Kentucky bluegrass (Poa pratensis L. ‘Parade’, ‘Adelphi’, ‘Glade’, and ‘Rugby’ # POAPR) and tall fescue (Festuca arundinacea Schreb. ‘Kentucky 31’ # FESAR) were treated in field experiments with chlorsulfuron {2-chloro-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino] carbonyl] benzenesulfonamide}. The objectives of the two experiments were to determine if this herbicide has the potential to be used for selective control of tall fescue in Kentucky bluegrass turf. Chlorsulfuron treatments included single rates of 0, 18, 35, 71, 141, 212, and 282 g ai/ha and split rates, applied 14 days apart, of 18 + 18, 35 + 35, 71 + 71, 141 + 141, and 212 + 212 g/ha. Clipping weights and turfgrass quality ratings were taken in both experiments. Kentucky bluegrass showed a higher tolerance to the chemical, with no decrease in turf quality at the highest single and split application rates in both experiments. However, as the chlorsulfuron rate increased, clipping weight decreased. Tall fescue showed a low tolerance to the chemical and was controlled at single rates of 141 g/ha and split rates of 141 + 141 g/ha and greater. Although the tall fescue recovered from damage at single rates of 71 g/ha and split rates of 71 + 71 g/ha, severe growth inhibition and discoloration of aboveground tissue occurred at the lower rates. Twelve months after the first chlorsulfuron was applied in each experiment, glyphosate [isopropylamine salt of N-(phosphonomethyl)glycine] was sprayed over the plots to kill all existing plant material, and Kentucky bluegrass was seeded into the plots 2 weeks later at the rate of 0.75 kg/100 m2. There was no inhibition of bluegrass seed germination at any of the rates of chlorsulfuron.

Virginia buttonweed and smooth crabgrass are problematic weeds in tall fescue and may warrant control with herbicides at similar timings. The objectives of these field experiments were to evaluate (1) aminocyclopyrachlor rate and application regimens for controlling Virginia buttonweed and (2) the influence of growth stage on aminocyclopyrachlor efficacy for controlling smooth crabgrass. Single applications of aminocyclopyrachlor at 0.05 and 0.08 kg ai ha−1 provided poor (< 70%) and fair (70 to 79%) control of Virginia buttonweed, respectively, but sequential applications improved control to 83 to 99%. Single and sequential applications of aminocyclopyrachlor at 0.11 kg ai ha−1 provided good (80 to 89%) and excellent (> 90%) control of Virginia buttonweed, respectively. Aminocyclopyrachlor at 0.11 kg ha−1 provided fair control of smooth crabgrass at the multileaf growth stage prior to tillering but control was poor when applied at the multitiller stage. Aminocyclopyrachlor at 0.05 and 0.08 kg ha−1 provided poor control of crabgrass at both timings and were less effective than fenoxaprop at 0.10 kg ai ha−1.

A survey of proteinaceous inhibitors of the serine proteinases, bovine trypsin and chymotrypsin, that are extractable from dry seeds of several cultivars of pasture grasses has been undertaken. Using crude extracts, most cultivars screened contained inhibitors of chymotrypsin, whereas trypsin inhibition was not detectable. Seeds from four cultivars, Lolium perenne L. cv. Grasslands Ruanui, Lolium × boucheanum cv. Grasslands Greenstone, Festuca arundinacea Schreb. cultivars Grasslands Roa and Grasslands Garland, that contained more potent chymotrypsin inhibition were purified further. After gel filtration chromatography, both trypsin and chymotrypsin inhibition could be observed in all four cultivars, and each separated into two discrete native molecular weights; one of ca. 20–22 kDa and one of ca. 8–10 kDa. However, activity staining, after polyacrylamide gel electrophoresis, revealed an array of iso-inhibitors with molecular weights that ranged from ca. 3 kDa to 20 kDa. One of these, a dual trypsin/chymotrypsin inhibitor of ca. 12 kDa that is present in all four cultivars examined, was purified to homogeneity from F. arundinacea cv. Grasslands Garland using anhydro-trypsin affinity chromatography and reverse-phase HPLC. The protein was found to comprise two closely related peptides and N-terminal amino acid sequencing revealed highest identity with a trypsin inhibitor identified in rye (Secale cereale) seeds.