Available at: https://digitalcommons.calpoly.edu/theses/699
Date of Award
MS in Agriculture - Crop Science
Horticulture and Crop Science
Vineyard management practices have an impact on grape berry development in ways that influence the quality of wine made from those grapes. The goal of this study was to determine whether exogenous applications of marine extracts on Syrah grapes can influence yield components, harvest juice quality parameters, and nutrient uptake. From 2009 to 2011, Syrah grape vines at the Trestle Vineyard on the California Polytechnic State University, San Luis Obispo campus received individual doses of marine extract via fertigation at berry set and veraison proportional to the amount they would receive on an annual per-acre basis based on the extract manufacturer’s recommended rate of application. In a separate experiment conducted in 2011, marine extracts were applied as foliar treatments. Treatments were analyzed for their effects on berry juice TSS, pH, TA, anthocyanins, tannins, and fruit yield per vine, clusters per vine, average berry weight, cluster weight, berries per cluster, vegetative yield, and foliar nutrient concentration. The marine extracts did not have any significant effects on yield components, harvest juice quality, or foliar nutrient concentration at any point in this experiment, except for a marginally significant increase in copper uptake with seaweed extract application as compared to the untreated control. Seaweed extract fertigation did result in a significant decline in net photosynthesis shortly after application as compared to control, while fish/seaweed extract blend fertigation resulted in a significant increase in net photosynthesis after application as compared to control. Though some minor effects of marine extracts were detected, there appears to be no benefit or drawback to applying these products in Syrah grapes growing in heavy clay soil in cool-climate conditions.