Physiological Evaluation and Field Assessment of Floricane Productivity of Cold-damaged Red Raspberry in a “Recovery” Year

Abstract

The two test sites paired perennially cold-damaged portions of field vs. controls were monitored and assessed the same as last season. The winter of 1996–97 did not produce the same level of winter injury as the previous winter, thus this season was an opportunity to evaluate the effects of a “recovery” year. The overall cane lengths and bud number per cane were higher in the previously winter injured plots of both fields compared to the control. It showed the previous injured plants with a reduced crop load in 1996 were able to devote more energy into developing the 1997 crop. However, damaged plots still had higher cane dieback, percentage of cane dieback, number of dead or dormant buds per cane, and percentage of dead or dormant buds in both sites, especially at site 2, even in a mild 1996–97 winter. The control plots had greater average lateral length, total lateral length, and higher berry numbers per lateral, especially in laterals from primary buds at both sites. Thus, a mild winter reduced productivity of the floricanes and its laterals in the cold damaged plots. The differences in fruit yield and its components between the check and the cold-damaged ones were not significant this season. Leaves on the cold damaged floricanes had greater photosynthetic activity after harvesting than the control. The winter-injured plants with a reduced leaf area may show higher demand for photosynthate.