Influence of different sowing dates of winter pea genotypes on winter hardiness and productivity as either winter catch crop or seed legume

The main purpose of this study was to examine the influence of three sowing dates (mid of September, beginning of October, mid of October) on the winter hardiness and productivity of six different genotypes of winter peas (Pisum sativum L.). The two field trials were conducted with winter peas in either pure stands as winter catch crop for biomass yield (three seasons) or mixed stands with rye as a seed legume (two seasons: seeding rate 20 and 225 germinable seeds m(-2), respectively) on the experimental farm of the University of Kassel, Germany. The main findings suggest that only those genotypes can be recommended for cultivation that have adequate winter hardiness. Results support the conclusion that winter peas have sufficient winter hardiness for cultivation in transitional climatic conditions when they display a rosette growth with small leaves and short internodes at the onset of winter and possess quantitative photoperiodic sensitivity. For these genotypes, no impact of the sowing date on the extent of winter hardiness could be determined. In the experiment winter pea pure stands, the highest biomass yield (assessed at the onset of flowering) was determined for the earliest sowings. In the experiment with winter pea/rye mixture, the influence of sowing date on seed yield of the frost-resistant peas was negligible. (C) 2012 Elsevier B.V. All rights reserved.