scholarly journals 808 PB 144 EFFECTIVNESS OF AEROSOL SPRAYS FOR CONTROLLING ROT IN TABLE GRAPES

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 549a-549
Author(s):  
M. Ahmed Ahmedullah
Keyword(s):  
Sulfur Dioxide ◽  
Relative Humidity ◽  
Vitis Vinifera ◽  
Aerosol Particles ◽  
High Relative Humidity ◽  
Viable Alternative ◽  
Thompson Seedless ◽  
Storage Size ◽  
Table Grapes ◽  
And Control

Fruit of Vitis vinifera cvs. Flame Seedless, Thompson Seedless and Black Monukka were fumigated with 4, 6 and 8 Deccodione Smoke Tables (DST) for 30 minutes. Fruit was stored at 32 F and high relative humidity. Decay control index, freshness of stems and bleaching around the capstem were recorded at 4, 8, 12 and 16 weeks of storage. Size of the aerosol particles was determined using an electrical aerosol analyzer. Fruit was analysed for Deccodione residues. Lower rates of the fungicide gave unsatisfactory decay control. Eight DSTs successfully controlled decay upto a period of 14 weeks. There was no bleaching of pigments commonly associated with sulfur dioxide fumigation. Majority of the aerosol particles were between 0.18 and 0.32 micrometers. Deccodione residues on the fruit were within the acceptable limits established for Deccodione. There was no perceptible difference in taste between treated and control fruit. This method of decay control could provide a viable alternative to sulfur dioxide fumigation.

scholarly journals DECAY CONTROL IN TABLE GRAPE CULTIVARS BY FUMIGATION WITH DECCODIONE SMOKE TABLETS FOR PROLONGING THE STORAGE LIFE

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 677d-677
Author(s):  
M. Ahmedullah
Keyword(s):  
Sulfur Dioxide ◽  
Relative Humidity ◽  
Good Condition ◽  
Table Grape ◽  
High Relative Humidity ◽  
Viable Alternative ◽  
Thompson Seedless ◽  
Smoke Particles ◽  
Fumigation Chamber ◽  
Grape Cultivars

Fruit of table grape cvs. Black Monukka, Flame Seedless, Thompson Seedless and Himrod were fumigated with 2, 4 and 6 Deccodione tablets for 30 minutes in a fumigation chamber. Fruit was brought to the cold rooms and stored at 32 F and high relative humidity for upto 10 weeks. Decay control index, freshness of stems and bleaching around the capstem were recorded at 2, 4, 6, 8 and 10 weeks of storage. Size of the smoke particles was determined using an electrical aerosol analyzer. Fruit was kept in good condition by fumigation with 6 smoke tablets upto 10 weeks. Lower doses failed to control the decay. No bleaching around the capstems commonly associated with sulfur dioxide fumigation was noticed. Majority of the smoke particles were between 0.18 and 0.32 micrometers. Fumigation with Deccodione tablets could be a viable alternative to sulfur dioxide fumigation.

scholarly journals ALTERNATIVES TO SULFUR DIOXIDE FUMIGATION FOR TABLE GRAPE STORAGE

HortScience ◽  
1996 ◽  
Vol 31 (6) ◽  
pp. 919
Author(s):  
A. Ahmedullah
Keyword(s):  
Sulfur Dioxide ◽  
Relative Humidity ◽  
Aerosol Particles ◽  
Table Grape ◽  
High Relative Humidity ◽  
Table Grapes ◽  
Evaluation Time ◽  
Fumigation Chamber

Clusters of four varieties of table grapes were packed in TKV lugs and fumigated with 4, 6, or 8 Deccodione Smoke Tables (DST) for a period of 30 minutes in a fumigation chamber. After fumigation, inoculum of Botrytis cineraria was placed among the berries in the clusters in predetermined locations. Fruit was stored at 0C and high relative humidity for up to 16 weeks. Fruit was examined at 4, 8, 12, and 16 weeks of storage. Decay control index, freshness of stems, and bleaching of pigments around the capstem was recorded at each evaluation time. Size of aerosol particles was determined. Satisfactory control of decay was obtained with 8 DSTs. Lower doses failed to give satisfactory decay control. Bleaching of capstems typically seen with sulfur dioxide fumigation was not noticed with DST fumigation.

scholarly journals Surface Colonization, Penetration, and Lesion Formation on Grapes Inoculated Fresh or After Cold Storage with Single Airborne Conidia of Botrytis cinerea

Plant Disease ◽  
1999 ◽  
Vol 83 (10) ◽  
pp. 917-924 ◽  
Author(s):  
Sonja Coertze ◽  
Gustav Holz
Keyword(s):  
Relative Humidity ◽  
Botrytis Cinerea ◽  
Cold Storage ◽  
Single Cells ◽  
Disease Incidence ◽  
High Relative Humidity ◽  
Lesion Formation ◽  
Surface Colonization ◽  
Table Grapes ◽  
Airborne Conidia

Infection of grapes by different densities of airborne conidia of Botrytis cinerea was investigated on table grapes (cultivar Dauphine) harvested ripe (16°Brix) and inoculated fresh, or after SO2 treatment and 8-week storage at -0.5°C. Berries were detached at each inoculation and dusted with dry conidia in a settling tower. Following inoculation, the fresh berries were incubated for 24 h at high relative humidity (≥93%), or were overlaid with wet sterile paper towels. Cold-stored berries were incubated at high relative humidity. The effect of conidial density on surface colonization, penetration, and lesion formation was determined by surface sterilization, isolation, and freezing studies on fresh berries. Only symptom expression was determined on cold-stored berries. Fluorescence microscopy of skin segments showed that conidia were consistently deposited as single cells, and not in pairs or groups, on berry surfaces. Individual conidia, at all densities tested, readily infected the cold-stored berries and formed separate lesions after 2 days. Although the cold-stored berries were highly susceptible, lesion numbers were not related to conidial density at low inoculum dosages (0.67 to 2.60 conidia per mm2 berry surface). Lesion numbers tended to increase exponentially at higher dosages (3.24 to 3.88 conidia per mm2 berry surface). Individual conidia, however, did not induce any disease symptoms on fresh berries. Removal of the pathogen after 24-h incubation from the surface of fresh berries by ethanol, and subsequent incubation of excised skin segments revealed that, irrespective of the conidial density or the wetness regime, less than 2% of skin segments were penetrated. Furthermore, increasing densities of conidia did not lead to higher rates of surface colonization and skin penetration. The low incidence of disease caused on fresh berries and high disease incidence induced after prolonged cold storage indicated that infection was not governed by conidial density on berry surfaces, but by the level of host resistance.

scholarly journals BiofumigationwithMuscodoralbus Pads for Controlling Decay in Commercial Table Grape Cartons

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1144D-1144 ◽  
Author(s):  
Julien Mercier ◽  
Paul Walgenbach ◽  
Jorge I. Jiménez
Keyword(s):  
Isobutyric Acid ◽  
Gray Mold ◽  
Fruit Weight ◽  
Table Grape ◽  
Fungal Decay ◽  
Isobutyl Alcohol ◽  
Thompson Seedless ◽  
Significant Control ◽  
Table Grapes ◽  
And Control

The volatile-producing fungus Muscodoralbus is being developed as a biological fumigant for postharvest use, as it can kill storage pathogens and control fungal decay in various commodities. A wettable pad or sachet system made of teabag paper containing desiccated rye grain culture of M. albus was designed for the biofumigation of individual fruit containers. The fungus is reactivated before use by a brief immersion of the pad in water. This research was conducted to determine the potential of the pad system for controlling decay of table grapes in commercial cartons. Individual pads containing 24 or 86 g of grain culture (to achieve a 1:10 ratio of fumigant to box volume or a 1:100 ratio of fumigant to fruit weight, respectively) were added to Styrofoam cartons containing 8.6 kg of freshly harvested `Thompson Seedless' (TS) or `Ruby Seedless' (RS) grapes, which were then placed in cold storage at –1 to 0 °C. Control cartons exposed to SO2 were placed in a separate storage room and SO2 fumigation was performed once for TS and weekly for RS. After 8 to 9 weeks, the grapes were taken out of storage and rated for decay. In the experiment with TS, the 24-g and 86-g pads provided significant control of gray mold rot when compared to untreated cartons and were not statistically different from cartons exposed to a single SO2 fumigation. In the experiment with RS, only the 86-g pads provided significant decay control. Measurements of the three most abundant volatile compounds in empty cartons containing 10 g of the biofumigant revealed that partial coverage of holes mimicking obstruction by packed fruit achieved levels of isobutyl alcohol, 2-methyl-1-butanol, and isobutyric acid of 0.7, 1.6, and 11.2 ppb, respectively.

scholarly journals Botrytis prunorum Associated to Vitis vinifera Blossom Blight in Chile

Plant Disease ◽  
2020 ◽  
Vol 104 (9) ◽  
pp. 2324-2329
Author(s):  
Marcela Esterio ◽  
Claudio Osorio-Navarro ◽  
Claudia Carreras ◽  
Madelaine Azócar ◽  
Charleen Copier ◽  
...  
Keyword(s):  
Vitis Vinifera ◽  
Central Valley ◽  
Development Stage ◽  
Thompson Seedless ◽  
Climate Conditions ◽  
Table Grapes ◽  
Pathogenicity Tests ◽  
White Mycelium ◽  
Multilocus Approach ◽  
Epidemiological Characteristics

Table grapes are highly susceptible to Botrytis cinerea infections during the bloom period. After reaching the flower development stage, B. cinerea remains quiescent until berry ripening or gives rise to blossom blight under specific climate conditions. A research study was conducted on the Chilean Central Valley during the 2018–2019 growing season. Flowers of Vitis vinifera cv. Thompson Seedless were collected and B. cinerea was isolated together to a second and morphologically different species, characterized by white mycelium and low to no sporulation (11.4% of total isolates). Three randomly selected isolates within this population were genetically examined and identified as Botrytis prunorum based on a phylogenetic multilocus approach using partial regions of genes RPB2, HSP60, and G3PDH or NEP1 and NEP2. Pathogenicity tests showed that B. prunorum infects and causes wilting in healthy table grape flowers. B. prunorum isolates were able to infect Thompson Seedless berries, inducing lesions between 13.11 and 41.53% with respect to the lesion diameter generated by B. cinerea B05.10. The fungicide sensitivity was evaluated. The three genetically characterized isolates were sensitive to boscalid and to cyprodinil/fludioxonil mixture with a mean EC50 value of 5.5 µg/ml and 0.065 µg/ml, respectively. However, loss of sensitivity to fenhexamid was determined, with a mean EC50 value of 5.13 µg/ml. Our understanding about blossom blight in V. vinifera has been limited to B. cinerea. Here we associated B. prunorum as a second causal agent of this disease in Chile. This data represents a first approach to the epidemiological characteristics of B. prunorum associated with blossom blight in table grapes.

scholarly journals Resistance of Vitis Germplasm to Elsinoë ampelina (de Bary) Shear Evaluated by Lesion Number and Diameter

HortScience ◽  
2013 ◽  
Vol 48 (12) ◽  
pp. 1433-1439 ◽  
Author(s):  
Atsushi Kono ◽  
Akihiko Sato ◽  
Yusuke Ban ◽  
Nobuhito Mitani
Keyword(s):  
Vitis Vinifera ◽  
Significant Positive Correlation ◽  
Table Grape ◽  
Wine Grapes ◽  
Thompson Seedless ◽  
Sources Of Resistance ◽  
Positive Correlation ◽  
Table Grapes ◽  
Lesion Number ◽  
Elsinoe Ampelina

We evaluated the resistance of 133 grapevine cultivars or selections, including Vitis vinifera and American hybrids, on the basis of lesion number and length to identify sources of resistance to grapevine anthracnose. All germplasms tested in this study showed anthracnose symptoms to some extent, and the distribution of lesion number and diameter was continuous. Most table grape V. vinifera cultivars were highly susceptible, showing many large lesions. However, V. vinifera wine grapes were more resistant with smaller lesions. Some American hybrid grapes such as ‘Ontario’ showed very few and small lesions. There was a significant positive correlation between lesion number and size in American (r = 0.63, P = 0.0041) and Japanese hybrids (r = 0.56, P < 0.001), whereas there was no correlation between these characters in V. vinifera. Japanese tetraploid cultivars were neither highly susceptible nor resistant. High anthracnose susceptibility of most well-known table grape V. vinifera cultivars, including ‘Muscat of Alexandria’, ‘Italia’, ‘Rizamat’, ‘Kattakurgan’, and ‘Thompson Seedless’, indicates that resistance should be introgressed from other cultivars such as American hybrids or wine grapes when these susceptible table grapes or their descendants are used in breeding anthracnose-resistant table grapes.

scholarly journals Hygroscopicity of Internally Mixed Ammonium Sulfate and Secondary Organic Aerosol Particles Formed at Low and High Relative Humidity

2022 ◽  
Author(s):  
Patricia N Razafindrambinina ◽  
Kotiba A Malek ◽  
Joseph Nelson Dawson ◽  
Kristin DiMonte ◽  
Timothy M Raymond ◽  
...  
Keyword(s):  
Organic Matter ◽  
Relative Humidity ◽  
Ammonium Sulfate ◽  
Secondary Organic Aerosol ◽  
Aerosol Particles ◽  
Organic Aerosol ◽  
High Relative Humidity ◽  
Volatile Organic

Volatile organic matter that is suspended in the atmosphere such as α-Pinene and β-caryophyllene undergoes aging processes, as well as chemical and photooxidation reactions to create secondary organic aerosol (SOA),...

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