Forage legumes are key components of livestock rations whether grazed or harvested as hay or silage. The predominant forage legumes grown in humid regions of the US, Canada, and northern Mexico belong to the Medicago, Trifolium, and Lotus genera. Cool-season legumes conduct symbiotic nitrogen fixation through a relationship with specific soil bacteria, Rhizobium, that allows plants to convert atmospheric nitrogen to protein for their growth. Alfalfa is the oldest crop grown solely for forage, having been cultivated for about 9000 years. Red clover is used for pasture and can produce high-quality hay and silage. Birdsfoot trefoil has many fine stems that lodge. Birdsfoot trefoil can be harvested for hay and silage, but because of its weak stems, it is best suited for pasture. Crownvetch is a long-lived perennial but winter hardiness and persistence are reduced by frequent harvest.

Slow germination of bermudagrass ( Cynodon dactylon [L.] Pers.) seed causes difficulty in stand establishment because of weed competition and drought. Temperature has a major influence on germination rate and total germination. Hulled and unhulled common bermudagrass seed were placed in a germinator for 28 days at night (12 hr)/day (12 hr) temperatures of 5/15, 10/20, 15/25, 20/30, 25/35, and 30/40 °C. Germinated seed were recorded every two days. The best germination of hulled seed was at 20/30°C followed by 25/35 °C and 15/25 °C temperature treatments. Optimum germination of unhulled seed was more specific with the most rapid and total germination at 25/35 °C. Temperature treatments lower than 15/25 °C severely reduced germination rate and total germination of both hulled and unhulled seed. In the southeastern U.S., hulled bermudagrass seed should be planted from mid-April through June and unhulled seed from mid-May through June.

ABSTRACTOverseeding warm‐season perennial grasses with annual ryegrass (Lolium multiflorum Lam.) is a common practice throughout the southeastern United States to extend the grazing season with high quality forage. ‘Coastal’ bermudagrass [Cynodon dactylon (L.) Pers.] competition to overseeded annual ryegrass was determined by light reaching the soil surface, ryegrass seedling density, and ryegrass herbage production. Treatments were 0, 56, and 112 kg ha−1 N 6 to 8 wk before planting ryegrass and sod management practices (SMPs) of a shallow disking (2.5 to 5.0 cm), applying a desiccant, and a control before planting in combination with mowing to a 2.5 or 10.0‐cm sod height (SH) for 3 yr. Applying N 6 to 8 wk before planting did not influence any of the plant parameters measured. The shallow disking SMP and 2.5‐cm SH allowed the most light to reach the soil surface and had the greatest ryegrass seedling density. At the 10‐cm SH the shallow disking SMP had a greater seedling density than the desiccant and control SMP. None of the SMP–SH combinations consistently improved first harvest or annual herbage mass yields over the control at the 2.5‐cm SH. Significant differences may have occurred if the first harvest was taken earlier. Spring bermudagrass recovery was reduced by the shallow disking SMP and 2.5‐cm SH. At a bermudagrass SH of 10 cm or less there was little advantage to disking or using a desiccant to enhance ryegrass production.

ABSTRACTForage legumes have the unique attributes of producing a high‐quality forage to enhance animal performance and the ability to utilize atmospheric N that eliminates the legume plants dependence on soil N. Biological N2 fixation (BNF) rates are dependent on the infection by an effective rhizobia strain on the root hairs for each legume species. Producers planting forage legumes have the potential to utilize both benefits. However, both forage quality and BNF are influenced by numerous factors, including legume species, management practices, and climate, which determine their contribution to a forage‐livestock system. Because of soil and climatic differences, the region of the United States dictates which legume species are grown, how productive they are, and how they are utilized in a forage‐livestock system. Major factors influencing the contribution of legumes will be reviewed followed by a discussion of predominant legume species and their utilization in various regions of the United States.

ABSTRACTNitrogen enhances annual ryegrass (Lolium multiflorum Lam.) growth on the infertile Coastal Plain soils in the southeastern United States but N can be antagonistic to clovers. Nitrogen rate and time of application were evaluated on an arrowleaf clover (Trifolium vesiculosum Savi.)–annual ryegrass mixture growing on a Coastal Plain soil for 3 yr in northeast Texas. Fertilizer treatments were 0, 34, 67, or 101 kg N ha−1 at planting or first true clover leaf (FCL) stage followed by 0 or 67 kg N ha−1 in December and March. Planting, FCL, and December N applications enhanced ryegrass production but had little effect on arrowleaf clover production by mid March. The general trend was for clover percentage and yield to decrease and ryegrass yield to increase as the total amount of N fertilizer applied increased. The no‐N treatment always had the greatest percentage clover usually followed by single N application treatments with clover percentages greater than 50%. Average annual yield of ryegrass alone without N was 1139 kg ha−1 compared to 4038 kg ha−1 with 201 kg N ha−1 Applying 67 kg N ha−1 at FCL and in December and March was always one of the most productive N treatments. Applying 67 kg N ha−1 only twice at FCL and in December was the best compromise for maintaining a high clover percentage and clover–ryegrass yield and was always equal to ryegrass alone with three applications of 67 kg N ha−1

Bahiagrass (Paspalum notatum Flugge) is an important perennial forage grass for the southeastern United States, being well adapted to conditions such as sandy or poorly drained soils, drought, and heavy continuous grazing. Current bahiagrass cultivars germinate over an extended period of time and the slow emergence produces incomplete stands, allowing weeds to compete and delaying grazing or first cutting for hay. A recurrent restricted phenotypic selection (RRPS) program began in 1996 and continued for four cycles for improving the emergence and establishment rates within Tifton 9 bahiagrass ('Pensacola' type). The resulting cycle-4 (C4) rapid-emergence 'TifQuik' was then increased and tested for seedling emergence, vigor, and establishment. TifQuik had a fourfold improvement of emergence compared to Tifton 9 after 1 wk in greenhouse trials. Emergence rates after 1 and 2 wk were significantly greater for TifQuik compared to Tifton 9 in replicated field trials. Plant heights after 3 wk from planting were 0.12 m for TifQuik versus 0.08 m for Tifton 9. The first harvest dry-matter yield of TifQuik was 3128 kg ha(-1) compared with 1539 kg ha(-1) for Tifton 9 and the total establishment year dry-matter yields were 9230 kg ha(-1) and 7466 kg ha(-1) for TifQuik and Tifton 9, respectively. TifQuik had greater first-clipping yields than Tifton 9 at Ona, FL, in 2005. The accelerated emergence and establishment of TifQuik will be useful in sod-based rotation systems with cotton (Gossypium hirsutum L.) and peanut (Arachis hypogaea L.).

Parameters describing the growth of cool‐season annual clovers are necessary for potential growth simulations, but have not yet been determined. Accordingly, the objective of this study was to quantify and compare the key parameter for biomass production, radiation use efficiency (RUE), for arrowleaf (Trifolium vesiculosum Savi.), crimson (T. incarnatum L.), rose (T. hirtum All.), and subterranean (T. subterraneum L.) clovers. Data on the fraction of light intercepted and biomass were collected biweekly over 2 yr at Overton, TX, and were used to calculate the RUE. Radiation use efficiency was calculated for biomass as a function of cumulative intercepted photosynthetically active radiation (IPAR) for aboveground biomass and for total biomass including roots. Similarly, RUE was calculated for regrowth following one or two cuttings. Over the 2 yr of this study, the mean RUEs for aboveground biomass original growth were 2.92, 2.52, 1.94, and 1.86 g MJ−1 for rose, arrowleaf, crimson, and subterranean, respectively. The mean RUEs for the total biomass including roots, during this time were 3.01, 2.59, 2.00, and 1.98 g MJ−1, respectively. Relative to the original growth aboveground RUE values, the RUE of aboveground regrowth following one cutting averaged 92% across the four species. Likewise, the mean RUE of aboveground regrowth of the four species following two cuttings was 119%. These values of RUE will aid modelers in simulating these important N2 fixing species.

Understanding the growth pattern of cool-season annual clovers is necessary to develop management practices that maximize forage production and identify compatible grass associations and farming systems. Plant density, light interception, shoot yield, and root yield of arrowleaf ( Trifolium vesiculosum Savi.), crimson ( T. incarnatum L.), rose ( T. hirtum All.), and subterranean ( T. subterraneum L.) clovers were compared for 3 yr on a sandy loam at Overton, TX. Clovers were sampled every 2 wk when uncut, and after being cut once or twice. Initial plant densities ranged from 200 to 250 m −2 and then declined to 100 to 150 m −2 during the growing season. The uncut treatment resulted in 3-yr average maximum shoot yields of 2480 g m −2 for arrowleaf, 1290 g m −2 for crimson, 1410 g m −2 for rose and 1000 g m −2 for subterranean clovers. Autumn growth and regrowth after cutting was greater for crimson and subterranean clovers than for arrowleaf and rose clovers. Crimson and subterranean clovers reached near 100% light interception 4 wk after cutting. Cutting usually decreased yield for all species except subterranean clover that increased with cutting because of a prostrate growth habit. When cut, rose clover always had one of the smallest shoot and root yields. Root yield increased for all clovers during the growing season when not cut and with no or small root yield decreases after cutting. Crimson and subterranean clovers are better suited for grazing and crop rotations because of their earlier maturity and response to defoliation.

Crimson clover ( Trifolium incarnatum L.) is a widely used cool‐season annual clover in the southeastern USA, but is not considered a dependable reseeder. Grazing termination dates (GTD) of 2‐wk intervals from 1 April to 15 May for 3 yr were used on small plots of seven crimson cultivars. Seed production characteristics, seed germination after seed harvest, remaining hard seed percentage after 90 d heat treatment, and volunteer reseeding were determined. There was a general decline in flower density, seed weight flower −1 and seed yield as GTD was delayed. There was variability among cultivars for flower density and seed weight flower −1 , but in only 1 out of 3 yr for seed production. Percentage germination, soft seed, and hard seed after seed harvest were not influenced by GTD. Cultivars did differ for percentage germination and hard seed in 2 of 3 yr. Cultivar ranking was not consistent among years except for Columbus that always had high germination and low hard seed percentages. ‘Auburn’ and ‘Flame’ maintained the best hard seed percentage after the 90 d heat treatment. Volunteer seedling densities of 100 m −2 or higher occurred if grazing was terminated by mid‐April except for Columbus. The poor reseeding of crimson clover is due to the initial low hard seed production and decline of hard seed percentage during the summer.

Forage & GrazinglandsVolume 3, Issue 1 p. 1-7 Forage and Grazinglands Guides A Guide to Overseeding Warm-Season Perennial Grasses with Cool-Season Annuals Gerald W. Evers, Corresponding Author Gerald W. Evers Regents Fellow and Professor g-evers@tamu.edu Texas A&M University Agricultural Research and Extension Center, Overton, 75684Corresponding author: Gerald W. Evers. g-evers@tamu.eduSearch for more papers by this author Gerald W. Evers, Corresponding Author Gerald W. Evers Regents Fellow and Professor g-evers@tamu.edu Texas A&M University Agricultural Research and Extension Center, Overton, 75684Corresponding author: Gerald W. Evers. g-evers@tamu.eduSearch for more papers by this author First published: 14 June 2005 https://doi.org/10.1094/FG-2005-0614-01-MGCitations: 1 Evers, G. W. 2005. A guide to overseeding warm-season perennial grasses with cool-season annuals. Online. Forage and Grazinglands doi: 10.1094/FG-200-0614-01-MG. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume3, Issue12005Pages 1-7 RelatedInformation

Since 1994, urban-absentee landowners have dominated rural landownership in Texas. This landownership change has created potential environmental problems associated with natural resource management. Few of the new landowners have any formal training in the basics of the soil–plant–animal interface. The solution may be to develop a vehicle that provides the new class of landowners with basic information regarding natural resource management. Faculty members from the Texas A&M University (TAMU) Agricultural Research and Extension Center–Overton (representing both Texas Cooperative Extension and the Texas Agricultural Experiment Station and having department affiliations with Soil and Crop Sciences, Animal Science, and Agricultural Economics) developed the Pasture and Livestock Management Workshop for Novices. The main goals in developing the program were to: (i) provide basic information regarding management of soil–plant–animal resources; and (ii) introduce the workshop participants to the educational resources available to them through the land-grant university system. To determine effectiveness of the program, pretests and posttests were administered to the workshop participants. To date, pretest scores have averaged 63.8 (D average), whereas posttest scores have averaged 80.3 (B average). Exit surveys were also conducted to determine the attitude of the workshop participants regarding the overall quality of their experience. The popularity of the workshop is such that, since the inception of the first workshop (2001), subsequent workshops have been booked nearly 1 year in advance. Given the combination of learning environment, mix of classroom and field laboratory exercises, and nonthreatening scientific presentations, we have little doubt that the Pasture and Livestock Management Workshop will continue to be a popular program with urban-absentee landowners.

Autumn desiccation of warm-season perennial grasses is one method to enhance the establishment and early production of overseeded cool-season annuals. Potential herbicides were compared with paraquat, glyphosate, and dalapon to desiccate a dallisgrass–bermudagrass sod for overseeding annual ryegrass over a 2-yr period. Fluazifop-P at ≥ 0.14 kg/ha, glufosinate at ≥ 1.12 kg/ha, and haloxyfop at ≥ 0.07 kg/ha provided good dallisgrass desiccation and ryegrass yields similar to those with dalapon and glyphosate. Dallisgrass recovery was inversely related to desiccation rating for all treatments except for paraquat. None of the herbicide treatments had the desired combination of acceptable dallisgrass desiccation, improved early ryegrass production, and acceptable dallisgrass recovery. Nomenclature: Dalapon; fluazifop-P; glufosinate; glyphosate; haloxyfop; paraquat; sethoxydim; annual ryegrass, Lolium multiflorum Lam. ‘Gulf’; bermudagrass, Cynodon dactylon (L.). Pers.; dallisgrass, Paspalum dilatatum Poir. Additional index words: Desiccant, overseeding.

Plantings of warm season perennial grasses from seed are slow to establish and often fail because of competition from fast growing weeds. Paraquat (1,1′‐dimethyl‐4,4′‐bipyridinium ion), a fast acting contact herbicide, has been used successfully in establishing cool season grasses from seed for seed production. Purpose of this study was to determine if the application of paraquat after planting, but before the desired grasses emerged, would reduce weed competition and promote rapid establishment of the desired grasses. In the spring of 1974 and 1975 ‘Pensacola’ bahiagrass ( Paspalum notatum Flugge) and dallisgrass ( Paspalum dilatatum Poir.) were planted on a prepared seedbed on a Morey fine‐silty loam [Typic Argiaquolls, fine‐silty, mixed (noncalcareous), thermic]. Experimental design was a split, split plot with four replications for each of the two grasses. Main plots were paraquat applied at 0.56 kg in 154 liters of water/ha at random time intervals after planting. Subplots were 12 fertilizer treatments consisting of a four by three factorial of 0, 22.4, 44.8 and 67.3 kg/ha of phosphorus and 0, 33.6, and 67.3 kg/ha of nitrogen applied on the day of planting. Plant densities were determined at two or three locations in each plot by randomly throwing a 0.09 m2 quadrant on to the plot. Dry matter yields were determined by cutting a 1 × 4.2 m area from the center of each plot to a 4 cm height. Paraquat was most effective when applied as late as possible but before bahiagrass and dallisgrass plants emerged. Dry matter yields of bahiagrass were tripled and dallisgrass doubled. Under the climatic conditions and soil type in this study, optimum time for applying paraquat to dallisgrass plantings was 10 but no later than 14 days and to bahiagrass plantings 14 to 21 but no later than 28 days after sufficient rainfall for grass seed germination. No consistent benefit was produced by any of the fertilizer treatments.

The effect of a 10‐, 12‐, and 14‐hr photoperiod on the seed production characteristics of eight apomictic buffelgrass lines was studied. Inflorescences were produced earlier and in larger numbers under a 12‐hr photoperiod than under a 10‐ or 14‐hr photoperiod. Also, seed per inflorescence, and spikelets and seed per involucre were greater under the 12‐hr photoperiod. The 14‐hr photoperiod resulted in the latest and least inflorescence production but was the most favorable for production of involucres per inflorescence and inflorescence length. The eight buffelgrass lines varied in their response to the three photoperiods for inflorescence numbers and characteristics. The possibility of developing hybrids for seed production under photoperiods up to 14‐hr is indicated.

Parameters describing the growth of cool-season annual clovers are necessary for potential growth simulations, but have not yet been determined. Accordingly, the objective of this study was to quantify and compare the key parameter for biomass production, radiation use effi ciency (RUE), for arrowleaf (Trifolium vesiculosum Savi.), crimson (T. incarnatum L.), rose (T. hirtum All.), and subterranean (T. subterraneum L.) clovers. Data on the fraction of light intercepted and biomass were collected biweekly over 2 yr at Overton, TX, and were used to calculate the RUE. Radiation use effi ciency was calculated for biomass as a function of cumu- lative intercepted photosynthetically active radiation (IPAR) for aboveground biomass and for total biomass including roots. Similarly, RUE was calculated for regrowth following one or two cuttings. Over the 2 yr of this study, the mean RUEs for above- ground biomass original growth were 2.92, 2.52, 1.94, and 1.86 g MJ -1 for rose, arrowleaf, crimson, and subterranean, respec- tively. Th e mean RUEs for the total biomass including roots, during this time were 3.01, 2.59, 2.00, and 1.98 g MJ -1 , respectively. Relative to the original growth aboveground RUE values, the RUE of aboveground regrowth following one cutting averaged 92% across the four species. Likewise, the mean RUE of aboveground regrowth of the four species following two cuttings was 119%. Th ese values of RUE will aid modelers in simulating these important N 2 fi xing species.