Yield of Indeterminate and Determinate Semidwarf Soybean for Several Planting Dates, Row Spacings, and Seeding Rates

Abstract

Determinate semidwarf cultivar of soybean [Glycine max (L.) Merr.] were developed to overcome the lodging barrier to high yield, but little work has been reported on their response to production systems or environments. The objective of this study was to determine the effect of planting date, row spacing, seeding rate, and their interactions on determinate vs. indeterminate cultivars. The cultivars ‘Sprite’ (determinate semidwarf) and ‘Williams’ (indeterminate) were compared at two Ohio locations over a 3‐yr period. Planting dates were 1 May, 20 May, and 10 June, and row spacings were 7, 10, 14, and 20 in. Seeding rates of 150 000 and 200 000 seeds/acre for Williams, and 150 000, 200 000, 250 000, and 300 000 seeds/acre for Sprite were used. Delayed planting reduced yield significantly. The response to increasing row spacing was a small decrease in yield for both cultivars, which was moderated by both planting date and seeding rate. The yield of Sprite—but not Williams—increased as seeding rate was increased, regardless of planting date or row spacing. Mean yield decreased 30% from the first to third date of planting, while row spacing and seeding rate effects were in the range of 5 and 6%, respectively. While Williams did not respond to seeding rate, there was a planting date × seeding rate interaction. Sprite responded to seeding rate, but there was no planting date × seeding rate interaction; however, there was a three way interaction (environment × seeding rate × planting date).

Growth and Yield Responses of Soybean to Row Spacing and Seeding Rate

“…Some studies (Weber et al, 1966;Oplinger and Philbrook, 1992) in northern latitudes, however, have reported row spacing by seeding rate interactions with soybean responding more positively to higher seeding rates in narrow vs. wide rows. Other studies in Ohio (Beurelein, 1988) and Ontario, Canada (Ablett et al, 1991) reported no row spacing by seeding rate interactions with similar optimum seeding rates in 0.18 vs. 0.36 m or 0.25 vs. 0.50 m rows, respectively. Kratochvil et al (2004) also reported that drilled soybean had the same response to seeding rates in 0.19 and 0.38 m rows.…”

“…Some studies (Weber et al, 1966;Oplinger and Philbrook, 1992) in northern latitudes, however, have reported row spacing by seeding rate interactions with soybean responding more positively to higher seeding rates in narrow vs. wide rows. Other studies in Ohio (Beurelein, 1988) and Ontario, Canada (Ablett et al, 1991) reported no row spacing by seeding rate interactions with across seeding rates. Nevertheless, yield showed a quadratic response to seeding rate (3.04, 3.25, and 3.12 Mg ha −1 at 321,000; 420,000; and 469,000 seeds ha −1 , respectively) with no row spacing interaction.…”

Texas Gulf Coast Soybean Yield Affected by Soybean Variety and Planting Date

“…Early planted soybeans also will tend to complete the critical flowering, seed set, and seed filling (8,10) during the late spring and early summer when precipitation is more common in this area than later in the growing season. Moisture and temperature stress during early reproductive stages can reduce soybean yield by reducing the number of pod, seeds, and seed mass (1,3). Both determinate and indeterminate soybean cultivars have reduced growth rates under drought stress but resume normal growth rates when the stress is removed (3,12).…”

Planting Date, Cultivar, and Seeding Rate Effects on Soybean Production along the Texas Gulf Coast

“…Each year's study was set up using a randomized complete block design with a split‐split plot arrangement of treatments. Treatment factors included the main plots of planting date (3), the split plots of cultivar (3), and the split‐split plots of seeding rate (2). Main plots were 24 rows wide by 30 ft long, split plots were 8 rows wide by 30 ft long and split‐split‐plots were 4 rows wide by 30 ft long.…”

“…Stress can reduce soybean yield by reducing number of pods, number of seeds, and seed mass (6). Both determinate and indeterminate soybean cultivars have reduced growth rates under drought stress and resume normal growth rates when such stress is removed (3,15). This may be an important growth attribute to consider if producers expect considerable soil moisture deficits due to several short, intermittent droughts during the growing season (15).…”