Preplant Incorporated, Preplant, or Preemergence

bensulide (Prefar 4-E)

Cantaloupe, cucumber, winter and summer squash, and watermelon

Rate 5 to 6 lb ai/a (5 to 6 quarts/a Prefar)

Time Apply preplant and incorporate 0.5 to 1 inch deep simultaneously or immediately after application, by cross-disking or using a power take-off rotary tiller. Or apply soon after planting before weeds emerge. For preemergence applications follow with sprinkler irrigation to wet soil 2 to 4 inches deep.

Remarks For furrow irrigation, thoroughly saturate bed top. Germinated or seedling weeds must be cultivated before application. Consult label for planting sensitive crops after treatment.

Caution Do not apply more than once every 12 months.

Site of action Group 8: lipid synthesis inhibitor but not an ACCase inhibitor

Chemical family Organophosphorus

clomazone (Command 3ME)

Preplant surface, pretransplant surface, and postplant surface;
Cucumber, winter and summer squash, pumpkin, and watermelon

Rate 0.15 to 0.75 lb ai/a (6.4 to 32 oz/a Command) depending on crop: cucumbers 6.4 to 16.2 fl oz (0.15 to 0.38 lb ai/a)); melons 6.4 to 10.7 oz/a; summer squash 10.7 to 21.3 oz/a; winter squash including processing pumpkin 10.7 to 32 oz/a.

Time Apply using a boom mounted on front of incorporation equipment to ensure immediate incorporation at 1 inch.

Remarks See label for crop-rotation restrictions for up to 16 months after treatment. Plant crop seed below treated layer. The ME (microencapsulated) formulation is designed to reduce or minimize drift but requires moisture to activate. Avoid overlaps in spraying and in treating very sandy soils. Inhibits chlorophyll development. PHI is 30 days.

Caution May discolor fruit of some orange varieties. Do not use on NK530, NK580, "Turk's turban," "Golden Delicious," all banana types and all other Cucurbita maxima that have a pink or burnt-orange color at harvest. Do not use on jack-o-lantern pumpkins. Clomazone may inhibit development of orange pigments. Before applying, check adjacent properties and avoid spraying within 300 to 1,200 ft of desirable plants. Sensitive crop and sites include landscapes, orchards, vegetable gardens, berry patches, and property lines. Do not graze cover crops or harvest food or feed within 9 months of applying or allow livestock to graze treated plants. Crop rotation interval for corn and snap beans is 9 months.

Site of action Group 13: inhibits DOXP synthase

Chemical family Isoxazolidinone

dimethenamid-P (Outlook)

Winter squash (var. "Golden Delicious," Oregon and Washington only)

Rate 0.56 to 0.84 lb ai/a (12 to 18 fl oz/a)

Time Apply postplant, preemergence, and irrigate with 0.5 inch water to activate herbicide.

Remarks Preharvest interval is 90 days. Planting at 1.5 inches or below will help to mitigate potential crop injury.

Caution Do not apply more than 21 fl oz/a per year. Replanting winter squash is not recommended if there is a crop failure. Other labeled crops can be planted immediately; cereals can be planted within 4 months of the Outlook application. Excessive rain after planting may temporarily injure crop. Failure to 'activate' the herbicide with irrigation or rainfall before the crop emerges may cause injury and desiccation of first true leaves, and slow crop growth.

Site of action Group 15: inhibits very long chain fatty acid synthesis

Chemical family Chloroacetamide

ethalfluralin (Curbit EC)

Cucumber, winter and summer squash, pumpkin, and watermelon

Rate 1.13 to 1.69 lb ai/a (3 to 4.5 pints/a Curbit EC)

Time Apply preemergence surface and activate with 0.5 inch of irrigation within 2 to 5 days, or cultivate soil surface above seed. Crop may be injured with excessive rain or irrigation or if seeding is too shallow.

Remarks Adjust rates depending on soil texture and organic matter content.

Caution Do not graze or apply to wet or cloddy soils. Note replanting restrictions for sugar beets and red beets listed on label. (Inhibits mitosis, primarily in shoots.)

Site of action Group 3: microtubule assembly inhibitor

Chemical family Dinitroaniline

ethalfluralin + clomazone (Strategy)

Cucumber, winter and summer squash, pumpkin, and watermelon

Rate 2 to 6 pints/a product, depending on soil texture (see label)

Time Apply only as a postplant surface treatment before crop and weeds emerge. Activate with 0.5 inch of irrigation within 2 to 5 days, or cultivate soil surface above seed. Crop may be injured with excessive rain or irrigation or if seeding is too shallow.

Remarks Adjust rates depending on soil texture and organic matter content. Do not preplant-incorporate, as crop will be injured. Inhibits mitosis, primarily in shoots. The clomazone in Strategy herbicide is not microencapsulated (ME) and therefore, more prone to movement than the clomazone formulation used in Command herbicide.

Caution Avoid drift onto neighboring plants. Clomazone will make affected plants turn white. Will occasionally "lift" from fields after application in the spring under certain conditions, and will cause adjacent crops to turn white for a short period of time. Use with caution within 300 ft of high value crops. Do not graze or apply to wet or cloddy soils. Note replanting restrictions for sugar beets and red beets listed on label. Clomazone in this premix is not microencapsulated (ME)

Site of action (ethalfluralin) Group 3: microtubule inhibitors; (clomazone) Group 13: inhibits DOXP synthase

Chemical family (ethalfluralin) dinitroaniline; (clomazone) isoxazolidinone

fomesafen (Reflex)

Winter and summer squash

Rate 0.125 to 0.25 lb ai/a (0.5 to 1 pints/a Reflex) depending on soil type

Time Postplant surface or pre-transplant

Remarks Must be activated with rainfall or irrigation of 0.5 inch or more and before weed seeds germinate for best efficacy. Failure to activate the herbicide before squash seedlings emerge increases the risk of damage to the crop if there is a heavy downpour and soil is splashed onto leaves. Reflex effectiveness will be reduced if later cultural practices expose nontreated soil. Preharvest interval is 32 days.

Caution Do not use Reflex on butternut squash (including Dickinson and other buckskin types) unless some injury can be tolerated. Do not exceed 1 pint/a of Reflex per season. Do not apply to a field more than once every 2 years. Snap beans, squash, and potatoes can be planted immediately after application. Wheat can be planted 4 months after application; sweet corn 10 months after application. Beets, brassica crops, and all other crops not listed on the label cannot be planted until 18 months after application.

Site of action Group 14: protoporphyrinogen oxidase (PPO) inhibitor

Chemical family Nitrophenylether

glyphosate (Touchdown HiTech, Roundup)

Winter squash, Oregon only

Rate 0.39 to 0.78 lb ai/a (10 to 20 fl oz/a product)

Time Apply to emerged annual weeds after planting winter squash in spring but before crop emerges. May be mixed with residual herbicides.

Remarks Oregon special local needs label OR-050006 in Benton, Lane, Linn, and Marion counties for Touchdown. Syngenta no longer markets Touchdown (glyphosate) as a standalone, but label extends to 2020 and existing stock may be used on squash.

Caution Do not apply if crop seeds are exposed because of poor row closure during planting. Do not apply if the radicle has emerged or if soil covering the seeds is cracking. Do not use on soils with less than 1% organic matter.

Site of action Group 9: inhibits EPSP synthase

Chemical family None generally accepted

halosulfuron-methyl (Sandea)

Rate 0.023 to 0.047 lb ai/a (0.5 to 1 oz/a) for cucumbers and other cucurbits approved for directed applications in row-middles; 0.023 to 0.036 oz ai/a (0.5 to 0.75 oz/a) for processing winter squash and pumpkins. Consult label for the diversity of rates recommended depending on crop and method of planting.

Time Apply before emerging crop cracks the soil, before transplanting, or before seeding or transplanting under plastic mulch.

Remarks For control of broadleaf weeds and nutsedge. Adjust rates, depending on soil texture and organic-matter content. Can be applied preemergence surface as a tank-mix with Outlook (dimethenamid-P) in processing squash to enhance control of lambsquarters control. To avoid crop stunting, if tank mixing with Outlook and if wet, cold soil conditions are expected, use 0.5 oz/a.

Caution Crop growth may be stunted briefly after emergence. Consult label for rotation crops, soil-applied organophosphate insecticides, and other precautions. Do not exceed 1 oz/a herbicide per year. Preharvest interval is 30 days for squash, cucumbers, and pumpkin, 57 days for melons.

Site of action Group 2: acetolactate synthase (ALS) inhibitor

Chemical family Sulfonylurea

S-metolachlor (Dual Magnum)

Pumpkin, inter-row or inter-hill only

Rate 0.95 to 1.27 lb ai/a (1 to 1.33 pints/a)

Time Apply preemergence or postemergence before weeds germinate or yellow nutsedge emerges.

Remarks Leave 1 ft of untreated area over the row, or 6 inches to each side of the planted hill and/or any emerged pumpkin foliage (inter-row or inter-hill means not directly over the planted seed or young pumpkin plants). Use the lower rate on soils light in texture (loamy sand or lighter) and low in soil organic matter (less than 3%).

Caution Consult label for specific rates, depending on soil texture and especially organic matter, or for restrictions on planting sensitive crops within 4 to 5 months. Inhibits roots and shoots. Preharvest interval is 30 days.

Site of action Group 15: inhibits very long chain fatty acid synthesis

Chemical family Chloroacetamide

terbacil (Sinbar)

Watermelon only

Rate 0.1 to 0.2 lb ai/a (2 to 4 oz/a, to a maximum of 4 oz/a per year)

Time Apply before transplanting or before crop emerges, if direct-seeding watermelon.

Remarks Supplemental label for watermelon only. Moisture is required to activate the herbicide and should arrive within 2 wk of planting. May be applied preemergence under plastic mulch. Preharvest interval is 70 days.

Caution Do not use on sand or gravel soil types. Use with caution if soil organic matter is less than 1%. Do not replant any crop for 2 years after applying terbacil.

Site of action Group 5: photosystem II inhibitor

Chemical family Uracil