Fig. 1.

The 30-yr mean precipitation and monthly precipitation in 2002 and 2003 for the University of Nebraska Agricultural Research and Development Center near Mead, NE. Total annual precipitation was 58 and 53 mm below the long-term average in 2002 and 2003, respectively.

 


Fig. 2.

Seedlot establishment test (SET) based seeding rate treatment effects on switchgrass aboveground biomass dry matter (DM) in 2003 4 or 5 mo after planting and aboveground biomass DM in 2004 13 or 14 mo after planting at two field sites (Sites 2 and 3) seeded on 28 May and 27 June in 2003 near Mead, NE. Treatments were: PLS, pure live seed; NP, no prechill; P, prechill; H, heat stress; E4, emergence through 4 cm of sand; and H+2, heat stress plus emergence through 2 cm of sand. Fisher's protected LSD (0.05) values at Site 2 were 325 and 1152 kg ha−1 for the harvests conducted 5 and 14 mo after planting, respectively. Fisher's protected LSD(0.05) values at Site 3 were 170 and 1173 kg ha−1 for the harvests conducted 4 and 13 mo after planting, respectively.

 


Fig. 3.

Establishment index for 20 switchgrass seedlots established using seeding rates based on different seedlot establishment tests for three field trials in 2002 and 2003 near Mead, NE. The establishment index is the ratio of the number of seeds emerged in the field relative to the number of germinable or emerging seeds planted. Treatments included: PLS, pure live seed; NP, no prechill; P, prechill; H, heat stress; E4, emergence through 4 cm of sand; and H+2, heat stress plus emergence through 2 cm of sand.