Browsing by Author "Zoffoli Guerra, Juan Pablo"
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- ItemAlternaria species causing moldy core of apple in Chile(AMER PHYTOPATHOLOGICAL SOC, 2017) Elfar Aedo, Karina Daniela; Latorre Guzmán, Bernardo; Zoffoli Guerra, Juan Pablo
- ItemAM-Toxin and virulence in Alternaria tenuissima isolated from apple moldy core(AMER PHYTOPATHOLOGICAL SOC, 2017) Elfar Aedo, Karina Daniela; Latorre Guzmán, Bernardo; Zoffoli Guerra, Juan Pablo
- ItemCalcium Sprays and Crop Load Reduction Increase Fruit Quality and Postharvest Storage in Sweet Cherry (Prunus avium L.)(MDPI, 2022) Matteo, Maritza; Zoffoli Guerra, Juan Pablo; Ayala, MarleneIn many fruit trees, the thinning of buds, flowers, or fruits is used to increase the leaf area-to-fruit ratio (LA:F) and reduce competition for carbohydrates. Meanwhile, calcium (Ca) sprays during fruit development are also used to increase fruit quality and postharvest storage. Such practices have been recommended to increase fruit firmness and reduce fruit cracking in sweet cherries. To understand the effects of foliar Ca sprays and crop load reductions in the combination 'Lapins'/'Colt', trained as the Kym Green Bush, a factorial experiment to determine the interactions between both managements was established in the Central Valley of Chile during the 2018/2019 growing season. Two levels of crop load (CL) were established-thinned (50% crop load) and unthinned (100% crop load) during Stage I of fruit development (31 days after full bloom, DAFB). Three timings of foliar applications of CaCl2 (TFA; 0.8%) were evaluated: early 26 DAFB, later 39 DAFB, or late 62 DAFB. Natural fruit contents and concentrations of Ca were determined on unsprayed control trees. Fruit from the thinned trees were significantly larger and heavier and had a higher titratable acidity than unthinned trees did. Significant interactions between TFA and CL were observed for SSC, without a clear trend. Thinned trees were less affected by pedicel detachment, browning, and fruit decay after 45 d of storage (0 degrees C). In unthinned trees, a foliar CaCl2 spray at Stage I allowed a higher fruit firmness than CaCl2 sprays at Stage II and III of fruit development. The CaCl2 applications at 39 or 62 DAFB reduced the incidence of cracking in thinned trees. Natural Ca concentrations decreased during fruit development, indicating a cessation of Ca import and a dilution by subsequent growth. Our results suggest that the early reduction of crop load has positive effects on fruit quality and condition during storage, and early Ca sprays (Stage I) improve fruit textural properties, even under high crop loads.
- ItemCurrent status of kiwifruit arm dieback in Chile(American Phytopathological Soc., 2015) Díaz, G. A.; Lolas, M.; Latorre Guzmán, Bernardo; Zoffoli Guerra, Juan Pablo
- ItemDetection of Speck rot on Pink Lady apple fruit in the Maule Region in Chile(American Phytopathological Soc., 2015) Díaz, G. A.; Latorre Guzmán, Bernardo; Zoffoli Guerra, Juan Pablo; Cáceres, M.; Méndez, R.; Lolas, M.
- ItemDetermination of harvest period of Chilean kiwifruit in relation to fruit quality and temperature during maturation(1999) Zoffoli Guerra, Juan Pablo; Gil, G.F.; Crisosto, C.H.The harvest period (optimum and minimum maturity stages) of thirteen Chilean kiwifruit orchards was determined following the development of harvest soluble solids (HSS), final soluble solids after forced ripening with Ethephon or storage (FSS), firmness and acidity of fruits on the vine from 90 to 170 days after fill bloom (DAB). A period of harvest (harvest window) was obtained for each orchard with the lowest value of HSS characterised by the inflexion point of the exponential curve of soluble solids accumulation and the upper limit of HSS was defined as the value that allowed maximum value of soluble solids to be attained in ripe fruit (FSS). A single given value of HSS was not useful to predict FSS in all cases. Shelf life of fruit harvested with the highest level of soluble solids was two times longer than that of fruit harvested with the lowest level. An exponential relationship (R-2=0.87) existed between accumulated degree hours below 10 degrees C and soluble solids concentration during maturation; the concentration of SS increased rapidly after 150 degree hours at temperature below 10 degrees C.
- ItemDiaporthe species identified from postharvest rot on kiwifruits during long term storage(American Phytopathological Soc, 2014) Díaz, G. A.; Latorre Guzmán, Bernardo; Jara, S.; Ferrada, E.; Naranjo, P.; Zoffoli Guerra, Juan Pablo
- ItemEffect of Modified Atmosphere Packaging and Maturity on Susceptibility to Mealiness and Flesh Browning of Peach Cultivars(2002) Zoffoli Guerra, Juan Pablo; Balbontín, S.; Rodríguez, J.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 P2UC 965 (Chile)). High incidence (>40%) of mealiness was detected in all the cultivars even at 3 weeks of storage at 0 degreesC. `Sweet September,' `September Sun' and `Rosario Red' were most susceptible to mealiness in more mature fruit. MAP reduced the incidence of meatiness after 3 weeks of storage to acceptable commercial level (<20%) only in `Sweet September' cultivar for the three maturities evaluated. Total control of flesh browning was obtained with MAP in all the maturity levels evaluated, but was not controlled on `Rosario Red' cultivar. High concentration of carbon dioxide was attained with MAP. This information suggests that MAP gives only partial control to physiological disorders of peaches, with mealiness symptoms being the most difficult to control.
- ItemEffectiveness and mode of action of gibberellic acid on grape berry thinning(AMERICAN SOCIETY ENOLOGY & VITICULTURE, 1994) Gil, GF; Rivera, M; Varas, F; Zoffoli Guerra, Juan Pablo; Rantz, JMFour trials were conducted to determine the influence of gibberellic acid on fruit set and cluster compactness of Flame Seedless and Thompson Seedless grapes. Spraying GA(3) at bloom time to the canopy of Flame Seedless (8 mg/L) and Thompson Seedless (15 mg/L) resulted in loose clusters due to rachis elongation. Spraying before bloom increased number of berries in spite of decreased pollen germination. In Flame Seedless, shoot pinching alone seven days before full bloom (DBFB) increased berry number per cluster. Shoot pinching combined with GA(3) to clusters at bloom time increased the number of berries in Thompson Seedless. Defoliation followed by GA(3) to the entire shoot, apex, or cluster decreased the berry set of both cultivars. In Thompson Seedless, GA(3) applied to the terminal half of the cluster or shoulder produced berry thinning in the basal non-treated half, while treatment to the cluster base reduced set on the top. GA(3)-treated shoulder halves increased the number of berries. The results support the idea that GA(3) acts as a thinning agent by inducing rachis elongation and stimulating competition among organs which reduces set when nutrients become limiting for berry growth.
- ItemEffects of gibberellic acid on the rheological properties of sweet cherry tissue(2017) Zoffoli Guerra, Juan Pablo; Naranjo, P.; Hanssens, C.; Param, N.The application of gibberellic acid (GA3) has been well documented in the literature to enhance the size, firmness and soluble solid accumulation in sweet cherry, but there is little information regarding the effect of GA3 on the rheological properties associated with the impact and compression damage sensitivity of the tissue. GA3 application was evaluated on 'Bing' and 'Sweetheart' sweet cherry cultivars in two separate experiments. In 'Bing' the effect of a single application of 30 ppm of GA3 at either the straw-color or pit-hardening stages was compared with the effect of half of the concentration (15 ppm) being applied at both physiological stages. 'Sweetheart' was treated with 15 or 20 ppm of GA3 at the straw-color and pithardening stages, which was compared with a single application of 25 ppm of GA3 at the straw-color stage. In both experiments, untreated fruits were used as the controls. The soluble solid accumulation and fruit size distribution were determined at harvest. The rheological properties were characterized using the curve of strain vs. stress, obtained by a texturometer. Impact and compression damages were induced in the laboratory, and the incidence and severity of injured tissues were determined after 10 days at 0 degrees C. The fruit size was improved and the fruit tissue was less sensitive to compression and impact damage following gibberellic acid treatment. 'Sweetheart' was more sensitive to impact and compression damage and had lower values of rheological parameters than 'Bing'. The timing of GA3 applications demonstrated that the application of 15 ppm of GA3 at both the pit-hardening and straw-color stages was more effective for improving the size and soluble solid accumulation and reducing the sensitivity of the tissue to injury than a single application of 30 ppm of GA3 at either the straw-color or pit-hardening stages in 'Bing' or of 25 ppm at the straw-color stage in 'Sweetheart'.
- ItemEvolución del daño por insolación de manzanas 'Granny Smith' durante el almacenaje refrigerado(2008) Contreras Monzón, Carolina Ivonne; Zoffoli Guerra, Juan Pablo; Alcalde Furber, José Antonio; Ayala Zapata, Chita MarleneSunburn is one of the major physiological disorders affecting fruit quality at harvest. The objective of this work was to study the effect of sunburn on the quality of Granny Smith apples during cold storage at 0 degrees C. Therefore, 'Granny Smith' apples with light, moderate, or severe sunburn damage were stored for three and six months at 0 degrees C plus 15 days at 20 degrees C. After harvest, the apples were treated with diphenylamine (DPA, 2,000 mu g.L-1) or 1-methylcyclopropene (1-MCP, 625 nL.L-1) to reduce scald (the physiological disorder), and an equal number of non-treated apples were used as controls. The concentration of conjugated trienes (CTs) was determined and compared between the apparently healthy and damaged side of the same fruits. Sunscald, characterized by brown skin tissue, developed on the sunburnt side of the fruit, and superficial and senescent scald symptoms developed on the healthy side of the apple. A significant and negative relationship between sunscald and scald were obtained in fruit treated with DPA. A low concentration of CT 281 was found on the sunburnt side of apples treated with DPA and 1-MCR Application of 1-MCP and DPA controlled scald but not sunscald. DPA treatment resulted in better control of scald after 6 months of storage on fruit with moderate sunburn damage at the time of harvest
- ItemFirst Report of Cadophora malorum Associated With Cordon Dieback in Kiwi Plants in Chile(The American Phytopathological Society (APS), 2016) Díaz, G. A.; Lolas, M.; Ferrada, E. E.; Latorre Guzmán, Bernardo; Zoffoli Guerra, Juan PabloChile is the third largest exporter of fresh kiwifruit (Actinidia deliciosa A. Chev.) worldwide, with over 10,000 ha cultivated. Cordon dieback of kiwi plants has increased considerably during the last decade in Chile. Symptoms include short internodes with small, chlorotic leaves, death of cane tips, and cordon dieback. Symptomatic cordons exhibited hard, brown, irregular cankers comprising between 5 to 45% of the cross section. An incidence of 25 to 75% of plants showing dieback symptoms was estimated (175 to 320 plants were observed per orchard) during a survey in seven commercial cv. Hayward orchards (>7 years old), located between Rancagua (34°00′ S) and Linares (35°48′ S), in 2013 and 2014. Symptomatic cordons (n = 82) were collected and cut into 5-cm2 pieces, surface disinfested with 96% ethanol for 10 s, and flamed for 8 s. Small wood pieces (2 to 3 mm) were taken from the edge of necrotic and healthy tissue, and plated on potato dextrose agar (PDA) amended with antibiotics and Igepal (Díaz and Latorre 2014). Grayish colonies (n = 18), with a Cadophora-like growth, were obtained after 21 days at 20°C. The remaining samples were in the Diaporthaceae and Botryosphaeriaceae families. On PDA, colonies grew slowly and exhibited a woolly to cottony center with regular white margins, and produced a yellow pigmentation. Microscopically, short, erect conidiophores had simple, hyaline or slightly pigmented erect monophialides, with single terminal collarettes. Conidia (n = 30) were hyaline, unicellular, oblong to ellipsoidal, biguttulate and, measured (1.7) 2.3 (3.6) × (3.7) 6.1 (7.8) µm (Gams 2000). Based on Travadon et al. (2015), three loci (ITS, β-tubulin, and EF1-α) were used for further molecular identification, using primers ITS4/ITS5, Bt2a/Bt2b and EF1-728F/EF1-986R. The sequences of four isolates were deposited in GenBank (Accession Nos. KT358979 to KT358982, KU532780 to KU532783, and KU532851 to KU532854 for ITS, β-tubulin, and EF1-α, respectively). BLAST analyses showed 99 to 100% identity with Cadophora malorum (Kidd & Beaumont) W. Gams (isolate CBS 165.42 ex-type, Accession Nos. AY249059, KM497134, and KM497090). Pathogenicity tests were conducted on kiwifruit canes (n = 16) and trunks (n = 10) of 15- and 3-year-old, respectively, Hayward vines during the winter months. The tips of the canes were pruned and 20 µl of a conidial suspension (106 conidia/ml) were placed on each pruning wound. Trunk inoculations were conducted at the base by creating a wound with a 5-mm-diameter cork borer and inserting a 5-mm mycelial plug, taken from 21-day-old cultures on PDA. An equal number of canes and trunks injured and treated with sterile agar plugs were used as negative controls. Vascular necrotic lesions of 111 and 62 mm in length developed on inoculated canes and trunks after 9 and 12 months, respectively, under field conditions. Lesions and dieback symptoms were observed in canes and trunks inoculated with C. malorum. Negative controls remained symptomless. Cadophora malorum was reisolated only from symptomatic canes and trunks. To our knowledge, this is the first report of C. malorum associated with cordon dieback in kiwi plants in Chile. Previously, C. malorum, C. luteo-olivacea, and C. melinii have been reported causing wood canker in kiwi plants (Prodi et al. 2008). These results require additional research to understand the role of C. malorum in the fungal complex associated with cordon dieback in kiwi in Chile.
- ItemFirst report of diaporthe novem causing postharvest rot of kiwifruit during controlled atmosphere storage in Chile(The American Phytopathological Society, 2014) Díaz, G. A.; Latorre Guzmán, Bernardo; Jara, S.; Ferrada, E.; Naranjo, P.; Rodríguez, J.; Zoffoli Guerra, Juan PabloChile 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.
- ItemFruit Firmness and Fruit Retention Strength in Raspberry Cultivars in Chile(2002) Bañados Ortiz, Maria Pilar; Zoffoli Guerra, Juan Pablo; Soto, A.; González, J.; Brennan, R. M.; Gordon, S. L.; Williamson, B.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.
- ItemIdentification of Botrytis spp. causing blossom blight in Japanese plums and nectarines in Chile(AMER PHYTOPATHOLOGICAL SOC, 2014) Ferrada Quiroz, Enrique Elias; Latorre Guzmán, Bernardo; Diaz Ulloa, Gonzalo Alberto; Zoffoli Guerra, Juan Pablo
- ItemIncidence of an Herbaceous/Bitter Flavor That Affects Quality of Sweet Cherry (Prunus avium L. cv. Regina) during Fruit Maturation and Storage(American Society Horticultural Science, 2019) Contreras Duarte, Carolina de los Ángeles; Zoffoli Guerra, Juan Pablo; Plotto, AnneChile’s sweet cherry production has grown by ~363% over the last two decades, and is currently mostly being exported to China. Shipping from Chile to China results in travel and commercialization periods up to 50 days. Among the top three cherry cultivars produced in Chile, ‘Regina’ (a German bred variety) is highly planted because it is a late season variety and it is resistant to cracking. However, a herbaceous/bitter taste has been reported to appear in ‘Regina’, both at harvest and during/after storage, affecting its fruit quality and commercialization. Therefore, the objective of this work was to study the development of the odd-flavor and to understand the associated sensory and quality aspects during fruit ripening and storage.‘Regina’ sweet cherries were harvested from an orchard with prior year high incidence of bitter taste. Six phenological stages were studied: pre-véraison, véraison, bright red, red (commercial harvest), dark red and black color (senescence). At commercial harvest, additional cherries from three different orchards from southern Chile were harvested and stored for 30 and 45 days at 0 °C, plus 3 days at 15 °C. Eighty sweet cherries were assessed for firmness, texture, soluble solid concentration, titratable acidity, color, ethylene production and respiration rate at each phenological stage and each storage date. Stem browning, and fruit internal browning and orange peel physiological disorders were also evaluated. Sensory evaluation was carried out with another eighty fruits to verify presence/absence of the odd-flavor taste. Cherries were halved, one half tasted by two panelists, and the other half liquid frozen and stored at -80 °C for further analysis. The herbaceous flavor was only present at the bright red and commercial harvest stages; no odd-flavor was found at the senescent stage. During storage, two out of three orchards presented herbaceous flavor at harvest and after 30 and 45 days of storage. Incidence was ~8-6% at harvest and remained constant throughout storage. Unlike the herbaceous flavor, bitter taste appeared only after 30 and 45 days of storage at 0 °C plus 3 days at 15 °C, and it showed independently from the herbaceous flavor. Interestingly, when fruit had internal browning incidence, neither herbaceous nor bitter flavor were present in the fruit. These preliminary results showed that the herbaceous flavor is a critical problem for ‘Regina’ storage. Quality and physiological relationships with the herbaceous flavor will be discussed.
- ItemManipulation of 'Van' sweet cherry crop load influences fruit quality and susceptibility to impact bruising(2008) Zoffoli Guerra, Juan Pablo; Muñoz, S.; Valenzuela, L.; Reyes, M.; Barros, F.Pitting caused by impact bruising is one of the main causes of deterioration of sweet cherry (Prunus avium L.) in commercial production. Different levels of crop load were obtained on four-year-old central leader 'Van' sweet cherry trees. The natural crop load (25 spurs/m, with no spur thinning) was compared with a spur thinning treatment (20 spurs/m) and fruit thinning treatments (3 to 4 fruits/spur or 1:2 non-fruiting/fruiting spur ratio). The incidence of impact bruising was evaluated at harvest by dropping a 10 g steel ball from a height of 5 cm on fruit from the different treatments. The natural crop load was 120 to 130 fruits/m, while spur thinning to 20 spurs/m gave similar to 100 fruits/m and the fruit thinning treatments gave 59 to 88 fruits/m. The fruit thinning treatment of 3 to 4 fruits/spur produced the largest fruit with high soluble solids concentration and was the most resistant to impact bruising. The tree:fruit parameters for this crop load were 3.0 leaves/fruit or around 60 fruits/m. The postharvest evaluation showed that both fruit thinning treatments yielded the lowest percentage of pitting after 50 days in modified atmosphere packaging, simulating commercial manipulation. However, the fruit thinning treatment of 3 to 4 fruits/spur was significantly more susceptible to fruit cracking after storage.
- ItemPost-Harvest calcium formulations induce skin Injury in fruits of 'Royal Gala' apple(1998) Zoffoli Guerra, Juan Pablo; Araya, E.; Castro, D.; Vieira, D.
- ItemPostharvest factors that influence the effectiveness of modified atmosphere packaging of kiwifruit(2007) Zoffoli Guerra, Juan Pablo; Rodríguez, J.; Levy, N.Harvest maturity of kiwifruit and the time at which fruit were packed into a modified atmosphere bag, were the two factors used to study the effectiveness of MAP (modified atmosphere packaging) technology, using fruit from two orchards. Fruit were harvested at four times, over a range of soluble solids from 5.8% to 9.8%, firmness 76 N to 62.3 N and dry matter 15.9% to 18.4%. Fruit were packed into a modified atmosphere bags after 0, 30 and 60 days of storage at 0 degrees C and MAP was evaluated after 30 and 60 days at 0 degrees C plus a ripening period at 20 degrees C. A perforated bag was included as control. Independent of harvest maturity, the best results of MAP were obtained with fruit packed immediately after harvest. A delay period of thirty days reduced fruit softening only for the subsequent 30 days of storage. MAP was ineffective in maintaining fruit firmness when fruit were packed after being held 60 days at 0 degrees C. The time to reach the eating ripening stage (<9 N) during 20 degrees C shelf life was extended with the modified atmosphere bag. Fruit from both orchards behaved similarly in response to the MAP technology.
- ItemPostharvest handling of table grape(2008) Zoffoli Guerra, Juan PabloMaturation of table grape (Vitis vinifera L.) extends from a period of almost 40 days from veraison to harvest. During this phase of fruit development occur the most significant physiological change that allows the accumulation of sugar, acid, phenolic compound and the increase of volume (Coombe and Bishop, 1980). The main deterioration factors of table grapes during storage at low temperature are decay and water loss. The non-climacteric (minimum ethylene production during ripening) response of fruit ripening and the low respiration rate determine that softening is not a relevant postharvest problem as in the majority of fruits. In the case of decay, gray mold is considered the universal disease and drying of the stem alters the appearance at the market level. These two aspects require a constant attention in the postharvest handling of table grape. Postharvest handling of table grape includes determination of optimum harvest time, harvest and cooling operations, sulfur dioxide application and water loss control.