Managing Tropic Croton with Cadre/Ultra Blazer Tank-Mixes in Peanut E. P. Prostko and J. A. Kichler Dept. of Crop & Soil Sciences University of Georgia APRES July 2003

Tropic Croton in Peanut u 3 rd most troublesome weed u limited biology data u NCSU competition research u less competitive than other broadleaf weeds

Cadre in Peanut u discovered (1981) u field tested (1989) u EUPs ( ) u labeled (1996) u excellent control of nutsedge complex u G-E control of many other species u weak on tropic croton

Ultra Blazer in Peanut u registered (1982) u formulation changed in 2000 u good on pigweed, morningglory, ragweed, croton u 6% of GA acres u injury concerns

The Question? u What happens when you tank-mix Ultra Blazer and Cadre?

Cadre/Blazer Tank-Mixes Source: Richburg et al., ozs/A + 1 pt/A % v/v Applied 3 WAP

Research Objective u The objective of this research was to determine if tropic croton control with Cadre could be improved with tank- mixes of reduced rates of Ultra Blazer.

Materials & Methods - I u on-farm (W. Dillard) u Webster County u small plot techniques u 4 replications u Georgia Green u planted 4/30/02 u crop injury u weed control

Materials & Methods - II u 1.44 ozs/A u Ultra 24 ozs/A u Cadre + Ultra * 2, 4, 8, 12, 16 ozs/A u 0.25% v/v u 6.5 plants/ft 2 * Test 1 = croton (< 1 tall) * Test 2 = croton (5-6 tall)

Results

Peanut Injury u In both tests, the additions of Ultra Blazer to Cadre did not significantly increase peanut injury when compared to either herbicide applied alone.

Tropic Croton Control in Peanut - I 19 DAT Weeds < 1 Tall LSD 0.05 = 10

Tropic Croton Control in Peanut - I 84 DAT Weeds < 1 Tall LSD 0.05 = 17

Tropic control control in peanut with Cadre + Ultra Blazer combinations applied to 1 tall weeds. A = untreated, B = 1.44 ozs/A + Ultra 8 ozs/A. Photos taken 19 DAT. AB

Tropic Croton Control in Peanut - II 15 DAT Weeds 5-6 Tall LSD 0.05 = 6

Tropic Croton Control in Peanut - II 65 DAT Weeds 5-6 Tall LSD 0.05 = 18

Tropic control control in peanut with Cadre + Ultra Blazer combinations applied to 5-6 tall weeds. A = untreated, B = 1.44 ozs/A + Ultra 16 ozs/A. Photos taken 15 DAT. AB

Summary - I u no significant increases in peanut injury were observed u when croton was 1 or less * Improved control with Ultra Blazer at rates at or above 4 ozs/A * Needed at least 8 ozs/A to provide control similar to full rate of Ultra Blazer

Summary - II u when croton was 5-6 tall * Improved control with Ultra Blazer at rates at or above 4 ozs/A but …….. * tank-mixes were less effective than full rate of Ultra Blazer

Preliminary Results 2003

Tropic Croton Control in Peanut Webster County - 10 DAT Weeds 1-2 Tall LSD 0.05 = 9

Tropic Croton Control in Peanut Wilcox County - 11 DAT Weeds 1-2 Tall LSD 0.05 = 9

University of Georgia Extension Weed Science (gaweed.com)