Suppression of Disease with Agronomic Practices in Recently Released Spring Wheat and Winter Wheat Cultivars

Suppression of Disease with Agronomic Practices in Recently Released Spring Wheat and Winter Wheat Cultivars, 2007 This study was designed to examine whether a synergy exists between chloride (Cl-) nutrition and fungicide application in winter and spring wheat. The study was conducted at two sites in North Dakota in 2007. Heading applications of Cl- were not effective in reducing scab in winter wheat. Soil application of Cl- as calcium chloride (CaCl2) reduced leaf diseases at one site.

IPNI-2006-USA-ND13

21 Mar 2006

Methodology


One site (possible two) in North Dakota and two sites in South Dakota will be prepared with conventional tillage to plant three to five of the most popular varieties of hard red winter wheat (HRWW in North Dakota) and hard red spring wheat (HRSW in South Dakota) according to local production practices. Soil samples will be removed to determine initial extractable soil Cl levels and to provide N, P, and K as required. Treatment plots will have dimensions of 5’ wide and 35’ long and each treatment set will have four replications. Soil applied treatments will be 60 lbs Cl as KCl, 60 lbs. Cl as CaCl2 along with several control plots. Plant tissue will be sampled at the late tillering stage to determine tissue Cl levels. After the flowering stage, plots will be rated for root rot, stem and leaf rust, tan spot, and head scab infection. Foliar treatments will be then applied to plots in which no fertilizer Cl was applied. A fungicide treatment (either Tilt or Quadris) according to recommended practices will be applied to another set of control plots. A 15 lbs./a Cl treatment as soluble ammonium chloride will be applied to another set of control plots. Two weeks after the foliar applications, diseases again will be rated. Wheat will be harvested at physiological maturity. Statistics will be applied to plant tissue, diseases ratings, and grain yield to determine the influence of these treatments on disease suppression and a report will be complied for distribution.