Heat Damage in Corn, Soybean Moisture Stress, Emergent La Nina

August 9, 2011

Corn Declining Sharply in Central Midwest

Corn has deteriorated in the “heart” of the Midwest grain belt. Crop ratings declined sharply the past 4 weeks in drought affected crops. Corn in the good-excellent category fell sharply in Iowa, Illinois, Indiana and Missouri. The number 2 corn state Illinois fell 17% in good-excellent since July 10, now reporting only 50% good and excellent.

 

The northern Midwest corn withstood July heat in better condition, due to generous rainfall from “ridge-rider” thunderstorms. See good-excellent corn by state on the map below and percent change from 4 weeks ago:

 

Poor pollinating conditions leads to damaged corn.   Open the  ugly corn PDF file to see pictures from around the Midwest. Blank kernels at the tip of the ear of corn illustrates unsuccessful fertilization. Twisted ears? Does anybody know what causes that? We know extreme heat damaging the past 4 weeks:

 

 

Shallow Rooting Contributes To Soybean Drought Damage

The US soybean condition was 61% good-excellent, 26% fair and 13% poor-very poor. This was much the same last week and not a good report, given that soybeans are in the reproductive stage. Pod-setting stage was 50% underway. Dry conditions in August would limit the number of pods developing on plants, and thus reducing the yield.

Eastern Midwest soybeans planted late into soggy fields are prone to drought stress, because of shallow rooting. Low rainfall the past 4 weeks depleted the topsoil moisture. Indiana soybeans stabilized August 7, benefiting from rainfall last week, but are badly damaged with 44% good-excellent, 37% fair and 19% poor-very poor. This is the United States 4th leading soybean state.

 

 

Spring Wheat Conditions Declined

Spring wheat prospects declined August 7 to 66% good-excellent, 27% fair and 7% poor-very poor. That compares with 73% good-excellent, 23% fair and 4% poor-very poor a month ago. Extreme wetness in the northern Plains may have contributed to the worsening crops conditions with severe storms again last week. North Dakota reported 32% surplus field moisture, 65% adequate and 3% short.

 

 

New La Nina Emerging

La Nina is redeveloping in August. Sea surface temperatures in the eastern equatorial Pacific Ocean have been cooling since July 1, the Nino 3.4 region. The Climate Prediction Center does not expect a full blown La Nina until the fall, though atmospheric circulations in the tropical Pacific already reflect aspects of La Nina.

 

Another La Nina would be devastating in the Southern Plains, promoting back-to-back droughts in hard red winter wheat. The La Nina is a known drought-maker in the Midwest also. A fast-developing La Nina would be bad for corn and soybeans, if it occurred, causing low rainfall in August.