Crop Highlights in Wheat, Corn and Soybeans

September 27, 2011

 

Rainfall Increases Wheat Planting, More Needed To Replenish Dry Fields

 

Rainfall over the past 10 days has been significant,  jumpstarting wheat planting in the Southern Great Plains.    Kansas winter wheat planting reached 20% complete, Oklahoma, 11%,  Texas 14%.   

 

Despite good progress last week, sowing is still behind normal, due to extreme drought previously in the Southern Great Plains.   The absence of subsoil moisture means that heavy, follow-up rainfall is needed to obtain favorable germination rates and high plant populations.    See where winter wheat is grown:

 

Of the 3 major hard red winter wheat states, Texas is driest, since June 1 receiving only 1.9 inch of rainfall.  That is 2% of normal in the 4 months.  Soil moisture improves, heading north through the bread-basket.   Oklahoma cumulative rainfall is 5.8 inches, and 47% of normal.    Kansas is the wettest with 10 inches of rainfall  and 80% of normal.     There is huge disparity in Kansas  soil moisture, however, plenty wet in the northern wheat areas but extremely dry in the  southwest.

 

 

 

 

 

Corn Ratings as a Predictor of Yield

The national corn rating September 25 was 52% good-excellent, 28% fair and 20% poor-very poor, ranking among the lowest quartile of years in the USDA records, dating  back to 1986.    Are low ratings ahead of the harvest a good predictor of the final outcome?    We tested the theory, comparing low-rated years against the final US corn yield to see if there was a correlation. 

 

 

There were 6 instances of low ratings similar to 2011.      Surprisingly, 2 of the years 2003 and 2005 finished with an average corn yield,  near trend, and much better than anticipated.    The other 4 cases 1988, 1991, 1993 and 2002 finished with a significantly reduced yields ranging from 8% to 25% below average.

 

 The worst corn rating was in 1988 from a historic drought.   Corn production fell to 4.93 billion bushels and 40% beneath the previous 3-year average.     There is no way corn production this year will be that badly damaged.     The USDA  current yield estimate 148.1 bushels per acre is 7% below-trend and close to the final results in 2002.

 

 

 

 

Drought and Freeze Damage in Northern Soybeans

Soybeans took a sudden turn for the worse in the northern Midwest the past 2 weeks suggesting either freezing temperatures or drought had caused damage.    Good-excellent soybeans have dropped like a stone in Minnesota from 61% good-excellent September 11 to 49% September 25, while poor soybeans increased 5% to 16%.

 

 

South Dakota and North Dakota soybeans experienced similar declines.   We’ve not been able to determine the exact cause, though a frost “shock” is suspected.   Following the early September frost , leaf shedding has rapidly increased and by September 25 was 75%-86% finished in the Upper Midwest soybeans.    Nationwide, leaf-shedding was only 58% underway suggesting stress in the northern areas.

 

Beside frost,  severe dryness in August-September may have been heavily responsible for stressing soybeans and worsening the crop ratings.    This is the key pod filling period, when yields are strongly affected by drought.   Minnesota was especially dry in August, reporting the lowest rainfall on record in the south-central district.

 

See where soybeans and corn are grown: