Vol. 51—1997 - NorthEastern Weed Science Society

52
1996 EUP RESULTS FOR ISOXAFLUTOLE IN CORN
IR. Stachecki, T.E. Vrabel, and C.B. Williams'
ABSTRACT
I oxaflutole is a member of a new class of isoxazole herbicides from Rhone-Poulenc Ag
Compan which disrupt pigment biosynthesis in susceptible plant species. Isoxaflutole is
formulat d as a 75 percent water dispersible granule and will be marketed under the trade name of
BALAN ETM. An Experimental Use Permit was conducted across 165 locations in the midwest
and nort east with the preemergence application of isoxaflutole on field com. Objectives were to
demonst ate weed control, crop safety, and crop yield response of isoxaflutole applied either
alone 0 in combination with reduced rates of preemergent com herbicides versus commercial
preemer ence corn herbicide programs. EUP trials were conducted by Rhone-Poulenc Sales
represen atives in conjunction with Rhone-Poulenc Field Development representatives.
esults from 195 trials which were conducted indicated minimal crop injury and excellent
weed co trol when isoxaflutole was applied at 105 g ai ha- l either alone or in combination with
half of e normal use rate of preemergence com herbicides such as acetochlor, metolachlor,
alachlor, dimethenamid, atrazine or chloracetamide plus atrazine combinations. These
isoxaflu loe treatments provided excellent control of weds such as velvetleaf (Abutilon
theophr sti Medik.), common ragweed (Ambrosia artemisiifolia L.), giant ragweed (Ambrosia
trifida .) lambsquarters (Chenopodium album L.), redroot pigweed (Amaranthus retroflexus
L.), tal waterhemp (Amaranthus tuberculatus (Moq.)ID. Sauer), common waterhemp
(Amara thus rudis Sauer), kochia (Kochia scoparia (L.)Schrad.), Pennsylvania smartweed
(Polygo m pensylvanicum L.), eastern black nightshade (Solanum ), Venice mallow (Hibiscus
trionum L.), wild mustard (Sinapsis arvensis L.), giant foxtail (Setaria faberi Herrm.), green
foxtail ( etaria viridis (L.)Beauv.), fall panicum (Panicumdichotomiflorum Michx.), wild proso
millet ( 'anicum mileaceum L.), woolly cupgrass (Eriochloa villosa (Thunb.)Kunth) and
bamyar grass (Echinochloa crus-galli (L.)Beauv.). Combinations of isoxaflutole plus half of the
recomm nded use rate of a chloracetamide herbicide provided excellent control of yellow foxtail
(Setaria glauca (L.) Beauv.). Performance of the isoxaflutole treatments was either comparable
or supe .or to the overall weed control performance provided by the commercial standard
herbicid program as chosen by the individual farmer cooperators.
As previously observed in small plot research trials, under dry conditions or in
situatio s where weeds emerge due to non uniform application coverage, control of weed
seedling less than 5 em tall occurred following rainfall. This "rechargeable activity" was
observe occurring in most locations for over 6 weeks following application and was a
charact .stic of isoxaflutole which was well received by the farmer cooperators. They also liked
the low dose technology of isoxaflutole and the ease of handling the dust free 75 WDG
formula ion.
one-Poulenc Ag Company, Research Triangle Park, NC 27709