WASHINGTON — Condition ratings of the U.S. winter wheat crop slipped in the latest evaluation period, while spring wheat planting made good progress but remained behind average, according to the May 20 weekly Crop Progress report from the U.S. Department of Agriculture.

Winter wheat in the 18 major states as of May 19 was rated 31% good to excellent, down from 32% a week earlier and 58% at the same time last year, the U.S.D.A. said, while 41% of the crop was rated poor to very poor, compared with 39% the prior week and 14% last year.

Mostly abysmal ratings in the hard red winter wheat states slipped further, with wheat in Kansas rated 42% poor to very poor (41% a week earlier), Oklahoma 52% (47%), Texas 76% (73%), Colorado 52% (47%), Nebraska 49% (48%), South Dakota 59% (61%) and Montana 14% (15%). Wheat rated good to excellent in those states was 28% in Kansas (28% a week earlier), 19% in Oklahoma (21%), 6% good in Texas (9% good to excellent), 16% in Colorado (16%), 11% in Nebraska (12%), 8% good in South Dakota (5% good) and 53% in Montana (52%).

In contrast, ratings in most soft winter wheat states improved from already strong ratings a week earlier. Winter wheat rated good to excellent was 75% in Illinois (73% a week earlier), 72% in Indiana (73%), 76% in Ohio (72%) 68% in Missouri (63%), 58% in Arkansas (57%), 75% in North Carolina (74%) and 63% in Michigan (60%), the U.S.D.A. said.

But wheat development remained behind average in many states, both hard winter and soft winter, reflecting the prolonged cool spring. Winter wheat headed in the 18 states as of May 19 was 43%, compared with 80% at the same time last year and 62% as the 2008-12 average for the date.

Spring wheat planting advanced to 67% completed in the six major states as of May 19, up from 43% a week earlier but behind 98% at the same time last year and 76% as the 2008-12 average for the date, with top-producing North Dakota the furthest behind at only 50% seeded compared with 67% as the average for the date. Planted in Minnesota was 71% of the crop (80% as the average), South Dakota 91% (94%), Montana 79% (78%), Idaho 99% (93%) and Washington 100% (96%). Spring wheat emerged in the six states was at 22%, up from 10% a week earlier, but far behind 82% at the same time last year and 49% as the 2008-12 average for the date.