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Background and Aims: Fungicides used against the mould Botrytis cinerea can also non‐specifically affect indigenous yeasts important for the development of complex wine aroma. Our aim was to determine the minimal inhibitory concentration of the fungicides iprodione, pyrimethanil and fludioxonil plus cyprodinil for 109 yeasts of the grape berry microbiota. Methods and Results: We measured the respiration activity of yeasts, changes in growth kinetics and adenosine triphosphate production. Fungicide tolerance may be a conserved feature within the yeast's genera, however, some heterogeneity between isolates remains. The viability and growth of 15 beneficial isolates were inhibited by fungicides at a residue concentration below the maximum permitted residue limits. These isolates belonged to the yeast species: Metschnikowia pulcherrima, Pichia kluyveri, Hanseniaspora uvarum and Bulleromyces albus. Furthermore, isolates of typical spoilage yeasts, such as Dekkera bruxellensis, Meyerozyma guilliermondii and Pichia membranifaciens, were found to be tolerant of a concentration of fungicides greater than that recommended for application by the suppliers. Conclusions: Fungicide residues hindered the viability of desirable isolates and promoted the growth of several spoilage isolates and thus may have a negative impact on wine aroma. Significance of the Study: For spontaneous fermentations the application of fungicides in the vineyard could add to the seasonal fluctuations of aroma and to the development of off‐flavours. [ABSTRACT FROM AUTHOR]

Background and Aims Fruit split is a well-known source of fruit loss in viticulture. Previous investigations on this topic have focused on determining the factors that influence the occurrence of fruit split. The purpose of this study was to examine and characterise the immediate effect of fruit split on grape tissue structure using diffusion magnetic resonance imaging ( MRI). Methods and Results Thirty-six ripe tablegrape berries were studied: 12 were assigned to a control group, 12 were wrapped in damp tissue and the remainder were wholly immersed in water. The berries were imaged over a period of 20 h with an MRI spectrometer. Grape berries that developed splits in the epidermis of sufficient length for imaging during this period exhibited an immediate increase in the mean apparent diffusivity in the pericarp tissue immediately surrounding these wounds. Further investigation determined that this increase in diffusivity was due to a loss of cell vitality. Physical trauma and oxygen shock were ruled out as the cause of cell death. Conclusions Standing water on the grape berry surface during the occurrence of fruit split will quickly lead to pericarp cell death as a result of the osmotic imbibition of water through the wounds in the berry epidermis. Significance of the Study The amount of standing water on the surface of split grape berries may be an important determinant of: (i) the cellular response of the fruit to this trauma; and (ii) the subsequent establishment of adventitious fruit pathogens. [ABSTRACT FROM AUTHOR]