Leaf hairiness may affect cotton farmers’ bottom lines, according to research on the correlation of airiness and leaf grade.

Texas A&M graduate student Zachary Eder is looking at variety characteristics to determine if leaf grade may be affected by leaf hairiness. Leaf grade has become an increasingly frequent and costly problem since 2000, based on reports from the USDA-AMS Classing office at Corpus Christi.

Eder reported on his research at the recent Texas Plant Protection Association annual conference in Bryan, Texas.

“Leaf grade has continued to increase over the past 10 years,” Eder says, “and has caused significant economic loss.” Discounts may be as high as 3.45 cents per pound for a leaf grade of 3. From 2000 through 2007, the Corpus Christi classing office reported an increased number of leaf grades of 4

Growers and ginners have been affected by the increased leaf grades. Consequently, based on concerns from ginners and producers in the Texas Coastal Plains, a research projected was initiated in 2010. Possible contributors to higher leaf grade include leaf hairiness and trichome density. Eder says results show that hairiness is a factor, which led to higher leaf grades.

The research evaluated six varieties, including smooth, semi-smooth, and hairy-leaf cotton. “The hairy leaf versus the smooth leaf does have an effect,” he says. “Also, larger bract size equals a higher leaf grade.”

Environmental conditions also affect leaf grade, but even in years with a relatively low leaf grade, the difference between the hairy leaf cotton and smooth leaf varieties remains consistent, Eder says.

“We will develop a hairiness rating system, but we need an improved counting method. We want to analyze the economic impact of leaf hairiness.”