Postemergent broadleaf control

clopyralid (Stinger)

Rate 0.093 to 0.187 lb ae/a (4 to 8 oz/a)

Time Apply when beets are in the cotyledon to eight-leaf stage, and when weeds are actively growing.

Remarks Target weeds are hairy and black nightshade. Preharvest interval is 30 days.

Caution Clopyralid will cause leaves to turn red with occasional epinasty. Use caution if tank mixing with other herbicides. Crop-rotation intervals: 12 months for sweet corn; up to 18 months for Brassica (cole) crops, peas, potatoes, and tomatoes.

Site of action Group 4: synthetic auxin

Chemical family Pyridine

phenmedipham (Spin-Aid)

Rate 0.24 to 0.5 lb ai/a (1.5 to 3 pints/a)

Time Apply to beets at 2-leaf (1.5 pints/a), 4-leaf (1.5 to 2.3 pints/a) or 6-leaf (2.3 to 3 pints/a). Results are best when weeds are at two-true-leaf stage.

Remarks Avoid applying if weather may change rapidly from cool and cloudy to warm and sunny, or if beets are stressed from insect, disease, or cultivation injury. Tip burn or temporary growth retardation and chlorosis are possible, although plants usually recover within 10 days. Repeat applications can be made 5 to 7 days later, or after another flush of weed emergence. May be tank mixed with UpBeet or Stinger herbicide.

Caution Restricted-use herbicide due to dermal irritation. Preharvest interval is 60 days. Avoid diluting herbicide more than 1 quart to 7 gal water in spraytank because chemical may precipitate.

Site of action Group 5: photosystem II inhibitor

Chemical family Phenylcarbamate

phenmedipham + desmedipham (Betamix, Sugar Beet Mix Herbicide)

Rate 2-leaf beets: 1.5 pints/a. 4-leaf beets: 1.5 to 2.3 pint/a. 6-leaf beets, 1.5 to 3 pints/a.

Time 2- to 6-leaf beets.

Remarks No longer available, but existing stock can be used. Avoid applying if weather may change rapidly from cool and cloudy to warm and sunny, or if beets are stressed from insect, disease, or cultivation injury. Tip burn or temporary growth retardation and chlorosis are possible, although plants usually recover within 10 days. Existing stocks of Betamix and Sugar Beet Mix can be used.

Caution Preharvest interval is 14 days for tops and 50 days for beets (roots). Do not apply when plants are wet with dew. Irrigation or rain within 6 hr may reduce efficacy.

Site of action Group 5: photosystem II inhibitors

Chemical family Phenylcarbamate

triflusulfuron methyl (UpBeet)

Rate 0.0156 lb ai/a (0.5 oz/a)

Time Apply when table beet seedlings have 2 to 4 true leaves. Use at least two sequential applications for best results. Apply 5 to 10 days apart, depending on weed size.

Remarks Supplemental label. Apply to small, actively growing weeds. Nonionic surfactants and crop oil concentrates should be used at 0.25% v/v but may increase risk of crop response. Up to 3 applications are permitted with a total of 1.5 oz/a per crop. Controls pigweed, kochia, shepherdspurse, and velvetleaf. Can be tank mixed with Spinaid and Stinger to improve weed control.

Caution Discoloration may be noted in some cases but effects are temporary. Do not contaminate water bodies, or rinse or flush spray near roots of trees and desirable plants, or injury may result.

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

Chemical family Sulfonylurea