Fungicides evaluated for the control of stem rot on aucuba, 2009.

摘要

Aucuba ‘Gold Dust’ in #1 (C-650) containers were purchased from a nursery. Plants were maintained outdoors on a clam shell-covered bed under 47% shade cloth and watered daily with overhead impact sprinklers. The experimental design was a randomizedcomplete block with four replications with two plants per replicate. Heavy spray treatments were applied to run-off to the leaves, stems, and media surface at the root collar using a CO2- pressurized back pack sprayer with a single TX-8 hollow cone nozzle in 100 gallons of spray volume/A at 45 psi. For the drench treatments, approximately 0.2 qt (200 ml) of fungicide suspension was poured directly to the surface of the pine bark/peat moss potting medium. The initial application of all drenches and heavysprays was made on 18 Jun and additional applications were made at the intervals specified in the table through 10 Sep. Inoculum was prepared by growing Sclerotium rolfsii, which previously was previously isolated from aucuba, on sterile oat seed in a flask at room temperature for 1 wk. On 19 Jun, approximately 1 g of inoculum (20 to 25 seeds) was placed in two to three holes around the base of each plant. No colonized oat seeds were placed into the potting medium of the non-inoculated controls. Plantsurvival where each plant was scored as alive or dead on 15 Sep is displayed in the table. Significance of treatment effects was tested by analysis of variance and Fishers protected least significant difference (LSD) test (P<=0.05).