one on the bottom of the packaged table grapes), promoted hairline cracking. Hairline incidence increased linearly when the concentration and time product (CT) of SO 2 exceeded 3 (mL L −1 ) h, and no hairline cracking was observed with CT below 0.8 (mL L −1 ) h. Hairline symptoms were greatly induced on Thompson Seedless table grapes that were immersed in acidic solutions (citric acid and disodium phosphate) at pH 2 or 4. To reduce this disorder, it is essential to use a minimal dose of SO 2 that allows adequate protection from decay without reducing the berry quality. Postharvest practices of table grapes, packaged with a SO 2 generating pad, such as extended delay cooling periods and those practices that involve a raise in temperature, considerably enhance this disorder. Hairline cracking is another expression of phytotoxicity due to overexposure of table grapes to SO 2 .

Blossom blight is a destructive disease of plums (Prunus salicina) when humid and temperate weather conditions occur in Chile. Disease incidence ranging from 4 to 53% has been observed. Symptoms include light brown petal necrosis, starting as light brown mottles or V-shaped necrosis at the margins of the petals, progressing to the stamen and pistils. In this study, the etiology of blossom blight of plums was determined. High- and low-sporulating isolates of Botrytis were obtained consistently from blighted blossoms and apparently healthy flowers of plums. Based on colony morphology, conidial production and molecular phylogenetic analysis, these high- and low-sporulating isolates were identified as B. cinerea and B. prunorum sp. nov., respectively. Phylogenetic analysis of the genes glyceraldehyde 3-phosphate dehydrogenase (G3PDH), heat-shock protein 60 (HSP60), and DNA-dependent RNA polymerase subunit II (RPB2) grouped B. prunorum isolates in a single cluster, distantly from B. cinerea and other Botrytis species. The phylogenetic analysis of necrosis and ethylene-inducing protein (NEP1 and NEP2) genes corroborated these results. Analysis of the internal transcribed spacer region and large-subunit (26S) ribosomal DNA and detection of Boty and Flipper transposable elements, were not useful to differentiate between these Botrytis species. Both species were pathogenic on plum flowers and the fruit of plums, apples, and kiwifruits. However, B. prunorum was less virulent than B. cinerea. These pathogens were re-isolated from inoculated and diseased tissues; thus, Koch’s postulates were fulfilled, confirming its role in blossom blight of plums. B. cinerea was predominant, suggesting that B. prunorum may play a secondary role in the epidemiology of blossom blight in plums in Chile. This study clearly demonstrated that the etiology of blossom blight of plums is caused by B. cinerea and B. prunorum, which constitute a species complex living in sympatry on plums and possibly on other stone fruit trees.

Chlorine dioxide (ClO2) is an alternative to hypochlorites (NaOCl, Ca(OCl)2) for fruit and vegetable sanitization to reduce postharvest decays caused, among other fungi, by Botrytis cinerea, Penicillium expansum and Rhizopus stolonifer. Due to economical reasons and because of its explosiveness, the use of chlorine dioxide has been relatively limited. However, the development of stabilized commercial formulations has allowed to reintroduce it. In this study, the efficacy of a new stabilized chlorine dioxide formulation (Tecsa®Clor, Protecsa S.A., Santiago,Chile) to inhibit conidial germination of B. cinerea and P. expansum, and sporangiospore germination of R. stolonifer was demonstrated. The efficacy was dependent primarily on concentration and exposure time but it was also affected by pH. Conidia germination of B. cinerea was inhibited over 98% at concentrations higher than 75 or at 25 mg·mL-1 after 1 or 30 min of contact, respectively. Similarly, over 90% inhibition of conidial germination of P. expansum was achieved with 100 and 25 m·mL-1 after 1 and 30 min, respectively. Sporangiospores of R. stolonifer were inhibited by 90% at 100 mg·mL-1 for 30 min. The pH of the solution increased as chlorine dioxide concentration increased, and the biological activity decreased considerably at pH higher than 8, after 5 and 15 min of contact. No phytotoxic effects were obtained on pear cv. Packham’s Triumph even at 1000 mg·mL-1 after 20-day-exposure at 20 oC. Therefore the stabilized commercial formulation of chlorine dioxide is an alternative to chlorinate water to treat fruits by immersion in order to control B. cinerea, P. expansum and R. stolonifer during postharvest. For a complete control, concentrations higher than 75 mg·mL-1 should be used at pH between 7 and 8. El dioxido de cloro (ClO2) es una alternativa al uso de hipocloritos (NaOCl, Ca(OCl)2) util para la sanitizacion de la fruta en poscosecha y reducir el riesgo de pudriciones causadas entre otros por Botrytis cinerea, Penicillium expansum o Rhizopus stolonifer. Razones economicas y la explosividad de este gas al mantenerlo bajo presion han limitado su uso. Sin embargo, el desarrollo de formulaciones comerciales, estabilizadas, ha permitido reintroducir el dioxido de cloro con estos propositos. En este trabajo se demostro la eficacia de este compuesto, formulado y estabilizado (Tecsa®Clor, Protecsa S.A., Santiago,Chile), en el control de la germinacion de conidias de B. cinerea y P. expansum y esporangiosporas de R. stolonifer. Sin embargo, la efectividad de este producto dependio primeramente de la concentracion y del tiempo de exposicion, pero tambien tuvo importancia en la mortalidad de las esporas el pH de la solucion. Una concentracion de dioxido de cloro > 75 o 25 mg·mL-1 1 o 30 min de exposicion, respectivamente, inhibio en mas de 98% la germinacion de conidias de B. cinerea. En forma similar, se obtuvo sobre un 90% de inhibicion de la germinacion de conidias de P. expansum con 100 y 25 mg·mL-1 por 1 y 30 min, respectivamente. La germinacion de esporangiosporas de R. stolonifer se inhibio por sobre un 90% unicamente con 100 mg·mL-1 por 30 min. El pH de la solucion acuosa de dioxido de cloro aumento considerablemente con la concentracion, disminuyendo la efectividad con pH superior a 8, tanto luego de 5 como 15 min de exposicion. No hubo efectos fitotoxicos en peras cv. Packham’s Triumph aun expuestas a concentracion de 1000 mg·mL-1, luego de 20 dias a 20 oC. Por lo tanto, el dioxido de cloro formulado comercialmente es una alternativa para el control de B. cinerea, P. expansum y R. stolonifer en poscosecha. Sin embargo, se recomienda corregir la dosis en funcion de los patogenos predominantes y verificar el pH de la solucion de modo que esta permanezca entre 7 y 8.

Postharvest diseases are the most important factors that limit commercial export of Chilean table grapes ( Vitis vinifera ). In recent years, blue mold decay caused by Penicillium expansum has frequently appeared on Red Globe (RG) grapes after long term (>60 days) cold storage, causing important economical losses. Isolates of P. expansum obtained from grapes were pathogenic and the susceptibility of grape berries cvs. RG and Thompson Seedless (TS) increased markedly as the soluble solids concentration (SSC) increased from approximately 4–20%. However, higher SSC appeared to limit blue mold development on RG grapes. On detached berries inoculated with P. expansum , fludioxonil (200 mg L −1 ) or cyprodinil + fludioxonil (250 + 170 mg L −1 ) completely controlled it, while cyprodinil (330 mg L −1 ) reduced it by 87.6%. On detached berries inoculated with B. cinerea , applications of cyprodinil (330 mg L −1 ) or cyprodinil + fludioxonil (250 + 170 mg L −1 ) completely controlled it, while fludioxonil (200 mg L −1 ) reduced it by 37.5%. Fenhexamid (400 mg L −1 ) was 100% effective against B. cinerea but ineffective against P. expansum . After vineyard applications of an aqueous spray or dust of cyprodinil + fludioxonil (375 + 250 g i.a. ha −1 ) 24 h before harvest, significant ( P P. expansum and B. cinerea was effectively reduced on packaged RG treated with either 0.85 g kg −1 Na 2 S 2 O 5 (G1, SO 2 -generating pad) or 1.22 g Na 2 S 2 O 5 kg −1 (G2, SO 2 -generating pads). Similar results were obtained on Flame Seedless (FS) and TS grapes using SO 2 -generating pads G1 and G3 (1.22 g kg −1 Na 2 S 2 O 5 ). These SO 2 -generating pads were placed inside a polyethylene bag with either 0.3 or 2% vented area. Regardless of the proportion of vented area, the effect of SO 2 -generating pads lasted for over 45 days. There were no significant differences between SO 2 -generating pads to control P. expansum ; even on RG with treatment G2 where a higher content Na 2 S 2 O 5 per box was attained compared with G1. Otherwise G2 was considerably better than G1 to control B. cinerea on RG table grapes stored for 90 and 120 days. Berry injuries were considerably higher when the G2 SO 2 -generating pad was used but were reduced when the fruit was packaged in a more ventilated bag (2% vented area). Our results demonstrated that both preharvest fungicide applications and SO 2 , applied as SO 2 -generating pads, effectively reduced decay of table grapes caused by P. expansum and B. cinerea in long term cold storage.

Flesh browning, mealiness and softening are the main causes of postharvest deterioration of peaches and nectarines. The gas application of three concentrations of 1Methylcyclopropene (1-MCP) (0.5; 1.0; 1.5 g/m) was evaluated on one peach (‘September Sun’), and two nectarine (‘Arctic Snow’ and ‘Flamekist’) cultivars stored for 17, 23 and 34 days at 0, 5 and 10°C. The gas was applied at 20 °C for a period of 48 hours and the different concentrations were compared with a delay cooling process done under the same conditions and with control fruit where the fruit were cooled rapidly. High incidence of flesh browning and mealiness was obtained with all the cultivars after 23 days of storage at 0 and 5°C, otherwise total reduction was attained at 10°C but with a high rate of fruit softening. 1-MCP did not reduce fruit softening at 10°C. Delay cooling reduced the incidence of mealiness in all the cultivars after 17 days of storage at all the temperatures evaluated, but high rate of softening was obtained. Although 1-MCP maintained fruit firmness, the combination with the delay cooling procedure reduced the effectiveness of the later to avoid mealiness. The best result of delay cooling and 1-MCP treatments was obtained with ‘Arctic Snow’ cultivar with the lowest concentration of 1-MCP evaluated.

The susceptibility of mealiness and flesh browning physiological disorders was evaluated after 3, 5 and 6 weeks on ripe 'Sweet September,' 'September Sun,' 'Ryan Sun' and 'Rosario Red' peach (Prunus persica (L.) Batsch) cultivars harvested at three maturities and stored under modified atmosphere packaging ((MAP) experimental bag P(2)UC 965 (Chile)). High incidence (>40%) of mealiness was detected in all the cultivars even at 3 weeks of storage at 0°C. 'Sweet September,' 'September Sun' and 'Rosario Red' were most susceptible to mealiness in more mature fruit. MAP reduced the incidence of mealiness after 3 weeks of storage to acceptable commercial level (

Raspberries have a short shelf life, which limits their fresh market potential. Fruit firmness is one of the most important characteristics for a fresh market cultivar, which is related to both the stage of maturity and the variety itself. Fruit retention strength define as the tension force needed to remove the receptacle from the fruit, decreases as fruit mature, and it is also cultivar dependent. The objectives of this work were to evaluate fruit firmness and fruit retention strength in 14 raspberry cultivars in Chile, and also to examine some morphological changes that occur during the fresh-frozen-thaw cycles fruits at the cellular level. To do these fresh berries were harvested at 3 different maturity stages: pink-red, red-ripe and over-ripe (processing ripe). Fruit firmness was measured using a Texture Expert TA-XT2 with a 2 mm embol. Fruit strength was measured with an adaptation of a Dindometer, an instrument that registers the tension force needed to remove the receptacle from the fruit. Electron microscopy was used to examine changes at cellular level between fresh and freeze-thaw berries in three cultivars. We found that in all 14 cultivars fruit firmness decreased with maturity. The largest differences in fruit firmness among cultivars were established at early stages of maturity. The firmest cultivar at pink-red stage was 'Chilliwack' (1.23 N), followed by 'Tulameen' (0.91 N), 'Heritage' (0.73 N) and 'Skeena' (0.68 N). 'Autumn Bliss' was the softest cultivar (0.24 N). Fruit strength also decreased as fruit matured in all 14 cultivars. In this case larger differences among them were also established at pink-red stage. 'Amity' (6.9 N) and 'Fallgold' (6.22 N) required higher amounts of force to remove the receptacle, producing in many cases broken fruits with missing drupelets. 'Yellow Meeker' (1.61 N) and 'Heritage' (2.12 N) had the lowest retention force, and therefore are the easiest cultivars to pick at early stages of maturity. Cellular dehydration was observed in 'Tulameen' after a freeze-thaw cycle. 'Heritage' showed cell dehydration and partial damaged on its epidermis. In 'Amity' a general plasmolysis was observed after a freeze-thaw cycle. Fruit firmness was not necessarily associated with morphological changes of individually quick frozen (IQF) berries. There are probably some physical characteristics of the epidermis of the fruit in the different cultivars that make some cultivars more susceptible to damage during the freeze-thaw process.

Continuous ozone exposure at 0.3 ppm (v/v) (US-OSHA Threshold Limit Value for short term exposure) inhibited aerial mycelial growth and sporulation on ‘Elegant Lady’ peaches wound inoculated with Monilinia fructicola, Botrytis cinerea, Mucor piriformis ,o rPenicillium expansum and stored for 4 weeks at 5 °C and 90% relative humidity (RH). Aerial growth and sporulation, however, resumed afterward in ambient atmospheres. Ozone exposure did not significantly reduce the incidence and severity of decay caused by these fungi with the exception of brown rot. Gray mold nesting among ‘Thompson Seedless’ table grapes was completely inhibited under 0.3 ppm ozone when fruit were stored for 7 weeks at 5 °C. Gray mold incidence, however, was not significantly reduced in spray inoculated fruit. Continuous ozone exposure at 0.3 ppm increased water loss after 5 weeks of storage at 5 °C and 90% RH in ‘Zee Lady’ peaches but not after 4 weeks of storage in ‘Flame Seedless’ grapes. Respiration and ethylene production rates of ‘O’Henry’ peaches were not affected by previous exposure to 0.3 ppm ozone. In every test, no phytotoxic injuries of fruit tissues were observed in ozonated or ambient atmosphere treatments. © 2002 Elsevier Science B.V. All rights reserved.

In the last 10 years, interest in research on polyphenol-rich fruit species has increased due to the potential health benefits of these species, mainly attributed to their high anthocyanin content and antioxidant activity. Six polyphenol-rich fruit species (blueberries, raspberries, blackberries, strawberries, pomegranates and maqui berries) were harvested at the same maturity stage during the same growing season and were compared according to their total phenolic (Folin-Ciocalteu method) and total anthocyanin (pH differential method) contents and antioxidant activity using ferric-reducing antioxidant power (FRAP assay) and 2,2-diphenylpicrylhydrazyl (DPPH) radical scavenging capacity methods. With the results of this study, the polyphenolic status of the main polyphenol-rich fruit species that are grown in Chile were compared, and maqui berry showed the highest total phenolic (14.6 g gallic acid equivalent kg -1 of fresh weight [g GAE kg -1 FW]), total anthocyanin (9.3 g cyanidin-3-glu kg -1 of fresh weight [g cy-3-glu kg -1 FW]) contents, and antioxidant activity (152.0 mmol Fe 2+ kg -1 of fresh weight [mmol Fe 2+ kg -1 FW] and 1.5 mg of fresh weight [FW]) with significant differences from the other fruit species that were analyzed. Nevertheless, bioavailability studies to test the benefits of the species’ dietary antioxidants should be performed in order to establish scientific evidence in this area. Durante los ultimos 10 anos, el interes en la investigacion de los frutos ricos en polifenoles ha incrementado debido a sus potenciales efectos beneficiosos para la salud atribuidos principalmente a contenidos altos de antocianinas y una alta actividad antioxidante. Seis especies de frutos ricos en polifenoles (arandanos, frambuesas, moras, frutillas, granadas y maquis) fueron cosechados en el mismo estado de madurez durante la misma temporada de produccion y comparadas de acuerdo a sus contenidos de fenoles totales (metodo Folin Ciocalteu), antocianinas totales (metodo pH diferencial) y actividad antioxidante determinada por los metodos de FRAP (poder antioxidante para reducir el hierro ferrico) y del radical DPPH (2,2-diphenylpicrylhydrazil). Los resultados de este estudio permiten comparar el estatus polifenolico de los principales frutos ricos en polifenoles que crecen en Chile, donde el maqui presenta el mayor contenido de fenoles totales (14,6 g EAG kg -1 pf), antocianinas totales (9,3 g ci-3-glu kg -1 pf), y actividad antioxidante (152,0 mmol E Fe +2 kg -1 and 1,5 mg pf) con diferencias significativas con las otras especies de frutos analizadas. Sin embargo, se deben realizar estudios de biodisponibilidad para probar los efectos beneficos sobre la salud humana de los antioxidantes de esta especie para poder establecer evidencia cientifica en esta area.