HERBICIDE SCREENING TRIALS IN GARBANZO BEANS. Kurt Hembree 1. Objective: Evaluate preemergent herbicides for weed control and crop response.

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1 HERBICIDE SCREENING TRIALS IN GARBANZO BEANS Kurt Hembree 1 Objective: Evaluate preemergent herbicides for weed control and crop response. Materials and Methods: The trial was located at the UC West Side Research and Extension Center in Five Points in a Panoche clay loam soil. The field was planted on 12/6/06 with garbanzo variety HB-14. Plots were four beds wide and 35 long, and arranged in a randomized complete block design with 12 treatments and 4 replications. Preemergent (PRE) herbicides were applied after planting on 12/7 and incorporated with the first furrow irrigation water. A combination of Prowl H 2 O plus GoalTender served as a conventional herbicide treatment and a hand weeded and untreated check was included in the trial. All treatments were applied with a CO 2 pressurized back-pack sprayer in a volume of 16 gpa. Yield and seed size was determined by mechanically threshing 30 of the center two beds of each plot. The MSTAT statistical program was used for analysis of variance and significant means were separated with Duncan s Multiple Range Test. Results and Discussion: None of the PRE treatments reduced bean stand (table 1), with each plot averaging about 4 beans/ft of bed. Chateau and the other PRE treatments provided excellent control of winter broadleaf weeds (primarily shepherd s-purse) and volunteer cereals were controlled, except when V was used. The area received less than 2 of rainfall since January, hence, there were very few summer weeds present to rate. The March 22 rating showed all treatments provided control of the summer weeds, although a few more prickly lettuce and sowthistle plants were seen in the Raptor treatment. While none of the treatments reduced crop stand, V and the standard Prowl plus Goal treatment resulted in slowed crop growth and injury through March (table 2). However, by mid- April, crop growth reductions or injury could not be detected in any of the treatments. There was a 20% reduction in yield in plots treated with V (table 3). All other treatments tested resulted in yields similar to the hand weeded control (about 3,200 lbs/acre). Percent seed by seed size category was similar for all treatments and there was no difference between treatments in the can count (number seeds/ounce). Most herbicides tested in the study gave effective PRE weed control without harming crop stand, growth, or yield. In particular, since Chateau (2 to 4 oz/acre) gave excellent weed control without injuring the beans, it would make a good alternative to Goal. Combining Outlook with Prowl could also provide growers with an alternative treatment. Although not tested in this trial, previous studies have shown that Outlook can be applied as a lay-by treatment for summer weed control without reducing crop growth or yield. The manufacturers of Chateau, Outlook, and Raptor are pursuing registration of these materials in garbanzo beans in California. 1 Kurt Hembree, UCCE Fresno County, 1720 S. Maple Ave., Fresno, CA kjhembree@ucdavis.edu, In: University of California Dry Bean Research: 2006 Progress Report published by the California Dry Bean Advisory Board, 531-D North Alta Avenue, Dinuba, CA

2 Table 1. Crop stand and weed control Crop and weed stand /10 on 2/16 Weed control 1 on 3/22 Preemergent Treatment Lb ai/a Beans Sp LR VC BL GR 1. Prowl H 2 O + GoalTender b 0 b 1.3 de 10 a 9.8 ab 2. Prowl H 2 O + Chateau b 0 b 1.8 d 9.9 b 9.9 ab 3. Prowl H 2 O + Chateau b 0 b 0.8 efg 10 a 9.9 ab 4. Prowl H 2 O + Chateau + Sandea b 0 b 0.3 fg 10 a 9.9 ab 5. Outlook b 0 b 0 g 10 a 9.6 ab 6. Outlook b 0 b 1 def 10 a 9.7 ab 7. Prowl H 2 O + Outlook b 0 b 0.3 fg 10 a 9.5 ab 8. Prowl H 2 O + Raptor b 0 b 0.3 fg 9.7 c 10 a 9. Prowl H 2 O + V b 0 b 5 a 10 a 0 c 10. DPX-GH b 0 b 1.3 de 9.9 b 9.2 b 11. Handweeded 2 times a 13 a 2.8 c 10 a 10 a 12. Untreated a 12.8 a 4 b 0 d 0 c 4.9% 28.3% % % % % 0.79 SP = shepherd s-purse, LR = London rocket, VC = volunteer cereals, BL = broadleaf weeds, and GR = annual grasses. 1 Control based on a visual rating of 0-10; 0 = no control and 10 = perfect control. Table 2. Garbanzo growth and injury Crop growth 1 Crop injury 2 Preemergent Treatment Lb ai/a 2/16 3/22 4/10 2/16 3/22 4/10 1. Prowl H 2 O + GoalTender e 9.1 b 10 a 4 a 0 b 0 2. Prowl H 2 O + Chateau a 9.8 a 10 a 0 b 0 b 0 3. Prowl H 2 O + Chateau cd 9.9 a 10 a 0 b 0 b 0 4. Prowl H 2 O + Chateau + Sandea cd 10 a 10 a 0 b 0 b 0 5. Outlook ab 10 a 10 a 0 b 0 b 0 6. Outlook cd 9.8 a 10 a 0 b 0 b 0 7. Prowl H 2 O + Outlook bc 9.8 a 10 a 0 b 0 b 0 8. Prowl H 2 O + Raptor a 10 a 10 a 0 b 0 b 0 9. Prowl H 2 O + V d 6.5 c 8.9 b 3.8 a 2.3 a DPX-GH a 10 a 10 a 0 b 0 b Handweeded 2 times 10 a 9.9 a 10 a 0 b 0 b Untreated a 10 a 10 a 0 b 0 b 0 3.2% % % % % Growth based on a visual rating of 0-10; 0 = no growth and 10 = vigorous growth. 2 Injury based on a visual rating of 0-10; 0 = no injury and 10 = all plants killed. Table 3. Garbanzo yield on 6/27 Yield 1 Seed size (% by category) Preemergent Treatment Lb ai/a (lb/a) <20 20 to 24 >24 Can count 2 1. Prowl H 2 O + GoalTender a 8.8 a Prowl H 2 O + Chateau a 7.2 b Prowl H 2 O + Chateau a 8.6 b Prowl H 2 O + Chateau + Sandea a 8.3 b Outlook a 7.1 b Outlook a 7.5 b Prowl H 2 O + Outlook a 8.3 b Prowl H 2 O + Raptor a 7.0 b Prowl H 2 O + V b 13.7 a DPX-GH a 7.7 b Handweeded 2 times 3208 a 8.0 b Untreated a 7.2 b % % % 12.4% 2.4% 1 Yield was calculated on harvest weight, less amount of debris taken from a sub-sample of 500 gm. 2 Can count determined by counting number of seeds in a 1 oz sub-sample of combined seed sizes >20..

3 ANNUAL MORNINGGLORY CONTROL IN BLACKEYE BEANS Kurt Hembree 1 and Blake Sanden 2 Objective: Evaluate preemergent and lay-by herbicides for annual morningglory control and crop response. Materials and Methods: The trial was located at the UC Shafter Research and Extension Center in a Wasco sandy loam soil. The field was preirrigated then treated with Dual Magnum plus Sonalan and incorporated with a 4-row bed shaper on 5/7/07. Blackeye bean variety CB-46 was planted on 5/8. The trial was set up in a randomized complete block design with 12 treatments and 4 replications. Each plot was four 40 beds wide and 65 long. Preemergent (PRE) herbicides (Chateau, Goal 2XL, and GoalTender) were applied after planting and incorporated with the 1 st furrow irrigation water on 5/15. Postemergence directed (PD) herbicides (Chateau, Shark, Venue,, Goal 2XL, GoalTender, ACB D33) were applied on 6/5 with a non-ionic surfactant when the beans were about 12 tall and the morningglory plants were emerged. The PD sprays were applied by contacting the lower 1/4 of the crop canopy to ensure sufficient contact with weeds growing in the crop row. Untreated and hand weeded treatments were included. All treatments were applied with a pressurized back-pack sprayer in a volume of 35 gpa. Shark was applied broadcast at 2 oz/acre to all treatments as a preharvest aid. Yield was determined by undercutting the center 50 (2 rows) of each plot, allowing the plants to dry, mechanically threshing on 9/19, and cleaning the samples. The MSTAT statistical program was used for analysis of variance and means were separated with Duncan s Multiple Range Test. Results and Discussion: The best morningglory control was achieved when Chateau was applied as a sequential PRE and PD treatment and was not different from the hand weeded control (table 1). While all the other treatments gave some degree of morningglory control, significant regrowth occurred, warranting the pre-harvest application of Shark so the plots could be more efficiently harvested. All treatments resulted in some degree of crop growth reduction, but most plats recovered by August (table 2). Bean plant growth was reduced the greatest where Goal 2XL was used both PRE and PD. All of the PD treatments resulted in some crop injury (20-40%), which was expressed as necrosis and limited to the parts of the plants contacted by the spray. GoalTender appeared to be slightly less injurious to bean plants than Goal 2XL. Plants treated with also showed evidence of general chlorosis of the entire foliage. There was no evidence of crop injury 1 month after treatment. Pod development and crop yield was similar for hand weeded and treated plots, which were significantly greater than the untreated plots (table 3). 1 Kurt Hembree, UCCE Fresno County, 1720 S. Maple Ave., Fresno, CA kjhembree@ucdavis.edu and 2 Blake Sanden, UCCE Kern County, 1031 South Mt. Vernon Ave., Bakersfield, CA blsanden@ucdavis.edu. In: University of California Dry Bean Research: 2006 Progress Report published by the California Dry Bean Advisory Board, 531-D North Alta Avenue, Dinuba, CA

4 In this study, Chateau applied PRE plus PD provided the best annual morningglory control with the least amount of crop injury. Although the other PD herbicides tested provided only marginal control, the addition of a pre-harvest application of Shark helped to clean up the plots with minimal weed seed production based on pre-harvest observations. The registrants appear to be interested in pursuing some of these treatments as possible solutions for controlling this weed. Table 1. Annual morningglory control Control rating 1 Treatment Rate/A Timing 6/14 7/11 8/1 1. Untreated b 0e 0e 2. Hand weeded times 10 a 9.8 a 9.3 ab 3. Chateau SW Preemerge 9.8 a 9.8 a 9.7a Chateau SW 4. Chateau SW 9.1 a 8.9 ab 8.6 abc 5. Shark EW a 7.9 cd 7.8 bc 6. Venue a 7 d 6 d 7. Venue a 7.8 cd 7.5 c 8. ACB D a 9.5 ab 8.6 abc 9. Goal 2XL Preemerge 9.4 a 9.1 ab 8.7 abc Goal 2XL 10. GoalTender Preemerge 9.8 a 9.2 ab 9.2 ab GoalTender 11. Goal 2XL 9.9 a 9 ab 7.5 c FirastRate 12. GoalTender 10 a 8.6 bc 7.6 c 6.51% % % Weed control based on a visual rating of 0-10; 0 = no control and 10 = perfect control. Table 2. Crop growth and injury Bean growth rating 1 Bean injury rating 2 Treatment Rate/A Timing 6/14 7/11 8/1 6/14 7/11 8/1 1. Untreated a 8.3 f 7.3 c 0 f Hand weeded times 10 a 10 a 10 a 0 f Chateau SW Preemerge 9.3 ab 9.8 abc 9.9 ab 2.3 cd 0 0 Chateau SW 4. Chateau SW 9.3 ab 10 a 10 a 2 d Shark EW* de 9.8 abc 10 a 4.3 a Venue* ab 10 a 10 a 1 e Venue* e 8.9 de 9.6 ab 3 bc ACB D33* e 9.9 ab 9.9 ab 4.3 a Goal 2XL Preemerge 7.1 e 8.8 e 9.1 b 4.3 a 0 0 Goal 2XL 10. GoalTender Preemerge 8.8 bc 9.4 bcd 9.8 ab 2 d 0 0 GoalTender 11. Goal 2XL* 8 cd 9.4 bcd 9.6 ab 3.5 ab 0 0 FirastRate 12. GoalTender* 7.3 de 9.3 cde 9.8 ab 3.5 ab % % % % Crop growth based on a visual rating of 0-10; 0 = no growth and 10 = healthy growing plants. 2 Crop injury based on a visual rating of 0-10; 0 = no injury and 10 = all plants killed.

5 Table 3. Pod set and crop yield Pod set 1 Bean yield on 9/19/07 Treatment Rate/A Timing 8/1 Lb/plot 2 Lb/acre 2 Gm/100 seed 3 1. Untreated b b 2511 b Hand weeded times 4.9 a a 4023 a Chateau SW Preemerge 5 a b a 21.7 Chateau SW 4. Chateau SW 5 a a 3917 a Shark EW* a ab 3164 ab Venue* a ab 3350 ab Venue* a ab 3564 ab ACB D33* a ab 3385 ab Goal 2XL Preemerge 4.6 a ab 3331 ab 21.5 Goal 2XL 10. GoalTender Preemerge 4.8 a a 3947 a 21.5 GoalTender 11. Goal 2XL* 4.6 a ab 3443 ab 21.4 FirastRate 12. GoalTender* 4.9 a a 3868 a % % % % 1 Pod set based on a visual rating of 0-10; 0 = no pods and 10 = lots of mature pods. 2 Amount of seed based on mechanically threshing center 50 of plot (2 rows) and cleaning. 3 Seed weight based on sub-sampling 100 seeds within each plot sample.