Fundamentally Speaking

Most Corn States Have Better-Than-Average Ratings

Joel Karlin
By  Joel Karlin , DTN Contributing Analyst
Chart by Joel Karlin, DTN Contributing Analyst

A look at the 30-day percent of normal precipitation really only shows Minnesota and the Dakotas with below average rains as the rest of Corn Belt, Plains, Southeast and Delta have normal to actually above average moisture.

We think Iowa may be the key state as that has occupied the middle ground between having favorable or less than favorable crop prospects but good rains over past two weeks have helped the situation.

Monday's weekly USDA crop progress and condition reports show a 1-2% improvement in U.S. corn and soybean conditions with spring wheat ratings staying steady.

Along these lines this graphic shows week 27 (mid-July) crop ratings for the U.S and the top 18 growing states and the 20 year average on the left-hand axis using our usual ratings system where we weight the crop based on the percent in each category and assign that category a factor of 2 for very poor, 4 for poor, 6 for fair, 8 for good, and 10 for excellent and then sum the results.

On the right-hand axis is where the 2021 week 27 rating ranks over the past 20 years with a ranking of 1 meaning it is the best rated crop for this time of year since 2002 while a ranking of 20 signifies is the worst rated crop over the past 20 seasons.

We also report in the yellow rectangle the correlation of week 27 crop ratings to the percent that the state's final corn yield deviates from 20-year trend.

The chart shows that only in 4 states, (Iowa, Minnesota, North Dakota and South Dakota) are 2021 crop ratings below the 20-year average, so 14 of the 18 actually have better than normal crop ratings as of mid-July.

That is a lot though some may say that those are four really important states and as we have noted before, the Dakotas and Minnesota themselves will represent 20% of U.S corn planted area and 24% of soybean acreage while Iowa is the top producing corn state and second for soybeans.

The caveat though is that though Iowa's correlation between mid-July crop ratings and the percent that final yields deviate from the 20 year trend is a relatively high 62.8%, the correlation rate for MN is 44.8%, SD is 42.9% and ND at just 1.3%.

Our takeaway is that these crops on average develop later since they are planted later in the season, so they are on average not as developed by mid-July as many other top corn producing states.

This leaves plenty of time for improvement in ratings should more favorable weather conditions develop which, though not in the cards at this time could still happen, especially for soybeans where August is the critical month.


To comment, please Log In or Join our Community .