Vol. 16—1962 - NorthEastern Weed Science Society

Newapproaches in the use of herbicides
turf llIlUIagement
c. Richard Sk~gleyl
in
The control of weeds always hils been and probably always will be an important
factor in the'maintenance o-f turf. A review of the literature dating
back prior to the advent of theintrQduction of 2,4-D, ancl modern day weed eontrol
practices .would bear this out.
Someof the earliest reports on selective weedcOl'ltrol in turfgrass callle
from the Rhode ISland Agricultural Experiment Station. Experiments had been
started in' 1905 to compare fertilizer mixtures' designed to affect the soil reaction
differently. An acid, neutral and alkaline· fertilizer was each applied
to different grasses. three years later differences became ~Jite apparent'
betweengrasse$ and by 1910 it was .noticed that weeds were least abundant on
the plots receiving the acid fertilizer. Although Kentucky bluegrass was .
favored by decreasing the soil acidity, clove~ and weeds were more prevalent.
ThiS work was continued for manyyears and a number'of publications wet.
written which included data from these trials (3, 5, 6, 8, 10). It is interesting
to note some of the early reactions to the ~&sultsobtained. Hartwell
and Dainon(8) in discussing the work !Stated that "Ongen.ral principles
perennial grasses will be permanent to the extent tha~ their specific requirements
are fUlf~lledeither naturally or artificiaJ1ly". They also wrote
that "Even when the specific needs' of a grass are known, it is not ,always advisable
to maintain these needs because the growth of certain undesirable
pl arrts, such as weeds and fOUl grasses, may be promoted by the same conditions".
For quite a number'of years the "Rhcqe' Island weedle•• lawns" received great
publicity. Here was an admitted case of penalizing the desirable grasses to
aid in weed control. In 1910 with little knowledge available what choice was
there?
,. .: - .. - . ',",
These investigators continued their efforts, however, until they were
convinced that it wasn't soil acidity 2!t 1! but rather differences in plant
tolerance to aluminumwhich increaseQ; in thesolls01utionwith increasing
acidity.
It wasn't until almost 1940'that Rhode Island gave up trying to control
weeds in turf by keeping the 5011 in.~ acid condition. It had becometoo"')
diffic1.ll t to maintain any kind of91'assunder these cc>nclitions'- even Co10ni/l,1
bent. .' . ,
Sprague and EV8ul'in a NewJersey bulletin, (13) published in 1930 made
this statement "In general it se,ms sensible that fertilization to control
weeds shOUldbe cor'lducted on the ,basis of ,encouraging vigorous growth of the
turf sa that grasses may successfully compete with weeds. The development of
excessive acidity may cause more trouble than the weeds themselves". Researchers
in both states seemed to agree that keeping soils 'very acid to prevent
lAssociateProfessor of Agronomy-TurfManagement.University of Rhode Island.