Replacing toxic, wild-type Neotyphodium coenophialum-infected tall fescue (E+) with nontoxic, N. coenophialum-infected tall fescue (NE+) has improved cow performance, but producer acceptance of NE+ has been slow. The objective was to compare performance by spring- and fall-calving cows grazing either E+ or NE+ at different percentages of the total pasture area. Gelbvieh×Angus crossbred cows (n=178) were stratified by BW and age within calving season and allocated randomly to 1 of 14 groups representing 5 treatments for a 3-yr study: i) Fall-calving on 100% E+ (F100); ii) Spring-calving on 100% E+ (S100); iii) Fall-calving on 75% E+ and 25% NE+ (F75); iv) Spring-calving on 75% E+ and 25% NE+ (S75); and v) Spring-calving on 100% NE+ (SNE100). Groups allocated to F75 and S75 grazed E+ until approximately 28 d before breeding and weaning, then were then moved to their respective NE+ pasture area for 4 to 6 wk; those allocated to F100, S100, and SNE100 grazed their pastures throughout the entire year. Samples of tall fescue were gathered from specific cells within each pasture at the time cows were moved into that particular cell (∼1 sample/mo). Blood samples were collected from the cows at the start and end of the breeding season. Stocking rate for each treatment was 1 cow/ha. Forage IVDMD, CP, and total ergot alkaloid concentrations were affected (P<0.05) by the treatment×sampling date interaction. Hay offered, cow BW, and BCS at breeding, end of breeding, and at weaning were greater (P<0.05) from fall-calving vs. spring-calving. Cow BW at weaning was greater (P<0.05) from F75 and S75 vs. F100 and S100. The calving season×NE+ % interaction affected (P<0.05) calving rates. Preweaning calf BW gain, actual and adjusted weaning BW, ADG, sale price, and calf value at weaning were greater (P<0.05) from fall-calving vs. spring-calving and from SNE100 vs. S75 except for sale price which was greater (P<0.05) from S75 vs. SNE100. Cow concentrations of serum prolactin at breeding and serum NEFA at the end of breeding were affected (P<0.05) by the calving season×NE+ % interaction. Serum Zn and Cu concentrations from cows were affected (P<0.05) by calving season. A fall-calving season may be more desirable for cows grazing E+, resulting in greater calving rates, cow performance, and calf BW at weaning, whereas limited access to NE+ may increase calving rates, serum prolactin, and NEFA concentrations during certain times in the production cycle, particularly in spring-calving cows.

Hydrocarbon media based metalation procedures involving “deficiency catalysis” are described for the ortho-lithiation of anisole (A), p-chloroanisole (p-ClA), o-, m-, p-methylanisoles (o-, m-, p-MA), the three dimethoxybenzenes (DMB’s), dimethylaniline (DMA), dimethybenzylamine (DMBA), m-methoxydimethylaniline (m-MeODMA), and tetramethyl-p-phenylenediamine (p-TMPDA). These procedures involve certain mechanistic considerations, which must be fine-tuned to maximize the extent of metalation (EoM). Our working hypothesis is that a controlled deoligomerization of the n-BuLi hexamer found in hydrocarbon media will afford a “sweet spot” of deoligomerization such that a maximally efficient metalation medium can be formed. In many cases, a substoichiometric ratio of equivalent TMEDA to n-BuLi is 0.1–0.2:1.0, but certain substrates suffer multiple sites of metalation under these conditions, so different promoted hydrocarbon media systems incorporating measured equivalents of an ether have been formulated. This paper represents the summary of our successful efforts to render ortho-lithiations safer, greener, and more atom-economical by use of hydrocarbon solvent media. EoM’s of 11 of the 12 substrates under these atom-economical conditions range from 87 to 97%.

treatment, than when planted after orchardgrass, and this result was attributed to autotoxicity. Interseeding alfalfa (Medicago sativa L.) to thicken declining al-Observations in Missouri indicate that alfalfa stand falfa stands is seldom successful due to autotoxicity. Our objective densities commonly decline to approximately 50 to 60 was to characterize the lateral zone of autotoxic influence around established plants. Experiments were conducted in South Missouri in plants m Ϫ2 by the third or fourth year after establishment alfalfa fields of 'Apollo' [Location 1 (L1)] and 'Cody' (L2) in 1992 and regardless of plant density the seeding year (Nelson et 'Cimarron' (L3) in 1993. Soils were Poynor cherty silt loam (loamyal., 1998). Competition and/or an allelopathic chemical skeletal over clayey, siliceous, mesic Typic Paleudult) at L1, Ashton or chemicals produced by the seedlings and young plants silt loam (fine-silty, mixed, mesic Mollic Hapludalf) at L2, and Waben may contribute to the decline because surviving plants very cherty silt loam (loamy-skeletal, siliceous, mesic Ultic Hapludalf) tend to be evenly spaced. Rice (1984) suggests that most, at L3. Established alfalfa was killed in May with herbicide within 2 m if not all, spatial patterns of plants are due to a combinaof selected alfalfa test plants, and then 1 yr later, Cody alfalfa was seeded within 1 m around the test plants. Granular chlorpyrifos and tion of allelopathy and competition and not to either seed treatment metalaxyl at planting did not improve alfalfa seedling factor alone. establishment or yield. Seedlings were smaller (p Ͻ 0.05) near both Allelochemicals from both foliage and root exudates live and dead test plants at L1, indicating mainly autotoxicity, but at contribute to allelopathy in certain ecosystems (Tukey, L2, yield per plant was reduced more within 25 cm from live than 1969; Putnam, 1985). Extracts of alfalfa top growth were from dead plants, indicating competition was involved. Clipping testreported to be more autotoxic to young alfalfa seedlings plants more frequently at L3 did not improve establishment and rethan were extracts from roots or crowns (Miller, 1996). duced seedling yield for six of eight harvests. Seedling density and dry matter yield averaged 70 and 44% (p Ͻ 0.05) of the control, Production and deposition of autotoxic chemicals from respectively, within 20 to 25 cm of test plants, an area equivalent to a an established plant may contribute to development of stand density of 8 plants m Ϫ2 . The zone of influence around established a zone of influence around it within which establishment alfalfa plants involves both competition and autotoxicity and needs and growth of new alfalfa plants would be reduced. In to be considered in replant decisions.Ontario, Canada, growth of peach (Prunus persica L.) seedlings was strongly inhibited within 0.9 m of old peach tree stumps or the sites where old stumps had

The objective of this study was to evaluate the effects of including alfalfa (ALF, Medicago sativa L.) or a combination of white (Trifolium repens L.) and red (Trifolium pretense L.) clovers (CLVR) inter-seeded into bermudagrass (Cynodon dactylon L. Pers.) on herbage nutritive value compared with monocultures of bermudagrass fertilised with 0 (0N), 56 (56N), or 112 (112N) kg nitrogen (N)/ha over four grazing seasons. At the end of the fourth year (during the winter), legume plants in ALF and CLVR were killed and the carryover N benefit on bermudagrass nutritive value was evaluated during the fifth year. Pre-grazing herbage of all pastures exceeded the dietary recommendations for growing steers to maintain 0.9 kg/day average daily liveweight gain for crude protein and total digestible nutrients, 118 and 617 g kg/DM, respectively. Post-grazing herbage in ALF was below 600 g/kg total digestible nutrients at all times during the grazing season, post-grazing total digestible nutrients of CLVR was below 600 g/kg during the late summer and autumn. Post-grazing herbage of monoculture bermudagrass pastures fell below 600 g/kg in the middle of summer regardless of N fertilisation. Carryover N benefits of legumes were similar to 112N in the early summer, but were not different than 0N and 56N during the late summer and autumn. Replacing applications of synthetic N in bermudagrass swards with inter-seeding of either clovers or alfalfa produce herbage with equivalent nutritive value to heavily N fertilised monocultures of bermudagrass during the early summer, and similar to moderately N fertilised in the late summer and autumn. The inclusion of legumes in bermudagrass swards can reduce the reliance on synthetic N fertilisation with little overall effect on herbage nutritive quality possibly decreasing environmental impacts of grazing production systems.

Tall fescue toxicosis adversely affects calving rate and weight gains reducing returns to cow-calf producers in the south–central United States. This grazing study estimated animal and economic performance implications of endophyte-infected fescue and calving season. Establishing novel endophyte-infected tall fescue on 25% of pasture acres resulted in improved calving rates (87% vs. 70%), weaning weights (532 lbs vs. 513 lbs), and partial returns per acre ($257 vs. $217). Additionally, fall-calving cows had higher calving rates (91% vs. 67%), weaning weights (550 lbs vs. 496 lbs), and partial returns per acre ($269 vs. $199) than spring calving cows.