Annual bluegrass [Poa annua ssp. reptans (Hauskins) Timm.] often comprises a large portion of golf course greens, yet its shallow root system and extensive seedhead production limit its turf quality. The purpose of this investigation was to determine if annual bluegrass seedheads could be suppressed and rooting enhanced by the plant growth regulator mefluidide [N ‐(2,4‐dimethyl‐5‐{[(trifluoromethyl) sulfonyl]amino} phenyl)acetamide] and the wetting agent Aqua‐Gro (polyoxyethylene esters and ether of cyclic acid and alkylated phenols, silicone anti‐foam emulsion). Chemicals were applied prior to seedhead emergence during 1983 and 1984 to annual bluegrass grown in a rhizotron in fine quartz sand. Root elongation of mefluidide‐treated annual bluegrass was superior to the control for 2 to 4 weeks following Spring 1983 application. Maximum rooting depth of mefluidide‐treated turf was significantly greater than that of Aqua‐Gro‐treated or untreated turf during May 1983. Aqua‐Gro applied at either 4.2 or 8.4 L ha−1 generally did not affect rooting. In 1983, mefluidide (0.07 or 0.14 kg ha−1) prevented seedhead emergence throughout the entire seedhead production period (approximately 8 weeks) when applied under environmental conditions favoring uptake. Leaf tip yellowing occurred for 3 to 4 weeks following mefluidide application. Mefluidide‐treated turf, however, exhibited quality superior to untreated turf for approximately 6 weeks following discoloration. Aqua‐Gro provided little seedhead suppression and reduced quality for about 10 days following application. In 1984, environmental conditions were not conducive to chemical uptake so 1983 results were not corroborated. Mefluidide appears promising as an annual bluegrass management tool; however, more information is needed to determine the influence of environmental conditions on mefluidide uptake and its ability to suppress seedheads and enhance rooting at low rates.

Alfalfa (Medicago sativa L.) has been reported as having autotoxic or autoallelopathic characteristics, but the plant fraction containing the autotoxic material and the responsible compound have not been isolated or identified. Greenhonse and laboratory studies were conducted to: (i) determine if ‘Vangard’ alfalfa exhibits autotoxicity, (ii) determine which plant fraction contains the autotoxic material, and (iii) separate the autotoxic fraction using paper chromatography procedures. In greenhouse studies, alfalfa plant material reduced alfalfa emergence by an average of 87 and 62% in a Kokomo silty loam soil (fine, mixed mesic, Typic Argiaquoll) previously cropped with alfalfa and corn (Zea mays L.), respectively. Incubating the soil and plant material under two contrasting moisture regimes did not alter the inhibitory activity. However, autoclaving the soil and plant material negated the autotoxic response. Laboratory studies indicate that the autotoxic compound was contained within the water‐extractable alfalfa fraction, and was not the direct result of microbial activity, although microbial activity may increase the dissipation of the compound. Ascending paper chromatographic separation indicated that the autotoxic compound had an Rf characterization similar to phenolic acid; however, phenolic‐absorbent polyvinylpolypryrrolidone did not affect the autotoxic response. The results indicate that alfalfa contains a water‐soluble autotoxic compound that has characteristics indicative of a phenolic compound.

A mixture of field peas and triticale was planted in spring, harvested as silage, and followed by a double crop of pearl millet, which also was harvested as silage. Eighteen Holstein cows were fed diets based on pea with triticale, pearl millet, or alfalfa plus corn silages. Dry matter digestibility of the pea with triticale diet was higher than for control (71.1 vs. 66.9%), but DM digestibility was not different between control and pearl millet diets. Milk production was not affected by diets containing pea with triticale or pearl millet compared with control diets (25.2, 23.2, and 24.5 kg/d). Cows fed pea with triticale produced milk with a higher concentration of fat (4.59 vs. 3.35%) and more FCM (27.3 vs. 22.1 kg/d) than those fed the control diet. However, cows fed the control diet gained more BW than those receiving pea with triticale or pearl millet diets. Partitioning of energy between body stores and milk production was different between cows fed pea with triticale and control diets; however, total energy use was not different (32.4 vs. 30.5 Mcal of NE(L)/d). Differences in energy partitioning may have been caused partly by differences in ruminal fermentation of the respective diets.

A rapid, effective method for identifying inbred lines of corn (Zea mays L.) that produce hybrids with a low grain‐moisture content at harvest would be helpful to corn breeders. We evaluated use of a hand‐held moisture meter to select for low ear‐moisture content in a set of St plants that had similar pollination dates. A set of 30 lines, derived from plants classified as low‐, medium‐, and high‐moisture 30 d after pollination, was identified. The lines were evaluated for moisture content in a randomized complete‐block experiment. Testcrosses of the lines to two testers were evaluated for yield and harvest moisture at five locations in 1 yr. The moisture meter produced estimates of moisture content that correlated well in 2 yr (r2 = 0.85 and 0.82) with estimates obtained by the oven method. Lines derived from ears selected for low moisture with the meter had lower moisture at harvest than lines from high‐moisture ears. Hybrids of low‐moisture lines were lower in harvest moisture than hybrids of high‐moisture lines but were similar in grain yield. The moisture meter should enable corn breeders to select for low harvest moisture in segregating populations.

The intense spring seed head production of annual bluegrass (Poa annua L.) is a major factor limiting its quality as a turfgrass. Developing seeds are unsightly, and monopolization of assimilates by developing seeds may be partially responsible for the shallow root system and poor stress tolerance of annual bluegrass. A greenhouse study was conducted to determine if seedhead suppression resulting from the plant growth regulator mefluidide (N-(2,4-dimethyl-5-l((trifluoromethyl)sulfonyl)aminol phenyl) acetamide) would result in a redistribution of carbohydrates to the roots of annual bluegrass. Mefluidide was applied prior to seedhead emergence at rates ranging from 0 to 0.21 kg a.i. ha-•. Complete seedhead suppression associated with the 0.14 and 0.21 kg a.i. ha-• rates resulted in greater concentrations of fructose and glucose in annual bluegrass roots compared to roots of untreated plants during peak seedhead emergence. Redistribution of carbohydrates was short lived, with no differences in carbohydrate content occurring among treatments after peak seedhead emergence. Mefluidide had little effect on leaf and stem carbohydrates. Regardless of mefluidide rate, concentrations of fructose, sucrose, and fructans were considerably greater in leaf and stem tissue than in roots. Annual bluegrass stems were the major storage organ for fructans, with only minor fructan storage occurring in roots. The carbohydrate content of mefluidide-treated annual bluegrass decreased substantially in leaf, stem, and root tissue following growth inhibition due to a post-inhibition growth surge.