WASHINGTON — Continued declines in crop condition ratings in most hard red winter wheat states more than offset gains in soft red winter wheat states, resulting in further slippage in the latest U.S. Department of Agriculture 18-state aggregate winter wheat condition ratings.

The U.S.D.A. rated the 2014 winter wheat crop at 31% good to excellent, 31% fair and 38% very poor to poor as of May 4, compared with 33% good to excellent, 33% fair and 34% very poor to poor a week earlier and nearly equal to 32%, 29% and 39%, respectively, a year ago.

The dismal ratings in Oklahoma and Kansas reinforced findings by crop tours in both states last week when participants forecast Oklahoma output the lowest since 1957 and Kansas production the lowest since 1996, based mostly on weather-reduced yields in both states.

“Most of the state (Kansas) is still seriously short of moisture,” said Ben Handcock, executive director of the Wheat Quality Council, which sponsored the Kansas wheat tour. “I believe our 33.2 bu average (yield) was appropriate for the 3 days we looked at it, but will likely be too high. With the heat and winds the crop has experienced since last Thursday, I believe we have already lost some yield potential. The 10-year average (production) for Kansas is around 332 million bus. Our estimators, at 260.7 million, are well below that number, and I believe even that number is too high.“

Ratings as of May 4 declined in all hard red winter states except Texas, which had dismal ratings coming into the week. The Texas crop was rated at 13% good to excellent (13% a week earlier) and 64% very poor to poor (65%), Oklahoma at 6% good with none excellent (9% good to excellent the prior week) and 73% very poor to poor (65%), Kansas at 17% good to excellent (21%) and 47% very poor to poor (37%) and Colorado at 31% good to excellent (36%) and 37% very poor to poor (33%). Good to excellent ratings also declined in Nebraska at 46% (56% a week earlier), South Dakota at 64% (65%) and Montana at 63% (64%).

Conditions were mixed but mostly better in the soft red winter wheat states with good to excellent ratings improving to 64% in Arkansas (63% a week earlier), 63% in Indiana (62%), 50% in Ohio (49%) and 46% in Missouri (43%), while slipping in Illinois to 60% (62%) and North Carolina to 69% (70%) and holding steady in Michigan at 42%.

Winter wheat headed in the 18 major states advanced to 29% as of May 4 from 18% a week earlier and compared with 19% a year ago and 35% as the recent five-year average for the date.

Spring wheat planting in the six major states advanced to 26% compared with 21% a year earlier and 41% as the 2009-13 average for the date. Planted in top-producing North Dakota was only 5% of the crop, up from 3% a week earlier but well behind 28% as the average, with Minnesota at 4% (45% average), South Dakota at 59% (64%), Montana at 37% (41%), Idaho at 95% (73%) and Washington at 92% (81%).

The spring wheat crop was 7% emerged as of May 4 compared with 17% average for the date, the U.S.D.A. said.

Corn planting in the 18 major states was 29% completed as of May 4, up from 11% a year ago but behind 42% as the average for the date. Planted in top-producing Iowa was 23% of the crop, far behind 50% as average. Corn in the 18 states was 7% emerged compared with 3% last year and 13% as the average.

Soybean planting in the 18 major states was 5% completed compared with 2% a year ago and 11% as the average, the U.S.D.A. said.