Louisiana State University Department of Agronomy and Environmental Management. Spring Burndown Test

Transcription

1 Louisiana State University Department of Agronomy and Environmental Management Spring Burndown Test Experiment number...: 03SC07JG Location...: Schexnayder Farm - St. James Parish, LA Experimental design...: Randomized complete block Number of reps...: 4 Plot size...: 6 x 15 Row width/# per plot...: 72 /1 Soil type...: silt loam %OM...: 1.5 ph...: 5.7 Planting date...: 2002 Harvest date...: N/A Crop/Variety...: Sugarcane/LCP (plant cane) Uniform std. treatment...: N/A Application type...: POST Date applied (mm/dd/yy)...: Time (hh:mm-hh:mm)...: 11:00-02:00p Incorporation equipment...: N/A Incorporation depth...: N/A Air/Soil temperature (F)...: 80/78 Wind (mph, direction)...: 2-3/S Cloud cover (%)...: 0 Relative humidity (%)...: 45 Soil/Leaf surface moist...: dry/dry Crop canopy height...: 8-15 Sprayer type/mph...: CO2bkpk/3.4 Nozzle type/size...: FF/8002VS Boom ht/#noz/spacing(in)...: 18 /4/15 GPA/psi...: 15/33 Applied by...: Etheredge Weed species (population)...: (height/# leaves) MEUSS...: 6-12 LOLMU...: 6-24 SETSP...: SONAS...: GERCA...: Others...: curly dock, chickweed, cutleaf eveningprimrose, daisy fleabane, swinecress Rainfall (in.) data from Paincortville, Assumption Parish, LA 0-24 hr/1-3 days...: 0.00/ days/2nd week...: 0.01/4.31 3rd week/4th week...: 0.01/0.37 1

2 For this test there was no attempt made to rate specific grasses or specific broadleaf weeds. Therefore, data for grass control represent both Italian ryegrass and timothygrass and broadleaf control data represent all broadleaf weeds present. There was considerable variability observed in this study related in part to the natural senescence that occurred for the various weeds as the growing season progressed. This test evaluated postemergence herbicides that would be commonly applied in the late winter and early spring to control winter weeds to include Weedmaster, 2, 4-D, or Gramoxone Max both alone and in combination with atrazine, Direx, DuPont K4, and Sencor, which have both foliar and soil activity. Since some of the herbicides work very slowly and others work very fast, differences in weed control were evident when ratings were made 11 days after treatment. Treatments containing Gramoxone Max were most effective 11 days after treatment. By 37 days after treatment, grass control was improved when DuPont K4 was applied with Weedmaster (100%) or when DuPont K4 or Direx were applied with 2, 4-D, but not when herbicides were applied with Gramoxone Max. DuPont K4 and Direx applied alone controlled grasses at least 98% 37 days after treatment. Broadleaf weed control 37 days after treatment was at least 97% for Weedmaster, 2, 4-D, Gramoxone Max, atrazine, Direx, DuPont K4, or Sencor applied alone. By 57 days after treatment grass control was 91% for all of these herbicide treatments. Velpar, Valor, or Spartan applied alone was not effective in controlling winter weeds. Both economical and rapid weed control were obtained with Gramoxone Max at 1.67 pt/a (85% grass and broadleaf weed control 11 days after treatment). Increasing the rate of Gramoxone Max to 3.33 pt/a improved weed control 6 to 9 percentage points. Addition of herbicides to Gramoxone Max at either rate did not improve weed control 11 days after treatment over that of Gramoxone Max alone. It should be noted that early removal of winter weeds from sugarcane promotes drying of soil and stimulates shoot development. Desiccation of winter weeds also helps to promote more efficient tillage. Even though herbicides other than Gramoxone Max were effective, 37 days and in some cases 57 days were needed to control weeds. This extended period of weed competition visually reduced sugarcane emergence and growth. It should be noted, however, that herbicides such as atrazine, Direx, DuPont K4, and Sencor not only provide postemergence control of winter weeds but also preemergence weed control. 2

3 Trt Treatment Form Form Rate Product Product Grow Appl No. Name Conc Type Rate Unit Rate Rate Unit Stg Code 11 DA-A 11 DA-A 1 Atrazine 4 L 2 lb ai/a 2 qt/a POST A 18 bcd 52 c-f 2 Atrazine 4 L 2 lb ai/a 2 qt/a POST A 3 ef 43 d-g 3 Atrazine 4 L 2 lb ai/a 2 qt/a POST A 78 a 91 a 4 Atrazine 4 L 2 lb ai/a 2 qt/a POST A 92 a 95 a 5 Atrazine 4 L 2 lb ai/a 2 qt/a POST A 10 c-f 35 gh 6 Direx 80 DF 2.4 lb ai/a 3 lb/a POST A 22 bc 57 bcd 7 Direx 80 DF 2.4 lb ai/a 3 lb/a POST A 17 b-e 55 b-e 8 Direx 80 DF 2.4 lb ai/a 3 lb/a POST A 89 a 93 a 9 Direx 80 DF 2.4 lb ai/a 3 lb/a POST A 92 a 93 a 10 Direx 80 DF 2.4 lb ai/a 3 lb/a POST A 13 c-f 43 d-g 11 DuPont K4 60 DF 2.4 lb ai/a 4 lb/a POST A 17 b-e 67 b 12 DuPont K4 60 DF 2.4 lb ai/a 4 lb/a POST A 28 b 63 bc 3

4 Trt Treatment Form Form Rate Product Product Grow Appl No. Name Conc Type Rate Unit Rate Rate Unit Stg Code 11 DA-A 11 DA-A 13 DuPont K4 60 DF 2.4 lb ai/a 4 lb/a POST A 89 a 91 a 14 DuPont K4 60 DF 2.4 lb ai/a 4 lb/a POST A 88 a 93 a 15 DuPont K4 60 DF 2.4 lb ai/a 4 lb/a POST A 20 bcd 40 fgh 16 Sencor 75 DF 1.5 lb ai/a 2 lb/a POST A 18 bcd 53 b-f 17 Sencor 75 DF 1.5 lb ai/a 2 lb/a POST A 10 c-f 55 b-e 18 Sencor 75 DF 1.5 lb ai/a 2 lb/a POST A 17 b-e 35 gh 19 Sencor 75 DF 1.5 lb ai/a 2 lb/a POST A 28 b 42 efg 20 Sencor 75 DF 1.5 lb ai/a 2 lb/a POST A 23 bc 35 gh 21 7 def 55 b-e 22 0 f 43 d-g a 85 a 4

5 Trt Treatment Form Form Rate Product Product Grow Appl No. Name Conc Type Rate Unit Rate Rate Unit Stg Code 11 DA-A 11 DA-A a 94 a 25 Nontreated 0 f 0 i 26 Velpar 75 DF 0.5 lb ai/a 10.7 oz/a POST A 20 bcd 32 gh 27 Valor 50 WP 0.25 lb ai/a 0.5 lb/a POST A 17 b-e 30 gh 28 Spartan 75 DF 0.28 lb ai/a 6 oz/a POST A 0 f 27 h LSD (P=.05) Standard Deviation CV Replicate F Replicate Prob(F) Treatment F Treatment Prob(F)

6 Trt Treatment Form Form Rate Product Product Grow Appl No. Name Conc Type Rate Unit Rate Rate Unit Stg Code 37 DA-A 37 DA-A 1 Atrazine 4 L 2 lb ai/a 2 qt/a POST A 7 c 99 a 2 Atrazine 4 L 2 lb ai/a 2 qt/a POST A 13 c 100 a 3 Atrazine 4 L 2 lb ai/a 2 qt/a POST A 100 a 99 a 4 Atrazine 4 L 2 lb ai/a 2 qt/a POST A 100 a 100 a 5 Atrazine 4 L 2 lb ai/a 2 qt/a POST A 15 c 100 a 6 Direx 80 DF 2.4 lb ai/a 3 lb/a POST A 20 c 99 a 7 Direx 80 DF 2.4 lb ai/a 3 lb/a POST A 99 a 100 a 8 Direx 80 DF 2.4 lb ai/a 3 lb/a POST A 100 a 100 a 9 Direx 80 DF 2.4 lb ai/a 3 lb/a POST A 100 a 100 a 10 Direx 80 DF 2.4 lb ai/a 3 lb/a POST A 100 a 100 a 11 DuPont K4 60 DF 2.4 lb ai/a 4 lb/a POST A 100 a 100 a 12 DuPont K4 60 DF 2.4 lb ai/a 4 lb/a POST A 100 a 100 a 6

7 Trt Treatment Form Form Rate Product Product Grow Appl No. Name Conc Type Rate Unit Rate Rate Unit Stg Code 37 DA-A 37 DA-A 13 DuPont K4 60 DF 2.4 lb ai/a 4 lb/a POST A 100 a 100 a 14 DuPont K4 60 DF 2.4 lb ai/a 4 lb/a POST A 100 a 100 a 15 DuPont K4 60 DF 2.4 lb ai/a 4 lb/a POST A 98 a 99 a 16 Sencor 75 DF 1.5 lb ai/a 2 lb/a POST A 20 c 99 a 17 Sencor 75 DF 1.5 lb ai/a 2 lb/a POST A 13 c 99 a 18 Sencor 75 DF 1.5 lb ai/a 2 lb/a POST A 100 a 100 a 19 Sencor 75 DF 1.5 lb ai/a 2 lb/a POST A 100 a 100 a 20 Sencor 75 DF 1.5 lb ai/a 2 lb/a POST A 20 c 100 a b 98 a c 97 a a 96 ab a 97 a 7

8 Trt Treatment Form Form Rate Product Product Grow Appl No. Name Conc Type Rate Unit Rate Rate Unit Stg Code 37 DA-A 37 DA-A 25 Nontreated 0 c 0 e 26 Velpar 75 DF 0.5 lb ai/a 10.7 oz/a POST A 70 b 79 bc 27 Valor 50 WP 0.25 lb ai/a 0.5 lb/a POST A 60 b 65 c 28 Spartan 75 DF 0.28 lb ai/a 6 oz/a POST A 10 c 30 d LSD (P=.05) Standard Deviation CV Replicate F Replicate Prob(F) Treatment F Treatment Prob(F)

9 Trt Treatment Form Form Rate Product Product Grow Appl No. Name Conc Type Rate Unit Rate Rate Unit Stg Code 57 DA-A 57 DA-A 1 Atrazine 4 L 2 lb ai/a 2 qt/a POST A 100 a 100 a 2 Atrazine 4 L 2 lb ai/a 2 qt/a POST A 100 a 100 a 3 Atrazine 4 L 2 lb ai/a 2 qt/a POST A 100 a 100 a 4 Atrazine 4 L 2 lb ai/a 2 qt/a POST A 100 a 100 a 5 Atrazine 4 L 2 lb ai/a 2 qt/a POST A 100 a 100 a 6 Direx 80 DF 2.4 lb ai/a 3 lb/a POST A 100 a 100 a 7 Direx 80 DF 2.4 lb ai/a 3 lb/a POST A 100 a 100 a 8 Direx 80 DF 2.4 lb ai/a 3 lb/a POST A 100 a 100 a 9 Direx 80 DF 2.4 lb ai/a 3 lb/a POST A 100 a 100 a 10 Direx 80 DF 2.4 lb ai/a 3 lb/a POST A 100 a 100 a 11 DuPont K4 60 DF 2.4 lb ai/a 4 lb/a POST A 100 a 100 a 12 DuPont K4 60 DF 2.4 lb ai/a 4 lb/a POST A 100 a 100 a 9

10 Trt Treatment Form Form Rate Product Product Grow Appl No. Name Conc Type Rate Unit Rate Rate Unit Stg Code 57 DA-A 57 DA-A 13 DuPont K4 60 DF 2.4 lb ai/a 4 lb/a POST A 100 a 100 a 14 DuPont K4 60 DF 2.4 lb ai/a 4 lb/a POST A 100 a 100 a 15 DuPont K4 60 DF 2.4 lb ai/a 4 lb/a POST A 100 a 100 a 16 Sencor 75 DF 1.5 lb ai/a 2 lb/a POST A 100 a 100 a 17 Sencor 75 DF 1.5 lb ai/a 2 lb/a POST A 100 a 100 a 18 Sencor 75 DF 1.5 lb ai/a 2 lb/a POST A 100 a 100 a 19 Sencor 75 DF 1.5 lb ai/a 2 lb/a POST A 100 a 100 a 20 Sencor 75 DF 1.5 lb ai/a 2 lb/a POST A 100 a 100 a a 100 a a 100 a a 100 a a 100 a 10

11 Trt Treatment Form Form Rate Product Product Grow Appl No. Name Conc Type Rate Unit Rate Rate Unit Stg Code 57 DA-A 57 DA-A 25 Nontreated 0 b 0 b 26 Velpar 75 DF 0.5 lb ai/a 10.7 oz/a POST A 100 a 100 a 27 Valor 50 WP 0.25 lb ai/a 0.5 lb/a POST A 100 a 100 a 28 Spartan 75 DF 0.28 lb ai/a 6 oz/a POST A 100 a 100 a LSD (P=.05) Standard Deviation CV Replicate F Replicate Prob(F) Treatment F Treatment Prob(F)