Browsing by Author "Zoffoli, J. P."

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    Calcium absorption by fruit and leaves of sweet cherry trees (Prunus avium L.) by isotope labeling
    (2024) Matteo, M.; Zoffoli, J. P.; van der Heijden, G.; Ayala, M.
    In sweet cherry, foliar Calcium-based products are used to mitigate rain-cracking in fruit and to improve its firmness during storage. Information on foliar Calcium (Ca) absorption efficiency by fruit and leaves in the field is scarce. In part, this is due to the limitations of the traditional analytical techniques for assessing Ca levels in these organs. Here, we hypothesize that leaves and fruit differ in their abilities to uptake surface applications of Ca and, moreover, that their abilities are influenced by phenology. To test this hypothesis, foliar Ca-44 (0.05% (CaCl2)-Ca-44) was used to enrich sweet cherry fruit and leaves of the combination 'Lapins'/'Colt' during the 2019-2020 growing season in the Central Valley of Chile (34 degrees 0' S, 71 degrees 41' W). Six treatments were applied, represented by different timings (days after full bloom, DAFB) of isotopic labeling of either fruit or leaves. Labeling was applied at Stage I, SII and SIII of fruit development. Fruit or leaves were 'painted' with (CaCl2)-Ca-44 (0.05%, 97 atom%) using a brush. Each labeling date considered a different group of similar fruiting spurs on the two-year-old wood of individual vertical branches. Additional samples were collected to measure natural abundance of Ca-44. Labeled fruit were removed 48 h after aerial Ca-44 enrichment and at harvest (87 DAFB). Uptake of Ca-44 by fruit and leaves was observed throughout the period of fruit development. Fruiting spur leaves (FSL) and fruit absorbed (CaCl2)-Ca-44 and were highly enriched 48 h after labeling. The earlier the labeling date, the higher the Ca-44 tracer recovery detected in both organs. However, FSL showed higher delta Ca-44 parts per thousand, Ca-44 concentrations and Ca-44 contents than fruit during the whole period of fruit development. After 48 h, the aerial uptake at SI (expressed as delta Ca-44 parts per thousand) was 3.4 times higher in immature FSL and 5.7 times higher in immature fruit than SIII of fruit development, which indicates that Ca sprays should start soon after fruit set. We conclude that in sweet cherry, foliar Ca is absorbed by fruit and spur leaves, but the absorption is more efficient in the early stages of fruit development and for young leaves.
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    Comparación de variables de textura en la medición de firmeza de bayas de uva Thompson Seedless.
    (2001) Vargas, A.; Pérez, J.; Zoffoli, J. P.; Pérez, A.
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    Effect of boscalid on postharvest decay of strawberry caused by Botrytis cinerea and Rhizopus stolonifer
    (2007) Sallato, B. V.; Torres, R.; Zoffoli, J. P.; Latorre, B. A.
    In Chile, gray mold (Botrytis cinerea) and leak (Rhizopus stolonifir) are the major storage diseases of strawberry (Fragaria x ananassa Duch.) that considerably reduce yields and quality, limiting its international commercialization. The effect of preharvest fungicide treatments and postharvest treatments against storage decays was studied. Based on the results obtained, the incidence of B. cinerea and R. stolonifer was significantly lower on 'Camarosa' strawberry fruits treated with boscalid or boscalid + pyraclostrobin between blossom and harvest. Similarly, incidence of B. cinerea and R. stolonifer significantly decreased at 5 degrees C and 20 degrees C after immersion treatments with boscalid (600 to 700 mg L-1) or cyprodinil + fludioxonil (371 + 250 mg U). These postharvest treatments provided 5 and 15 days protection against these molds when strawberry fruits were stored at 20 degrees C and 5 degrees C, respectively. Fenhexamid (750 mg L-1) arrested B. cinerea, but it was ineffective against R. stolonifer. Variable results were obtained with iprodione (750 mg L-1). Fungicide treatments bad no adverse effect on total soluble content, titrable acidity and firmness. Only boscalid+pyraclostrobin affected the external color of the treated fruits. In conclusion, fungicide treatments using new reduced-risk fungicides can be useful to extend strawberry shelf life for over a 15 day period. However, further research is needed to establish a commercial recommendation.
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    Rachis browning and water loss description during postharvest storage of 'Krissy' and 'Thompson Seedless' table grapes
    (ELSEVIER, 2022) Hamie, N.; Zoffoli, J. P.; Tarricone, L.; Verrastro, V.; Perez Donoso, A. G.; Gambacorta, G.
    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 degrees C or 20 degrees C), relative humidity (Saturated or reduced RH), and previous storage at 0 degrees 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 degrees 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 (R-2 = 0.82 and 0.84), hue color (R-2 = 0.68 and 0.72) and water loss (R-2 = 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.