Sensibilidade ao rachamento de bagas das videiras 'Concord', 'Isabel' e 'BRS Rúbea'

Abstract

RESuMO-Com o objetivo de avaliar a sensibilidade ao rachamento de frutos, foram realizados diferentes testes de laboratório com bagas de uva para processamento das cultivares Concord, Isabel e BRS Rúbea. Para a determinação do índice de rachamento, bagas maduras foram imersas em água destilada e avaliadas a cada hora, durante um período de dez horas. Com o auxílio de um texturômetro, foram realizados testes mecânicos. Em testes de compressão, foram avaliadas, no momento de rompimento das bagas, pressão de compressão, energia de deformação e força máxima de compressão. Com uma sonda de menor calibre, as bagas foram perfuradas, obtendo-se a força máxima de perfuração e deformação de perfuração no rompimento da película. Em testes de relaxação, foram avaliados o grau de solidez e a velocidade inicial de decaimento. Foram avaliadas também as correlações entre o índice de rachamento, e os testes mecânicos. Tanto o índice de rachamento quanto os testes mecânicos apontaram para a cultivar BRS Rúbea como a mais resistente ao rachamento e a cultivar Concord como a mais suscetível. A 'Isabel' apresentou resistência intermediária. O índice de rachamento, apresentou forte correlação com as variáveis avaliadas nos testes mecânicos e possui bom potencial para a avaliação da sensibilidade ao rachamento de materiais distintos de videira. Termos para indexação: uva, índice de rachamento, compressão, perfuração, relaxação. SENSIVITY TO BERRY CRACKING OF 'CONCORD', 'ISABEL' AND 'BRS RÚBEA' GRAPEVINESABSTRACT -In order to evaluate the sensitivity of fruit cracking, different laboratory tests were performed in grape berries of the processing varieties Concord, Isabel and BRS Rubea. To determine the cracking index, ripe berries were dipped in distilled water and evaluated every hour during a period of ten hours. Mechanical tests were performed using a texturometer. In compression tests, at the cracking time, pressing pressure, strain energy, maximum force of compression and compression strain were evaluated. With a smaller diameter probe, berries were drilled to the breakup of the skin resulting in maximum force of drilling and drilling strain. In stress relaxation tests the degree of solidity and initial stress decay rate were evaluated. The correlations between the cracking index and mechanical testing were evaluated too. Both the cracking index and mechanical testing pointed to the BRS Rúbea as the most resistant to cracking and the Concord cultivar as the most susceptible. Isabel presented intermediate resistance. The cracking index showed strong correlation with the parameters evaluated in the mechanical tests and has good potential for assessing the sensitivity to cracking of different grape cultivars.

Faunal analysis and injuries characterization of Polistinae (Hymenoptera, Vespidae) in niagara rosada vineyards in Bento Gonçalves, Rio Grande do Sul state, Brazil

“…There are anatomical and physiological differences between the varieties of grapes, such as size, cell turgor and extensibility and plasticity of cell wall and these factors along with environmental conditions are responsible for the splits and cracks in the berries (DOKOOZLIAN, 2000). Variation in berry volume combined with its thin skin is an important factor that can lead to cracks in grapes (BORGES et al, 2012).…”

Phenology and Yield of the Hybrid Seedless Grape ‘BRS Melodia’ Grown in an Annual Double Cropping System in a Subtropical Area

“…Each berry was placed on the base of the texturometer and compressed with a cylindrical probe with a flat section tip 35 mm in diameter and parallel to the base. The compression was in the direction of the equatorial portion of the berries up to 8 mm, with a force of 0.05 N, at the speed of 1 mm•s −1 , sufficient to cause the skin to rupture [17].…”

Exogenous Abscisic Acid Promotes Anthocyanin Biosynthesis and Increased Expression of Flavonoid Synthesis Genes in Vitis vinifera × Vitis labrusca Table Grapes in a Subtropical Region

“…A constant force of 0.05 N at a speed of 1.0 mm/s was applied to promote the cracking of the sample. The berry firmness (N) was then determined ( Borges et al, 2012 ).…”