Submitted to: Transactions of Kentucky Academy of Science
Publication Type: Abstract Only
Publication Acceptance Date: 11/16/1995
Publication Date: N/A
Technical Abstract: Black plastic mulches are widely used to conserve water and control weeds in production of high-value crops. Light quantities and wavelength ratios reflected from other colors can regulate plant size, shape, and shoot/root relationships. In a taste test, 24 of 25 panelists indicated that turnips which received more reflected blue light during development had roots with a sharper flavor. The majority of the tasters also indicated that roots from plants grown with green mulch had the mildest (almost sweet) flavor. In a two-year laboratory study, roots from turnips grown in field plots over blue, green, silver, and white surfaced mulches were analyzed for concentrations of total glucosinolates (GSL's), ascorbic acid, and sugar. Total GSL's and total sugars were lower and concentrations of ascorbic acid were higher in 1992 than in 1993. The greatest concentrations of GSL's and ascorbic acid were found in roots grown with blue mulches. Reducing sugars were higher in roots grown with green than in those grown with blue mulches. The comparison of chemical composition of roots from plants grown with blue versus green mulches is important because both blue and green surfaces reflected about the same amount of photosynthetic light, very little red, about the same FR/R ratio, and different amounts of blue. We conclude that changing the surface color of mulches can influence not only shoot/root biomass ratio but also flavor-related chemical composition of field-grown food crop plants.