Characterizing an outperforming pea cultivar for intercropping with oat at high latitudes

Abstract

The cereal often dominates the grain legume in intercrops, especially when sown in larger amounts. This study assessed yield formation of pea (Pisum sativum L.) and oat (Avena sativa L.) in an intercropping system in high-latitude conditions. Three pea cultivars (Hulda, Karita and Perttu) and one oat cultivar (Roope) were grown as sole crops and intercrops with shares of either 7.5% or 15% of oat (as weight of sown seed mixture). Experiments were organized in three (southern, western and northern) locations of Finland for three years. Yield and vegetative above-ground biomass, their land equivalent ratio (LER, i.e., the yield in intercrop compared to that of the component yields in pure stands), and a number of yield components were measured prior to harvest at crop-stand and single-plant levels. The share of oat in the intercrop did not have any impact on variation in LER yield . Oat yield and yield components generally benefitted from a pea companion crop. The pea cultivar Perttu was superior in intercrops: it had a LER yield >1 in seven out of eight experiments (mean LER yield =1.06), while Karita had a LER yield >1 in four (mean LERyield =1.00) and Hulda only in one experiment (mean LER yield =0.98). Perttu proved to be a compatible pea companion for a pea-oat intercrop, likely because it was successful in overcompensating for decline in relative yield (RGY) of oat in intercrops, contrary to Hulda. However, none of the measured yield components of Perttu were associated with LER yield , suggesting compensation ability between them, while in Karita and Hulda, e.g., higher grain yield and number of grains and pods per square meter were associated with decline in LER yield . It was concluded that the success of Perttu as a companion for oat in intercrops is likely attributable to its flexibility in building yield through a variable combination of yield components rather than being outperformed due to some superior traits. Such flexibility, likely attributable to long duration of flowering supports resilience to weather variability that is typical for northern European conditions allowing Perttu to consistently sustain a LER yield >1.

Faba Bean Variety Mixture Can Modulate Faba Bean–Wheat Intercrop Performance Under Water Limitation

“…The present study demonstrates, in a controlled greenhouse environment, that benefits of varietal diversity are apparent in intercrop situations with and without water limitation, although the observed effects of intraspecific diversity on intercrop performance were somewhat inconsistent. We found that the faba bean variety influences several important measures of intercrop performance, supporting the results of studies conducted on oat-pea intercrops (Peltonen-Sainio et al, 2017), maize-common bean intercrops (Isaacs et al, 2016), and maize-cowpea intercrop (Abera et al, 2017). In the present study, variations in above-and below-ground parameters related to plant growth, nodulation, and nutrient acquisition demonstrated that faba bean-wheat intercrops buffered biomass dry matter accumulation, nodulation, and N accumulation in water-limited faba bean (in intercrops containing the varieties WAJ) and wheat (in intercrops containing the variety Gloria).…”