EFFECT OF ROW WIDTH AND POPULATION ON SOYBEAN YIELD IN SOUTHWESTERN ONTARIO

Abstract

The effect of seeding rate (seeds per hectare) and row width (distance between rows) was examined for various adapted soybean (Glycine max (L.) Merr.) cultivars in southwestern Ontario. Maple Arrow, Harosoy 63 and Harcor cultivars were grown in 18-, 35-, 53-, 71-, and 89-cm row widths seeded at 198 000, 395 000, and 593 000 seeds/ha during 1978 and 1979. The greatest yields were associated with the two narrowest row widths and the two highest seeding rates. Plant height, lodging, and bottom pod height varied mainly with seeding rate and cultivar. In another 2-yr study (1980 and 1981) Maple Arrow, Evans, S1346, Hodgson, A2575, and Harcor were grown at four row widths (18, 35, 53, and 71 cm) and two seeding rates (395 000 and 593 000 seeds/ha). A significant cultivar × row width interaction for yield occurred with Maple Arrow and Harcor showing the greatest yield response. Although a small seeding rate × cultivar interaction occurred, generally, seeding rates between 395 000 and 593 000 seeds/ha were adequate for all cultivars and all row widths.Key words: Glycine max (L.) Merr., seeding rate, row spacing, lodging, yield