Buffalograss Establishment with Preemergence Herbicides

Field studies were conducted at two sites in Nebraska (NE1 and NE2) and one site in Kansas (KS) in 1994 to determine the influence of selected preemergence herbicides on establishment of seeded `Sharp's Improved' buffalograss [ Buchloe dactyloides (Nutt.) Engelm.]. Herbicides were applied within 2 days after seeding. Application of imazethapyr at 0.07 kg·ha -1 usually resulted in buffalograss seedling density, vigor, and foliar cover that were superior to buffalograss stands where other herbicides were applied. Buffalograss response to AC 263,222 at 0.07 kg·ha -1 was variable and appeared to be influenced by level of weed interference. Seedling density and vigor of buffalograss on areas treated with AC 263,222 were the same or less than on nontreated areas at KS and NE2, where weed infestations were low and moderate [5% and 45% weed foliar cover 12 weeks after treatment (WAT) on nontreated areas]. In contrast, buffalograss establishment was similar in AC 263,222- and imazethapyr-treated plots at NE1 where the weed infestation was high (>70% weed foliar cover 12 WAT on nontreated areas). At 12 WAT, weed foliar cover was <25 % at NE1 and <1 % at NE2 where imazethapyr and AC 263,222 were applied. Of all herbicides evaluated, imazethapyr at 0.07 kg·ha -1 was superior for suppressing annual grass and broadleaf weeds with no observable deleterious effects on buffalograss establishment from seed. Chemical names used: ±2-[4,5-dihydro-4-methyl-4-(l-methylethyl)-5-oxo-l H -imidazol-2-yl]-5-methyl-pyridine carboxylic acid (AC 263,222); 2-[4,5-dihydro-4-methyl-4-(l-methylethyl)-5-oxo-l H -imidazol-2-yl]-5-ethyl-3-pyridinecarboxylic acid (imazethapyr); 6-chloro- N,N ′-diethyl-l,3,5-triazine-2,4-diamine (simazine).