Okra-Leaf-Shaped Cotton May Increase
By Tara Weaver
July 30, 1997
Okra-leaf type cotton plants could help
U.S. cotton growers cut their production costs without sacrificing yields.
Scientists with USDAs Agricultural
Research Service say okra-leaf type cotton is less prone to boll rot than
conventional cotton types, matures earlier and is more resistant to attacks by
insects, particularly whiteflies and pink bollworms. The cotton gets its name
from its unusual leaves, which are narrower and more evenly distributed on the
plant compared with conventional cotton plants.
Boll rot refers to a number of diseases that destroy bolls maturing in warm
and humid cotton canopies, a situation more common in normal-leaf types.
Growers can harvest okra-leaf types three to nine days earlier and often
achieve the same yield as normal-leaf types, a plus during early cold spells or
extended wet periods.
Nearly all cotton cultivars grown in the United States have the more typical
broader leaf shape. Public and private U.S. research attempts to breed
competitive okra-leaf cultivars have been generally unsuccessful.
In the Mississippi Delta, farmers typically spray insecticides on their
cotton plants eight to 10 times during the growing season, significantly
increasing production costs. Normal-leaf cotton types have a dense canopy of
leaves at the top of the plants. These leaves block the chemicals from reaching
the middle and lower portions of the plant, where many insects feed.
In contrast, the more open okra-leaf canopy allows better insecticide
distribution and insect control throughout the plant. The okra-leafs open
canopy plus its early maturity can eliminate at least one spray treatment per
Okra-leaf types have been a hit in other parts of the world, particularly in
Australia where they represent 40 percent of the cotton acreage.
ARS scientists are trying to find the
right management practices that will allow wider use of okra-leaf types in the
United States. More studies are planned to evaluate okra-leaf cottons
competitiveness and adaptability in the Mississippi Delta.
Scientific contact: James J. Heitholt,
and Genetics Research, Stoneville, Miss., phone (601) 686-5219, fax (601)