Two 1-yr field studies were conducted to evaluate preemergence and preplant incorporated treatments of alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide], EPTC (S-ethyl dipropylthiocarbamate), fluridone {1-methyl-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4(1H)-pyridinone}, and metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] for the control of yellow nutsedge (Cyperus esculentus L.). Preemergence applications of metolachlor at 2.24, 3.36, and 4.48 kg/ha gave the best control with no significant differences observed among rates of metolachlor. Depth of herbicide incorporation did not result in any significant increase in control. Preplant incorporation of metolachlor at all rates, or fluridone at 0.56 and 0.84 kg/ha provided seasonal control of yellow nutsedge. Translocation of 14C-metolachlor applied to the root or shoot of yellow nutsedge was primarily acropetal with some limited basipetal movement. Application of 14C-metolachlor to the root or shoot of purple nutsedge (Cyperus rotundus L.) resulted in mostly acropetal translocation with little movement of 14C from the treatment site.

Research was conducted to determine environmental and cultural factors influencing triallate phytotoxicity to hard red spring wheat. Triallate injured ‘Alex’ wheat more than ‘Coteau’ but injury was not influenced by triallate application date. Wild oat control was greater when triallate was applied immediately before seeding compared to 12 d before seeding. Triallate tolerance in wheat did not relate to solid stem characteristic. Injury was highest when wheat was seeded in a 4-cm incorporated triallate layer and least when wheat was seeded below the treated layer. However, triallate injury to wheat was similar at both seeding depths within the 8-cm incorporated triallate layer. Triallate at 1.1 kg ai ha-1 reduced wheat fresh weight approximately 33% with a soil at 8 C but over 84% with a soil at 24 C.

When trifluralin [α,α,α - trifluoro - 2,6 - dinitro -N,N-dipropyl-p -toluidine] was manually incorporated in small field plots to a depth of 10 cm, ivyleaf morningglory [Ipomoea hederacea (L.) Jacq.] was controlled more effectively than when incorporation was only 5 cm deep. No significant differences in ivyleaf morningglory control were observed between different incorporation depths when trifluralin was mechanically incorporated in large field plots. Ivyleaf morningglory emerging from 10 cm deep was controlled to a greater degree than that emerging from 5 cm deep. Preplant incorporated (PPI) trifluralin plus alachlor [2 - chloro – 2′, 6’ - diethyl - N- (methoxymethyl)acetanilide ] applied preemergence (PE) controlled up to 92% of the ivyleaf morningglory compared to 33 and 15% respectively, when these herbicides were applied alone at equal rates. This indicates a synergistic interaction between these two compounds. Trifluralin PPI plus RH 8817 [5-(2-chloro-4-trifluoromethyl phenoxy) - 2 - nitrobenzoic acid ethyl ester] and alachlor applied PE controlled ivyleaf morningglory more effectively (88 to 94%) than all other treatments. Soybean [Glycine max (L.) Merr.] injury and stand reduction were less than 5% in all studies.