Vegetation Management Along Transmission Utility Lines in the United States and Canada

Article Figures & Data

Table 1. Sample and responses to transmission vegetation management survey 1995, including acre (hectare) representation.

	No. of survey recipients	No. of surveys returned	Acres (hectares) reported	% of total
Canada	9	4	777,414 (314,609)	30
Northeastern U.S.	39	12	211,876 (85,744)	8
North central U.S.	59	22	627,518 (253,948)	24
Southern U.S.	70	29	824,101 (333,503)	32
Western U.S.	43	14	159,578 (64,579)	6
Total	220	81	2,600,487 (1,052,383)	100
% returned overall		37

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Table 2. Total reported transmission line right-of-way acres (hectares) with land type characteristic percentages.
Vegetation control Agriculture/ grazing Open without control Other Total
Acres (hectares) 1,794,336 (726,144) 546,102 (221,000) 182,034 (73,667) 78,014 (31,571) 2,600,487 (1,052,383)
% of acres/hectares 69 21 7 3 100

Table 3. Most common herbicides used by respondents along transmission rights-of-way: 1995.

Herbicide	Frequency reported	Projected gallons (liters) of sample population
Garlon 3A	10	162,880 (616,566)
Garlon 4	19	57,694 (218,395)
Accord	14	42,447 (160,679)
Accord/Arsenal	9	32,349 (122,454)
Arsenal	10	19,143 (72,464)
Krenite S	9	8,807 (33,338)
Other	56	94,663 (358,337)
Total		417,983 (1,582,233)

Table 4. Herbicide application methods, and their selectivity, ranked by total acres (hectares) treated: 1995.

Method	Type	Acres (hectares)	% of total
Basal	Selective	50,363 (20,381)	28
High-volume foliar	Nonselective	42,128 (17,049)	24
Low-volume foliar with backpack or hand sprayer	Selective	40,231 (16,281)	23
Cut surface	Selective/non-selective	34,025 (13,769)	19
Aerial	Nonselective	7,357 (2,977)	4
Low-volume foliar broadcast	Selective	3,974 (1,608)	2
Total		178,078 (72,066)	100

Table 5. Acres (hectares) of ROWs treated with mowing and hand equipment by region: 1995.

Region	Mowing	Hand equipment	Total	% of total
Canada	135,000 (54,633)	46,500 (18,818)	181,500 (73,451)	38
Northeastern U.S.	1,386 (561)	4,152 (1,680)	5,538 (2,241)	1
North central U.S.	6,202 (2,510)	11,004 (4,453)	17,206 (6,963)	4
Southern U.S.	249,253 (100,869)	22,505 (9,107)	271,758 (109,976)	56
Western U.S.	3,156 (1,277)	2,610 (1,056)	5,766 (2,333)	1
Total	394,997 (35,114)	86,771 (35,114)	481,768 (194,965)	100
% of total	82	18

Table 6. Miles (km) of transmission ROWs controlled by side trim methods by region: 1995.

Region	Bucket truck	Manual	Helicopter	Total	% of total
Canada	0	30 (48)	600 (966)	630 (1,014)	4
Northeastern U.S.	171 (275)	3,346 (5,385)	120 (193)	3,637 (5,853)	22
North central U.S.	1,414 (2,276)	2,110 (3,396)	167 (269)	3,691 (5,940)	22
Southern U.S.	6,385 (10,276)	1,196 (1,925)	535 (861)	8,116 (13,061)	48
Western U.S.	370 (595)	173 (278)	150 (241)	693 (1,115)	4
Total	8,340 (13,422)	6,855 (11,032)	1,572 (2,530)	16,767 (26,983)	100
% of total	50	41	9

Table 7. Ratio comparisons of actual to recommended active ingredient per acre for all respondents.

↵* LVF = Low-volume foliar with backpack or hand sprayer, HVF = high-volume foliar, LVFB = low-volume foliar broadcast.

Table 8. Regional average annual budget allocations (U.S.$) for vegetation control 1990–1995.

Region	Herbicide dollars	% of total region dollars	Mechanical dollars	$ of total region dollars	Total dollars	% of dollars
Canada	2,405,625	34	4,625,625	66	7,031,250	13
Northeastern U.S.	7,395,490	57	5,431,510	43	12,827,000	17
North central U.S.	9,126,802	29	17,805,546	71	26,932,348	31
Southern U.S.	8,039,400	31	22,846,100	69	30,885,500	34
Western U.S.	381,920	10	3,578,080	90	3,960,000	5
Total (U.S.$)	27,349,237		54,286,861		81,636,098
% of total dollars		34		66		100

Table 9. Estimated vegetation control for the United States (Canadian data not included).

Treatment	Data from sample	Estimated amount (column 2 × 2.537)
Total acres (hectares) of transmission ROWs requiring vegetation control	1,166,767 (472,175)	2,960,088 (1,197,909)
Acres (hectares) treated mechanically	300,268 (121,515)	761,780 (308,282)
Acres (hectares) treated with herbicide	172,221 (69,696)	436,925 (176,818)
Gallons (liters) of Garlon 3A applied	130,304 (493,253)	330,581 (1,251,383)
Gallons (liters) of Garlon 4 applied	37,075 (140,344)	94,059 (356,052)
Total gallons (liters) of all herbicide applied in the U.S.	333,742 (1,263,347)	846,703 (3,205,111)