Seed Size and Seeding Depth Influence on Canola Emergence and Performance in the Northern Great Plains

Abstract

Dramatic increases in canola (Brassica napus L.) production in the Northern Great Plains and lack of regional research prompted evaluating seeding depth and seed size effects on crop performance. Seedling emergence and yield of four seed size categories of an open‐pollinated and a hybrid cultivar were evaluated at 25‐ and 50‐mm seeding depths at Casselton and Prosper, ND, in 1999 and 2000. The study was a randomized complete block design with a 2 × 8 factorial arrangement of seeding depth and genotype seed size (GS) category. Agronomic characters evaluated included pure live seed emergence (PLSE), flower initiation and duration, seed yield, seed oil concentration, plant lodging, and white mold [Sclerotinia sclerotiorum (Lib.) de Bary]. The environment × depth interaction for PLSE indicated 24 to 41% lower PLSE from the deeper seeding depth at three environments; however, PLSE was not influenced by seeding depth at one environment. Genotype seed size treatments did not influence PLSE. The hybrid GS treatments produced 26% greater yield than the open‐pollinated GS treatments when averaged across environments. White mold incidence was 4.5 times greater from stands at the 25‐ than 50‐mm depth, at one environment, because of high PLSE that enhanced disease development. Seed yield and oil concentration, plant height, and lodging were not affected by GS treatments. Although seeding at the 50‐mm depth reduced PLSE, yield may be maintained provided sufficient stands exist. However, due to the uncertainty in stands from deep seeding, the recommendation would be not to seed deeper than 25 mm.