1996 Volume 62 Issue 5 Pages 517-522
Flower buds of kiwifruit grown in plastic tunnel were inoculated with Pseudomonas syringae, a causal pathogen of bacterial blossom blight, 6 to 8 times from April to May in 1990 and 1992. Occurrence of the bacterial blossom blight was evaluated in relation to the day required for calyx splitting and flowering as well as the correlation between bud development and disease incidence. Disease incidence was significantly high when the buds were inoculated 10 to 19 days before flowering. Buds at 10 days before calyx splitting resulted in high disease incidence and the average days required from calyx splitting to flowering were 10 days. Disease incidence of early developmental stage (A to D) was higher than the late stage. These results showed that flower buds between 10 and 19 days before flowering was the most susceptible to the bacterial infection, suggesting that P. syringae needs to infect the flower buds before calyx splitting followed by the rapid increase of bacterial density within the buds.
