Caracterização fenológica e produtiva da variedade de uva Superior Seedless cultivada no Vale do São Francisco

A variedade Superior Seedless, devido não somente às excelentes características morfológicas, mas também ao agradável sabor de seus frutos, tem se destacado nos últimos anos como a principal uva sem sementes cultivada no Vale do São Francisco.Este trabalho teve por objetivo caracterizar o comportamento fenológico e produtivo da variedade de uva Superior Seedless cultivada no Vale do São Francisco. As avaliações foram realizadas em uma área comercial, durante o segundo semestre de 1999 e primeiro semestre de 2000. A variedade Superior Seedless apresentou ciclo médio de 94 dias, sendo que, quando a poda foi realizada no primeiro semestre, ocorreu uma antecipação da colheita em 14 dias. A produtividade foi muito baixa (5,3 t.ha-1), mas as características qualitativas como diâmetro e comprimento de baga, sólidos solúveis totais e acidez total titulável, atendem aos padrões exigidos pelo comercio internacional.

Phenolic Composition of the Brazilian Seedless Table Grape Varieties BRS Clara and BRS Morena

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biorreguladores na brotação da videira ‘superior seedless’

Aiming to study the affect of commercial biorregulators Stimulate (R) e X-Cyte (R) over sprouting uniformity of Superior Seedless grape cultivar, pruned in May 22, 2006, a field trial was carried out at at Koshiyama farm, in Juazeiro municipality (Bahia State / Northeastern Brazil). The trial was carried out in randomized blocks with four replications and three useful plants per plot, six stakes per plant were evaluated. Forty-eight hours after yield prun, the stakes were sprayed with T1: Dormex (R) (5%); T2: Dormex (R) (5%) + Nitro Plus 9 (R); T3: Stimulate (R) (0,5%); T4: Stimulate (R) (0,5%) + Nitro Plus 9 (R); T5: Stimulate (R) (1,0%); T6: Stimulate (R) (1,0%) + Nitro Plus 9 (R); T7: X-Cyte (R) (0,25%); T8: X-Cyte (R) (0,25%) + Nitro Plus 9 (R); T9: X-Cyte (R) (0,5%); T10: X-Cyte (R) (0,5%) + Nitro Plus 9 (R); T11: X-Cyte (R) (0,25%) + Stimulate (R) (0,5%); T12: X-Cyte (R) (0,25%) + Stimulate (R) (0,5%) + Nitro Plus 9 (R), Nitro Plus 9 (R) used at a rate of 100 L ha(-1) via ferti-irrigation. Results show that Stimulate (R) and X-Cyte (R), when compared to the commercial product Dormex (R) commercially, did not show significant effects on the sprouts number after sproutings and proportion of grown stems; products that as an alternative the Dormex (R) in yield the grape 'Superior Seedless', at the studied conditions.

Atmosfera modificada na conservação da qualidade de uva 'Thompson Seedless' e na redução da podridão de Aspergillus

Existe uma demanda, na região semiárida produtora de uvas no Submédio São Francisco, por medidas sustentáveis de controle de doenças pós-colheita, uma vez que o modelo atual de revestimento de caixas com polietileno de alta densidade, associado ao metabissulfito de sódio, não tem se mostrado eficiente no controle dos fungos que ocorrem na região. O objetivo desse trabalho foi estudar um controle da podridão por Aspergillus em uvas 'Thompson Seedless' por meio da modificação da atmosfera, pelo envolvimento de caixas de uva em bolsões de poliamida. Comparou-se o bolsão de poliamida (PA) ao de polietileno alta densidade (PEAD), comumente usado na região, combinados ou não com o metabissulfito de sódio (SO2). Frutos provenientes de propriedade comercial, após serem selecionados e desinfestados foram feridos com alfinete entomológico e inoculados com uma suspensão de Aspergillus niger na concentração de 10(6) conídios.mL-¹ e submetidos à câmara úmida por 24 horas. em seguida as caixas de uva foram colocadas em bolsões específicos de acordo com o tratamento e armazenadas em câmara fria à temperatura de 2 ºC e umidade relativa de 75%, durante 40 dias. A partir do 12º dia de armazenagem foram feitas avaliações semanais da incidência da doença e de variáveis físico-químicas: perda de massa, sólidos solúveis totais (SST), pH, acidez titulável (AT), ratio (SST/AT); peroxidase (POD) e medição das concentrações de CO2 e O2 até o 40º dia. O delineamento experimental utilizado foi inteiramente ao acaso em parcelas subdivididas com cinco repetições. O revestimento de caixas de uva em bolsões de poliamida, mesmo sem o uso de metabissulfito de sódio, apresenta-se como uma alternativa viável na manutenção da qualidade pós-colheita de uva Thompson Seddless, bem como na redução de podridão causada por A. Niger. A enzima peroxidase pode ter atuado no processo de manutenção de qualidade da fruta, contribuindo para uma redução dos níveis da doença em uvas.

Ação de biorreguladores na brotação, produção e algumas características físico-químicas de uva do cultivar Superior Seedless

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos do thidiazuron e do ácido giberélico sobre as características dos cachos dos cultivares de videira vênus, centennial seedless e niagara rosada

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Giberelina, citocinina e auxina na qualidade química de bagas de uva superior seedless

Trials were carried out in Juazeiro, Bahia State, Brazil, aiming to test plant regulators composed by gibberellin, cytokine and auxin effects on chemical quality of Superior Seedless grape berries. The first trial studied the effects of Stimulate (R) (bio regulator) and X-Cyte (R) (cytokine) associated to a new gibberellin formulation (N-Large (R)) and associated to Pro-Gibb (R), which is a product used as source of gibberellin. Products were sprayed at berries development phase (18, 21, 51 and 56 days after spur-pruning). Treatments were: T1: Pro-Gibb (R); T2: Stimulate (R) (Dose 1); T3: Stimulate (R) (Dose 2); T4: Stimulate (R) (Dose 3); T5: Pro-Gibb (R) + X-Cyte (R) (Low Dose - DB); T6: Pro-Gibb (R) + X-Cyte (R) (Intermediate Dose - DM); T7: Pro-Gibb (R) + X-Cyte (R) (High Dose - DA); T8: N-Large (R); T9: N-Large (R) + X-Cyte (R) (DB); T10: N-Large (R) + X-Cyte (R) (DM); T11: N-Large (R) + X-Cyte (R) (DA). The second trial aimed to assess the effect of the new gibberellin formulation (N-Large (R)) associated or not with cytokine (X-Cyte (R)) also sprayed straight over the bunches at berries development phase (17, 55 e 66 days after spur-pruning). Treatments were: T1: Pro-Gibb (R) - blank; T2: N-Large (R) (DB); T3: N-Large (R) (DM); T4: N-Large (R) (DA); T5: N-Large (R) (DB) + X-Cyte (R) (DB); T6: N-Large (R) (DB) + X-Cyte (R) (DM); T7: N-Large (R) (DB) + X-Cyte (R) (DA); T8: N-Large (R) (DM) + X-Cyte (R) (DB); T9: N-Large (R) (DM) + X-Cyte (R) (DM); T10: N-Large (R) (DM) + X-Cyte (R) (DA); T11: N-Large (R) (DA) + X-Cyte (R) (DB); T12: N-Large (R) (DA) + X-Cyte (R) (DM); T13: N-Large (R) (DA) + X-Cyte (R) (DA). Experimental design was random blocks with four repetitions with each repetition/parcel having three useful plants in the same row. At harvest, when bunches average had soluble solids over 15 degrees Brix, berries were collected for soluble solids, pH, titratable acidity analysis as well as (SS/AT) ratio calculation. In both trials, plant regulators evaluated did not provide significant changes on chemical quality of 'Superior Seedless' grape berries. Therefore, the lack of differences on response between the commercially used product (Pro-Gibb (R)) and the other products tested (Stimulate (R), X-Cyte (R) e N-Large (R)) prove the last as promising for the ` Superior Seedless' grape cultivation, leaving a larger range of alternative for grape farmers in the Sao Francisco Valley, Bahia.

Leaf water potential and sap flow as indicators of water stress in Crimson ‘seedless’ grapevines under different irrigation strategies

Vitis vinifera L. cv. Crimson Seedless is a late season red table grape developed in 1989, with a high market value and increasingly cultivated under protected environments to extend the availability of seedless table grapes into the late fall. The purpose of this work was to evaluate leaf water potential and sap flow as indicators of water stress in Crimson Seedless vines under standard and reduced irrigation strategy, consisting of 70 % of the standard irrigation depth. Additionally, two sub-treatments were applied, consisting of normal irrigation throughout the growing season and a short irrigation induced stress period between veraison and harvest. Leaf water potential measurements coherently signaled crop-available water variations caused by different irrigation treatments, suggesting that this plant-based method can be reliably used to identify water-stress conditions. The use of sap flow density data to establish a ratio based on a reference ‘well irrigated vine’ and less irrigated vines can potentially be used to signal differences in the transpiration rates, which may be suitable for improving irrigation management strategies while preventing undesirable levels of water stress. Although all four irrigation strategies resulted in the production of quality table grapes, significant differences (p ≤ 0.05) were found in both berry weight and sugar content between the standard irrigation and reduced irrigation treatments. Reduced irrigation increased slightly the average berry size as well as sugar content and technical maturity index. The 2-week irrigation stress period had a negative effect on these parameters.

Leaf water potential and sap flow as indicators of water stress in Crimson 'seedless' grapevines under different irrigation strategies

Abstract Vitis vinifera L. cv. Crimson Seedless is a late season red table grape developed in 1989, with a high market value and increasingly cultivated under protected environments to extend the availability of seedless table grapes into the late fall. The purpose of this work was to evaluate leaf water potential and sap flow as indicators of water stress in Crimson Seedless vines under standard and reduced irrigation strategy, consisting of 70 % of the standard irrigation depth. Additionally, two sub-treatments were applied, consisting of normal irrigation throughout the growing season and a short irrigation induced stress period between veraison and harvest. Leaf water potential measurements coherently signaled crop-available water variations caused by different irrigation treatments, suggesting that this plant-based method can be reliably used to identify water-stress conditions. The use of sap flow density data to establish a ratio based on a reference ‘well irrigated vine’ and less irrigated vines can potentially be used to signal differences in the transpiration rates, which may be suitable for improving irrigation management strategies while preventing undesirable levels of water stress. Although all four irrigation strategies resulted in the production of quality table grapes, significant differences (p ≤ 0.05) were found in both berry weight and sugar content between the standard irrigation and reduced irrigation treatments. Reduced irrigation increased slightly the average berry size as well as sugar content and technical maturity index. The 2-week irrigation stress period had a negative effect on these parameters.

Detection of dsRNA from Cleistothecia and Conidia of the Grape Powdery Mildew Pathogen, Uncinula Necator

Double-stranded RNA species ranging in molecular weight from 0.95 to 6.3 × 106 were detected in grapevines in New York. We recently showed that two of the species (Mr = 5.3 and 4.4 × 106) are associated with rupestris stem pitting disease. In this report, we show that the other eight detectable dsRNA species are associated with the powdery mildew fungus, Uncinula necator. These dsRNAs associated with the powdery mildew fungus were previously detected in leaves and epidermal stem tissue of grapevines infected with powdery mildew. The same dsRNA species were also detected from extracts of isolated cleistothecia and conidia of U. necator devoid of plant tissue. Isometric and rigid rodlike particles were observed in single cleistothecia preparations when examined under transmission electron microscopy.

Drying kinetics of two grape varieties of Italy

Two varieties of grapes, white grape and red grape grown in the Campania region of Italy were selected for the study of drying characteristics. Comparisons were made with treated and untreated grapes under constant drying condition of 50o C in a conventional drying system. This temperature was selected to represent farm drying conditions. Grapes were purchased from a local market from the same supplier to maintain the same size of grapes and same properties. An abrasive physical treatment was used as pretreatment. The drying curves were constructed and drying kinetics was calculated using several commonly available models. It was found that treated samples show better drying characteristics than untreated samples. The objective of this study is to obtain drying kinetics which can be used to optimize the drying operations in grape drying.

Drying kinetics, quality changes and shrinkage of two grape varieties of Italy

Two varieties of grapes, white grape and red grape grown in the Campania region of Italy were selected for the study of drying characteristics, moisture diffusion, quality changes (colour) and shrinkage behaviour. Comparisons were made with treated and untreated grapes under constant drying condition of 50o C in a conventional drying system. This temperature was selected to represent farm drying conditions. Grapes were purchased from a local market from the same supplier to maintain the same size of grapes and same properties. An abrasive physical treatment was used as pretreatment. The drying curves were constructed and drying kinetics was calculated using several commonly available models. It was found that treated samples shows better drying characteristics than untreated samples. The objective of this study is to obtain drying kinetics which can be used to optimize the drying operations in grape drying.

Drying kinetics, quality changes and shrinkage of Two grape varieties of Italy

Two varieties of grapes, white grape and red grape grown in the Campania region of Italy were selected for the study of drying characteristics, moisture diffusion, quality changes (colour) and shrinkage behaviour. Comparisons were made with treated and untreated grapes under constant drying condition of 50o C in a conventional drying system. This temperature was selected to represent farm drying conditions. Grapes were purchased from a local market from the same supplier to maintain the same size of grapes and same properties. An abrasive physical treatment was used as pretreatment. The drying curves were constructed and drying kinetics was calculated using several commonly available models. It was found that treated samples shows better drying characteristics than untreated samples. The objective of this study is to obtain drying kinetics which can be used to optimize the drying operations in grape drying.