Effect of chloride fertilization on yield and development rate of winter wheat varieties
The effect of Cl fertility on small grain production is currently of great interest in the Northern Great Plains. Research from South Dakota and Montana has shown that application of fertilizers containing Cl may increase grain production. However, little is known about the mechanism of response. Several studies have found that Cl applications reduced disease severity from plant pathogens. However, the Cl-plant disease relationship does not explain many instances of Cl induced yield response. Chloride has been shown to reduce plant disease severity without affecting grain yield. In other cases Cl has increased grain yield without affecting the severity of plant diseases. This research led to information documenting chloride deficiency and response to chloride in small grain cereals.
IPNI-1991-USA-MT10
1996 Annual Interpretive Summary
Both non-disease and disease related Cl yield responses by winter, spring and durum wheat have been studied in this 5-year project in eastern Montana with a focus on non-disease leaf spotting that has been observed on certain wheat varieties. Research revealed that wheat yields are frequently improved by Cl fertilization. In 1995, the response averaged across 9 cultivars was 10 bu/A at both of the two sites studied. Soil and plant analyses provide important diagnostic tools in response prediction. Significant yield responses to Cl fertilization were observed in 70% of the cultivar x site x year episodes when whole plant Cl levels were < 0.10%. Response frequency drops to 29% at plant Cl values of 0.10 to 0.40%. Few responses to Cl fertilization were observed at plant Cl levels > 0.40%. A soil Cl level of 30 lb/A (0-24”) appears to be critical for ensuring adequate Cl nutrition. Yield responses were associated with a reduction in leaf spot foliar symptoms and an increase in kernel weight when Cl was applied. Studies like this one support the concept that balanced nutrition for wheat should include Cl management. It also helps explain the many responses by wheat reported over the years to KCl fertilization on soils high in available K. The objectives of this study were completed at the end of 1995, but the project was extended an additional year to evaluate the potential of foliar-applied magnesium chloride (MgCl2) to correct Cl deficiencies. Based on the observations at one research location, foliar-applied MgCl2 appears to be equal to KCl in effectiveness. MT-10F