This guide provides conventional pest management recommendations for commercial tree fruit, small fruit, and grape producers throughout the Midwest and surrounding states. These recommendations have been formulated to provide up-to-date information on pesticides and their application.
View PDFSelection of grape cultivars adapted to Iowa’s climate and soil is essential for successful vineyard and wine production. New cultivars and advanced selections with sufficient winter hardiness and quality and quantity of grapes are critical for sustained profitability. Research to evaluate new cultivars and selections provides useful information to Iowa growers for their sustainable production of winegrapes.
View PDFThe harvest parameter of total soluble solids (TSS) is a measure of the density (mass/volume) of all soluble solids. A component in determining ripeness of the berries is the concentration of sugars. This determines the potential alcohol content achievable during fermentation through yeasts consumption of sugars.
View PDFTo estimate grape harvest maturity, technological parameters including total soluble solids or °Brix, pH and titratable acidity are commonly measured. In addition to the increase of °Brix and pH and the decrease of titratable acidity during berry ripening, qualitative parameters can be used to evaluate the right time to harvest. The qualitative parameters are skin tannins, seed color, berry detachment, and berry aroma and flavors. Evaluation of these parameters involve four senses: taste, visual, touch and smell.
View PDFThis publication will show how to measure titratable acidity in wine samples. Titratable acidity is a measurement that approximates total acidity in must and wine, and is indicative of the sensory perception of tartness. TA measures both the dissociated and un-dissociated acids neutralized by a base. A solid understanding of the organic acid composition of the must is very important for the winemaker to: Determine the harvest time and wine style, decide on any must treatments prior to fermentation, monitor the stability of a wine, and comply to minimum and maximum acid level regulations set by the TTB.
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