Fruiting of Cranberry Uprights Reduces Fruiting the Following Year

Abstract

Flower initiation begins in June-July for flowering the following year in American cranberry (Vaccinium macrocarpon). This study investigated the effect of the previous year's fruiting on the percentage of return flowering and fruiting in cultivars Stevens and Ben Lear at sites in Massachusetts, New Jersey, Wisconsin, Washington and Oregon. In the autumn and winter of 1990-91, uprights that had and had not fruited were tagged. After fruit set in 1991, uprights were sampled to determine return flowering and fruiting (at least 1 viable fruit/upright). Uprights that did not fruit in 1990 were more likely to flower and fruit in 1991, for both cultivars and all sites. For uprights of Ben Lear that had flowered in 1990, 54% fewer produced flowers and 60% fewer produced fruits in 1991 than uprights that had not set fruit in 1990. In Ben Lear, but not in Stevens, the percentage of 1991 flowering uprights that set fruit was reduced if the upright had flowered in 1990. Some differences were noted in percentage of repeat flowering and fruiting between sites, possibly due to climatic or management differences.