IMTRADE PRE-EMERGENT HERBICIDE TRIAL · 2018. 1. 29. · 3 1.2 L/ha Triﬂuralin + 1.6 L/ha...

INDEPENDENT AGRONOMY ADVICE + CUTTING EDGE RESEARCH

IMTRADE PRE-EMERGENT HERBICIDE TRIALBeelbangera, 2017

2Ag Grow Agronomy & Research | Imtrade Pre-emergent Herbicide Trial , Beelbangera 2017

BACKGROUNDAnnual ryegrass (Lolium rigidum) is one of the most important weeds competing with our winter crops and has become a major constraint to productive and profitable cropping systems.

Contributing factors to this have been ineffective weed control, caused possibly by poor post-emergent herbicide options due to herbicide resistance; and cropping intensity, as crop rotations have tightened and leaned more towards no-till farming systems, which have relied heavily on herbicides for weed control.

TRIAL DETAILSA trial was established in April 2017 at Beelbangera NSW, 16km NE from Griffith, in conjunction with Imtrade Australia.

It aimed to demonstrate and compare to growers and agronomists the efficacy and crop safety of various pre-emergent herbicides compared to

current standard options.

The paddock chosen for the trial had a known natural infestation of ryegrass. The paddock was sown to canola in 2016. A crop of Scepter wheat was sown on 28th April 2017 at 18 kg/ha, with 80 kg/ha of MAPStar using a John shearer no-till drill, over the treatments within 4 hours of spraying.

The trial in 2017 consisted of 10 treatments, including an untreated control (Table 1). It was set out in a randomised complete block design and treatments were replicated three times, with plot sizes of 11m x 30m (330m2). All treatments also received 1.5 L/ha of Weedmaster Argo.

The herbicide treatments were boom sprayed, using a 6m wide boom mounted onto an ATV, on 28th April at 9:30am. They were applied at 8 km/hr, with a water volume of 80 L/ha.

The environmental conditions at the time of application were temperature 14oC, dew point 9.8oC, relative humidity 75.8% and wind 0.8m/s.

PRE-EMERGENT HERBICIDE TRIAL

KEY POINTS

• Annual ryegrass is a key problem weed in the Western Riverina cropping region.

• Lack of reliable post-emergent herbicide control options for ryegrass mean we are relying on pre-emergent herbicides for control in cereal phases.

• Weed control was effective in all treatments of the trial, with Diablo Duo at 3L/ha providing the same level of control as Sakura®, with 85% control at approximately 56DAS.

• Crop safety is very important as crops generally don’t fully recover from early set backs. Although all treatments had some crop effect early, Boxer Gold® and Diablo Duo 3L/ha had the biggest effect on both crop biomass and phyto-toxicity in this trial.

• Cost effectiveness plays a major role in selecting pre-emergent packages on broadacre farms in the low rainfall zone.

3Ag Grow Agronomy & Research | Imtrade Pre-emergent Herbicide Trial, Beelbangera 2017

Observations and assessments on crop safety and herbicide efficacy were carried out throughout the trial.

These included crop establishment (plant/m2), a visual assessment of crop biomass reduction, crop phyto-toxicity and percent weed control at approximately 28 and 56 days after sowing. A ryegrass panicle count was also undertaken on the trial.

A summary of these measurements are shown in figures 1 to 3 and tables 2 to 3 in the results section.

A visual representation of the treatments are also shown from figures 4 to 13.

Table 1: Treatment and product list for the pre-emergent herbicide trial

Treatment Number

Treatment

1 Untreated Control2 1.8 L/ha Je� Duo3 1.2 L/ha Trifluralin + 1.6 L/ha Triallate4 2.25 L/ha Bolta Duo5 3.0 L/ha Bolta Duo6 2.25 L/ha Diablo Duo7 3.0 L/ha Diablo Duo8 2.0 L/ha Trifluralin9 2.5 L/ha Boxer Gold®10 118 g/ha Sakura®

ProductsJe� Duo 550 g/L Triallate + 350g/L TrifluralinTrifluralin + Tri-allate 480 g/L Trifluralin + 500g/L TriallateBolta Duo 670 g/L Prosulfocarb + 250g/L TrifluralinDiablo Duo 666 g/L Prosulfocarb + 333g/L TriallateTrifluralin 480 g/L TrifluralinBoxer Gold® 800 g/L Prosulfocarb + 120 g/L S-MetolachlorSakura® 860 g/kg Pyroxasulfone


RESULTS AND DISCUSSION The 2017 season was a dry one with 221 mm of rain falling till November, compared to the long term average rainfall of 371mm till November. Growing season rainfall was well below average with only 92mm falling from 1st April to 30th September, compared to a long term average of 201mm.

Frosts throughout August were prolific with temperatures getting as low as -4.7oC on the 20th and -5.2oC on the 28th August in the paddock (data taken from temperature loggers at wheat head height in a semi enclosed plastic drum at Rankins Springs). These frost events were 11 hours and 12 hours in duration, respectively.

The trial was heavily frosted and as such the trial was not harvested.

Emergence:The average plant population of the trial was 38 plants/m2, with plant counts ranging from 26 to 51 plants/m2, (Figure 1).

The Trifluralin and Jetti Duo treatments had the least effect on crop emergence, with plant numbers similar to the UTC. Diablo Duo at the high rate of 3L/ha had the most significant effect on crop

emergence, with an average of 25 plants/m2. All other treatments had a similarly slight effect on emergence with counts around 35 plants/m2.

Biomass Reduction and Crop Phyto-toxicity:Two measurements were taken in this trial. These were percent reduction in biomass and percent phyto-toxicity at approximately 28 and 56 DAS, as shown in tables 2 and 3.

Biomass reduction was a measure of the reduction in biomass compared to the untreated control. The percent phyto-toxicity included the health and colour of the plants as well as any leaf spotting or blotching.

Boxer Gold® and Diablo Duo had the biggest effect on both biomass reduction and crop phyto-toxicity in this trial. However the Diablo Duo plots recovered more rapidly than the Boxer Gold® treated plots. The lighter rate of Diablo Duo had a slightly lower effect. All other treatments caused a slight reduction in biomass, and some crop phyto-toxicity. Treatments that had the least crop effect were Sakura®, Trifluralin and Jetti Duo.

Figure 1: Crop emergence - average plant count (plants/m2) for each treatment taken 31st May, at 5 leaf to early tillering stage.

0

10

20

30

40

50

60

Plan

ts/m

2


Weed Control:Weed control was assessed 28 and 56 DAS, with a ryegrass panicle counts taken at maturity, (Figures 2 and 3). Percent weed control was a measure of the weed control of each treatment in comparison to the untreated control and was taken on 31st May and 12th

July.

A weed count was also taken on the untreated control to provide a base for assessment. The untreated control averaged between 152 and 168 ryegrass plants/m2 respectively for each timing.

Weed control was effective in all the treatments of the trial. This shows that resistance to pre-emergent herbicides is not an issue at this site. However there were some standout treatments in the trial.

Jetti Duo, Trifluralin and Trifluralin + Avadex treatments showed very similar levels of weed control, with the main weed presence being in the seed furrow. Diablo Duo at 3L/ha provided the same level of weed control as Sakura®, with 85% control.

Bolta Duo showed no increase in efficacy by increasing the rate from 2.25L to 3L/ha. It provided the same level of control as 2.5L/ha of Boxer Gold® and Diablo Duo at 2.25L/ha.

Ryegrass panicle counts at maturity also reflected this. The average ryegrass panicle count for the trial was 70 panicles/m2, with counts ranging from 21 panicles/m2 for Sakura® to 213 panicles/m2 for the UTC.

Table 2: Crop Vigour Reduction (%) for each treatment taken 31st May and 12th July 2017

Treatment Crop Vigour

Reduc�on (%) 31st May

Crop Vigour Reduc�on (%)

12th July

Untreated Control 0 0Je� Duo 1.8L/ha 20 0Trifluralin 1.2L/ha + Tri-allate 1.6L/ha 23.33 0Bolta Duo 2.25L/ha 26.67 3.33Bolta Duo 3L/ha 23.33 6.67Diablo Duo 2.25L/ha 20 3.33Diablo Duo 3L/ha 30 0Trifluralin 2L/ha 20 0Boxer Gold 2.5L/ha 30 13.33Sakura 118 g/ha 21.67 1.67

Table 3: Crop Phyto-toxicity (%) for each treatment taken 31st May and 12th July 2017

Treatment Crop

Phyto-toxicity (%) 31st May

Crop Phyto-toxicity (%)

12th JulyUTC 0 0Je� Duo 1.8L/ha 33.33 0Trifluralin 1.2L/ha + Tri-allate 1.6L/ha 23.33 0Bolta Duo 2.25L/ha 30 0Bolta Duo 3L/ha 33.33 0Diablo Duo 2.25L/ha 30 0Diablo Duo 3L/ha 40 0Trifluralin 2L/ha 23.33 0Boxer Gold 2.5L/ha 38.33 0Sakura 118 g/ha 18.33 0


0102030405060708090

100

Wee

d Co

ntro

l (%

)

Weed Control (%) 31.05.2017 Weed Control (%) 12.07.2017

Figure 2: Percent Weed Control for each treatment taken 31st May and 12th July 2017

Figure 3: Ryegrass panicle count for each treatment taken 17th October, 2017

0

50

100

150

200

250

Ryeg

rass

Pan

icle

s/m

2


Figure 4: Treatment 1 - Untreated Control - June (left) and October (right)

Figure 5: Treatment 2 - 1.8 L/ha Jetti Duo

Figure 6: Treatment 3 - 1.2 L/ha Trifluralin + 1.6 L/ha Triallate


Figure 7: Treatment 4 - 2.25 L/ha Bolta Duo

Figure 8: Treatment 5 - 3.0 L/ha Bolta Duo

Figure 9: Treatment 6 - 2.25 L/ha Diablo Duo


Figure 10: Treatment 7 - 3.0 L/ha Diablo Duo

Figure 11: Treatment 8 - 2.0 L/ha Trifluralin

Figure 12: Treatment 9 - 2.5 L/ha Boxer Gold®


ACKNOWLEDGEMENTSThis trial was a collaboration between Ag Grow Agronomy and Research and Imtrade Australia.

Further contacts

Albert Gorman Ag Grow Agronomist [email protected]

Rachael Whitworth Ag Grow Research Manager [email protected]

Michael Macpherson National Technical Manager [email protected]

Peter Knight NSW Sales Manager [email protected]

Figure 13: Treatment 10 - 118 g/ha Sakura®

IMTRADE PRE-EMERGENT HERBICIDE TRIAL · 2018. 1. 29. · 3 1.2 L/ha Triﬂuralin + 1.6 L/ha...

Documents

Transcript of IMTRADE PRE-EMERGENT HERBICIDE TRIAL · 2018. 1. 29. · 3 1.2 L/ha Triﬂuralin + 1.6 L/ha...