The dramatic difference showed two extremes in Siebert's research project to determine how planting rate affects cotton plant performance.

Siebert, a graduate student from Eunice, La., explained his research project to more than 100 visitors at the LSU AgCenter's Dean Lee Research Station near Alexandria on Thursday.

Siebert, who's studying under Stewart, an agronomist at the LSU AgCenter research facility, planted seeds as thickly as 4.5 plants per foot of row and as thin as three plants per hill with the hills spaced 24 inches apart.

Stewart said the results should be viewed "not in terms of yield but in terms of cost of production and management."

He pointed out that in normal production, the less-thickly planted field may not produce the same overall yield as a thicker-planted field, but the costs of seed and other inputs could make the first field more profitable.

Grady Coburn, who operates Pest Management Enterprises in Cheneyville, La., said he enjoyed seeing Siebert's study and how different varieties respond to different management programs.

For more than 30 years, what had been the Rapides Parish cotton tour visited individual fields on private farms. This year's event was the second field day that's now being held yearly at the Dean Lee station.

Coburn said he's glad to have the opportunity to see the diversity of research at the LSU AgCenter's research station.

"I'm extremely pleased to have Dean Lee be a central location for the future," Coburn said. "The support of the AgCenter is phenomenal."

Jerome Dekeyzer, who grows 1,000 acres of cotton near Bayou Rapides, said growers are interested in new varieties and new management methods.

"It's great," Dekeyzer said of the field day. "They have at the station what we need. Dr. Stewart is doing a great job.

"This is what people want to see," he said. "We come here to find out."

Dekeyzer and Coburn reaffirmed comments made earlier by Bill Brown, the LSU AgCenter's vice chancellor for research.

"There's no substitute to being out in the field and seeing the information first hand," Brown said. "It's our role to take some of the risk, to try some things on small acreages to see what works."

Stewart's cotton variety trials - which include yield tests with more than 50 varieties - are an example of finding out what works on small plots before trying them on full-size farm fields.

Sharing some of the points he has learned from the research, Stewart said late-maturing varieties need more management because of insect considerations and defoliation late in the season when the plants are still growing vigorously. He also warned that a move to too much acreage planted with late-maturing varieties could lead to pressures from a significant amount of harvest later in the year.

Stewart said new technology like Liberty Link cotton and other new varieties are constantly changing the ways growers have to manage their crops and adjust their practices.

"The differences in most of the popular new varieties this year are significant compared with earlier varieties," he said.

Field day visitors also heard several other presentations.

Stewart talked about defoliation treatments, pointing out that it may be more difficult to defoliate this year because of dry weather.

Ralph Bagwell, an LSU AgCenter entomology specialist, also discussed options for late-season insect control.

Bagwell said there's a point when growers have to stop worrying about boll insects, because the bolls they're attacking won't be harvestable anyway. He added that foliage insects should be controlled until growth is no longer a factor.

Other LSU AgCenter presenters included Roy Vidrine, who discussed weed control in cotton, and David Lanclos and Steve Moore, who talked about soybean variety evaluations.

Rick Bogren is a writer for the LSU AgCenter.

e-mail: rbogren@agcenter.lsu.edu