The effect of sand application to `Stevens' cranberry (Vaccinium macrocarpon Ait.) was studied for 3 years in a 24-year-old (site 1) and an 8-year-old (site 2) commercial planting. Treatments in Apr. 1991 consisted of a onetime sand application of 1.3 or 2.5 cm on the surface of the cranberry bed and a nonsanded control. Yield component data were collected in Fall 1991 through 1993. In 1991, 2.5 cm of sand reduced yield 50% at site 2 compared to the nonsanded control. At site 1, the 2.5-cm sand depth did not reduce yield, while the 1.3-cm-deep application improved yield 18% compared to the control. The year after sanding (1992), yields equalized across all treatments at both sites. In 1993, there was no significant difference in yield for treatments at site 1. At site 2, however, heavy sanding reduced yield 63% compared to 1.3 cm of sand. Our work suggests that heavy sanding is not recommended for `Stevens' cranberry beds in Oregon.
Bernadine C. Strik and Arthur P. Poole
Bernadine C. Strik, Teryl R. Roper, Carolyn J. DeMoranville, Joan R. Davenport, and Arthur P. Poole
This research was undertaken to document the extent of biennial bearing in flowering uprights by American cranberry (Vaccinium macrocarpon Ait) cultivar and growing region. Seven cultivars were studied: three found in all states considered (Massachusetts, New Jersey, Wisconsin, Oregon), two common to Massachusetts and New Jersey, and two other commercially grown cultivars, one each from Wisconsin and Oregon. There were significant cultivar, region, and cultivar × region interaction effects for both percent return bloom (%RB) and percent return fruit (%RF). Percent RB ranged from 74% for `Ben Lear' in Wisconsin to 14% for `Howes' in New Jersey. `Ben Lear' differed the most in %RB among regions, from 74% in Wisconsin to 14% in Massachusetts. However, in some regions, especially in Wisconsin, many blossoms did not set viable fruit. There was no significant difference in %RB among cultivars grown in Massachusetts or Oregon; however, cultivars grown in these regions did differ in %RF.
Carolyn J. DeMoranville, Joan R. Davenport, Kim Patten, Teryl R. Roper, Bernadine C. Strik, Nicholi Vorsa, and Arthur P. Poole
Fruit mass development in `Crowley', `Pilgrim', and `Stevens' cranberry (Vaccinium macrocarpon Ait.) was compared in five states for two seasons. Comparing all locations, `Stevens' and `Pilgrim' cranberries had similar growth curves with a faster growth rate than that of `Crowley'. Regional differences in fruit development were observed. Shorter growing seasons, especially in Wisconsin, were compensated for by more rapid growth rates. Conversely, low initial mass and slower growth rates were compensated for by the longer growing season in the Pacific Northwest. Solar radiation intensity accounted for little of the variability in fruit growth. Neither growing degree days nor numbers of days were good predictors of cranberry fruit fresh mass accumulation. Instead, numbers of moderate temperature days (between 16 and 30 °C) appeared to be key, accounting for greater than 80% of the variability in cranberry fresh biomass accumulation. The most rapid growth rates occurred when temperatures were in this range. High temperatures were limiting in New Jersey while low temperatures were limiting in Oregon and Washington. In one of two seasons, low temperatures were limiting in Wisconsin: accumulation of 0.5 g fresh mass took 11 d longer. Massachusetts had the fewest periods of temperature extremes in both seasons, resulting in the shortest number of days required to accumulate 0.5 g fresh mass.