Seeding Rate and Variety Effects on Yield, Yield Components, and Economic Return of Field Pea in the Northern Great Plains

Field pea (Pisum sativum L.) has been introduced recently as a rotational crop in the semi‐arid region of the northern Great Plains. Very little is known about the response of field pea varieties to management practices such as planting date and seeding rate in this environment. This study was conducted at two locations in 2004 to 2006 to determine the effect of seeding rate on field pea establishment, yield, and yield components. In addition, seeding rates required for economic optimum yield were determined. The study had four varieties with contrasting morphology and six seeding rates ranging from 25 to 90 viable seeds/m2. Increasing seeding rate increased seedling density and seed yield. Harvest index and plant height were relatively constant across seeding rates. Pea plants compensated for low plant populations by producing more pods per plant and more seeds per pod although this compensation mechanism was not enough to maintain high yield at low populations in all environments. Seeding rates that gave best partial net economic returns varied from year to year, but with a trend for lower returns at seeding rates greater than 77 seeds/m2. A target seeding rate of 64 to 77 seeds/m2 is suggested for the region.