carfentrazone (Aim EC)
Rate 0.031 lb ai/a (2 fl oz/a product)
Time Spray only the basal 18 inches of bines and the sucker mat at the base of the bine.
Remarks Apply in at least 20 gal of spray solution with boom-type ground application equipment. Allow 14 days between treatments. Use a nonionic surfactant with at least 80% ai at 2 pints per 100 gal of spray solution or a quality crop oil concentrate at recommended rates. Controls only susceptible broadleaf weeds less than 4 inches tall or across.
Caution Avoid applications until newly trained bines have developed sufficient barking to avoid damage to the stem, and are high enough up the string to avoid contact with the apical bud. Do not exceed 0.119 lb ai/a (7.6 fl oz/a product) per season. Do not apply within 7 days of harvest. Avoid spray or drift outside the intended area.
Site of action Group 14: protoporphyrinogen oxidase (PPO) inhibitor
Chemical family Triazolinone
flumioxazin (Chateau SW, Redeagle, Tacoma, Tuscany SC, Warfox)
Rate 0.19 lb ai/a (6 oz/a of 51% ai products).
Time Direct application to basal 2 feet of hop plants when hops have reached a minimum height of 6 feet.
Remarks Do not apply more than 6 oz/a in a single application. Do not apply more than 6 oz/a during a growing season. Do not add any adjuvant. Will provide residual control of numerous broadleaf and some grass weeds.
Caution Do not apply to hop vines less than 6 ft tall. Preharvest interval is 30 days. Avoid spray or drift outside the area. Do not mow or rake over treated area as dust created by mowing may drift onto sensitive crops or vegetation, resulting in injury. Pears are sensitive.
Site of action Group 14: protoporphyrinogen oxidase (PPO) inhibitor
Chemical family N-phenylphthalimide derivative
paraquat (several trade names)
Rate 0.5 lb ai/a in at least 10 gal/a water. Add nonionic surfactant or crop oil concentrate to spray mix.
Time Chemical pruning: To burn back existing vines and obtain even emergence of subsequent vines, spray when vines are less than 3 ft tall. Suckering and stripping: Spray only the basal 2 ft of vines. Repeat as necessary.
Remarks Higher water volumes were more effective in desiccating hops in research trials. Hop response differs by variety. To determine sensitivity to injury, test selected use-rate on a few plants of each hop variety to be treated. Reduce rate, or do not use, on varieties showing unacceptable injury. Hop vine refuse and silage may be fed to livestock..
Caution A restricted-use herbicide. Applications to hop vines less than 6 ft tall may cause unacceptable injury. Do not apply more than three times per season. Preharvest interval is 14 days. Do not allow animals to graze in treated hop yard. Follow all safety precautions on the label.
Site of action Group 22: photosystem I electron diversion
Chemical family Bipyridilium