Vegetable Production Guide

Asparagus
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Table 1 Asparagus Weed Control

This section was updated - 29 May 2017
Table 1. Asparagus Weed Control

Product

Rate

PHI*

Comments

Seed-bed Asparagus

Ignite 15 SN

(glufosinate ammonium)

Group 10

2.7 to 5.0 L/ha (1.1 to 2.0 L/acre)

Apply in 110 to 330 L water/ha (45 to 135 L/acre) at 275 to 310 kPa
N/A
  • As recommended under the section on Stale Seed-bed Technique (Pest Management Section, this guide), may be used prior to asparagus seedling emergence to kill the first flush of weeds in nursery beds.
  • Rainfall within 4 hours of application may reduce effectiveness.
  • Do not handle with bare hands or with leather or cloth gloves.
  • Do not enter treated area for 12 hours.

Sinbar
 

(80% terbacil)

Group 5

375 g/ha (152 g/acre)

Apply in at least 200 L/ha (80 L/acre) of water
N/A
  • Apply within 2 days of planting seed.
  • Do not apply within 2 weeks before or after an application of Venture.
  • Do not apply to soils containing less than 1% organic matter.
  • Crop injury may occur if applied on weak or diseased plants.
  • See label for planting depth instructions based on soil texture.
  • Do not enter treated area for 12 hours.

Venture L

(fluazifop-P-butyl)

Group 1

0.8 to 2.0 L/ha (320 to 800 mL/acre)

Apply in 50 to 200 L/ha (20 to 80 L/acre) of water at 200 to 300 kPa
N/A
  • For control of most annual grasses, use 0.8 to 1.4 L/ha (320 to 550 mL/acre) when weeds are at the 2 to 5 leaf stage.
  • Annual bluegrass and broadleaved weeds are not controlled.
  • Also registered for use during production years (see label for more detail).
  • For seasonal quackgrass control, use 2.0 L/ha (800 mL/acre) when grass is at the 3- 5 leaf stage.
  • Do not make more than 1 application per year.
  • Warning: Women capable of bearing children should avoid exposure to Venture.

Guardsman/ Agricultural Weedkiller

No. 1 (mineral spirits)

500 L/ha
(200 L/acre)
N/A
  • Apply when asparagus seedlings are 5 cm high and weeds have 3 to 4 true leaves.
  • Controls chickweed, bluegrasses, barnyard grass, redroot pigweed, lamb’s quarter and purslane.
  • Pineappleweed and wormseed mustard are not controlled consistently.
  • Crop damage may result if sprays are applied in hot, dry weather, or when plants are wet with rain or dew.
  • Note: Other solvents may cause crop damage.
  • See label for use in the producing field.

Lorox L

(linuron)

Group 7

 

PLUS:

Gramoxone

(paraquat)

Group 22

2.08 to 4.17 L/ha (0.84  to 1.69 L/acre)

 

 

PLUS:

2.5 L/ha (1.0 L/acre)

N/A
  • Make a single application. pre-emergence of asparagus seedlings.
  • Do not use on coarse-textured soils with less than 2% organic matter.
  • Requires 3 to 5 cm of irrigation or rainfall within 7 days of application.
  • Will not control atrazine resistant weeds.
  • RESTRICTED:  Gramoxone can only be used by individuals holding a pesticide applicator's certificate.
  • Note:  Registration of Gramoxone Liquid Herbicide With Wetting Agent (#8661) expires December 31, 2018.

Sandea

(halosulfuron)

Group 2

35 to 105 g/ha (14.2 to 42.5 g/acre)

Apply in 140 L/ha (57 L/acre)
N/A
  • Use post-emergence.
  • To prevent crop injury, do not use with an adjuvant.
  • Controls broadleaf weeds including ladysthumb, wild mustard, yellow nutsedge and redroot pigweed.
  • Suppresses shepherd's purse and smartweed.
  • Will not control ALS-inhibitor resistant weeds.
  • Applications should be made to actively growing weeds at the heights defined in the "USE RATE GUIDE" section of the label.
  • Treat actively growing nutsedge plants at the 3 to 5 leaf stage.
  • Do not use more than 140 g/ha (57 g/acre) of product per season.
  • Do not apply more than two times per season.
  • Wait to overhead sprinkler irrigate for 2 to 3 days after application
  • If a timely soil cultivation is necessary to improve control, wait 7 to 10 days after treatment.
  • A sequential application may be necessary for some annual and perennial weeds.
  • Sequential application should be repeated in 21 days.
  • Do not enter treated area for 12 hours.

1st Year Crowns and New Plantings

Devrinol 50-DF

(napropamide)

4.5 to 9.0 kg/ha (1.8 to 3.6 kg/acre) N/A
  • Apply pre-emergent to crop and weeds for control of annual grassy and broadleaved weeds.
  • See label for weeds and rates.
  • Apply in 200 to 900 L/ha (80 to 365 L/acre) of water.
  • Make only one application per season.
  • Irrigate if rainfall does not occur within two days of application.
  • Use the lower rate on coarse-textured sandy and sandy-loam soils.
  • Do no use on soils with more than 10% organic matter.
  • There is a 12 month plant back restriction on crops not found on the label.
  • Do not enter treated area for 12 hours.
  • Goup 15 insecticides.

Devrinol 2-XT

(napropamide)

9.38 to 18.75 L/ha (3.80 to 7.60 L/acre)

Sandea

(halosulfuron)

Group 2

35 to 105 g/ha (14.2 to 42.5 g/acre)

Apply in 140 L/ha (57 L/acre)
1
  • Use post-emergence/post transplant.
  • For first year transplants, apply no sooner than six weeks after fern emergence.
  • See comments in "Seed-bed Asparagus" section of this table.

2nd Year and Established Plantings Before Spear Emergence or After Last Cutting

Linuron 400L

(linuron)

Group 7

4.25 to 5.5 L/ha (1.7 to 2.2 L/acre) N/A
  • Rates depend on soil type, check label.
  • Make a single application immediately after 1st discing, before asparagus emerges.
  • Do not apply on coarse textured soils with less than 2% organic matter.
  • Sufficient moisture by rain or irrigation within 7 to 10 days is needed for good control.

Lorox L

(linuron)

Group 7

3.4 to 4.5 L/ha (1.4 to 1.8 L/acre)

Apply in 300 L/ha (120 L/acre) of water
N/A
  • Make a single application immediately after 1st discing, before asparagus emerges.
  • Do not use on coarse-textured soils with less than 2% organic matter.
  • Requires 3 to 5 cm of irrigation or rainfall within 7 days of application.
  • Treatment may be repeated after the last cutting.
  • Will not control atrazine resistant weeds.
  • Can also be used for 1st year crowns.
  • For use on seedling asparagus, see Seedbed Asparagus section of this table for details on rate and tankmix directions.

Roundup Ultra

(glyphosate)

0.83 to 1.67 L/ha
(330 to 680 mL/acre)
7
  • Fall-seeded rye grass can be ‘burned’ down in the spring before fertilizer is applied.
  • Apply in spring before emergence of crop shoots.
  • Do not make more than 1 application per year.
  • Do not enter treated area within 12 hours of application.
  • Group 9 herbicide.

Roundup WeatherMax

(glyphosate)

Credit 45

(glyphosate)

1.0 to 2.0 L/ha
(400 to 800 mL/acre)

Bonanza 480

(trifluralin)

Group 3

2.1 to 4.2 L/ha (0.8 to 1.7 L/acre)

Apply in at least 100 L/ha (40 L/acre) water
N/A
  • Rates depend on soil type, see label for more detail.
  • For control of germinating annual grasses, lamb’s-quarters, chickweed and redroot pigweed.
  • Use only on established plantings of 3 years or older.
  • Do not use on soils with less than 2% or more than 15% organic matter.
  • Do not apply to wet soils that may flood.
  • Incorporate within 24 hours application, in the same direction of application at a depth of 8 to 10 cm.
  • If manure is spread prior to application, ensure it has been thoroughly mixed into soil with at least 2 tillage operations prior to application.
  • Do not enter treated area for 12 hours.

Chateau

(flumioxazin)

Group 14

Coarse-textured soils: 280 g/ha (115 g/acre)

Medium-textured soils: 420 g/ha (170 g/acre)
N/A
  • Apply prior to weed emergence.
  • Apply only to dormant asparagus established for at least one year.
  • Apply once per growing season.
  • Do not apply on soils with >5% organic matter.
  • Do not apply to fine-textured soils.
  • To prevent crop injury, ensure an irrigation or rain event occurs between applicaton and spear emergence.
  • Controls redroot pigweed, lamb’s quarters, hairy nightshade, dandelion and black nightshade.

Authority 480

(sulfentrazone)

Group 14

0.292 L/ha (0.118 L/acre)

Apply in 100 to 400 L/ha (40 to 160 L/acre) of water at 175 kPa

14
  • Apply as a broadcast treatment in the spring before the crop and weeds emerge.
  • Authority 480 requires adequate rainfall or irrigation to activate.
  • A shallow incorporation may be necessary if irrigation is not available or if rainfall has not provided activation.
  • Do not use on coarse-textured soils classified as sand that have less than 1% organic matter.
  • Do not use on fine-textured soils with less than 1.5% organic matter.
  • Do not apply on soils with an organic matter content greater than 6%.
  • Do not use on soils with a pH of 7.8 or greater.
  • Do not enter treated area for 12 hours.
  • Observe a plantback interval of 24 months for sweet corn and 16 months for winter wheat.
  • Controls redroot pigweed, lamb's quarters, Eastern black nightshade and common groundsel.

Sencor 75 DF

(metribuzin)

1.5 kg/ha (0.6 kg/acre)

Apply in 100 to 300 L/ha (40 to 120 L/acre) of water at 150 to 275 kPa
14
  • Apply in early spring before spears emerge and/or following last cutting.
  • If the field is to be disced, apply after discing but before crop emerges.
  • Do not use on coarse soils with less than 2% organic matter.
  • Do not use on newly seeded asparagus nor on young plants during the first growing season after setting crowns.
  • Do not apply once crop has emerged.
  • Controls many annual grassy and broadleaved weeds.
  • Do not enter treated area for 12 hours.

Sencor Solupak 75 DF

(metribuzin)

Group 5

Simazine 480

(simazine)

Group 5

4.7 to 7 L/ha (1.9 to 2.8 L/acre)

Apply in 300 L/ha (120 L/acre) of water.
7
  • Apply in spring to established fields after discing, but prior to weed and spear emergence, at least 7 days before first cutting.
  • A 2nd application may be made after harvest completion if weeds are removed. In arid regions where Simazine would break down very slowly in the soil (especially under non-irrigated conditions), only one application per year is advised.

Princep Nine-T

(simazine)

Group 5

2.5 to 3.75 kg/ha (1.0 to 1.5 kg/acre)

Apply in 300 L/ha (120 L/acre) of water at 200 to 300 kPa.
  • Use the lower rates on sandy or silt loams; the higher rates on silty-clay to clay loams.
  • Rainfall or irrigation is necessary to activate simazine.
  • Do not apply during cutting season.
  • Resistant populations of redroot pigweed, lamb’s-quarters, groundsel and other weeds may develop from the continuous use of simazine over several years.
  • Do not enter treated area for 12 hours.
Poast Ultra plus Merge at the following rates:    
  Poast Ultra Merge
Annual grasses (incl volunteer cereals) 320 mL/ha (130mL/ac) 0.5-1.0L/ha (0.2-0.4L/ac)
Annual grasses & quackgrass suppression 470 mL/ha (190mL/ac) 0.5 - 1.0L/ha (0.2-0.4L/ac)
Quackgrass 1.1L/ha (445mL/ac) 1.0 - 2.0L/ha (0.4-0.8L/ac)
40
  • Annual bluegrass is not controlled.
  • Apply when annual weeds are in the 1 to 6 leaf stage and quackgrass is in the 1 to 3 leaf stage.
  • Spray pressure varies with water volume see label for details.
  • Group 1 herbicide.
  • Do not enter treated area for 12 hours.
  • There is a 30 day plant back restriction on crops not found on the label.
  • Apply in 50 to 200 L/ha (20 to 80 L/acre) of water.

Devrinol 50 DF

 

(napropamide)

Group 15

Tank mixed with:

 

Princep Nine-T

(simazine)

Group 5

9.0 to 13.4 kg/ha (3.6 to 5.4 kg/acre)




Plus


1.5 to 2.75 kg/ha (0.6 to 1.1 kg/acre)

6
  • Apply in spring to established fields prior to spear emergence.
  • Make only one application per season.
  • Do not apply to soils with more than 10% organic matter
  • Apply in 150 to 300 L/ha (60 to 120 L/acre) of water.
  • There is a 12 month plant back restriction on crops not found on the label.

Devrinol 2-XT

 

(napropamide)

Group 15

Tank mixed with:

 

Princep Nine-T

(simazine)

Group 5

18.75 to 27.92 L/ha (7.59 to 11.30 L/acre)




Plus


1.5 to 2.75 kg/ha (0.6 to 1.1 kg/acre)

Karmex DF

(diuron)


Diurex 80 WDG

(diuron)

Group 7

1.1 to 2.25 kg/ha (0.4 to 0.9 kg/acre) in light sandy or low clay and organic matter soils

OR

2.25 to 4.50 kg/ha (0.9 to 1.8 kg/acre) in soils high in clay or organic matter
N/A
  • Controls weed seedlings for pigweed, lamb’s quarter, crabgrass, foxtail and ragweed.
  • Apply to established asparagus only, no earlier than 4 weeks before spear emergence and no later than the early cutting period.
  • Apply in 250 to 400 L/ha (100 to 160 L/acre) of water.
  • Requires rainfall or irrigation to be carried into the root zone of germinating weeds.
  • If irrigation is used, apply only once at 4.5 kg/ha (1.8 kg/acre) in late September or October.
  • A second application may be made immediately following completion of harvest, if rainfall is expected.
  • When making two applications in one season do not exceed 3.25 kg/ha (1.3 kg/acre) per application.
  • Do not apply on sandy, loamy sandy or gravelly soils with less than 1% organic matter.
  • Do not enter treated area for 12 hours.

Sinbar

(terbacil)

Group 5

375 g/ha (152 g/acre)

Apply in at least 200 L/ha (80L/acre) of water
5
  • Use prior to spear emergence for annual grassy and broadleaved weed control.
  • Application may be made immediately after clean cutting.
  • Apply before annual weeds emerge or grow more than 5 cm tall or across.
  • Apply only once per season.
  • Do not use on soils containing less than 1% organic matter or on areas where subsoil or roots are exposed.
  • Crop injury may occur if used on weak, diseased or slow-growing plants.
  • Use only on estabilished platings of 3 years or older.
  • Do not enter treated area for 12 hours.
  • Do not plant treated areas to any crop within 2 years of the last application.

MCPA Amine 500

(MCPA)

Group 4

3.75 L/ha (1.5 L/acre)

Apply in 50 to 200 L/ha (20 to 80 L/acre) of water at 200 to 350 kPa
N/A
  • Application should be made following a cultivation just before first spears appear.
  • Controls most annual broadleaf weeds, and set back field bindweed, Canada thistle and perennial sow thistle.
  • Weeds are most sensitive when they are rapidly growing.
  • A second application may be made immediately after the cutting season at least 21 days after first application.
  • Do not enter treated area for 12 hours.
  • Use drop nozzles to avoid spraying the fern.

Dual II Magnum

(S-metachlor)

Group 15

1.55 to 1.75 L/ha (0.65 to 0.7 L/acre)

Apply in at least 150 L/ha (60L/acre) of water at 200 to 300 kPa
16
  • Controls nightshade, barnyard grass, foxtail & suppresses redroot pigweed.
  • In the spring, apply to dormant asparagus beds prior to spear emergence or post-harvest.
  • When using post-harvest, apply after the last cut and before fern regrowth occurs.
  • Do not tank mix with fluid fertilizers, oils, oil concentrates or surfactants.
  • Rain is required within 10 days of application, or a shallow cultivation.
  • Do not apply to soils with less than 1% or more than 10% organic matter.
  • Make only one application per year.
  • Do not enter treated areas for 12 hours.

Gramoxone

(paraquat)


Group 22

Note:  Registration expires December 31, 2018.

2.75 to 5.5 L/ha (1.1 to 2.2 L/acre)

Apply in 300 to 1100 L/ha (120 to 445 L/acre) of water
N/A
  • Apply prior to and/or immediately after harvest to control emerged seedling weeds and grasses in established asparagus.
  • Do not apply to emerged spears which are to be used for human consumption.
  • Will provide contact control only.
  • The higher rate is recommended when weeds are over 5 cm tall.
  • Do not spray the asparagus fern.
  • RESTRICTED:  can only be used by individuals holding a pesticide applicator's certificate.
  • Do not enter treated areas within 24 hours of application.

 Callisto

(mesotrione)

Group 27

300 mL/ha (120 mL/acre)

Apply in 100 to 200 L/ha (40 to 80 L/acre) of water at 206 to 300 kPa

N/A
  • Controls lamb's quarters, redroot pigweed and wild mustard.
  • Apply after fern mowing, disking, or other tillage operation but prior to spear emergence.
  • Can be applied by broadcast or banded application.
  • For banded application, the application must be made to account for band width to deliver the desired rate per hectare.
  • Do not apply more than once per season.
  • If weeds are emerged, use with Agral 90 (0.2% v/v).
  • Do not enter treated area for 12 hours.

Sandea

(halosulfuron)

Group 2

35 to 105 g/ha (14.2 to 42.5 g/acre)

Apply in 140 L/ha (57 L/acre)
1
  • May be applied post-emergence to the weeds before or during the harvesting season.
  • See comments in "Seed-bed Asparagus" section of this table for post-emergence application before harvesting.
  • See comments in "After Last Cutting" section of this table for post harvest directions.
Note: for dryland asparagus growers: Residual herbicides such as linuron and simazine require irrigation or rain within 4 to 7 days of treatment to activate them.

After Last Cutting

Excel Super

(fenoxaprop-p-ethyl)

Group 1

670 mL/ha (270 mL/acre)

Apply in at least 110 L/ha (45 L/acre) of water at 275 kPa
N/A
  • Apply when weeds are at the 1 to 6 leaf stage.
  • Controls green and yellow foxtail, barnyard grass, crabgrass, fall panicum, Proso millet and old witch grass.
  • Does not control quackgrass, sedges or other perennial grasses.
  • Apply after harvest only.
  • Do not apply any other pesticides or chemicals 4 days before or after applying Excel Super.
  • Do not spray the asparagus fern.

Ignite 15 SN

(glufosinate ammonium)

Group 10

2.7 to 5.0 L/ha (1.1 to 2.0 L/acre)

Apply in 110 to 330 L/ha (45 to 135 L/acre) of water at 275 to 310 kPa.
N/A
  • Apply after spears have been harvested.
  • Rainfall within 4 hours of application may reduce effectiveness.
  • Do not handle with bare hands or with leather or cloth gloves.
  • Do not use pre-plant or pre-emergence on sandy soils lacking clay minerals.

Sandea

(halosulfuron)

Group 2

35 to 105 g/ha (14.2 to 42.5 g/acre)

Apply in 140 L/ha (57 L/acre)
1
  • See "Seed-bed Asparagus" section of this table for labelled weeds.
  • Applications should be made to actively growing weeds at the heights defined in the "USE RATE GUIDE" section of the label. 
  • For heavy yellow nutsedge infestations, split applications should be made.
  • To minimize crop injury and for more effective control, apply using drop nozzles directing the spray below the fern.
  • May cause temporary yellowing of the fern.
  • A nonionic surfactant or crop oil concentrate should be used with post-harvest applications.
  •  A sequential application may be necessary for some annual and perennial weeds.
  • Do not apply more than two times per season.
  • Repeat application at a 21 day interval.
  • Do not re-enter treated area for 12 hours.
  • Do not use more than 140 g/ha (57 g/acre) of product per season.
*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements. See also Pesticide Regulations and Safety section of this guide.
PESTICIDE GROUP DETAILS – see Pesticide Toxicity Table of this guide.


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