Narrower row spacing and higher plant populations have some advantage in dry bean production, according to research by North Dakota State University.
For the past decade, NDSU has been conducting field research examining the response of black, navy and pinto beans to different combinations of row spacings and plant populations to identify optimum seed yield.
Research focused on black and navy beans grown in reduced row spacing and with increased plant populations, compared with wide rows of 28 to 30 inches and the standard 90,000 plants/acre.
Researchers found that black bean seed yield averaged across four trials was similar among row spacings of 14, 21 and 28 inches.
Averaged across eight trials, yield increased slightly — less than 100 pounds per acre — with just under 120,000 or 140,000 plants per acre, compared with yield with an average of slightly fewer than 100,000 plants per acre.
Narrow, 14-inch rows with navy bean plant populations of 117,000 or 140,000 plants per acre increased yield 24 per cent to 28 per cent respectively, compared with wide rows with slightly more than 90,000 plants per acre.
More information about this research is available in the NDSU Extension publication Black and Navy Bean Response to Row Spacing and Plant Population in Eastern North Dakota, and is available online.
Similar research is also underway for pinto beans.
The average pinto bean seed yield among four trials conducted in eastern North Dakota with 18-inch rows was 11 per cent and 16 per cent greater versus 12-inch and 30-inch rows, respectively.
In a series of five trials conducted at Carrington, North Dakota, pinto bean yield increased 18 per cent with intermediate row spacing (21 to 22 inches) compared with wider rows.
Averaged across four pinto bean trials at Carrington and Minot, North Dakota, a plant population of about 70,000 plants per acre had a yield advantage of six per cent compared with 53,000 plants per acre. Preliminary results with intermediate row spacing and plant populations near 90,000 plants per acre are showing yield and economic advantages, compared with wide rows and the standard plant population.
The research with the three dry bean market types has been supported by the NDSU Agricultural Experiment Station and Northarvest Bean Growers Association.