Evaluation of foliar fungicides for control of Fusarium head blight and foliar diseases of spring malting barley in New York, 2016

摘要

The fungicide trial was conducted at the Musgrave Research Farm in Aurora, NY in a Lima silt loam soil planted with the two-rowed, spring malting barley variety 'Conlon' sown at 100 lb/A with a no-till grain drill into disked corn residue on 18 Apr. Nine foliar treatments (combinations of products and timings of applications) were arranged in a randomized complete block design with four replicates. Plots were 20 x 10 ft including 15 rows with 7.5 in. row spaces. The plots were fertilized at planting(200 lb/A of 10-20-20) and topdressed on 23 May (60 lb/A of urea, providing an additional 27.6 lb/A of nitrogen). Fungicides were applied on 9 Jun at Feekes growth stage (FGS) 9 (ligule of flag leaf just visible) and on 16 Jun at FGS 10.5 (head emergence), depending on the treatment. All plots were inoculated with a conidial suspension of Fusarium graminearum (40,000 conidia/ml) on 9 Jun and 16 Jun, after fungicide applications were completely dried, to augment natural inoculum for initiation of Fusarium head blight (FEB). Treatments were applied with a backpack sprayer with 8002DG flat fan nozzles, 18.5-in. apart, pressurized at 34 psi, and calibrated to deliver 20 gal/A. The F. graminearum was applied by a tractor-mounted sprayer with TJ-60 8003VS nozzles, 20-in. apart, pressurized at 30 psi, and calibrated to deliver 20 gal/A. Incidence and severity (percent of symptomatic spikelets on symptomatic heads) of FHB in each plot were rated on 18 Jul. Spot blotch, caused by Bipolaris sorokiniana, and Netblotch, caused by Pyrenophora teres were rated collectively as "leaf blights" on 18 Jul as percent disease severity on flag leaves and one leaf below flag leaf (average rating for whole plot). Leaf rust, caused by Puccinia hordei, was also rated on 18 Jul as percent disease severity on flag leaves and one leaf below flag leaf (average rating for whole plot). Grain was harvested on 2 Aug from a 20 x 5 ft area in each plot using an Almaco plot combine. Grain moisture, grain yield, and test weight for individual plots were recorded and yield and test weights were recalculated to bu/A at 14.5% moisture. Analysis of deoxynivalenol (DON) content in grain was conducted in the US Wheat and Barley Scab Initiative-supported mycotoxin analysis laboratory at theUniversity of Minnesota, St. Paul, MN. Treatment means were calculated, subjected to analysis of variance, and separated by Tukey-Kramer HSD test (P = 0.05).