Vol. 15—1961 - NorthEastern Weed Science Society

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403.
the stumps flush with the ground and leaving them splintered. The' equipment'
used by TVAwas underpowered and could climb only about a 15-percent slope, ­
which is not adequate for this region. Also, it was too wide and heavy for
the bridges on country roads that it had to travel. The equipment was moved
on a large tractor-trailer unit. Rocks kept the spikes broken off, and the
services of a welder were required with the machine. Across our rough, rocky
terrain the operator did not cut as cl~se to the ground as was desirable; and
of course during the next growing season there were several sprouts for each
bush cut the previous year. The growth was vigorous, apparently as a result
of the established root system.
Power saws with clearing attachments bave been used during the past 4 ye ars and
have proved to be a very effective and practical mechanical clearing method.
These are I-man saws, and brush up to 5 inches in diameter may be ,cut from a
standing position. Because of the clearing attachments, these saws do a highly
satisfactory job where mechanical methods are employed.
Chemical Maintenance
In the early 1940's leading chemical companies, after extensive e~qperimental
work, had faith enough in the so-called growth-regulating chemicals to place
them on the market. In the latter part of the 1940' 5 TVAbecame interested in
these chemicals and established experimental plots on some of its rights-ofway.
Chemicals were applied in accordance with the manufacturers' directicns.
Evaluation of this work showed enough promise to continue experiments on a
large scale. For the first few years low-volatile esters containing 2 pounds
of 2,4-D and 2 pounds of 2,4,5-T acid a gallon were used. These were mixed
with water as a carrier at the rate of 1 gallon of esters, or 4 pounds acid
equivalent, in 100 gallons of water and applied at the rate of 300 to 500
gallons of mixture an acre for foliage spraying by ground crews using hand
guns. The brush was ~roughly wet; and the amount of mixture depended on
the density, height, and species.
For the past several years, after extensive experimental work, 2,4,5-T esters
only have been used. Also nonvolatile Ammate (95-percent ammoniumsulfamate)
at the rate of 60 pounds in 100 gallons of water with 4 ounces of spreadersticker
acid added was applied at the rate of 300 to 500 gallons of mixture an
acre, depending on the height, species, and density of the brush being sprayed.
During the early years if the weather was dry during the latter part of July
and August, we would add 10- to 2O-percent diesel oil to an ester-and-water
mixture for foliage application. However, this procedure has been discontinued,
along with many other ideas tried during the early years of chemical
brush control.
A wide variety of equipment has been used during this period for chemical
right-of-way maintenance. The knapsack sprayer has been used to some advantage,
but experience has proved that this method has only limited use in.a
program the size of TVA's. The first spray units purchased were 15-gpm pumps
used with 2OO-gallon tanks. The second units purchased were 2O-gpmpumps used
with the same 200-gallon capacity tanks. In order to treat brush in remote