Evaluation of fungicides for postharvest control of Rhizopus soft rot in sweetpotato, 2017

摘要

This experiment was conducted at North Carolina State University in Raleigh, NC. Sweetpotato roots used in the study were obtained from a commercial packing facility at the time of each inoculation and were rinsed with water prior to use. Roots were previously cured and were selected based upon similar size, shape, and disease-free appearance. Sweetpotatoes were wounded using a calibrated, rubber-band-propelled wooden dowel. After wounding, roots were inoculated with a spore suspension (1.0 x 106 spores/mL) suspended in a 0.2% agar solution, applied with a micropipette. Following inoculation, roots were allowed to air dry. Roots were placed on a roller bed and fungicides were applied at specific rates using a CO2-pressurized backpack sprayer. For the dip application, wounded roots were placed into a perforated metal basket and submerged into the fungicide mixture for 1 minute. After fungicide applications, roots were allowed to air dry, and then placed into clear, plastic containers (40 by 50 by 17.9 cm) and stored at 27°C and 99% relative humidity for 21 days. Four replications per treatment were included with 20 roots per replication. Roots were rated for disease incidence and severity at 7, 14 and 21 days after inoculation. Data were analyzedin the software ARM (Gylling Data Management, Brookings, SD) using analysis of variance (AOV) and Fisher's Protected LSD test to separate means.