Vegetable Production Guide

Cucurbits
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Table 1 Cucurbit Weed Control

This section was updated - 23 September 2021

Table 1 Cucurbit Weed Control

Product

Rate

PHI*

Comments

Pre-plant Incorporation

Prefar 4.8-E
 

(bensulide)

Group 8
12 to 14 L/ha
(4.9 to 5.7 L/acre)

Apply in 100 to 500 L/ha (40 to 200 L/acre) of water
N/A
  • Registered on cucumbers.
  • Controls barnyard grass, crabgrass, and foxtail.
  • Does not control emerged weeds.
  • Do not make more than 1 application per year.
  • Rotate only to cucurbits, peppers, cole crops, carrots, lettuce, or tomatoes.
  • Use on mineral soils only.
  • Apply as broadcast spray to well worked soil that is dry enough to permit thorough incorporation.
  • Incorporate to depth of 2.5 to 5 cm before planting.

Sandea

(halosulfuron)

Group 2
cucumbers, cantaloupes, honeydews, Crenshaw melons:
35 to 70 g/ha (14.2 to 28.3 g/acre)
30:  cucumbers, pumpkins & winter squash
 
57:  watermelon, cantaloupes, honeydews & Crenshaw melons
Pre-Seeding or Pre-Transplant:
  • See Pre-emergence and Post-emergence sections of this table for additional uses.
  • Do not use pre-plant for direct-seeded pumpkins and winter squash.
  • Water volume rates vary.  Check label.
  • Apply as a pre-plant (except for pumpkins and winter squash) or pre-tranplant application to bare ground or under plastic mulch.
  • If using plastic mulch, apply following final bed shaping and just prior to installation of the plastic mulch.
  • Seed or transplant crop into the treated area no sooner than 7 days after application and the installation of plastic mulch (if using plastic mulch).
  • Use lower rate on lighter textured soils with low organic matter.
  • For watermelon, pumpkin and winter squash, do not apply more than 70 g/ha (28 g/acre) of product per season.
  • For cucumbers, cantaloupes, honeydews and Crenshaw melons do not apply more than 140 g/ha (57 g/acre) of product per season.
  • Sandea-treated soil in the transplant hole may result in crop injury.  Care should be taken to limit movement of soil during transplanting.
  • Can be applied as a broadcast or band application.
  • For band applications, use proportionally less spray mixture based on the area actually sprayed so that a full rate is not concentrated into the band.
  • Controls labelled broadleaf weeds including ladysthumb, wild mustard and redroot pigweed.
  • Suppresses nutsedge.
  • 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.
  • Observe plantback interval of 15 months for cabbage and carrots, 18 months for broccoli and cauliflower, 24 months for spinach and 36 months for beets.  See label for other crops listed.
  • Do not enter treated area for 12 hours.
watermelon, pumpkins & winter squash:
35 to 52.5 g/ha (14.2 to 21.2 g/acre)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Pre-emergence

Devrinol 50 DF
 

(napropamide)

Group 15
2.24 to 4.5 kg/ha
(0.9 to 1.8 kg/acre

Apply in 200 to 900 L/ha (80 to 365 L/acre) water
N/A
  • Registered on direct-seeded pumpkins and squash.
  • Apply only once per season.
  • Use the lower rate on light soils.
  • Do not use on soils with more than 10% organic matter.
  • Some rainfall or irrigation after application is necessary for adequate weed control.
  • There is a 12 month plant back restriction for crops not on the label.
  • Do not enter treated area for 12 hours.

Reflex
 

(fomesafen)

Group 14
1.0 L/ha
(0.40 mL/acre)

Apply in 200 L/ha (80 L/acre) of water
42
  • Registered on cucumbers only.
  • Controls labelled broadleaf weeds including redroot pigweed, wild mustard, lady's-thumb and Eastern black nightshade.
  • Suppresses lamb's-quarters.
  • If target weeds have emerged, apply with a non-ionic adjuvant (Agral 90 or Citowett at 0.1% v/v of spray solution).
  • Do not apply to any field more often than once every two years.
  • Make a banded application to row middles just after seeding but prior to crop emergence; or just prior to transplanting.
  • Adjust the rate according to band and row width.
  • Do not apply directly to plants.
  • Crop injury may result if application is made too close to the plants.
  • Some varieties are more tolerant to Reflex than others.  Test a small area before applying to the entire crop.
  • Reflex can remain active in the soil for several months after application and the residues present a potential carry-over damage to certain crops.  See label for details.
  • Do not re-enter treated area for 12 hours.

Sandea

(halosulfuron)

Group 2
cucumbers, cantaloupes, honeydews & Crenshaw melons:
35 to 70 g/ha (14.2 to 28.3 g/acre)
30:  summer squash for processing, cucumbers, pumpkins & winter squash
 
57:  watermelon, cantaloupes, honeydews & Crenshaw melons
  • Water volume rates vary.  Check label.
  • See PPI and Post-Emergence sections of this table for additional uses.
  • If weeds are present, use with a nonionic adjuvant or crop oil concentrate.
  • Apply after seeding, but prior to soil cracking.
  • For watermelon, where soil is fumigated prior to planting, allow at least 5 days after soil fumigation before applying.
  • Incorporate with 0.5 to 1.25 cm irrigation to improve weed control.
  • For processing pumpkins and processing winter squash, use the cucumber rate.
  • Use lower rate on lighter textured soils with low organic matter.
  • For pumpkins and winter squash, apply 3 to 5 cm of sprinkler irrigation to settle the soil after planting and prior to application.
  • For summer squash for processing, use the rate of 47 to 70 g/ha (19 to 28.3 g/acre).
  • For summer squash for processing do not apply more than 140 g/ha (57 g/acre) of product per season.
  • See PPI section of this table for total maximum product allowed for application per season on other crops listed.
  • Can be applied as a broadcast or band application.
  • For band applications, use proportionally less spray mixture based on the area actually sprayed so that a full rate is not concentrated into the band.
  • See PPI section of this table for weeds controlled and suppressed, plantback interval precautions and re-entry interval.
  • Applications should be made to actively growing weeds at the heights defined in the "USE RATE GUIDE" section of the label.
  • May cause temporary stunting in summer squash for processing, pumpkins and winter squash.
watermelon, pumpkins & winter squash:
35 to 52.5 g/ha (14.2 to 21.2 g/acre)

 

 

 

 

 

 

 

 

 

 

 

 

Pre-emerge or early post-emergence

Dual II Magnum
 

(s-metalochlor)

Group 15

Banded to row middles (after plastic mulch has been laid):  1.15 – 1.56 L/ha
(465 mL-  630 mL/acre)

Broadcast:   1.15 L/ha (465 mL/ha)

Apply in 150 L/ha (60 L/acre) of water.

30
  • Apply pre-emerge to labeled weeds.
  • Transplants:  apply prior to or within 48 hours after transplanting.
  • Direct seeded:  apply pre-emerge or to the 1- to 2- leaf stage of crop development.
  • Make only one application per year.
  • Controls nightshade and annual grasses.
  • Suppresses redroot pigweed.
  • To avoid crop injury, minimize foliar contact with Dual II Magnum.
  • Rain is required within 10 days of pre-emerge application, or a shallow cultivation.
  • Do not apply to soils with less than 1% or more than 10% organic matter.
  • Do not enter treated areas for 12 hours.

Post-emergence

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 80L/acre) of water at 200 to 300 kPa
30
  • Registered on cucumbers.
  • Use the lowest rate for barnyard grass at the 2 to 5 leaf stage.
  • Use 1.4 L/ha (0.565 L/acre) for green and yellow foxtail at the 2 to 4 leaf stage.
  • Use 2.0 L/ha (0.8 L/acre) for quackgrass at the 3 to 5 leaf stage.
  • Apply once per season.
  • Warning: Women capable of bearing children should avoid exposure to Venture.

Assure II
 

(quizalofop-P-ethyl)

Group 1
380 mL to 750 mL/ha
(150 to 300 mL/acre)

Apply in 100 L/ha (40 L/acre) of water.
30
  • Registered on cantaloupe.
  • Apply with Merge at 5 to 10 litres per 1000 litres of spray solution, or Sure-Mix at 0.5% (0.5 L per 100 L of spray solution).
  • Apply at the 2 to 6 crop leaf stage.
  • Apply at the 2 to 5 leaf stage of annual grasses and up to the 3 leaf stage of quackgrass.
  • Maximum of 1 application per year.
  • Rainfall within 1 hour of application may reduce effectiveness.
  • After applying a broadleaf herbicide not listed on the label as a tankmix, wait at least 7 days before making an application of Assure.
  • Do not enter treated area for 4 days.

Sandea

(halosulfuron)

Group 2
cucumbers, cantaloupes, honeydews, Crenshaw melons & watermelon:
35 to 70 g/ha (14.2 to 28.3 g/acre)
30:  summer squash for processing, cucumbers, pumpkins & winter squash
 
57:  watermelon, cantaloupes, honeydews & Crenshaw melons
  • Water volume rates vary.  Check label.
  • See PPI and Pre-emergence sections of this table for additional uses. 
  • A sequential application may be necessary for some annual and perennial weeds.
  • For all crops listed except summer squash for processing, do not apply more than two times per season.
  • Repeat using a 21 day interval.
  • See PPI section of this table for total maximum product allowed for application per season.
  • For pumpkins and winter squash, apply 3 to 5 cm of sprinkler irrigation to settle the soil after planting and prior to application.
  • 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.
Post transplant:
  • Do not use this post-transplant method for watermelon.
  • Apply to transplants that are estabished and actively growing and in the 3- to 5-leaf stage or no sooner than 14 days after transplanting, but before first flowers appear.
  • Apply as an over-the-top application, a directed spray or with crop shields to minimize contact of the herbicide with the crop.
  • If plastic mulch is used, additional phytotoxicity may occur when applications are made over plastic due to concentration of product in the transplant hole.
(Direct Seeded and Transplant) Row Middle/Furrow Applications:
  • For summer squash for processing, pumpkins and winter squash, use the cucumber rate.  
  • Row middle/furrow application method may be used for cucurbit crops listed, including watermelon.
  • May be applied between rows of crop.
  • Avoid contact of the herbicide with the planted crop.
  • If plastic is used on the planted row, adjust equipment to keep the application off the plastic.
  • Reduce rate and spray volume in proportion to area actually sprayed.
Other comments:
  • Controls broadleaf weeds including ladysthumb, wild mustard, yellow nutsedge and redroot pigweed.
  • Suppresses horsetail, 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.  Heavy infestations may require sequential applications.
  • See comments in PPI section of this table for plantback interval details and re-entry.
pumpkins & winter squash:  35 to 52.5 g/ha (14.2 to 21.2 g/acre)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Poast Ultra plus Merge at the following rates:
  Poast Ultra Merge
Annual grasses (incl volunteer cereals) 320 mL/ha
(130 mL/ac)
0.5 - 1.0 L/ha
(0.2-0.4 L/acre)
Annual grasses & quackgrass suppression 470 mL/ha
(190 mL/ac)
0.5 - 1.0 L/ha
(0.2-0.4 L/acre)
Quackgrass 1.1L/ha
(445 mL/ac)
1.0–2.0 L/ha
(0.4-0.8 L/acre)
30
  • Do not use on melons.
  • Annual bluegrass is not controlled.
  • Apply when annual weeds are in the 1 to 6 leaf stage and when quackgrass is in the 1 to 3 leaf stage.
  • Apply in 50 to 200 L/ha (20 to 80 L/acre) of water.
  • Pressure varies with different water volumes see label for detail.
  • 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.

Aim EC

(carfentrazone-ethyl)

Group 14

 

37 to 117 mL/ha
(15 to 47 mL/acre)

Apply in 100 L/ha (40 L/acre) of water

1

 

  • Registered on transplanted cucurbit vegetables including:  cucumber, muskmelon, pumpkin, summer & winter squash & watermelon. 
  • Controls annual weeds.
  • Must be applied using hooded sprayers to weeds between the rows of the emerged crop.
  •  Use an adjuvant such as Agral 90 or Agral-Surf at 0.25% v/v (0.25 L/100 L of spray solution) or Merge at 1% v/v (1 L/100 L of spray solution).
  • PRECAUTION:  crop injury will occur when spray drift is allowed to come in contact with green stem tissue, leaves, blooms or fruit of the crop.
  • Apply only once per growing season.
  • Do not apply if used as a pre-plant burn-down in the same season.
  • See Pest Management section of this guide for pre-plant burn-down precautions.
*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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