Vol. 15—1961 - NorthEastern Weed Science Society

Results
and Discussion
;llien the first ~ytron treatments were made the bluegrasses had hardly commenced
germination. The seedlings of the other species ranged in size up to
about 2 inches with some seed still gernunating. The soil was moist and cool
and the .grass growth was slow.
.
The emulsion sprayiapplied bvo weeks after planting severely damaged or
actually killed the seedlings of most species within a few days. The application
of the dry formulation had little visual effect on the seedlings until
several "leeks after the application.
~jith each succeeding application the chemical treatment apneared less
camaging to the grasses but at each interval the emulsion caused more rapid
discoloration than the dry formulation. Table 1 gives the average number of
grass plants present on July 5. These plant counts also indicate that the
eJ:1ulsion in general was more damaging than the dry formulation and that the
earlier the date of treatment the greater the grass n~rtality.
The Lgrostis species were most seriously injured lvith the earlier treatments.
Of the bluegrasses the her ion variety ap,eared less tolerant of the
chemical as did Chewings fescue when compared with creeping red fescue.
It was interesting to note that in most instances there were more pl~ts
present on those plots receiving treatment on the eighth week than on the untreated
plots. Perhaps the treatment at the eighth week weakened the plants
sufficiently to eliminate mortality usually occuring as a result of natural
competition in dense turf stands.
The test area received only natural precipitation during the treatment
period and at the 6 and 8 week intervals the soil was dry and the seedlings
were making very slow growth. It is possible-that this factor had an influence
on the results indicated.
~uring i~gust the test area was fertilized with an 8-6-2 fertilizer and
water was supplied to insure an amount adequate for good grass growth. The recovery
of the grass on many of the plots, even on many severely injured.by.early
treatments, was of interest. The estimates of percentage turf cover taken on
November 3rd would indicate this. Certain plots with no plants present on July 5
had as much as a 75 percent coverage in early November.
It is probable that a few seeds germinated after the nl.ant; counts wer-e
taken in July but most of the coverage was due to the spread of a few plants
remaining in all plots even though the stand was so thin as to show a zero reading
when quadrat counts were made. \fuen the stands wer-e thinned by chemical
treatment the remaining plants became large and aggressive. This characteristic
of the grasses appeared to eliminate much of the earlier differences attributed
to formulation and apnl.Lcat.Lon interval.
.1ith very few exceptions, however, all treatments reduced the stands of
grasses. In some instances the dry formulation ~ave lower coverage readings