CHICAGO: Chicago Board of Trade (CBOT) wheat futures rallied on Wednesday, with traders saying they had begun unwinding the corn-wheat spread after the US spring wheat tour found inconsistent yields in parts of North Dakota.

* CBOT September soft red winter wheat ended the day up 10-1/2 cents at $4.97-3/4 per bushel.

* K.C. September hard red winter wheat ended up 8 cents at $4.39-1/2 a bushel, and MGEX September spring wheat up 1-3/4 cents to $5.22-1/4 a bushel.

* Harvest potential for the spring wheat crop in north central North Dakota is variable, with fields that were planted in a timely fashion on track for bumper yields, scouts on an annual tour found on Wednesday.

* But fields that were seeded late were expected to come in with below average yields as the crop struggled through early development in muddy fields.

* That, in turn, convinced dealers to short wheat and go long on corn, traders said.

* A diminished outlook for production in top wheat exporter Russia was also supportive. SovEcon said it had lowered its forecast for this year's Russian wheat crop to 73.7 million tonnes from an earlier estimate of 76.6 million.

* The forecast is slightly below the US Department of Agriculture's current projection of 74.2 million tonnes.