1. A synergistic herbicidal composition comprising a herbicidally effective amount of (a) a compound of formula (I) or an agriculturally acceptable salt or ester thereof and (b) clomazone or an agriculturally acceptable salt, carboxylic acid, carboxylate salt or ester. 2. The composition of claim 1, wherein (a) is a compound of formula (I), a C1-6 alkyl ester of a compound of formula (I), or a benzyl ester of a compound of formula (I). The composition according to any one of paragraphs. 1 or 2, optionally containing an agriculturally acceptable excipient or carrier. 4. The composition according to any one of paragraphs. 1 or 2, additionally containing a herbicide antidote. 5. A method for suppressing unwanted vegetation, which comprises, in order to prevent the emergence or growth of the vegetation, bringing the vegetation or its locus into contact with, or introducing into the soil or water, a herbicidally effective amount of (a) a compound of formula (I) or an agriculturally acceptable salt or ester thereof, and (b) clomazone or its agriculturally acceptable salt, carboxylic acid, carboxylate salt or ester. 6. The method of claim 5, wherein (a) is a compound of formula (I), a C 1-6 alkyl ester of a compound of formula (I), or a benzyl ester of a compound of formula (I). The method according to any one of paragraphs. 5 or 6, where undesirable vegetation is suppressed in areas with direct sowing, water planting and planting seedlings of rice, cereals, wheat, barley, oats, rye, sorghum, corn / maize, sugarcane, sunflower, oilseed rape, canola, sugar beets, soybeans, cotton, pineapple, on pastures, grasslands, pastures, steamed fields, lawn grasses, in wood and1. Синергетическая гербицидная композиция, содержащая гербицидно эффективное количество (a) соединения формулы (I)или его сельскохозяйственно приемлемой соли или сложного эфира и (b) кломазона или его сельскохозяйственно приемлемых соли, карбоновой кислоты, карбоксилатной соли или сложного эфира.2. Композиция по
