KANSAS CITY — Hurricane Isaac raged ashore across the Delta states this week with strong winds and torrential rain submerging crops in some areas and interrupting power to hundreds of thousands of residents and hundreds of businesses. Flood waters overtopped levees at points, but the walls separating the neighborhoods of New Orleans from another disaster held.

The storm’s general path was known for days allowing civil authorities and emergency responders to make their preparations.

Grain export elevators along the lower Mississippi river were closed in advance of the storm as were sugar mills and other food facilities. The U.S. Coast Guard closed the Port of New Orleans to shipping for the duration of the storm. Barges on the river were at dock until it was safe to travel once again.

Delta farmers rushed to complete their corn harvest before the storm, but soybean harvesting was in early stages. The U.S. Department of Agriculture indicated 88% of Louisiana corn was harvested by Aug. 26 compared with 73% as the recent five-year average for the date. The harvest pace recently was slowed because of transportation problems. The Midwest drought dropped water levels in the Mississippi river, which meant barges could not be loaded to capacity, which, in turn, backed up corn loadings.

The Louisiana soybean harvest was 18% completed by Aug. 26 compared with 12% as the average for the date.

The Louisiana sugarcane crop, which was about a month from harvest, was susceptible to wind and rain damage. And Hurricane Isaac may cause considerable lodging or even breakage of cane tops in some areas. It was pointed out unlike farther north, Louisiana sugarcane areas have received ample moisture in recent weeks and did not stand to benefit from rains from Hurricane Isaac.

Even more susceptible to damage was the Louisiana cotton crop. John Kruse, Louisiana State University cotton and grain specialist, indicated the state’s cotton crop was at the same stage of development as it was when Hurricane Gustav made landfall in 2008. Mr. Kruse noted Hurricane Gustav virtually destroyed the Louisiana cotton crop.

The Mississippi corn harvest was 72% completed by Aug. 26 compared with 42% as the average for the date, and 9% of the state’s soybeans were harvested, which was equal to the average pace.

Most damage from Hurricane Isaac was expected to be consigned to southern portions of the Delta states. Farther north, producers hoped heavy rains from the storm would help dent even if not break the worst and most extensive drought for at least the past 50 years.

Assessments of crop damage in the Delta states was expected to be reflected in the U.S.D.A.’s weekly Crop Progress report to be issued on Sept. 3.