Response of Cabernet Sauvignon and Chardonnay to Fungicide Applications and Deficit Irrigation

Introduction Fungicides have been widely used on nearly every crop imaginable and are continually being developed and reformulated as more information on their efficacy on specific crops and pathogens is discovered. It is well known that fungicides are developed and used in order to have a direct effect on one or more pathogens, usually to prevent their establishment on a crop. By spraying fungicides, the occurrence of pathogens can be eliminated or minimized which reduces plant stress and allows for improved yields and crop quality. However, relatively little research has been done on the effects of fungicides on the crops they are applied to. The effects of fungicide use on plants have the potential to affect genetic expression, physiological responses, and aspects of plant development not fully understood yet. One purpose of this experiment is to discover the effects of using the fungicides trifloxystrobin (Flint®), quinoxyfen The second purpose of this experiment was to test the effects of deficit irrigation on the genetic expression, physiological responses, and plant development-similar to the first purpose mentioned. In arid regions such as California, rainfall is not adequate enough to supply all the water needs of wine grape vines and drip irrigation is often used to supplement. Previous research has indicated that plants can tolerate a certain level drought stress without significant detrimental effects and that in a few circumstances the drought stress can be used as a management technique to reduce costs while improving specific aspects of plant or fruit development. In this experiment, deficit irrigated vines received twenty-five percent of the The information gained from this experiment could be potentially useful for wine grape breeders, vineyard managers, and wine makers. By testing the genetic responses, specifically which genes are being turned on, off, upregulated, or downregulated, wine grape breeders will have better knowledge of the cultivars and genotypes they should or shouldn't use under specific conditions. If specific genes can be identified as responsive to fungicides and deficit irrigation, plant breeders and geneticists may better understand the mechanisms plants use to resist fungal infection and tolerate drought conditions. These genes could then be used to develop new wine grape cultivars. Expanded knowledge on the genetic responses to fungicide use and deficit irrigation could possibly shorten a breeder's time-line to creating a new cultivar by using varieties known to show positive or neutral responses to fungicide applications and deficit irrigation. Vineyard managers could …