EVALUATION OF A SINGLE AUTUMN SPRAY OF TASKFORCE (flupropanate) HERBICIDE FOR CONTROLLING KANGAROO GRASS IN MARLBOROUGH

Transcription

1 EVALUATION OF A SINGLE AUTUMN SPRAY OF TASKFORCE (flupropanate) HERBICIDE FOR CONTROLLING KANGAROO GRASS IN MARLBOROUGH Ward, Marlborough, NEW ZEALAND 2011 Study Reference: Submitted to: Client Contact: Submitted by: Project Manager: Project Biologist: Marlborough District Council Ben Minehan Ben.Minehan@marlborough.govt.nz Agrivet Services Ltd P.O. Box St Georges Road Havelock North, 4157 New Zealand Andre Geelen, B.Sc andre@agrivet.co.nz Sean Lange Date: 05 January 2012

2 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 2 of 19 - CONTENTS - Page Number 1. SIGNATURE PAGE 3 2. SUMMARY 4 3. EXPERIMENTAL DETAILS Site Details Trial Design Target Weed Non-Target Weeds Product Identification Treatment List Application Details Treatment Method Assessments Statistical Analysis RESULTS AND DISCUSSION Pasture composition Kangaroo grass Common Needle grass Other grasses Broadleaf weeds Pasture Vigour TASKFORCE Leaching Formulation Comments CONCLUSIONS APPENDICES Trial Location Rainfall Data Soil Analysis Results Photographs... 18

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4 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 4 of SUMMARY A small scale non-replicated trial was conducted to evaluate a single autumn application of TASKFORCE herbicide for the control of Kangaroo grass (Themeda triandra). This study was conducted in the Ward area of Marlborough, New Zealand over the 2011 period. The following treatments were evaluated: Treatment Active Ingredient Formulation Product Rate per hectare Water Rate per Hectare 1. UNTREATED TASKFORCE 745 g/l flupropanate WSL 2.0 L 200 L 3. TASKFORCE 745 g/l flupropanate WSL 3.0 L 200 L 4. +PULSE PENETRANT 360 g/l glyphosate 800 g/litre organo-silicone modified polydimethysiloxane EC EC 0.2% 200 L 5. TASKFORCE 745 g/l flupropanate WSL 2.0 L 1000 L 6. TASKFORCE 745 g/l flupropanate WSL 3.0 L 1000 L 7. +PULSE PENETRANT 360 g/l glyphosate 800 g/litre organo-silicone modified polydimethysiloxane EC EC 0.2 % No spreader, sticker or other adjuvant was added to any of the TASKFORCE treatments L TASKFORCE at 2.0 L per hectare applied in a boom in 200 Litres per hectare, or as a single nozzle spray in 1,000 Litres, resulted in some knockdown of Kangaroo grass being evident after six months, but only 30-40% reduction after 10 months. Increasing the rate of TASKFORCE to 3.0 L per hectare, applied by boom or by single nozzle, resulted in 99% Kangaroo grass control, with only one new seedling plant being seen. There was no obvious differences between the two water rates in terms of Kangaroo grass control with TASKFORCE. at 6 Litres per hectare + Pulse had no effect on new Kangaroo grass seedlings so that by trial termination both plots were almost entirely covered with Kangaroo grass. Other grasses, namely Danthonia, Cocksfoot and Prairie grass, became established in TASKFORCE-treated plots, while they were absent in plots. Eradication of Kangaroo grass in the TASKFORCE-treated plots resulted in much higher levels of broadleaf weeds compared to and the Untreated control.

5 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 5 of EXPERIMENTAL DETAILS 3.1 Site Details Grower Location Crop Composition Soil Type Soil Profile Troqueer Farm, D.Roberts Kaka Rd, Ward, Marlborough Pasture Almost 100% Kangaroo Grass Awatere clay ph = 5.8 (medium range is ) CEC value = 13 (medium range is 12-25) Organic Matter = 3.9% (medium range is 7-17%) 3.2 Trial Design Design Non-replicated split plot design Replicates One Plot Size 15 m long by 4.0 m wide (60 m area) 3.3 Target Weed Kangaroo grass (Themeda triandra) 3.4 Non-Target Weeds Common Needle grass (Stipa nodosa) Prairie grass (Bromus willdenowii) Danthonia (Danthonia spp) Cocksfoot (Dactylis glomerata) Hawksbeard (Crepis capillaris) Centaury (Centaurium erythraea) Plaintain (Plantago spp) 3.5 Product Identification Product Name TASKFORCE Lot/Batch # 26520/2 Date of Manufacture March 2006 Active Constituent and Concentration Nominal Concentration g/l flupropanate (as sodium salt) Type of Formulation Water soluble liquid

6 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 6 of Treatment List Treatment Active Ingredient Formulation Product Rate Water Rate Per Hectare Plots 1. UNTREATED TASKFORCE 745 g/l flupropanate WSL 2.0 L / ha 200 L 2 3. TASKFORCE 745 g/l flupropanate WSL 3.0 L / ha 200 L PULSE PENETRANT 360 g/l glyphosate 800 g/litre organo-silicone modified polydimethysiloxane EC EC / ha 200 ml/100 L 200 L 6 5. TASKFORCE 745 g/l flupropanate WSL 2.0 L / ha 1000 L 3 6. TASKFORCE 745 g/l flupropanate WSL 3.0 L / ha 1000 L PULSE PENETRANT 360 g/l glyphosate 800 g/litre organo-silicone modified polydimethysiloxane EC EC / ha 200 ml/100 L No spreader, sticker or other adjuvant was added to any of the TASKFORCE treatments L Application Details APPLICATION 1 Date 08-February-2011 Pasture growth stage Kangaroo grass small seedling to seeding plants Common needle grass small seedling to seeding plants Water / plot TRT s L; TRT s 5-7 Water / ha TRT s L; TRT s L Wind speed 1-3 km/hr Wind direction NW Off target spray drift Very slight Temperature o C Relative humidity % Drying time minutes Cloud cover 100 % Crop surface Damp (early morning dew + rain from previous day) Accumulated rainfall (mm) - 24 hrs hrs hrs week weeks Treatment Method Trial Type Boom Application ( 200 L/ha) Single nozzle Application (1,000 L/ha) Treatments Applied: 2, 3,4 5, 6, 7 Equipment: Motorised knapsack sprayer Manual knapsack pump-up sprayer Method: Broadcast Dilute spraying Nozzles: Four AI air induction flat fan Single 8006 flat fan

7 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 7 of 19 Pressure: 420 kpa Approx. 400 kpa Sprayer Output: 3.77 L per minute 1.68 L per minute 3.9 Assessments Pasture Composition - Just prior to application the total area covered with the weed and main pasture species were assessed and this was repeated at one month, six months and 10 months after spraying. The percentage of individual grass species in each plot was also assessed. Weed Control - Overall grass knockdown was evaluated on a 0-10 scale (where 0 = no control) at 1, 6 and 10 months after application Statistical Analysis This was a non-replicated trial and so no statistical analyses carried out. 4. RESULTS AND DISCUSSION Results are summarised in Table 4.1 to Table Pasture composition Table 4.1: Effect on pasture composition at time of spraying (08-Feb-11) and trial termination (04-Dec-11) Treatment Rate per hectare Area in herbage (%) Pre-Trt (08- Feb-11) 10 Months (04-Dec- 11) Broadleaf weed area (%) Pre-Trt 10 (08-Feb- Months 11) (04-Dec- Bare ground area (%) Pre-Trt (08-Feb- 11) 10 Months (04-Dec- 11) 11) UNTREATED < Boom application (200 L/ha) TASKFORCE 2.0 L < TASKFORCE 3.0 L < < Single nozzle application (1,000 L/ha) TASKFORCE 2.0 L < TASKFORCE 3.0 L < < At the start of the trial all plots were completely covered with herbage, primarily Kangaroo grass, as well as some Chilean needle grass (see below). Only the very occasional broadleaf weed was seen. When the trial was terminated 10 months later the scene had changed dramatically. Untreated plots were very obvious with extensive Kangaroo grass present. Plots sprayed with were also virtually completely covered with herbage and had only 2-5%

8 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 8 of 19 bare ground. Plots sprayed with TASKFORCE at 2.0 L/ha had 2-10% bare ground, whereas where the 3.0 L/ha rate was applied 20-30% of the ground was bare and 40-50% of the area was covered in broadleaf weeds. 4.2 Kangaroo grass Table 4.2: Effect on established Kangaroo grass over 10 months trial duration. Treatment Area plot covered with established Kangaroo grass (%) Rate Pre-Trt 1 Month 6 Months 10 Months per hectare (08-Feb-11) (08-Mar-11) (22-Aug-11) (04-Dec-11) UNTREATED Boom application (200 L/ha) TASKFORCE 2.0 L TASKFORCE 3.0 L Single nozzle application (1,000 L/ha) TASKFORCE 2.0 L TASKFORCE 3.0 L When the trial commenced the hillside was almost entirely covered with Kangaroo grass, with all treatments having 75-85% of the plot covered. After one month the situation only slightly with most plots having more Kangaroo grass present. At three months both treatments showed significant knockdown, whereas no damage was yet seen with TASKFORCE. A further assessment in late August still showed high levels of Kangaroo grass in the TASKFORCE treatments with only just the hint that control was starting to occur with plants looking weak and some deadening of the outer leaves. In the treatments the grass had bounced back and looked healthy. The slow acting nature of TASKFORCE was apparent at the 10 month assessment with obvious weed control having occurred. This was particularly noticeable with the 3.0 L/ha rate where 99% control was obtained. At 2.0 L/ha TASKFORCE was less effective with 30-40% of the plot still covered. Although appeared to have worked well, in fact the death of established plants had been replaced with new seedlings (see Table 4.3), so that the overall effect was a plot entirely covered with Kangaroo grass. also has the distinct disadvantage of killing out most other plants, both the good and bad. There was also a noticeable difference between the two application spray volumes, with the more concentrated (200 L/ha) giving better control than where the single nozzle knapsack sprayer was used, delivering 1,000 Litres per hectare. This was most evident in the above table with, while on seedling re-growth it was more evident with TASKFORCE.

9 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 9 of 19 Table 4.3: Effect on Kangaroo seedlings and total Kangaroo grass during trial duration. Treatment Area with Kangaroo grass seedlings (%) Rate Pre-Trt 10 Months per hectare (08-Feb-11) (04-Dec-11) UNTREATED Boom application (200 L/ha) TASKFORCE 2.0 L 0 10 TASKFORCE 3.0 L (1 plant) 0 60 Single nozzle application (1,000 L/ha) TASKFORCE 2.0 L 0 20 TASKFORCE 3.0 L No seedling kangaroo grass was present when the trial started, but by 10 months later seedlings were readily found in the treatments and to a lesser extent where TASKFORCE was applied at 2.0 L/ha. By sharp contrast TASKFORCE at 3.0 L/ha gave complete suppression of seedlings in the 1,000 L water rate and only one seedling was seen in the entire plot where the 200 L/ha water rate was used. Table 4.4: Effect on total Kangaroo grass levels. Treatment Rate per hectare Area with Kangaroo grass (%) Reduction in Kangaroo grass (%) Pre-Trt (08-Feb-11) 10 Months (04-Dec-11) UNTREATED Boom application (200 L/ha) TASKFORCE 2.0 L TASKFORCE 3.0 L Months (04-Dec-11) Single nozzle application (1,000 L/ha) TASKFORCE 2.0 L TASKFORCE 3.0 L The area covered in established and seedling Kangaroo grass at the conclusion of the trial clearly demonstrated the effectiveness of TASKFORCE at 3.0 L/ha, with almost complete control being obtained. Applied at the 2.0 L rate it was far less effective with a reduction of only around 30-40%. As has been shown by farmers themselves alone gave initial knockdown only and no reduction in Kangaroo grass one year later.

10 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 10 of Common Needle grass Table 4.5: Effect on established Common needle grass over 10 months trial duration. Treatment Area plot covered with established Common needle grass (%) Rate Pre-Trt 1 Month 6 Months 10 Months per hectare (08-Feb-11) (08-Mar-11) (22-Aug-11) (04-Dec-11) UNTREATED Boom application (200 L/ha) TASKFORCE 2.0 L TASKFORCE 3.0 L Single nozzle application (1,000 L/ha) TASKFORCE 2.0 L TASKFORCE 3.0 L Prior to spraying all plots had 15-25% Common Needle grass present, but by on month this seemed to have been dramatically reduced in all treatments, including the untreated control. This was most likely due to increase in Kangaroos grass growth and the difficulty in separating the two species, which can be quite difficult in the absence of seed heads. After 10 months, when both species were in seed, the amount of Common needle grass was very low in the Untreated control. None was seen in any of the sprayed plots. 4.4 Other grasses Table 4.6: Effect on other grasses over 10 months trial duration. Treatment Area plot covered with other live grasses (%) Rate Pre-Trt 1 Month 6 Months 10 Months per hectare (08-Feb-11) (08-Mar-11) (22-Aug-11) (04-Dec-11) UNTREATED Boom application (200 L/ha) TASKFORCE 2.0 L TASKFORCE 3.0 L Single nozzle application (1,000 L/ha) TASKFORCE 2.0 L TASKFORCE 3.0 L Some other grasses were also present, becoming more apparent as winter rainfall enabled them to become established. These included Danthonia along with some Cocksfoot and

11 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 11 of 19 Prairie grass. These gradually became more frequent in the TASKFORCE treated plots, while they were absent where was applied. 4.5 Broadleaf weeds Table 4.7: Effect on broadleaf weeds over 10 months trial duration. Treatment Area plot covered with Broadleaf weeds (%) Rate Pre-Trt 1 Month 6 Months 10 Months per hectare (08-Feb-11) (08-Mar-11) (22-Aug-11) (04-Dec-11) UNTREATED - < Boom application (200 L/ha) TASKFORCE 2.0 L < TASKFORCE 3.0 L < < Single nozzle application (1,000 L/ha) TASKFORCE 2.0 L < TASKFORCE 3.0 L < < Prior to spraying only the very occasional broadleaf weed (Hawksbeard, Plantain) were found. At the six month assessment broadleaf weeds were more common in the four TASKFORCE treated plots, although levels were still quite low. There was also more bare ground as control of Kangaroo grass occurred. When the trial was terminated the area covered in broadleaf weeds was very noticeable in TASKFORCE-treated plots. Centaury had become more readily apparent as well as the other weeds. Broadleaf weeds were also more common in the plot sprayed at 200 L/ha, a reflection of the much better control of established Kangaroo grass, although seedling Kangaroo grass levels were high. 4.6 Pasture Vigour None of the treatments showed any adverse effect on pasture vigour compared to the untreated control areas surrounding the trial. 4.7 TASKFORCE Leaching The trial block was located on a very steep north-facing slope and there was no evidence of TASKFORCE leaching down through the plots, even where it was applied at 3.0 L/ha in 1,000 litres of water. A line could be drawn where a sprayed plot met an adjacent plot with no obvious downhill movement of the product at all (see photos). 4.8 Formulation Comments TASKFORCE was easily mixed into solution and no issues arose with cleaning of the rinsate with either means of application.

12 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 12 of CONCLUSIONS A single autumn spray of TASKFORCE at 2.0 L per hectare applied in a boom in 200 Litres, or as a single nozzle spray in 1,000 Litres, resulted in 30-40% reduction in Kangaroo grass after 10 months. The slow working nature of this herbicide was evident as little obvious effect until six months after spraying. Increasing the rate of TASKFORCE to 3.0 L per hectare, by boom or by single nozzle, resulted in 99% Kangaroo grass control and only one new seedling plant being seen. at 6 Litres pr hectare + Pulse worked well initially, but had no effect on new seedlings so that by trial termination each of the Roundup-treated plots was almost entirely covered with Kangaroo grass. Spring rainfall resulted in other grasses, namely Danthonia, Cocksfoot and Prairie grass, to become established in TASKFORCE-treated plots, while they were absent in plots. At trial termination the eradication of Kangaroo grass in the TASKFORCE-treated plots resulted in much higher levels of broadleaf weeds compared to and the Untreated control.

13 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 13 of APPENDICES 6.1 Trial Location

14 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 14 of 19 General location of trial Close-up of trial location WSG84: 41 48'26.40"S; 174 7'4.78"E

15 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 15 of Rainfall Data Name Agent Network Latitude Number Number (dec.deg) Longitude (dec.deg) Height (m) Position Observing Precision Authority Awatere Valley, Dashwood Ews G H N/A Event Date WSpd (km/hr) Rain (mm) Tdry (C) TWet (C) RH (%) Tmax (C) Tmin (C) 01-Feb Feb Feb Feb Feb Feb Feb Application 08-Feb Feb Feb Feb Feb Feb Feb Feb Feb Feb Feb Feb Feb Feb Feb Feb Feb Feb Feb Feb Feb Mar Mar Mar Mar Mar Mar Mar Mar Mar Mar Mar

16 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 16 of 19 Event Date WSpd (km/hr) Rain (mm) Tdry (C) TWet (C) RH (%) Tmax (C) Tmin (C) 12-Mar Mar Mar Mar Mar Mar Mar Mar Mar Mar Mar Mar Mar Mar Mar Mar Mar Mar Mar Mar Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr

17 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 17 of Soil Analysis Results

18 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 18 of Photographs Photo 1 - General view of trial site Photo 2 - Crop growth stage at treatment application (08-Feb-11) Photo 3 Established Kangaroo grass at treatment application (08-Feb-11) Photo 4 - Kangaroo grass seeding at treatment application (08-Feb-11) Photo 5 Untreated control at trial termination (04-Dec-11) Photo 6 Taskforce at 2 L/ha in 200 L water at trial termination (04-Dec-11)

19 Agrivet Services Ltd Kangaroo grass / Marlborough Final Report Page 19 of 19 Photo 7 Taskforce at 3 L/ha in 200 L water at trial termination (04-Dec-11) Photo 8 Taskforce at 2 L/ha in1000 L water (04-Dec-11) Photo 9 Taskforce at 3 L/ha in1000 L water at trial termination (04-Dec-11) Photo 10 Roundup at 6 L/ha + Pulse in1000 L water at trial termination (04-Dec-11) Photo 11 Taskforce at 3 L/ha above and Roundup at 6 L/ha + Pulse below at trial termination (04-Dec-11) Photo 12 Untreated control at trial termination (04-Dec-11)