Vol. 16—1962 - NorthEastern Weed Science Society

3~
.!2.§Q- The me applied pre-pI_tins, as shawn in'f8hle 3, had about the' 'ame
pattern of control as indicated for 1959. Good early season control was obtained
but thb contt"Ol tac1ed samewhatAt the end of the '•• 'ason. Two analogs of EPTC,
R-1607 and a-206O,were also i1UiobJdedin the pr."~lng applications. ot
these the R-,2060 was considerably less active than,BPTC but the R-1607 was as
effective or perhaps a little more so. -t-
Atrazine as a pre-emergence' treatment did not '~control the nutgrass
adequately at3 -pounds.. However,. 'at 6.5 or9.S 'pc1lllid.'sea.on long control
was obtained., There were no sianificant differenc •• in yield between
treatments in the pre-emergence experiment.
".,
In a sepa,r,at~ exp~riment, At¥,wne wasuse.d .at. .1" 4, and 6 pounds at two
stages of nutgrass growth. The results as shawn in Table 4 indicate that at
stage I, when nutgrass was 3 to 5 inches tall, 2 pounds of Atrazine did a
fair job of control but was not entirely satisfactofY. The 4 and 6 pound
treatments were satisfactory the entire season. ~ application of 2 pounds
of Atrazine at stage 2 did not control the nutgrass" and 4 pounds did not give
season long control. The nutgra'as at time of treatillent of stage '2 was 8 to
10 inches tall. -The' 6 pound application on thls'mature'nutgrass'resulted
in axcellentcontrol.
TABLE4. Rat~ngs of Nutgraas control and yield of florn for postemergence
treatments at ~o stages of growth in 1960•
..
Rate zi!te of RaiQif * yield
atment Ibs/acre 7.. ,ill 10 6 butalire
Irt
N~t8rass
3 - 5 inches
Atrazine 2 7 4 3 125.8
Atrazine 4 10 10 8 ',134.0
Atrazine 6 10 10 10 130.2
Nutgrass
8 - 10 inches,'
Atraz:lne ' 2 j' 2 2 119.5
Atrazine 4 7 8 4 ,123.8
Atrazine 6 8 9 9 ' '133'.4
Check 0 0 0 97.2
'UD 05
• 29.%" - '
LSDol • 39.3
* Ratings on a scale of 0 • no contrpl) ,10 • complete kill