Yield and Agronomic Advantages of Pea Leaf Type Mixtures under Organic Management

Abstract

Field pea (Pisum sativum L.) is an important organic crop due to its contribution to soil fertility and other rotational benefits. Leafed (wild‐type) pea cultivars tend to be more weed suppressive, but their poor standing ability limits yield compared with semi‐leafless cultivars. Growing mixtures of leafed and semi‐leafless cultivars may improve weed suppression and yield compared with monocultures of the same cultivars by altering canopy morphology. To test this hypothesis, replicated field experiments were conducted under weedy, organic conditions in Saskatchewan, Canada, in 2011 and 2012. Mixtures of a leafed and semi‐leafless cultivar, CDC Sonata and CDC Dakota, were sown in ratios of 0:100, 25:75, 50:50, 75:25, and 100:0 leafed to semi‐leafless pea, at target seeding rates of 88 and 132 plants m−2. Mixtures that included 50% or more semi‐leafless pea had similar lodging resistance and weed biomass suppression to the agronomically superior semi‐leafless cultivar grown alone. The strong competitive ability of the semi‐leafless cultivar was unexpected based on previous accounts. The combined yield of the two cultivars grown in a 75% semi‐leafless mixture exceeded the seed and biomass yield of either single cultivar by at least 18 and 12%, respectively. Yield enhancement was attributed to the leafed cultivar, whose seed yield increased by more than two and a half times in this mixture relative to its monoculture. Results suggest that breeding of leafed cultivars specifically for mixture with semi‐leafless pea may be a future source of yield gains in organic and low‐input systems.

Soil microbial properties during decomposition of pulse crop and legume green manure residues in three consecutive subsequent crops

“…The green pea variety was semi-leafless and the forage pea variety was normal leafed. Semi-leafless peas are currently the preferred type for grain production because they are resistant to lodging, but leafed varieties are still preferred for biomass used for forage or GM (Syrovy et al 2015). The amounts of N 2 fixed, aboveground biomass, and the N contained and released by the residues during decomposition, were all greater in forage pea than in green pea (Lupwayi and Soon 2015).…”

Developing an Integrated Weed Management System for Herbicide-Resistant Weeds Using Lentil (Lens culinaris) as a Model Crop

“…These results agree with previous findings in lentil (Ball et al 1997), but only partially agree with findings in field pea, another weakly competitive pulse crop (Beckie and Kirkland 2003). In a study under organic conditions, weed biomass decreased as field pea crop density increased over a range of 13 to 149 plants m −2 (Syrovy et al 2014). In another study, however, field pea weed biomass did not decrease significantly when crop seeding rate was increased, even in the presence of uncontrolled weeds (Beckie and Kirkland 2003).…”

Evaluation of yield and agronomic performance of leafed and semi‐leafless pea blends

“…In contrast, Syrovy et al. (2015), under organic growing conditions, reported that a leaf blend resulted in 156 and 18% more seed yield than the L and SL monocultures, respectively. The differences between studies could be due to the differences in cropping systems or simply a function of the single pair of unrelated crop varieties that Syrovy et al.…”