Vol. 15—1961 - NorthEastern Weed Science Society

155.
flowering and growth in the spring of 1961 Will be necessary to properly
evaluate crop tolerance. '
Dahlia
(Dahlia pinnata)
Treatments on newly planted dal:111-.swith S1maZ1ne, cm, and Diuron
in 1959 showed good crop tolerance and' good weed control. This limited
test was repeated in 1960 with s1m11arresults. , A large scale series of
treatments was made on June 10 on a dalIl1a planting at the U. S. Veterans
Hospital"No~thport" L.I-"N.Y. dThe 'rows were 200 feet lons and 4 feet
apart. 'Plants had not yet emerged from the sol1 a1ld the area was fairly
free of 'Weeds. . Replicate treatments were made Oil half rowan th liquid
Simazine 80~ lv.P. at 1" 2" '3, and 4 J>Ounds actual per 100 gallons of water per
acre and Diuron' 80~ W. P. at )." 1 112 and 2 pounds actual per 100 gallons of
water per acre. ' ,
None of the treatments injured the dahlias • Weed control was
evaJ.uated on July 25. S1ma.zine at 1 and 2 pound rates gave good weed
control except for a few crabgrass" barnyard grass" and purslane.
S1ma.zine,at 4 po6.nds controlled all weeds except a few grasses. Diuron at 1
Jamau
pound gave fairly goodi1'1itia1coz;1trol but by July 25'afew ,grasses,
purslane" and red root were com:1ngin.D:L~on at l 1/2: pouDds gave better
controlbutsim1lar weeds:'to those in the 1 pound plots' were coming up. At
the 2 pound rat,e of Diuron only, a few purslane were emerging.
l?t&lily (Hemerocallis sp.)
~lilies are very desirable perennials that are left in the same
10ca.tion for many years. In the fell of 1959 and the sPring of 1960"
herbicidal treatments with Sima.zine 4}&G·at 4,6,8, and lO' EPI'C 6% G at 3
and 6, and Amiben 10% G at 4 and 8 pounds actual per acre were apPlied to
established dqlUies. During the 1960 growing season there were nO signs of
injury from any of the treatments. Fall applications of Simazine resulted
in the best weed, control. Larger scaJ.e treatments with Si.m$Zine at 4·6 pounds
per acr,e were made d'ltring.'early November 1960.
German Iris (Iris sp.) ,
Trea.tments made on iris .several years ago showed CIPC to be fairly safe
on iris and to gi ve fair, weed control. Quackgiass is the most troubJ.esome
weed in iris plantings and it is not controlled by CIPO. S1maz1,hecontrols
quackgrass in peonies. 'In the fall of 1959 iris plants at the Martin
Viette Nursery were treated With Sima.zine 4~ G at 4,6,8, and 10 pounds
actual
per acre , EPro 6% G at 3 and 6 pounds actual per acre, and with
Amiben 10~ G at 4 and 8 'ppun4s actual per acre. 'The treatments were
repeated on adjacent rows in the early sPring of 1960.
None of the herbicidaJ. treatments produced any signs of injury during
the growing season. Simazine applied during the faJ.l gave the best weed control.
Six pounds of S1mazine per acre gave gOOdweed control.