2008 Joint Annual Meeting (5-9 Oct. 2008): Planting Date and Seed Treatment Effects on Soybean in the Northeast USA.

558-1 Planting Date and Seed Treatment Effects on Soybean in the Northeast USA.



Monday, 6 October 2008: 1:00 PM
George R. Brown Convention Center, 370EF
William J. Cox, Elson Shields and Jerry Cherney, Dep. of Crop & Soil Sci., Cornell Univ., Cornell Univ., 620 Bradfield Hall, Ithaca, NY 14853
Soybean {Glycine max (L.) Merr.} production is limited in the Northeast USA so research on optimum planting date is scarce. Soybean production is expected to increase in the heavily-trafficked region so we initiated a 2-yr study in New York that compared soybean planted in mid-May, late May, and mid-June with and without seed-applied fungicide/insecticide treatments. Soybean planted in mid vs. late May had a longer emergence time (15 vs. 6 d) and lower plant densities (35.6 vs. 39.5 plants/m2), but produced more pods/side branch (7.4 vs. 5.5), which contributed to more pods/plant (30.9 vs. 25.7) and pods/m2 (1079 vs. 958, respectively). The late vs. mid-May planting date, however, had more seeds/pod (2.28 vs. 2.19), which contributed to similar seeds/m2 (2180 vs. 2357) and seed yield (3.8 vs. 3.9 Mg ha-1, respectively). Soybean planted in mid-June vs. mid-May had more plants/m2 (38.0) but fewer pods/side branch (3.4), pods/plant (22.5), pods/m2 (879), seeds/m2 (1910), and lower seed yield (3.5 Mg ha-1). Seed treatments did not affect plant density, pod density, and seed yield, but had inconsistent effects on seeds/pod, seeds/m2, and seed mass. The results of this study indicate that there is a fairly broad optimum planting date range and that insecticide/fungicide treatment is not required for soybean production in the Northeast USA, but more research under more diverse growing conditions is necessary to corroborate these findings.