Vol. 54—2000 - NorthEastern Weed Science Society

NICOSULFURONIRIMSULFURON COMBINATIONS FOR
POSTEMERGENCE WEED CONTROL IN FIELD CORN
R. R. Hahn and P. 1. Stachowski'
ABSTRACT
Fieldexperimentswereconductedatseverallocationsin 1999 to compareearly
posternergenee (EPOSn applications of nicosulfuronlrimsulfuron combinations with glyphosate
in glyphosate-resistant com (Zea mays L.) and with preemergence (PRE) programs in
conventional com. At three locations, EPOST applications of 12.6 oz ailA of
nicosulfuronlrimsulfuron plus atrazine (Basis Gold) alone, and in combination with 2 oz ailA of
dicamba, and of 0.38 oz ailA ofnicosulfuronlrimsulfuron (DPX-79406) plus 2.05 oz ailA of
clopyralidltlumetsulam (Hornet) were compared with EPOST applications of lib ailA of
glyphosate. These EPOST nicosulfuronlrimsulfuron treatments were compared with a PRE
application of 2.89 lb ailA of s-metolachlor/atrazine (Bieep II Magnum) followed by a MPOST
application of 4 071A of dicamba or a PRE standard of 2.25 lb ailA of s-metolachlor/atrazine
(Bicep Lite II Magnum) plus 1.5 lb ailA of pendimethalin in experiments with conventional
hybrids.
In two experiments, EPOST applications of nicosulfuronlrimsulfuron plus atrazine and of
nicosulfuronlrimsulfuron plus clopyralidltlumetsulam controlled an average of 90 and 99% of the
velvetleaf (Abuti/on theophrasti Medicus) respectively compared with 95% velvetleaf control
with the EPOST glyphosate application. Green foxtail (Setaria viridis (L.) Beauv.) control
averaged76%withthenicosulfuron/rimsulfuroncombinationswhile glyphosatecontrolled99%
in one experiment.Therewereno differencesin com yields amongthesetreatmentsat either
location. Control of triazine-resistant (TR) common lambsquarters (Chenopodium a/bum L.) was
63% with EPOST application ofnicosulfuronlrimsulfuron plus atrazine alone and 100% when
applied with dicamba. The EPOST nicosulfuronlrimsulfuron plus chlorpyralidltlumetsulam
treatmentcontrolled70%of theTR lambsquartcrswhile glyphosateprovided100%control.
With a conventional hybrid, PRE application of s-metolachlor/atrazine plus pendimethalin
controlled 89% ofa TR lambsquarters population producing a yield of74 buiA. MPOST
applicationof nicosulfuron/rimsulfuronplusatrazinealoneandwithdicambacontrolled40 and
75% of the TR lambsquarters and yielded IS and 76 buiA respectively. Yield from the uotreated
check was 2 buiA. Finally EPOST application ofnicosulfuronlrimsulfuron plus atrazine alone
orof nicosulfuronlrimsulfuronplusclopyralid/flumetsulamcontrolledanaverageof 97%of the
triazine-susceptiblelambsquartersandof the yellow foxtail(Setaria glauca (L.) Beauv.)and
yielded an average of 103 bulA of grain com with a conventional hybrid. The PRE standard
followed by a MPOST dicamba application also provided 97% lambquarters control but only
63% foxtail control and yielded 64 buiA. Yield from the untreated check was 23 buiA.
'Assoc. Prof and Res. Supp. Spec., Dept. of Crop and Soil Sci., Cornell Univ., Ithaca, NY
14853.
3S