Effect of seaweed extract on fruit set, yield, and quality in Pinot noir winegrapes.

ABSTRACT Certain winegrapes cultivars, such as Pinot noir can be difficult to set to desired levels. Additionally, set can be low in cold, hot, or wet weather. Growers often look for ways to increase set within a bunch (i.e. decrease shatter). Seaweed extracts from Ascophyllum nodosum have the potential to improve fruit set. Ascophyllum nodosum, native to the north Atlantic, has been studied extensively, and survives under extreme growing conditions. Acadian extracts are processed with fresh Ascophyllum nodosum, using a proprietary alkaline extraction process. Seaweed extracts are used to stimulate metabolic processes and help the plant to exploit nutrients that are unavailable, as well as improve nutrient uptake, and improve water stress tolerance. Seaweed extracts can also stimulate PGR’s within the plant. All of these effects may increase the overall health of a plant, resulting in a healthier, less stressed plant which may be more likely to set fruit. The objective of this study is to determine if season long applications of Acadian LSC will enhance cluster architecture, set and yield of winegrapes. A Pinot noir vineyard in San Luis Obispo County CA was selected for this trial. This vineyard is known to have production issues stemming from a loss of grapes post bloom due to shatter (initial loss of small berries from the rachis). A replicated strip trial was began in 2006. Seven in-season treatments of foliar and soil applied Acadian LSC at 3 pints per acre were applied. The control consisted of grower standard practices, which were also applied to the Acadian treatment. In 2006, Early season shoot length was significantly longer in Acadian treated vines compared to the control vines (Figure 1). This was particularly beneficial in this vineyard where the vines are somewhat weak.