Influence of Seed Size and Planting Date on the Performance of Austrian Winter Field Peas

Production of Austrian winter field pea [Pisum sativum spp. arvense (L.) Poir] is limited by a lack of information on cultural practices and potential productivity. Field studies were conducted to determine the influence of seed size and planting date upon spring seedling vigor, seed yield, and seed weight of several Austrian winter field pea cultivars. The Moscow studies were situated on a Palouse silt loam soil (fine-silty, mixed, mesic, pachic Ultic Haploxeroll) and the Grangeville study on a Chicane silt loam (fine, montmorillonitic, mesic Xeric Argialboll). Small-sized seed (<5.2 mm diam) significantly reduced spring seedling vigor of Austrian winter field pea planted in October under cool, wet conditions. Seed yields of Austrian winter field pea planted in October under cool, wet conditions in 1977 at Grangeville, Idaho, and in October under dry conditions in 1978 at Moscow, Idaho were reduced by 742 and 255 kg ha⁻¹, respectively when Austrian winter field peas were established from small vs large-sized seed. Improved seedling vigor of Austrian winter field pea from large-sized seed did not improve yield of Austrian winter field peas planted at locations, planting dates, and environments favorable for pea growth. At Grangeville in 1977, the Austrian winter field peas planted in September produced 1298 kg ha⁻¹ more seed than October-planted Austrian winter field pea. September and early October planting dates had no influence on seed yield at Moscow, but Austrian winter field peas planted in late October failed to establish economic stands in both years, probably because of low October precipitation in both years and very low winter temperatures in 1978 to 1979. Seed weight of most Austrian winter field pea lines declined an average of 1.6 g 100⁻¹ seed as seeding date was delayed from September until October. Reduced seed weight accounted for part of the seed yield reduction observed at Grangeville. Seed weight of a semi-dwarf Austrian winter field pea increased significantly as seeding date was delayed from September until October. ‘Melrose’ had the best seedling vigor and ‘Common’ the worst seedling vigor of all cultivars tested. No differences in seed yield were observed between ‘Fenn’, Melrose, and Common at either location.