Oat Response to Imazapic Residues E. P. Prostko, T.L. Grey, and R. N. Morgan Department of Crop & Soil Sciences University of Georgia Tifton WSSA

Imazapic u trade named - CADRE u BASF product ulabeled for peanut in 1996 u postemergence –nutsedges –broadleaf –small grasses u very popular –64% in GA u$15-16/A u rotation restrictions

Cadre Rotational Restrictions

Small Grains in Georgia Planted Acres Source: GASS

Materials and Methods - I u small plot techniques u 4 replications u 1.44 ozs/A applied to bare ground u first week of May, June, July, August, September u ‘Coker 227’ oats planted first week of October u 3 locations u no tillage after initial bed formation

Materials and Methods - II Data Collected u stand counts –1-2 WAP u forage yields –machine harvested in December and January u grain yields –machine harvested in May

Soil Types

Results

The influence of imazapic on oat stand Averaged over 3 tests P = 0.60

The influence of imazapic on forage yield Averaged over 3 tests a a a ab b c LSD

The influence of imazapic on grain yield Averaged over 3 tests P =

Cadre Injury Symptoms

Untreated Sept 3 June 4 May 1 Aug 5 July 1 CADRE/OATS TEST December 3, 2002 Oats planted October 2, 2002

CADRE/OATS TEST January 21, 2003 Untreated Sept 3 June 4 May 1 Aug 5 July 1 Oats planted October 2, 2002

UntreatedCadre 1 Month Before Planting Photo 21 DAP, Tifton 2003

Summary u oat stand was not reduced by any timing of imazapic u oat forage yield reduced when imazapic was applied in August and September (1-2 months before planting) u oat grain yield was not reduced by any timing of imazapic

Conclusions u the oat rotation restriction does not need to be 18 months u should be equivalent to other small grains (4 months)