MISSISSIPPI STATE -- Cotton is looking fairly good across the state despite a faltering start, but the message to growers is that their job is not over yet.

"We can't walk off and leave the crop," said Will McCarty, cotton specialist with the Mississippi State University Extension Service.

Much of the crop will reach maturity between Sept. 10 and Oct. 1, but cotton in northeast Mississippi got a late start and continues to be late. South of Highway 82, the cotton looks good with some in excellent shape, but north of that highway, cotton has been very wet and is variable.

"About 25 percent of the crop is on schedule, 30 percent is a week late and the rest is further behind," McCarty said. "This is mostly because of wet weather that spread planting out from the first of April to the first 10 days of June, rather than the window between April 10 and May 20."

Cool temperatures and rain led to higher than normal replanting in north Mississippi, and continued rains delayed field work all season.

The U.S. Department of Agriculture's August crop production report estimated Mississippi growers will harvest 807 pounds per acre from about 1.1 million acres of cotton.

All the wet weather has many producers concerned that rain may have washed away too much of the nitrogen fertilizer applied early to the cotton.

"If you have a field of cotton that you feel has tremendous yield potential and is showing some signs of nutritional stress or nitrogen deficiency, have a crop professional look at it with you and discuss your options before you arbitrarily add supplemental fertilizer," McCarty said. "Making fertilizer applications this late in the season can backfire."

McCarty said adding nitrogen to push a crop to maturity, especially a late crop, can delay maturity, cause rank growth, create problems with defoliation and reduce the cotton's grade.

Defoliation should start the last week of August, with picking to begin in early September. Because there is a wide range of maturity, the defoliation and harvest season will be long.

"This puts the crop in great jeopardy, as cotton is most susceptible to weather damage during harvest," McCarty said. "A cotton crop cannot be counted until it is ginned. The main thing now is not to mess up the crop with human error on the tail end."

Producers should continue to watch for insects, especially late season stink bugs and plant bugs. McCarty said a large percentage of the crop will need insect control later into the season than normal. Those with irrigation -- which account for about 30 percent of the state's crop -- should be careful to meet the plants' needs for moisture.

"When you see the oldest bolls on the plant begin to crack open in a normally fruiting field, it's time to make the last application of water and get out of the field," McCarty said. "Research shows that on a normally fruiting crop, the best results come by terminating irrigation at the first week of open boll."