Evaluation of antibiotics and biological control products for control of fire blight, 2008.

摘要

The test was carried out in a mature Rome Beauty and Red Delicious apple orchard at thePenn State Fruit Research and Extension Center in Biglerville, PA. Trees received insecticide and fungicide applications, including the dormant coppersprays, consistent with standard commercial practice for the northeastern U.S. Experimental treatments included three biological control products: Serenade Plus, Pantoea agglomerans products, or a yeast-containing product) and two antibiotics(Mycoshield, or Kasumin); a streptomycin standard treatment and an untreated check for comparison. The yeast product and P. agglomerans II treatments were applied on 25 and 30 Apr and 4 May; all other products were applied only on 30 Apr and4 May. Treatments were applied using a commercial air-blast sprayer at a rate of 100 gal/A and 400 psi. The experimental design was a split-plot arrangement with treatments and cultivar as main-plot and sub-plot factors, respectively. Eachtreatment was replicated four times. Between 27 and 60 clusters were tagged on each tree and inoculated on 2 May with a suspension of 1X108 CFUs of Erwinia amylovora strain Ea273. Trees were rated for fire blight incidence and disease severityon a 1-to-5 scale (1=no infection; 5=infection with characteristic shoot wilt symptoms) on May 14. Data were analyzed with PROC GLM of SAS and means separated with Fisher’s protected LSD test (P = 0.05).