Effect of machine-harvester wounds and Leptosphaeria coniothyrium on yield of red raspberry

When wounds on raspberry canes caused by machine harvesting in the previous year were infected by Leptosphaeria coniothyrium the potential yield per cane was reduced by 45% compared with that of uninfected hand harvested canes. However, the corresponding reduction per plot was less (c. 25%) because the yield of wounded but uninfected canes was not reduced and some canes were not wounded. The advantages and disadvantages of recording potential yield per cane are discussed.