Evaluation of Host Resistance to Botrytis Bunch Rot in Vitis spp. and Its Correlation with Botrytis Leaf Spot

Botrytis cinerea, the causal agent of Botrytis bunch rot and gray mold, is the number one postharvest disease of fresh grapes in the United States. Fungicide applications are used to manage the disease, but fungicide-resistant isolates are common and postharvest losses occur annually. Host resistance is needed for long-term management of the disease. Sources of resistance in grape have been identified, but often have poor fruit quality. In this study, 27 grape lines (cultigens and species), including high fruit–quality Vitis vinifera, were evaluated for fruit and leaf susceptibility to two isolates of B. cinerea. No significant differences in virulence or pathogenicity were detected between the two isolates, but differences in disease incidence were evident among lines in leaves and berries. Most V. vinifera cultivars evaluated had high disease incidence in berries, whereas complex hybrids, Vitis aestivalus and Vitis arizonica, had low- to moderate disease incidence. Two V. vinifera breeding lines had moderate susceptibility (<50% disease) to Botrytis bunch rot when inoculated with either isolate. Only one V. vinifera line had little (<5%) to no berry or leaf disease when inoculated with either isolate. Moderate resistance (10% to 25%) was detected in Vitis spp., and a single V. vinifera line. Correlations were examined among soluble solids, leaf susceptibility, and fruit susceptibility. No correlations between soluble solids and disease susceptibility (leaves or berries) were identified, but moderate correlations between leaf and berry susceptibility were observed. Moderate resistance to Botrytis bunch rot and leaf spot were detected in Vitis breeding lines, suggesting these may be useful for developing grape cultivars with high fruit quality and resistance to B. cinerea.

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Field Evaluations of Leaf Spot Resistance and Yield in Peanut Genotypes in the United States and Bolivia

Plant Disease ◽

10.1094/pdis-06-10-0454 ◽

2011 ◽

Vol 95 (3) ◽

pp. 263-268 ◽

Cited By ~ 4

Author(s):

S. K. Gremillion ◽

A. K. Culbreath ◽

D. W. Gorbet ◽

B. G. Mullinix ◽

R. N. Pittman ◽

...

Keyword(s):

United States ◽

Disease Resistance ◽

Leaf Spot ◽

Field Experiments ◽

Disease Incidence ◽

The United States ◽

Yield Potential ◽

Cercospora Arachidicola ◽

Breeding Lines ◽

Progress Curve

Field experiments were conducted in 2002 to 2006 to characterize yield potential and disease resistance in the Bolivian landrace peanut (Arachis hypogaea) cv. Bayo Grande, and breeding lines developed from crosses of Bayo Grande and U.S. cv. Florida MDR-98. Diseases of interest included early leaf spot, caused by the fungus Cercospora arachidicola, and late leaf spot, caused by the fungus Cercosporidium personatum. Bayo Grande, MDR-98, and three breeding lines, along with U.S. cvs. C-99R and Georgia Green, were included in split-plot field experiments in six locations across the United States and Bolivia. Whole-plot treatments consisted of two tebuconazole applications and a nontreated control. Genotypes were the subplot treatments. Area under the disease progress curve (AUDPC) for percent defoliation due to leaf spot was lower for Bayo Grande and all breeding lines than for Georgia Green at all U.S. locations across years. AUDPC for disease incidence from one U.S. location indicated similar results. Severity of leaf spot epidemics and relative effects of the genotypes were less consistent in the Bolivian experiments. In Bolivia, there were no indications of greater levels of disease resistance in any of the breeding lines than in Bayo Grande. In the United States, yields of Bayo Grande and the breeding lines were greater than those of the other genotypes in 1 of 2 years. In Bolivia, low disease intensity resulted in the highest yields in Georgia Green, while high disease intensity resulted in comparable yields among the breeding lines, MDR-98, and C-99R. Leaf spot suppression by tebuconazole was greater in Bolivia than in the United States. This result indicates a possible higher level of fungicide resistance in the U.S. population of leaf spot pathogens. Overall, data from this study suggest that Bayo Grande and the breeding lines may be desirable germplasm for U.S. and Bolivian breeding programs or production.

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Effect of Electronic Cold-PasteurizationTM (ECPTM) on Fruit Quality and Postharvest Diseases during Blueberry Storage

Horticulturae ◽

10.3390/horticulturae4030025 ◽

2018 ◽

Vol 4 (3) ◽

pp. 25 ◽

Cited By ~ 2

Author(s):

Savithri Nambeesan ◽

John Doyle ◽

Helaina Capps ◽

Chip Starns ◽

Harald Scherm

Keyword(s):

Fruit Quality ◽

Disease Incidence ◽

Titratable Acidity ◽

Fruit Weight ◽

Soluble Solids ◽

Coliform Bacteria ◽

Postharvest Disease ◽

Dependent Manner ◽

Postharvest Diseases ◽

Four Levels

With the growing popularity of blueberries and the associated increase in blueberry imports and exports worldwide, delivering fruit with high quality, longer shelf-life, and meeting phytosanitary requirements has become increasingly important. The objective of this study was to determine the effects of electron beam irradiation using a new Electronic Cold-PasteurizationTM (ECPTM) technology on fruit quality, microbial safety, and postharvest disease development in two southern highbush blueberry cultivars, ‘Farthing’ and ‘Rebel’. Fruit packed in clamshells were subjected to four levels of ECPTM irradiation (0, 0.15, 0.5, and 1.0 kGy) and evaluated for fruit quality attributes, surface microbial load, and postharvest disease incidence during various storage times after treatment and cold storage. Overall, there was no effect of irradiation on visual fruit quality in either cultivar. Fruit firmness and skin toughness in ‘Farthing’ was reduced following irradiation at 1.0 kGy, but no such effect was observed in ‘Rebel’. Other fruit quality characteristics such as fruit weight, total soluble solids content, or titratable acidity were not affected. Irradiation at 1.0 kGy significantly reduced total aerobic bacteria and yeast on the fruit surface, and in the case of ‘Rebel’, also levels of total coliform bacteria. There was no significant effect of irradiation on postharvest disease incidence in these trials. Overall, data from this study suggests that an irradiation dose lower than 1.0 kGy using ECPTM can be useful for phytosanitary treatment in blueberry fruit while avoiding undesirable effects on fruit quality in a cultivar-dependent manner.

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Relative host resistance to Alternaria leaf spot in canola and mustard varieties is defined by Alternaria species

Crop and Pasture Science ◽

10.1071/cp20024 ◽

2020 ◽

Vol 71 (7) ◽

pp. 689

Author(s):

Hebba F. D. Al-Lami ◽

Ming Pei You ◽

Martin J. Barbetti

Keyword(s):

Host Resistance ◽

Leaf Spot ◽

Disease Incidence ◽

Severe Disease ◽

Indian Mustard ◽

Moderate Level ◽

Alternaria Leaf Spot ◽

Ethiopian Mustard ◽

Alternaria Species ◽

Collapse Index

Both Alternaria japonica and A. brassicae cause severe Alternaria leaf spot on canola (Brassica napus) and mustard (B. juncea). We tested 103 Brassicaceae varieties including 93 Australian canola, nine Indian mustard, and a single variety of Ethiopian mustard (B. carinata) under greenhouse conditions to identify host resistance to Alternaria leaf spot caused by A. japonica and A. brassicae in terms of disease incidence (percentage leaf disease incidence, %LDI), disease severity (percentage leaf area diseased, %LAD) and defoliation (percentage leaf collapse index, %LCI). Against A. japonica, across the three parameters, B. napus Surpass 404 CL was the most resistant (%LDI 7.5, %LAD 5.0, %LCI 0). Varieties Hyola 635 CC, Oscar, AG-Outback and Rottnest, with %LDI 15.6–19.4 and %LAD 12.5–15.6, also showed strong resistance, and with %LCI 10. Varieties 47C02, ATR-Signal and Clancy of B. napus showed a moderate level of resistance across %LDI (21.2–25.6) and %LAD (15.0–20.6), along with a low level of defoliation (%LCI 10). Varieties 46C03, 46C72, ATR-Cobbler and Granite TT of B. napus also showed a moderate level of resistance, with %LDI 23.1–28.7, %LAD 18.1–20.6 and %LCI 11.2–14.4. The significance of this resistance against A. japonica is highlighted by the severe disease on B. napus Thunder TT (%LDI 78.8, %LAD 72.5, %LCI 47.5). Against A. brassicae, all varieties showed susceptibility; however, B. napus ATR-Grace was the least susceptible in relation to disease incidence (%LDI 41.2) and severity (%LAD 36.2), and B. napus Hyola 450 TT the most susceptible (%LDI 90.0, %LAD 82.5). Variety Hurricane of B. napus was the least susceptible in terms of consequent defoliation (%LCI 11.2) and B. napus CBTM Tribune the most susceptible (%LCI 81.2). The B. carinata variety BCA 1 (ATC 95065) and all test B. juncea varieties showed susceptibility to both pathogens. These findings demonstrate high levels of resistance across Australian canola varieties against A. japonica that can be directly deployed where A. japonica is important and can be utilised by breeders for improving resistance in future varieties. By contrast, susceptibility across Australian canola and mustard varieties to A. brassicae is concerning, highlighting a need to locate suitable resistances and, until effective host resistance can be located, to develop and deploy cultural and chemical options.

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Response of `Chardonnay' Grapevines to Training and Crop Control

HortScience ◽

10.21273/hortsci.30.4.800g ◽

1995 ◽

Vol 30 (4) ◽

pp. 800G-801

Author(s):

Thomas J. Zabadal ◽

Gary R. VanEe ◽

Thomas W. Dittmer ◽

Richard L. Ledebuhr

Keyword(s):

Fruit Quality ◽

Soluble Solids ◽

Training Systems ◽

Intermediate Response ◽

Cluster Compactness ◽

Bunch Rot ◽

Growing Conditions

Growing conditions in Michigan can threaten the yield and acceptable fruit quality of `Chardonnay' grapevines. Three grapevine training systems, mid-wire cordon (MWC), umbrella kniffin (UK), and a combination of the two (MWC-UK) were evaluated under Michigan growing conditions to determine their influence on yield, fruit quality, cluster compactness, incidence and severity of Botrytis bunch rot, and trellis fill. Vines were grown on C3309 rootstock and pruned to 44 nodes per kilogram of cane prunings. The MWC-UK treatment had an additional 30 nodes per vine retained, and the crop level on these nodes was removed after fruitset. Over a 2-year period, UK and MWC-UK trained vines had fruit soluble solids about 1 °Brix higher and yields were 48% and 63% higher than MWC trained vines, respectively. MWC-UK trained vines consistently out-performed MWC trained vines for all variables measured, while UK-trained vines provided an intermediate response.

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Sensory and Analytical Analyses of Fruit Quality Constituents of Fresh-cut Orange- and Green-fleshed Honeydews and Orange-fleshed Cantaloupe

HortScience ◽

10.21273/hortsci.39.4.806b ◽

2004 ◽

Vol 39 (4) ◽

pp. 806B-806

Author(s):

Robert A. Saftner* ◽

Judith A. Abbott ◽

Gene E. Lester

Keyword(s):

Fruit Quality ◽

Ethylene Production ◽

Soluble Solids ◽

Eating Quality ◽

Production Rates ◽

Breeding Lines ◽

Retail Markets ◽

Fresh Cut

New fresh-cut melon products prepared from orange-fleshed honeydews have recently become available in retail markets. We compared fresh-cut chunks of orange-fleshed honeydew (`Temptation' and four breeding lines), green-fleshed honeydew (`Honey Brew'), and cantaloupe (`Cruiser'). All genotypes had similar respiration and ethylene production rates and soluble solids contents: genotype means for soluble solids contents were between 9.4% and 10.1 %. Five hundred untrained consumers preferred the flavor, texture, and overall eating quality of the orange honeydews to the green cultivar, with `Temptation' scoring highest. `Temptation' chunks were less firm at the time of processing and after 12 days storage than chunks prepared from all other genotypes. The color of orange-fleshed honeydew chunks was intermediate between that of cantaloupe and green-fleshed honeydew and the color was maintained during 12 days storage. Total aromatic volatiles from juice extracts of orange-fleshed honeydew chunks was 1.2 to 4.7 times higher than that of green-fleshed honeydew extracts and volatiles from cantaloupe was >4.8 fold greater than extracts from `Temptation' and >9.3 fold higher than that of other honeydew extracts. Many individual volatiles were identical in cantaloupe and honeydews; however, honeydew genotypes, particularly the orange-pigmented types, were distinctive from cantaloupe in having relatively high levels of various nonenyl and nonadienyl acetates of uncharacterized aromas. The results indicate that `Temptation' and other orange-fleshed honeydews are a promising new melon type for fresh-cut processing.

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Root-knot Nematode Resistance, Yield, and Fruit Quality of Specialty Melons Grafted onto Cucumis metulifer

HortScience ◽

10.21273/hortsci.49.8.1046 ◽

2014 ◽

Vol 49 (8) ◽

pp. 1046-1051 ◽

Cited By ~ 14

Author(s):

Wenjing Guan ◽

Xin Zhao ◽

Donald W. Dickson ◽

Maria L. Mendes ◽

Judy Thies

Keyword(s):

Fruit Quality ◽

Crop Production ◽

The United States ◽

Field Trials ◽

Fruit Yield ◽

Soluble Solids ◽

Egg Mass ◽

Root Knot Nematode ◽

Population Densities ◽

Honeydew Melon

Interest in specialty melons (Cucumis melo) with distinctive fruit characteristics has grown in the United States in recent years. However, disease management remains a major challenge in specialty melon production. In this study, grafting experiments were conducted to determine the effectiveness of using Cucumis metulifer, a species known for its genetic resistance to root-knot nematodes (RKNs; Meloidogyne spp.), as a potential rootstock for managing RKNs in susceptible specialty melon cultivars. In the greenhouse experiment, honeydew melon ‘Honey Yellow’ was grafted onto C. metulifer and inoculated with M. incognita race 1. The grafted plants exhibited significantly lower gall and egg mass indices and fewer eggs compared with non- and self-grafted ‘Honey Yellow’. Cucumis metulifer was further tested as a rootstock in conventional and organic field trials using honeydew melon ‘Honey Yellow’ and galia melon ‘Arava’ as scions. ‘Honey Yellow’ and ‘Arava’ grafted onto C. metulifer exhibited significantly lower galling and reduced RKN population densities in the organic field; however, total and marketable fruit yields were not significantly different from non- and self-grafted plants. Although the improvement of RKN resistance did not translate into yield enhancements, incorporating grafted specialty melons with C. metulifer rootstock into double-cropping systems with RKN-susceptible vegetables may benefit the overall crop production by reducing RKN population densities in the soil. At the conventional field site, which was not infested with RKNs, ‘Honey Yellow’ grafted onto C. metulifer rootstock had a significantly lower total fruit yield than non-grafted ‘Honey Yellow’ plants; however, fruit yields were similar for ‘Arava’ grafted onto C. metulifer rootstock and non-grafted ‘Arava’ plants. Although no significant impacts on the fruit quality attributes of ‘Honey Yellow’ were observed, grafting onto C. metulifer decreased the flesh firmness of ‘Arava’ in both field trials and resulted in a reduction in total soluble solids content under conventional production. In summary, grafting RKN-susceptible melons onto C. metulifer rootstock offers promise for growing these specialty melons; however, more studies are needed to elucidate the scion–rootstock interaction effect on fruit yield and quality.

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Early Performance of Jujube Fresh Eating Cultivars in the Southwestern United States

HortScience ◽

10.21273/hortsci14312-19 ◽

2019 ◽

Vol 54 (11) ◽

pp. 1941-1946

Author(s):

Shengrui Yao ◽

Robert Heyduck ◽

Steven Guldan

Keyword(s):

United States ◽

Fruit Quality ◽

The United States ◽

Soluble Solids ◽

Department Of Agriculture ◽

Growing Seasons ◽

The 1950S ◽

And Performance ◽

Early Performance ◽

Performance Results

Jujube (Ziziphus jujuba Mill.), also called chinese date, cultivars have not been formally trialed in the United States after the 1950s. Currently, there are five to six commercially available jujube cultivars, with ‘Li’ as the dominant one. Both growers and consumers demand a wider range of cultivars to extend the maturation season and for different uses. We tested jujube cultivars at three locations in New Mexico [U.S. Department of Agriculture (USDA) hardiness zones 6a, 7a, and 8a] to assess their adaption and performance. These are early performance results for fresh eating cultivars. Jujubes were precocious; 50% to 95% of trees produced during their planting year, depending on cultivar and location. The average yield per tree for trees in their second to fourth year after planting were 409 g, 4795 g, and 5318 g at Alcalde; and 456 g, 3098 g, and 5926 g at Los Lunas, respectively. The yields varied by cultivar and location. ‘Kongfucui’ (‘KFC’) was the most productive cultivar at Alcalde and Los Lunas in both 2017 and 2018, followed by ‘Daguazao’, ‘Gaga’, ‘Honeyjar’, Maya’, ‘Redland’, and ‘Sugarcane’. ‘GA866’, ‘Alcalde #1’, ‘Zaocuiwang’, and ‘Sandia’ had the lowest yields among the 15 cultivars tested. ‘Alcalde #1’ was the earliest to mature with large fruit, suitable for marginal regions with short growing seasons, whereas ‘Sandia’ had the best fruit quality among all cultivars tested, suitable for commercial growers and home gardeners. ‘Maya’, ‘Gaga’, ‘Honeyjar’, and ‘Russian 2’ were very productive, early-midseason cultivars with small fruit but excellent fruit quality—a perfect fit for the home gardener market. ‘Li’, ‘Daguazao’, ‘Redland’, and ‘Shanxi Li’ were productive with large fruit. Cultivars grew faster and produced higher yields, larger fruit, and higher soluble solids at more southerly locations. This article discusses cultivars’ early performance up to the fourth year after planting. This is the first jujube cultivar trial report in the United States since the 1950s.

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Postharvest Disease Development on Southern Highbush Blueberry Fruit in Relation to Berry Flesh Type and Harvest Method

Plant Disease ◽

10.1094/pdis-03-12-0307-re ◽

2013 ◽

Vol 97 (2) ◽

pp. 213-221 ◽

Cited By ~ 17

Author(s):

L. K. Mehra ◽

D. D. MacLean ◽

A. T. Savelle ◽

H. Scherm

Keyword(s):

Cold Storage ◽

Disease Incidence ◽

Storage Period ◽

The United States ◽

Colletotrichum Acutatum ◽

Postharvest Disease ◽

Fresh Market ◽

Fruit Samples ◽

Southern Highbush ◽

Harvest Method

Postharvest decay, incited by various fungal pathogens, is a major concern in most blueberry production areas of the United States. Because the risk of infection is increased by fruit bruising, which in turn is increased by machine-harvesting, it has been difficult to harvest fruit from the early-maturing but soft-textured southern highbush blueberries (SHB) mechanically for the fresh market. This could change fundamentally with the recent development of SHB genotypes with crisp-textured (“crispy”) berries, i.e., fruit with qualitatively firmer flesh and/or more resistant skin. Four replicate row sections of two or three SHB genotypes having crispy fruit and three with conventional fruit were either hand- or machine-harvested at a commercial blueberry farm in northern Florida in April 2009 and May 2010. Harvested fruit were sorted, packed, and placed in cold storage (2°C) for up to 3 weeks. Average counts of aerobic bacteria, total yeasts and molds, coliforms, and Escherichia coli on fruit samples before the cold storage period were below commercial tolerance levels in most cases. In both years, natural disease incidence after cold storage was lowest for hand-harvested crispy fruit and highest for machine-harvested conventional fruit. Interestingly, machine-harvested crispy fruit had the same or lower disease incidence as hand-harvested conventional fruit. Across all treatments, natural postharvest disease incidence was inversely related to fruit firmness, with firmness values >220 g/mm associated with low disease. In separate experiments, samples from the 0-day cold storage period were inoculated at the stem end with Alternaria alternata, Botrytis cinerea, or Colletotrichum acutatum, and disease incidence was assessed after 7 days in a cold room followed by 60 to 72 h at room temperature. In response to artificial inoculation, less disease developed on crispy berries. No significant effect of harvest method was observed, except for A. alternata inoculation in 2009, when hand-harvested fruit developed a lower level of disease than machine-harvested fruit. Taken together, this study suggests that mechanical harvesting of SHB cultivars with crisp-textured berries is feasible from a postharvest pathology perspective.

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Transgressive Segregation and Long-Term Consistency for High TSWV Field Resistance in the ‘Georgia-06G’ Peanut Cultivar

Plant Health Progress ◽

10.1094/php-04-18-0018-rs ◽

2018 ◽

Vol 19 (3) ◽

pp. 201-206 ◽

Cited By ~ 1

Author(s):

W. D. Branch ◽

A. K. Culbreath

Keyword(s):

Disease Incidence ◽

The United States ◽

Transgressive Segregation ◽

Field Resistance ◽

Breeding Lines ◽

Tomato Spotted Wilt ◽

Arachis Hypogaea L ◽

Production Area ◽

Wilt Virus

Tomato spotted wilt disease caused by tomato spotted wilt virus (TSWV) is a major peanut (Arachis hypogaea L.) production problem in the United States. TSWV has become endemic since the mid-1980s in the southeastern U.S. peanut production area. ‘Georgia-06G’ is a large-seeded, TSWV-resistant, runner-type peanut cultivar, whereas ‘Georgia Greener’ is a sister line with a smaller seed size than Georgia-06G. Both Georgia-06G and Georgia Greener have greater TSWV general field resistance with higher yields, total sound mature kernels grade, and dollar values than the parents (‘Georgia Green’ and ‘C-99R’), which shows transgressive segregation for these desirable quantitative traits. Therefore, the objective of this 12-year study was to evaluate the higher TSWV host-plant resistance found in the Georgia-06G over time compared with many other runner- and virginia-type peanut cultivars and advanced breeding lines. Despite yearly variability in TSWV and total disease incidence, the data indicate that Georgia-06G exhibited long-term high TSWV and total disease field resistance at midseason and late season, respectively. Georgia-06G was also found to have among the highest pod yield and dollar value every year. The higher general TSWV field resistance of Georgia-06G appears to be consistent across many years and locations, similar to the moderate TSWV resistance in Georgia Green.

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Combining Chitosan and Vanillin to Retain Postharvest Quality of Tomato Fruit during Ambient Temperature Storage

Coatings ◽

10.3390/coatings10121222 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1222

Author(s):

Zahir Shah Safari ◽

Phebe Ding ◽

Jaafar Juju Nakasha ◽

Siti Fairuz Yusoff

Keyword(s):

Shelf Life ◽

Disease Incidence ◽

Tomato Fruit ◽

Antioxidant Properties ◽

Ascorbic Acid Content ◽

Soluble Solids ◽

Postharvest Quality ◽

Postharvest Disease ◽

Postharvest Diseases ◽

Negative Effects

Tomato, being a climacteric crop, has a relatively short postharvest life due to several factors such as postharvest diseases, accelerated ripening, and senescence that trigger losses in quantity and quality. Chemicals are widely used to control postharvest disease. Inaptly, it leads to detrimental effects on human health, environment and it is leads to increased disease resistance. Chitosan and vanillin could be an alternative to disease control, maintain fruit quality, and prolong shelf life. The aim of this research was to evaluate the potential of chitosan and vanillin coating on the tomato fruit’s physicochemical quality during storage at 26 ± 2 °C/60 ± 5% relative humidity. Chitosan and vanillin in aqueous solutions i.e., 0.5% chitosan + 10 mM vanillin, 1% chitosan + 10 mM vanillin, 1.5% chitosan + 10 mM vanillin, 0.5% chitosan + 15 mM vanillin, 1% chitosan + 15 mM vanillin, and 1.5% chitosan + 15 mM vanillin, respectively, were used as edible coating. The analysis was evaluated at 5-day intervals. The results revealed that 1.5% chitosan + 15 mM vanillin significantly reduced disease incidence and disease severity by 74.16% and 79%, respectively, as well delaying weight loss up to 90% and reducing changes in firmness, soluble solids concentration, and color score. These coatings also reduced the rate of respiration and the rate of ethylene production in comparison to the control and fruit treated with 0.5% chitosan + 10 mM vanillin. Furthermore, ascorbic acid content and the antioxidant properties of tomato were retained while shelf life was prolonged to 25 days without any negative effects on fruit postharvest quality.

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