EFFECT OF ROSE BLOOM DISEASE ON THE YIELD COMPONENTS OF CRANBERRY (VACCINIUM MACROCARPON AIT.)

Morphological components of yield in ‘McFarlin’ cranberry were studied to determine the impact of the rose bloom disease (Exoba sidium oxycocci Rostr.) on growth and productivity.
Yields in 1986 and 1987 from flowering uprights with the pink fleshy abnormal branches were less than from healthy uprights.
Each year infected uprights had fewer flowers, lower fruit set and smaller berries.
Compensation may occur between some yield components as larger berries were produced on infected uprights at one of two test sites in 1987. Rose bloom also resulted in shorter vine growth and fewer leaves.
The rate of vine growth on infected uprights did not increase once the fleshy rose blooms had shrivelled and died in late June.
Flowers on infected uprights were more sensitive to frost injury.
Rose bloom reduced flowering by preventing some of the flower primordia from developing into mature flowers, as the number of primordia in unopened buds from healthy and infected uprights was the same.
The pathogen apparently does not survive as an overwintering perennial mycelium in the host as uprights infected in 1986 were no more likely to be infected in 1987 than those which were disease free in 1986.

IV International Symposium on Vaccinium Culture

P.R. Bristow, G.E. Windom

https://doi.org/10.17660/ActaHortic.1989.241.55