Buckwheat - How Late Can One Plant?

Some growers may be looking at an alternative crop because they were not able to get into their fields due to weather conditions. One alternative may be buckwheat, according to Duane Berglund, North Dakota State University Extension agronomist.

A buckwheat planting date trial was conducted at the NDSU Carrington Research Extension Center in the mid-90's. The varieties 'Mancan' and 'Manor' were planted on four dates: May 25 or 26, June 6, June 21 or 23, and July 6 (one year trial).

During the first year, seed yields averaged 1410 pounds per acre for the late May planting, 960 on the early June and 810 pounds per acre on the late June planting. During the second year, yields were 1435 pounds per acre with the late May planting, 970 with the early June, 865 with the late June and 705 pounds per acre with the early July planting.

"The data indicates that seed yield may be satisfactory with late-planted buckwheat but yield is reduced 30 to 50 percent with the July planting compared to the late May planting," Berglund says. "The crop is also at risk if an early killing frost occurs."

An established stand of buckwheat should have a density of about 800,000 plants per acre or 16 to 20 plants per square foot. Buckwheat has the ability to compensate if stand density is less than desired. In a planting rate study at the NDSU Langdon Research Extension Center, no significant differences in yield were reported between low and high plant populations of 6 and 24 plants per square foot ( 261,000 vs. 1,045,000 plants per acre). Stands as low as 6 plants per square foot have produced adequate yields. An average of 9.2 plants per square foot yielded 1280 pounds per acre or only about 10 percent less than a stand of 14.4 plants per square foot that yielded 1430 pounds per acre.

Buckwheat is most easily established on a well-prepared, firm seedbed similar to flax or other small seed crops. Under good growing conditions buckwheat will germinate and shade the ground quickly. Cultural control of weeds is important as there are no herbicides currently labeled for weed control in buckwheat.

Buckwheat begins to flower four to five weeks after seeding and continues to flower and produce seed until there is a hard freeze. "The crop should be swathed prior to a killing frost at a stage when it appears the crop will produce the largest seed yield," Berglund says. "A killing frost on a standing crop results in considerable harvest difficulty plus yield loss because of shattering and lodging. Swathing is sometimes made difficult by the succulent nature of the stalks."

Research conducted in Canada indicates the optimum time for swathing, to obtain maximum yields, is when flowering is near completion and about 25 percent of the seeds are still green. If shattering becomes severe, the crop should be swathed immediately. "The crop should be swathed in the morning when the crop is wet with dew or in damp periods to avoid seed shattering," Berglund says. "However, stalks are succulent at that time and require a considerable amount of drying time. A frost while the crop is in the swath speeds drying."

Buckwheat is almost always grown under contract with seed of the preferred variety furnished by the contracting company, Berglund notes. Buckwheat must be marketed the year it is produced, so most buckwheat is sold under contract. Not all local grain elevators handle buckwheat. Inquiries should be made regarding possible contracts and market outlets before beginning a production program. The North Dakota State Seed Department has established market grading factors for buckwheat. Berglund advises potential growers to contact the department for grading standards information.

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