Cranberry Yield and Fruit Quality Reduction Caused by Weed Competition

Abstract

The relationships between canopy density of three perennial weed species (Potentilla pacifica Howell, Aster subspicatus Nees, and Lotus corniculatus L.) and `Mcfarlin' and `Stevens' cranberry (Vaccinium macrocarpon Ait.) yield and fruit quality were evaluated. Yield was more severely affected by weed interferences than fruit size or color. Best-fit regression equations for the effects of weed density on yield, fruit size, and color were linear or quadratic polynomials with a strong linear component. For each bog, the slope of the linear relationship between yield and weed density was more negative as the mean yield of weed-free controls increased. `Stevens' fruit size and yield were more sensitive and fruit color was less sensitive to changes in P. pacifica population density than those of `McFarlin'.