Field Efficacy of Fungicides and Biofungicides in the Control of Spur Blight of Raspberries in Serbia

Abstract

In order to control the causal agent of spur blight of raspberry (Didymella applanata), the efficacy of five conventional fungicides and two biofungicides was evaluated during 2009 and 2010 in one locality in Serbia where a strong epidemic of the target disease was expected. The following materials were tested: Acanto Plus, applied at 1.0 L/ha (picoxistrobin + ciproconazol, DuPont); Amistar Extra, applied at 1.0 L/ha (azoxystrobin + cyproconazole, Syngenta); Folicur EM 50-WP, applied at 2.5 kg/ha (tolylfluanid + tebuconazole, Bayer CropScience); F-Stop, applied at 10.0 L/ha (Bacillus subtilis, Bio-eko centar); Polyversum, applied at 1.0 kg/ha (Pythium olygandrum, Biopreparaty); Signum (boscalid + pyraclostrobin, BASF); and Switch 62.5-WG, applied at 1.0 kg/ha (fludioxonil + cyprodinil, Syngenta). The trials were arranged as randomized plots (10 m long rows), replicated four times with 90-100 plants/plot. The mean percentage values of disease control were calculated from the assessments made towards the end of the trials, when differentiation between treatments was most obvious. Data were analysed by one-way completely randomized ANOVA, and the comparison of means was performed by using Duncan's test. The infection of raspberry canes in untreated control plots was 2.47 (2009) and 3.82 (2010) (expressed as a class of cane infection). In both years, biofungicides F-Stop (7.98 and 11.16%) and Polyversum (14.19 and 16.94%) exhibited the lowest efficacy among the tested products. Acanto Plus, Amistar Extra, Folicur EM 50-WP, Signum and Switch 62.5-WG were effective against the spur blight pathogen and they significantly reduced the disease severity compared with the untreated plots. Among the tested conventional fungicides, Acanto Plus (81.29 and 87.63%) and Switch 62.5-WG (82.28 and 85.29%) showed the highest efficacy in all trials. There was no statistically significant difference in the efficacies of the tested conventional fungicides.