2021: Evaluation of Various Fungicide Treatments at Different Application Times on Two Cultivars of Barley
(Research Report, Langdon REC, December 2021)Objective: To evaluate the efficacy of fungicides in single and sequential applications to manage Fusarium head blight (FHB) in barley.
Methods:
Location: NDSU Langdon Research Extension Center
Experimental design: Randomized complete block with split plot arrangement, four replications.
Previous crop: Canola
Cultivars of barley tested: ND Genesis (moderately susceptible/susceptible, released by NDSU) and AAC Synergy (moderately resistant, Syngenta)
Planting: 1.25 million pure live seeds/acre planted on April 30, 2021. A border plot was planted between treated plots to minimize interference from spray drift.
Plot size: Seven rows at six inch spacing, 5 ft. x 20 ft., mowed back to 5 ft. x 16 ft.
Herbicides applied: Wide Match (1.33 pt/a) + Axial Bold (15 fl oz/a) and 2 4-D Amine (1 pt/a) on June 14, 2021.
Inoculation: Plots were inoculated by spreading corn spawn inoculum at boot stage (Feekes 9-10) at the rate of 300 g/plot.
Disease development: Supplemental moisture was provided for a month starting from boot to soft dough stage by running overhead irrigation from Feekes 9 to 11.2.5 at the rate of one hour per day to create a conducive environment for FHB development.
Fungicide treatments: Fungicides were applied with a CO2-pressurized backpack sprayer with a three-nozzle boom (XR-8002) and the water volume used was 20 GPA. Fungicide (Miravis Ace) application was made at half head emergence on June 25. Miravis Ace, Prosaro, and Caramba were applied at full head emergence stage on June 29 and repeated 5 days after the full head emergence (July 5) as per protocol requirements. Refer to Table 2 for the treatments, dosages and application timings.
Disease assessment: FHB incidence and severity was obtained on 50 random heads showing FHB symptoms excluding two outer rows. FHB head severity was rated using 0-100% scale. FHB index (Index) was calculated using the formula: Index = (SEV*INC)/100.
Harvest: Plots were harvested on August 23 with a small plot combine and the yield was determined at 13.5% moisture.
Data analysis: Statistical analysis was done using Agrobase Generation II software. Fisher’s least significant difference (LSD) was used to compare means at p (α = 0.05).
Results: There were no statistically significant differences found in any of the variables tested among the two barley cultivars (Table 1). However, there were significant differences in FHB incidence, severity, index, DON, and test weight observed between non-treated check and the fungicide treatments tested at different application stages (Table 2). There was no interaction effect found between the main plot (cultivars) and the subplot (fungicide) treatments.
Table 1: Mean values of the variables tested on the barley cultivars ND Genesis and AAC Synergy obtained on application of fungicide treatments.
NS: Indicates the variables are statistically non-significant between the cultivars tested.
Table 2: Mean values of the variables tested on application of various fungicide treatments applied at different timings on two barley cultivars.
