Table 4.

Mean percent tunnel length of Bt hybrids and their near isogenic hybrids caused by C. partellus at Kiboko, Kenya, in three seasons. Entries with odd numbers have Bt gene and those with even numbers do not have Bt gene (near isogenic hybrids). Plants were artificially infested with C. partellus 14 and 24 days after planting; tunnel length was assessed at harvest. Pair mean values with the same letter in a column are not significantly different at P = 0.05 using t-tests (±indicates standard error of the mean).

Tunnel length (%)
Entry	Season 1	Season 2	Season 3
1 (Bt)	0.0 ± 0.0a	0.0 ± 0.0a	0.0 ± 0.0a
2 (Non-Bt)	4.4 ± 0.7b	3.5 ± 0.3b	2.6 ± 0.6b
3 (Bt)	0.1 ± 0.1a	0.1 ± 0.0a	0.0 ± 0.0a
4 (Non-Bt)	4.7 ± 0.47b	2.6 ± 1.0b	1.6 ± 0.3b
5 (Bt)	0.3 ± 0.3a	0.0 ± 0.0a	0.0 ± 0.0a
6 (Non-Bt)	3.5 ± 1.6b	6.3 ± 1.0b	1.6 ± 0.3b
7 (Bt)	0.7 ± 0.5a	0.3 ± 0.3a	0.0 ± 0.0a
8 (Non-Bt)	4.5 ± 0.9b	5.5 ± 0.5b	2.9 ± 0.8b
9 (Bt)	1.4 ± 1.4a	0.0 ± 0.0a	0.2 ± 0.1a
10 (Non-Bt)	2.8 ± 0.2a	2.8 ± 0.8b	2 ± 0.5b
11 (Bt)	1.5 ± 0.6a	0.0 ± 0.0a	0.2 ± 0.1a
12 (Non-Bt)	7.0 ± 0.4b	7.9 ± 2.0b	4.1 ± 0.5b
13 (Bt)	1.3 ± 1.3a	0.0 ± 0.0a	0.0 ± 0.0a
14 (Non-Bt)	3.1 ± 0.4a	2.6 ± 0.1b	2.2 ± 0.4b