WASHINGTON — The condition of the corn crop as of July 21 in the 18 main corn-growing states declined three percentage points from a week earlier in the good to excellent categories, the US Department of Agriculture said in its most recent Crop Progress report.

As of July 21, a total of 63 percent of the crop was rated good to excellent, down from 66 percent the previous week. A total of 11 percent was rated very poor to poor in the latest week, compared with 9 percent the previous week, the USDA said. Despite the decline, the crop fared far better than a year ago when good to excellent ratings were only 26 percent and poor to very poor ratings were 45 percent.

Corn development advanced rapidly in the most recent week, the USDA said, with 43 percent of the crop in the silking stage, up from 16 percent the previous week and compared with 56 percent as the five-year average for the date.

The weekly decline in the condition rating was about what was expected by the trade, but corn futures were down sharply early July 23 due to improved rainfall in parts of the Corn Belt. The rainfall would be occurring during the key pollination stage.

The soybean crop also advanced rapidly but still lagged the five-year average for some growth benchmarks. The USDA said 46 percent of the crop was blooming in the 18 main soybean-growing states, up from 26 percent as of July 14 but below the five-year average of 59 percent. A total of 8 percent of the crop was setting pods as of July 21, behind the five-year average of 19 percent, the USDA said.

Soybean conditions were rated 64 percent good to excellent, down slightly from 65 percent a week earlier but well above 31 percent a year ago. The crop was rated 8 percent poor to very poor, the same as a week earlier but far better than 35 percent a year ago.