Basal branching in field pea cultivars and yield-density relationships

Abstract

The current recommended plant density in field pea (Pisum sativum L.) in western Canada is 88 plants m–2. This rate may exceed the optimum for yield in cultivars with more basal branching than typical. The objective of this research was to determine how the seed yield of pea cultivars differing in basal branching ability responds to changes in plant density. Ten pea cultivars were sown at target plant populations of 10, 30, 90, 120, and 150 plant m–2 for 3 yr at Rosthern and Saskatoon, Saskatchewan. At very low plant densities there was greater than a twofold difference in branching potential between cultivars (range 0.85 to 1.99 branches plant–1). Increasing field pea plant density reduced branching by 0.097 branches for each additional plant. The response of yield to plant density differed, as the forage cultivars 40-10 and CDC Sonata reached their potential yield at lower densities, while Courier required higher densities to reach the same proportion of yield. Field pea cultivars with greater basal branching achieved their maximum yield at lower plant densities compared with cultivars with low basal branching. The optimum economic plant density for the pea cultivars ranged from 59 to 84 plants m–2, which is below the current recommended plant density. However, with the exception of the forage cultivars and the low-branching cultivar Courier, the optimum seeding rate was within 8% of 88 seeds m–2. It is recommended that pea growers avoid low-branching pea cultivars and seed at a rate of 88 viable seeds m–2.Key words: Basal branching, seeding rate, plant density, light interception, leafed pea, semi-leafless pea, forage pea