Traditional agriculture in Kansas means wheat, grain sorghum, corn and soybeans, but environmental changes in recent years have opened the door to crops such as cotton, canola - and now sesame.
"Sesame is a centuries-old oilseed crop that has typically been grown for the oil content in its seeds," said Kansas State University agronomist Vic Martin. "Its oil is used as a salad or cooking oil and in shortening, margarine and soap. But in recent years it has been grown in the southern Plains for its seeds - mainly for `confectionary´ purposes on buns and as a condiment."
Now, K-State Research and Extension scientists are studying the crop as a potential alternative crop for south central and southwest Kansas.
Climatic changes in recent years resulting in somewhat warmer temperatures have opened the door to the possibility of growing crops in Kansas that have not been feasible before, said K-State Research and Extension scientist Bill Heer. He and Martin are in their second year of conducting field trials in south central Kansas to determine the crop´s suitability for Kansas.
"Sesame is extremely drought-, heat-, and insect-tolerant and develops a deep tap-root," Martin said. "It needs less water than corn, soybeans, grain sorghum and cotton and has no significant disease or insect problems currently in this region."
Previous efforts to grow sesame resulted in shattering problems, which made mechanical harvesting difficult, Martin said. However, new non-shattering varieties and increased global demand have renewed interest in the crop that can be planted and harvested using the same equipment as traditional crops such as wheat.
"There are five non-shattering varieties currently available with three likely well-adapted to Kansas," the agronomist said.
Sesame´s potential as a double-crop after wheat harvest looks promising, Martin said, and it is a good broadleaf to interrupt pest cycles. Since sesame is a tropical crop, the key to double-cropping is planting as soon after wheat harvest as possible.
"Sesame requires low levels of inputs, particularly fertilizer, for optimal yields," he said.
Seed prices and contracts are competitive with other dryland summer crops, especially when one takes into account that input costs are lower than most traditional crops, he added.
Some other characteristics and cautions of the crop, Martin said, include:
- Typical height of 3 to 4 feet, but as high as 6 feet;
- Physiological maturity comes about 100 days after emergence, with drydown to harvest from 125 to 140 days.
- Seed is produced in capsules (pods) - approximately 70 seeds per pod. It is harvested at 6 percent moisture with dryland yields of 600 to 800 pounds per acre and irrigated yields of up to 1200 pounds per acre. There are typically 130,000 to 150,000 seeds per pound.
- Growth is slow for the first 30 days. A good, clean seedbed is necessary to carry the crop until rapid growth begins.
- Only two herbicides are labeled in the United States for weed control.
- Extremely susceptible to 2,4-D and drift from other phenoxy herbicides.
- Tall, standing wheat residue can inhibit early plant growth and development.
Sesame in Oklahoma and Texas is planted in 15- to 40-inch row spacing, Martin said.
"We (K-State) are evaluating current and experimental varieties in narrower rows because of a more limited growing season and for improving weed control," he added. "Work at K-State is also focusing on nitrogen fertilizer levels, seeding rates, and variety evaluation."
In 2009, the scientists plan to expand the research to several sites in the area to better evaluate sesame across a range of soil types and elevations.