Influence of Soybean Production Practices on Lodging and Seed Yield in Highly Productive Environments1

Abstract

AbstractThe effect of planting date, variety, row spacing, and seeding rate on lodging and seed yield of soybeans (Glycine max (L.) Merr.) in highly productive environments was studied at Ashland and Chenoa, Illinois, in 1969. Three planting dates, seven varieties, two row spacings, and three seeding rates were used.Highly significant date, variety, spacing, rate, and interaction effects were obtained on lodging and yield at both locations. Seed yield was generally unaffected by seeding rate where no lodging differential occurred, but tended to be significantly lower where the higher seeding rates caused severe early lodging. These results indicated that early lodging was a major factor contributing to the yield decrease that occurred at the higher seeding rates. Whether a lodging differential occurred between seeding rates was dependent on location, date, variety, and row spacing used. These data also suggested that lodging may be an important factor in preventing yield increases from earlier planting and from narrower rows. At Ashland, in absence of a lodging differential between dates, the highest yields were obtained from the earliest planting, but at Chenoa, where the first two planting dates were more severely lodged than the latest planting date, there was no yield advantage. The yield advantage of narrow rows was greatest for the third planting date, at both locations, where lodging was essentially the same in both row spacings. At the earlier planting dates, 17‐cm rows tended to be more severely lodged than 50‐cm rows, cancelling out potential benefits from more uniform plant distribution. This was attributed, in part, to the less effective natural thinning that occurred in the 17‐cm rows.