scholarly journals Potential Abscission Agents for Raisin, Table, and Wine Grapes

HortScience ◽  
2007 ◽  
Vol 42 (7) ◽  
pp. 1626-1630 ◽  
Author(s):  
Matthew W. Fidelibus ◽  
Kimberley A. Cathline ◽  
Jacqueline K. Burns

Effective abscission agents that decrease fruit detachment force (FDF) are sought by the California raisin industry to improve the continuous tray mechanical harvesting method. Such agents might also enable mechanical harvest of table and wine grapes (Vitis vinifera L.), but few agents are known to be effective for grape. Thus, methyl jasmonate (MeJA) and six other compounds known to stimulate abscission of other fruits were screened for their ability to reduce FDF of mature ‘Thompson Seedless’ grapes. Most compounds tested reduced FDF to some extent, but MeJA was particularly effective. Solutions containing between 45 and 4500 ppm MeJA reduced FDF by at least 50% to 85% compared with nontreated fruits. Application of 2250 and 4500 ppm MeJA to ‘Thompson Seedless’ vines caused 25% to 50% fruit drop, respectively, within 10 d after treatment (DAT). The efficacy of MeJA was verified in a second experiment in which solutions of 0, 1125, 2250, or 4500 ppm MeJA were applied to clusters of ‘Crimson Seedless’ grapes; at 14 DAT, FDF declined as a linear function of MeJA applied. The grapes did not abscise, but berries treated with 2250 to 4500 ppm MeJA had slightly lower soluble solids than nontreated fruits. Solutions of 0 or 4500 ppm MeJA applied to clusters of ‘Cabernet Sauvignon’ and ‘Merlot’ grapevines reduced FDF by 66% and 75%, respectively. Fruit drop was estimated to be less than 10%. Thus, a solution containing up to 4500 ppm MeJA may be an effective abscission agent to facilitate mechanical harvest of ‘Cabernet Sauvignon’ or ‘Merlot’.

HortScience ◽  
2009 ◽  
Vol 44 (5) ◽  
pp. 1330-1333 ◽  
Author(s):  
Raquel González-Herranz ◽  
Kimberley A. Cathline ◽  
Matthew W. Fidelibus ◽  
Jacqueline K. Burns

The application of methyl jasmonate (MeJA) to grapes (Vitis vinifera L.) may decrease fruit detachment force (FDF) and promote the development of dry stem scars on the berries, both of which could improve the quality of machine-harvested raisin grapes. However, treatment with MeJA also promotes preharvest fruit drop, which is undesirable. Thus, experiments were conducted to determine how the concentration of MeJA applied and time after treatment affect FDF and abscission of grapes. Mature ‘Thompson Seedless’ grapevines were treated with one of five different solutions containing 0, 0.2, 2, 10, or 20 mm MeJA, and FDF and fruit abscission were monitored for ≈2 weeks. Treatment with 2 mm or less MeJA had inconsistent effects on FDF and did not promote abscission, whereas treatment with 10 to 20 mm MeJA reduced FDF within 2 to 3 days after treatment (DAT) and promoted abscission, which began on ≈3 DAT and persisted for ≈8 DAT. Thus, to optimize the use of MeJA as a harvest aid for ‘Thompson Seedless’ may require application of between 2 and 10 mm MeJA followed by harvest within 3 DAT.


Agriculture ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 176
Author(s):  
Gastón Gutiérrez-Gamboa ◽  
Irina Díaz-Galvéz ◽  
Nicolás Verdugo-Vásquez ◽  
Yerko Moreno-Simunovic

A trial was conducted during the 2005–2006 season in order to determine the effects of different leaf-to-fruit ratios on yield components and fruit composition in four Vitis vinifera L. cultivars. The treatments consisted of selecting shoots of four lengths (>1.3 m, 1.3–0.8 m, 0.8–0.4 m, and <0.4 m) with two crop levels (1–2 clusters/shoot), which allowed defining eight ratios. Berry composition and yield components were measured. The treatments affected the accumulation of soluble solids in “Sauvignon blanc”, “Cabernet Sauvignon”, and “Syrah”, delaying it as the ratio decreased. All yield components were affected in “Sauvignon blanc”, while bunch weight and the number of berries per bunch were altered without a clear trend. None of the yield components were affected in “Cabernet Sauvignon”, while the lowest ratio presented the lowest number of berries per bunch in “Syrah”. Total polyphenol index (TPI) was affected in “Carmenère” without a clear trend. A highly significant correlation was found between shoot length and leaf area in all studied cultivars. As the ratio increased, the shoot lignification increased in “Sauvignon blanc”. However, studies must be conducted during more seasons to establish better conclusions about the effects of leaf-to-fruit ratios on yield and fruit composition.


2017 ◽  
Vol 30 (1) ◽  
pp. 97-108 ◽  
Author(s):  
PATRÍCIA FERNANDA INÁCIO VILAR ◽  
◽  
EDER IGNÁCIO DE SOUZA ◽  
LAISE DE SOUSA SANTOS ◽  
EMANUEL ALMEIDA MARTINEZ ◽  
...  

ABSTRACT The objective of this work was to evaluate the influence of Trinexapaque-ethyl (TrixE) and benzyladenine (BA) on the fertility of buds and the quality of bunches of „Thompson Seedless‟ grapes grafted onto „Ramsey‟ rootstock, in the Vale São do Francisco. The experimental design consisted of randomized blocks with 16 treatments (doses and number of applications of the plant regulators TrixE and BA), with four replications, each composed of three plants, with one plant per plot. The variables analyzed were: overall potential bud fertility, potential of the basal, median and apical branches of the plant; fertility of potential buds from the basal region of the basal and median branches; fertility of overall real buds, and of the median and apical branches; diameter of the basal, median and apical branches; Falker chlorophyll index a, b and total; sprouting buds, number of clusters per branch, clusters per plant, branches per plant; berry diameter, length, volume; fresh material mass; soluble solids content (SS), titratable acidity (AT) and SS/AT relationship; diameter, length, mass of fresh material from the clusters; shatter, fresh material mass of the rachis and rachis diameter . It was shown that the TrixE applied in isolation , one, two or three times in doses of 20 mg L -1, or associated with BA in a single application of 120 or 240 mg L-1, increased the rate of real fertility, but did notaffect the length of the clusters or the vegetative vigor of the plants.


1973 ◽  
Vol 13 (62) ◽  
pp. 319
Author(s):  
RM Cirami

Grapes from 15 wine varieties of Vitis vinifera selected for suitability in warm areas were sampled over their ripening period in 1971 and 1972. Samples were analysed for total soluble solids, titratable acidity, pH, tartrate and malate. At maturity, titratable acidities ranged from 7.3 to 14.0 g l-1and pH from 2.8 to 3.6. In every instance pH was lower in 1971 than in 1972, but there was no pattern evident for titratable acidities. At the commencement of ripening the concentration of malate was always higher than of tartrate, and the rate of decrease of malate was faster than of tartrate. In the final stages of maturity acid losses of up to 1 g l-1 every ten days were common. Based on tartrate : malate ratios, the following varieties warrant further investigation: Barbera, Cabernet Sauvignon, Emerald Riesling, Gewurztraminer, Merlot, Petite Sirah, Pinot Noir, Semillon and White Riesling.


Plant Disease ◽  
2008 ◽  
Vol 92 (12) ◽  
pp. 1635-1642 ◽  
Author(s):  
Erika X. Briceño ◽  
Bernardo A. Latorre

Cladosporium rot (Cladosporium spp.) of grapevine (Vitis vinifera) is a common disease in Chile, particularly in Cabernet Sauvignon and other red wine grape cultivars. It is favored by delayed harvest to obtain the phenolic maturity necessary for high-quality red wine. This study expands on previous investigations of the specific causal agents, the histopathological host:pathogen relationship, and the population dynamics of Cladosporium spp. during the seasonal development of grape clusters. Over 100 isolates were obtained and identified as C. cladosporioides and C. herbarum, confirming previous results. The identity of a subset of isolates was confirmed by molecular analysis. Isolates of both C. cladosporioides and C. herbarum from grapevines were pathogenic on inoculated table grapes and wine grapes. These pathogens were reisolated, fulfilling Koch's postulates. Berry injuries and total soluble solids content above 15% were necessary for Cladosporium spp. to infect wine grapes. The mycelia of C. cladosporioides and C. herbarum grew between 0 and 30°C, but no growth was obtained at 35°C in vitro. The histological studies showed that Cladosporium spp. superficially colonize mature V. vinifera berries, invading the epidermis but scarcely penetrating the hypodermis. The Cladosporium populations obtained on apparently healthy berries of V. vinifera cvs. Cabernet Sauvignon and Chardonnay were significantly larger (P = 0.05) than the populations obtained under similar conditions on berries of V. champini cv. Ramsey and hybrids Kober 5BB and Couderc 1613. Considering the importance of Cladosporium rot in Chile compared with other grape production areas, the development of control strategies is needed to prevent high disease severity, which affects both yield and wine quality.


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 880B-880
Author(s):  
Matthew Fidelibus* ◽  
Steven Vasquez ◽  
Donald Katayama

Pruning efficiency, fruitfulness, and yield and quality of raisins of `Thompson Seedless' (Vitis vinifera L.) grapevines subjected to several canopy separation and defoliation treatments for DOV raisin production were evaluated. Canopy separation treatments, tested in vineyards at Easton, and at the Kearney Agricultural Center (KAC), Parlier, Calif., were as follows; horizontal canopy separation with vine sections of fruiting or renewal zones (Peacock), horizontal canopy separation with vine sections of fruiting zones of one vine adjacent to renewal shoots of the next vine (wave), or non-separated (control). Defoliation treatments included burning or blowing leaves (Easton), application of concentrated solutions of calcium ammonium nitrate or Etherel to leaves (KAC), or no defoliation (both vineyards). Canopy separation treatments did not affect berry size, soluble solids, or raisin yield. Vines subjected to Peacock training had more cluster layers than vines subjected to wave training, at Easton, and more cluster layers than vines subjected to control training at KAC. Canopy separation reduced harvest pruning time by 20% at Easton, but not at KAC. No treatments affected raisin moisture at Easton but, at KAC, raisins of vines trained in the Peacock style had 10% higher moisture contents at harvest than raisins of wave or control vines. Vines subjected to conventional training and leaf blowing had about 40% higher “B and better” raisin grades than vines with separated canopies that were not defoliated, and about 30% higher grades than vines with conventional training and leaf burning. However, raisins of vines subjected to blowing had about 60% more mold than raisins of non-defoliated vines. Defoliation treatments at KAC did not affect any variables measured.


HortScience ◽  
2013 ◽  
Vol 48 (12) ◽  
pp. 1433-1439 ◽  
Author(s):  
Atsushi Kono ◽  
Akihiko Sato ◽  
Yusuke Ban ◽  
Nobuhito Mitani

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.


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