Table 1. Soil insecticide efficacy data1 for DeKalb, Monmouth, and Urbana, Illinois, 1988-1997.

1 Iowa State University 1-to-6 root rating scale (Hills and Peters, 1971).
2 Planting date: May 5, 1988; root evaluation date: July 13, 1988, DeKalb, IL.
3 Planting date: May 8, 1989; root evaluation date: July 12, 1989; Fortress 5G applied at 6.1 oz product/1,000 row ft, DeKalb, IL.
4 Planting date: May 8, 1990; root evaluation date: July 12, 1990; Aztec 2.1G applied at 7.0 oz product/1,000 row ft, Urbana, IL.
5 Planting date: May 10, 1991; root evaluation date: July 22, 1991; Aztec 2.1G applied at 7.0 oz product/1,000 row ft, DeKalb, IL.
6 Planting date: May 9, 1991; root evaluation date: July 15, 1991; Aztec 2.1G applied at 7.0 oz product/1,000 row ft, Monmouth, IL.
7 Planting date: May 2, 1991; root evaluation date: July 11, 1991; Aztec 2.1G and Fortress 5G applied at 7.0 oz and 3.0 oz product/1,000 row ft, respectively, Urbana, IL.
8 Planting date: April 30, 1992; root evaluation date: July 13, 1992, Monmouth, IL.
9 Planting date: May 5, 1992; root evaluation date: July 24, 1992, Urbana, IL.
10 Planting date: May 13, 1993; root evaluation date: July 14, 1993, Urbana, IL.
11 Planting date: May 13, 1994; root evaluation date: July 18, 1994, Urbana, IL.
12 Planting date: May 31, 1995; root evaluation date: July 18, 1995, Monmouth, IL.
13 Planting date: May 20, 1996; root evaluation date: August 2, 1996, Urbana, IL.
14 Planting date: May 13, 1997; root evaluation date: August 6, 1997, Monmouth, IL.
15 Planting date - May 6, 1997; root evaluation date: July 24, 1997, Urbana, IL.
16 Root rating data were not collected.
17 Rainfall total (inches) from planting date through root evaluation date.
18 Heat-unit accumulation (base 52 deg F) using air temperatures from January 1 through July 31.
19 Heat-unit accumulation (base 52 deg F) using air temperatures from January 1 through May 31.