Table 2 Comparison of time and percent bent needles for conventional and driver electrode insertion methods by species.

		Electrode insertion method				Differential^*
		Conventional		Driver		Differential^*
Scientific name	Common name	Time (Sec)	Needles bent (%)	Time (Sec)	Needles bent (%)	Time (Sec)	Needles bent (%)
Hardwoods
Acer rubrum	Red maple	3.38	52.6	1.20	0.0	2.18	52.6
Betula nigra	River birch	2.84	46.6	1.48	0.0	1.36	46.6
Carya glabra	Pignut hickory	3.73	82.7	1.78	7.5	1.95	75.2
Carya tomentosa	Mockernut hickory	4.68	85.3	2.11	15.1	2.57	70.2
Castanea dentata	American chestnut	1.25	15.0	1.07	0.0	.18	15.0
Catalpa bignonioides	Catalpa	1.40	17.5	.80	5.5	.60	12.0
Celtis occidentalis	Hackberry	3.68	45.2	2.01	0.0	1.67	45.2
Cercis canadensis	Eastern redbud	1.88	22.6	1.48	7.4	.40	15.2
Cornus florida	Dogwood	3.58	82.6	1.47	7.4	2.11	75.2
Fagus grandifolia	American beech	3.02	32.6	1.45	0.0	1.57	32.6
Fraxinus pennsylvanica	Green ash	3.34	78.7	1.40	7.4	1.94	71.3
Ilex opaca	American holly	2.74	45.2	1.72	15.0	1.02	30.2
Juglans nigra	Black walnut	2.25	45.3	1.46	0.0	.79	45.3
Liquidambar styraciflua	Sweetgum	3.08	37.6	1.54	7.6	1.54	30.0
Liriodendron tulipifera	Yellow poplar	2.14	41.0	1.04	2.5	1.10	38.5
Nyssa sylvatica	Black tupelo	2.50	37.5	1.35	7.3	1.15	30.2
Ostrya vlrginiana	Eastern hophornbeam	3.80	77.7	1.79	5.5	2.01	72.7
Oxydendrum arboreum	Sourwood	2.64	52.6	1.16	7.3	1.48	45.3
Plantanus occidentalis	Sycamore	3.16	45.0	1.66	0.0	1.50	45.0
Populus deltoides	Eastern cottonwood	1.39	27.6	1.07	0.0	.32	27.6
Prunus serotina	Black cherry	2.71	52.6	1.47	0.0	1.24	52.6
Quercus alba	White oak	2.78	65.0	1.10	5.0	1.68	60.0
Quercus coccinea	Scarlet oak	3.59	62.0	1.57	7.1	2.02	54.9
Quercus falcata	Southern red oak	4.89	71.2	1.39	5.2	3.50	66.0
Quercus marilandica	Blackjack oak	2.02	57.6	1.15	7.2	.87	50.4
Quercus nigra	Water oak	3.98	65.2	1.88	15.1	2.10	50.1
Quercus prinus	Chestnut oak	2.26	61.0	1.24	9.8	1.02	51.2
Quercus stellata	Post oak	2.54	52.6	1.14	0.0	1.40	52.6
Quercus velutina	Black oak	4.99	73.1	1.63	12.6	3.36	60.5
Robinia pseudoacacia	Black locust	2.18	42.6	1.47	0.0	.71	42.6
Ulmus americana	American elm	2.20	35.1	.89	0.0	1.31	35.1
Average		2.92	51.9	1.42	5.1	1.50	46.8
Conifers
Juniperus virginiana	Eastern redcedar	2.11	62.7	1.38	17.5	.73	45.2
Pinus echinata	Shortleaf pine	2.01	32.6	.99	0.0	1.02	32.6
Pinus elliottii	Slash pine	1.52	17.5	.96	0.0	.56	17.5
Pinus palustris	Longleaf pine	2.11	22.6	1.24	7.6	.87	15.0
Pinus strobus	White pine	1.67	27.6	1.26	0.0	.41	27.6
Pinus taeda	Loblolly pine	1.90	31.8	.98	3.2	.92	28.6
Pinus virginiana	Virginia pine	2.33	47.6	1.21	12.5	1.12	35.1
Taxodium distichum	Baldcypress	1.56	25.2	.99	0.0	.57	25.2
Tsuga canadensis	Eastern hemlock	1.87	12.3	1.23	7.0	.64	5.3
Average		1.90	31.1	1.14	5.3	.76	25.7
Overall Average		2.69	47.2	1.36	5.2	1.34	42.1

↵* Differential is defined as conventional minus driver values.