Vol. 15—1961 - NorthEastern Weed Science Society

Sunderiand,' Mass..Experiment:
In this experiment, trials were conducted on a well drained aravelly
sandy loam. The area was heavily and uniformly infested with a quacksrass
sod which had not been tilled for three yearl. On April 14 the area was
plowed 61"7 u ,',ck!epand disked. Treatments 2,3,9,10,15,16 were applied on
.y'19 "'(Table II). ; There were two replicates. At that t1me quacksras s .
. "wa'labout 6 'in. tall. Six days lateT on May 25, the whole area was plowed,
disked; fertilized and the .eedbed prepared. OnMay 26 all pre-planting
treatments were applied and the herbicides in treatments 4,5,6,7,8,11,12,
11 and ',18were immed1,.&telydisked into the 8011. On May 27 Ohio M-15
silaaecon was planted. Four days later, on May 31, 0.75 lnches of rain
fell.· On June 2 the whole experimental area was sprayed with 6 IblA of DNBP
to cont~ol anDual weeds. Dur1na the growina season the corn was not cultivated.
Quackaras8 stand e8ttm&tes made on July 26 are shown in Table II.
" In aeneral, the best quackgraas control was obtained with, both Triazines
and EPTAM.Atrazine provided better control than comparable rates of
. Slmazine. Mixing in the applied Atrazine or Simazine with the so11 slightly
increased their effectiveness. Relatively poor control was obtained from
spring applications made on quackgrasl foliaae, possibly due to the fact
that sod was plowed under early the same sprina. Someof the rhizomes,
which were turned under, did not produce shoots and therefore did not come
lnto contact with materials applied on the foliage. Someof these rhizomes
were exposed durina seedbed preparation and produced a healthy growth of
quackaTass. Corn was injured by both Feuac treatments. Mixins Feuae with
the soil significantly increaled its effectiveness in controlling quackgraaa.
Bowever, injury to the corn was also increased even to the point of
depre,sed yields.
Leverett.
Mass. Experiment:
In this experiment, trials were conducted on a well drained aravelly
sandy loam. The area had a good uniform stand of quackarass. Plots w~re
12 ft. by 30 ft. Five replicates were used. In this experiment we use9 in
all treatments 5 IblA of actual Atrazine. Treatments 2 and J were applied
April 28 on 6 in. tall quackaraas (Table III). Treatment 3 was rototilled
about 5 in. deep following application of materials. The same day treatments
4 and 5 were also rototilled. Close observations showed that this
rototil11ng cut the rhizomes into 3-6 inch seam-nts. On May 16 the expert·
mental area was plowed, disked, fertilized and prepared for plantins.
By thie time, plots which had been rototilled on April 28, had a thick
re-srowth of quackgrasl. It appeared that rototillina had activated
dormant rhizome buds (1) and produced more shoots. It was postulated
that this practice would provide better absorption of Atrazine and finally
provide a better control of quackgrass. Atrazine was applied on treatments
4, 5, 6 and 1 on May 20. According to the plan (Table III) tTeatmenU S
and 7 were rototilled immediately after application of the herbicide.
Silase corn Ohio M-lS was planted on all treatments on the same day,
May 23. Frolll May 23 into May 24, 0.52 inches of rain fell. It seems
that 8011 moisture conditions were favorable for Atrazine. On June 2
the whole experimental area was sprayed with 3 pound. per acre of