Recent studies in the northern Great Plains have confirmed that the ch
loride (Cl-) component of fertilizers can reduce disease severity and
increase grain yield for wheat (Triticum aestivum) and barley (Hordeum
vulgare). Field studies were conducted in Manitoba in 1989 and 1990 t
o determine the effect of rates of 25 and 50 kg Cl- ha(-1) (applied as
KCl or NaCl) applied with or without Cochliobolus sativus inoculum on
plant nutrient status, disease severity and grain yield for Katepwa w
heat and Bedford barley. Chloride application, regardless of placement
or source, increased the Cl- concentration in plant tissue sampled at
the boot to heading stages. Rates of 25 and 50 kg Cl- ha(-1) resulted
in significant reductions in the severity of common root rot for barl
ey in two of six experiments and for wheat in one of four experiments.
Chloride applications did not reduce spot blotch severity on barley i
n either of two experiments conducted. Inoculum did not have a consist
ent effect on any of the parameters measured. The application of 50 kg
Cl- ha(-1) significantly increased grain yield for barley by an avera
ge 393 kg ha(-1) in two of eight experiments, but did not increase gra
in yield for wheat in any of eight experiments, Yield responses to Cl-
were not related to soil Cl- content, Cl- concentration in plant tiss
ue or observed reductions in disease.