Vol. 16—1962 - NorthEastern Weed Science Society

The petunial in the Till .. treated plots exhibited little to moderate
reduetion in 8rowth due to weed competition. Thi. injury decreas.d a. the
herbicide concentration was increased. No injury WI obaened due to
220
and 3 weeks.' . In' the Yorl~ 'tnatad p10te n add4t¢oaal planting. was .......
the fourth week following treatment. All of the p1ants'vere watered at
the time of traD.p1anting and throughout tha grow:l.n8 season rainfell was
supplemented by 'OYUbead' irrigation. .
RBSULt8..1!mDlSCYSSIQl(:'~_
The jlote were checked tot weed control July' and Ap8. 22, 1961~'i"
appro~il88te1y 5 and 12 wee~.'ter treatment. Table 1.• ~ri.es the
perfol'lll&nce of the pre-plant·;~rbic:l.de. on weed control. The following
chemietl. _bowedgOod ",.4 CQ~Cr91 after 5 .. e~1I j ..CI,-otOIl at 2. 4aluL_.
8 PO_I per acre, BPTCat 5&fld 10 pound. per acl'~, a-1607 at 5 and 10.,..
pounda .pel' ecre, and Tillam .• e,-.10 pounda per acre. After· 12 weeka the .'.
followiD8 chamicala .howed~cl weed control j Caeoron at 8 pound. per
acre and a-1607 at 10 pounda'Par ecre.
. . .
Predominant weedl in the ,lou were 18111baquar~er. yellow foxtai1,.;\ ....
green p~d, Caneda thiltl •• Pennly1vania 8I88rtWed.aad purslane.Weed.
of 1e.. ~r frequency included ,d,nde1:l.0n. yellow wood.orre1., three leeded
mercurf, .tinkgra.s, barnyard'Sras •• v.lvet1eaf, b1ack;~indweed. common
rapreed. lren.f.osa:aU, hairy .crabll'a .. , pur,ple 1o.Y-ara.. , mustard,r.Q\IIb
pipeed, .'181 's p1aDtain, 8ro\1ndcherry, timothy. ~urdock. wild 1ettu,ce •.
and ttab~.... ed.
On September 13.1961, approximately 15 weeke efter.herbicide application,
the.. petUDi.. were eX8lil1l\8d.for aDy detr.:I.alHt.•t ..•ffect. due to '. ..
herbicideand from weed competition. The data on ~e type of plant 8~
produced L. 11IIIIUri.ed in Table 2. , •. ..... .' .
, . \
The petunias in the check plots were IIIOde;r.t. \:0' .evere .tunting due
to. weedcompetit;1og. '.'the plant.~p the. Caeoron titaeed plota .. I" f~ ....
sUsht to moderately stunted. The petuniaa in the 2 pound per acra.plota
exhibited a1:l.sht to moderata injury due to weed cOllJ1)~tit:l.on. SU$Ilt ..',:
stunting aDd necro.il waa observed in the 4 poundaper acre p10ta, this'
injurt .a. due to a combination of weed competition and herbicidal action.
Plantl in the 8 pound per acre plot. Ihowed moderate Itunting and .nacrosis
due to the herbic:l.de. The herbic:l.de in the 4 and 8 poundl per acre treatmenta
appeared to have long ree:l.duel activity.
The lIetunia plants in the BPTCtreated plote exhibited sli8ht to moderate
stuntins becaute of weed competition. No injury from herbicide wa. obsened
even wilen they were tr.lplanted one day after treatment in the hiBbelt rate
per acra plote.
The plant. in the a-1607 treated plota had 111lht to levere reduction
in growth Where weeda were not controlled by the chemical. The petunia.
in the 10 pound pel' acre plotl were not injured. The petunias Ihowed no
herbic:l.da1 injury even when planted one day after treatment.