The crop condition ratings indices

Last week USDA began reporting condition ratings for the 2013 corn crop. These weekly ratings will be updated throughout the summer and into fall. We convert the condition ratings into an index so that we can compare the condition of the crop to other weeks and other years. The index is constructed according to the following formula: (4 * share excellent) + (3 * Share good) + (2 * share fair) + (1 * share poor) + (0 * share very poor). For most crops the data go back to the early 1990s. It is too early for the condition ratings to be very informative, but we will trace the progress of the crops this year using the index as a measure compared to other years and to the 10-year average.

The crop condition ratings indicesThe first crop condition ratings for corn showed that 11 percent of the crop is in excellent condition, 52 percent in good condition, 30 percent in fair condition, 5 percent in poor condition and 2 percent in very poor condition. This works out to a condition index of 265. The 10-year average for the index at this point in the season is 278, well above this year's starting point. The index for this year is identical to the index at the beginning of 201.1. The wet weather across the country is the key factor for the relatively low start to the crop condition ratings. Condition ratings for corn are highest in the East with 78 percent of the crop in Indiana rated wither good or excellent in Ohio and 76 percent in those categories in Indiana. In contrast 57 percent of Iowa's crop and only 50 percent of the crop in Missouri are rated in these two categories. Typically the condition rating index declines as we go through the season.

The crop condition ratings indicesUSDA has also started reporting condition ratings for spring wheat. Condition ratings for cotton will begin this week and the one for soybeans will probably begin in the middle of June. These ratings are converted to our index using the same formula as the one used for corn. The weekly Crop Progress report showed that spring wheat in North Dakota was only 64 percent planted, and the Prospective Plantings report showed that farmers in the state planned to plant 6.2 million acres of spring wheat. That implies that about 2.2 million acres of spring wheat were still to be planted in the state and another 500,000 acres of durum. But the crop that has been planted is in generally good condition with 16 percent rated excellent and 52 percent rated good.

The overall condition rating index for spring wheat at this point in the season is 263. The 10-year average for the index at the beginning of June is 289. In 2008 the rating index came in at 298, the highest for the week in at least the last 20 years. As is the case with corn, the ratings typically decline as we go through the rest of spring and early summer. If farmers can get the crop planted, soil moisture conditions should be favorable for good yields. As of last Sunday only about 60 percent of the spring wheat crop had emerged, suggesting that this year's crop may mature later than "normal.