Grazing Termination Dates of Summer-Dormant Flecha Tall Fescue

Summer-dormant, Mediterranean-type tall fescue (Festuca arundiancea Schreb.) has potential to replace summer-active, Continental-type tall fescue and trad-itional, annual small grain graze-out systems in the Southern Great Plains region of the USA. This region is characterized by severe water deficits accompanied by extreme heat in summer, and by relatively mild, rainy winters (Malinowski et al. 2009). Although the climate of the southern Great Plains is different from the Mediterranean climate, the temperature and precipitation patterns during summer are historically similar. However, in the past decade, the bimodal precipitation pattern with peaks in May and September has become highly unpredictable, resulting in delayed planting of small grains in autumn and lack of winter forage for grazing livestock (Malinowski et al. 2009). As a perennial forage crop, summer-dormant tall fescue provides a source of forage during the winter months when warm-season grasses are dormant, reducing pasture establishment costs, soil erosion, and the time and labor associated with annual forage systems (Kindiger and Conley 2002; Beck et al. 2008; Islam et al. 2011). Replacing summer-active with summer-dormant cool-season grasses can provide some resilience in the forage systems to extreme seasonal precipitation and temperature patterns (Clark and Harris 2009; Malinowski et al. 2005). These conditions, combined with relatively mild winters, allow summer-dormant tall fescue to be better adapted and more persistent in the southern Great Plains than traditional, summer-active types of tall fescue and other cool-season perennial grasses (Hopkins and Bhamidimarri, 2009; Malinowski et al. 2009). However there are no best-management practices that address the timing of grazing cessation as it relates to summer-dormant tall fescue stand persistence and animal production. The objectives of this study were to determine the effects of four grazing termination dates on endophyte-free ‘Flecha’ summer-dormant tall fescue forage production, animal production (average daily gain [ADG], gain, and grazing days), and tall fescue persistence (% stand and root mass)

Annual Forage Legume Response to Herbicides Labelled for Lucerne Establishment

Weed competition reduces stand establishment, thus lowering forage production and quality. However, there are no herbicides labelled for annual legume establishment, despite several labelled for the establishment of lucerne (Medicago sativa). Some of these may be useful in the establishment and production of annual forage legumes. Lucerne herbicides have greater potential for use on other legumes, since they have grazing and feeding clearance. The objective of this paper is to summarize annual legume yield response trials to herbicides labelled for lucerne establishment

ADAPTATION OF ANNUAL FORAGE LEGUMES IN THE SOUTHERN GREAT PLAINS

Our objective was to evaluate adaptation and compatibility of cool-season annual legumes overseeded into perennial grasses in the southern Great Plains. Freeze damage, vigor, and standing crop of 14 annual legume species were evaluated during spring at three locations in Oklahoma and Texas from 2006 to 2008. Across locations and years, standing crop of hairy vetch (Vicia villosa Roth) and Austrian winter pea (Pisum sativum L. ssp. arvense (L.) Poir.] averaged 3,513 and 3,210 kg dry matter (DM) ha-1, respectively. Standing crop of crimson clover (Trifolium incarnatum L.) and arrowleaf clover (T. vesiculosum Savi) averaged 1,138 and 1,071 kg DM ha-1, respectively. Although subject to freeze damage, annual medics produced more spring forage than annual clovers on soil with pH \u3e 8.0. Most of the annual legumes survived winter, demonstrating their adaptability to pastures in the southern Great Plains, but hairy vetch and Austrian winter pea consistently provided the most spring forage

ADAPTATION OF ANNUAL FORAGE LEGUMES IN THE SOUTHERN GREAT PLAINS

Our objective was to evaluate adaptation and compatibility of cool-season annual legumes overseeded into perennial grasses in the southern Great Plains. Freeze damage, vigor, and standing crop of 14 annual legume species were evaluated during spring at three locations in Oklahoma and Texas from 2006 to 2008. Across locations and years, standing crop of hairy vetch (Vicia villosa Roth) and Austrian winter pea (Pisum sativum L. ssp. arvense (L.) Poir.] averaged 3,513 and 3,210 kg dry matter (DM) ha-1, respectively. Standing crop of crimson clover (Trifolium incarnatum L.) and arrowleaf clover (T. vesiculosum Savi) averaged 1,138 and 1,071 kg DM ha-1, respectively. Although subject to freeze damage, annual medics produced more spring forage than annual clovers on soil with pH \u3e 8.0. Most of the annual legumes survived winter, demonstrating their adaptability to pastures in the southern Great Plains, but hairy vetch and Austrian winter pea consistently provided the most spring forage

Improving Dual-Purpose Winter Wheat in the Southern Great Plains of the United States

This chapter covers the production and breeding status of winter wheat (Triticum aestivum L.) used for early-season animal grazing and late-season grain production in the Southern Great Plains of the United States. Besides, in the chapter, the current production status and needs, the drawbacks of current cultivars, breeding strategies of the crop, novel genomics tools, and sensor technologies that can be used to improve dual-purpose winter wheat cultivars were presented. We will focus on traits that are, in general, not required by cultivars used for grain-only production but are critical for cool-season forage production

Small Grains as Winter Pasture in the Southern Great Plains of the United States

Small-grain cereals are widely adapted and used as annual cool-season pastures in the Southern Great Plains (SGP) of the United States, where livestock and forage production are the largest contributors to agricultural income. The advantage of growing small grains in the region is evident due to the widespread adoption and flexibility of production for grain only, forage only, or both grain and forage (i.e., dual purpose). Farmers in the SGP often prefer the use of small grains for dual purpose mainly because of alternative income options from livestock and/or grain, ensuring stable income especially when product prices fluctuate with market demands. Small-grain forage is exceptionally important during autumn, winter, and early spring when forage availability from other sources is low. By providing nutritionally high-quality forage, small grains minimize the need for protein and energy supplements. Besides being used for winter pasture, small grains also serve as cool-season cover crops. While small grains offer different advantages in the integrated crop-livestock system in the region, farming management practices can play an important role to maximize the benefit. The objectives of this chapter are to summarize the significance of small grains as winter pasture and highlight the production status of each small-grain species in the SGP of the United States

Endophyte Status in Summer-Dormant Tall Fescue in the Southern Great Plains of USA

Non-toxic fungal endophytes provide persistence-related benefits to summer-active, continental-type tall fescue (Festuca arundinacea Schreb.), as well as reduced animal toxicosis compared to toxic endophytes. However, the benefits of fungal endophytes to summer-dormant, Mediterranean-type tall fescue persistence or production are unclear. Summer-dormant tall fescue has potential to replace traditional, annual small grain graze-out systems in the Southern Great Plains region of the USA. This region is characterized by severe water deficits accompanied by extreme heat in summer, and by relatively mild, rainy winters (Malinowski et al. 2009). Summer-active tall fescues are better suited to high rainfall areas (\u3e 900 mm annual average rainfall (AAR)) east of the 97° longitudinal meridian, while summer-dormant tall fescues are best adapted to lower rainfall areas (600 to 900 mm AAR) between the 97° and 99° longitudinal meridian (Butler et al. 2011). The objective of this field study was to determine the effects of the ‘novel’ endophyte strain AR542 on persistence of summer-dormant tall fescue ‘Flecha’ in the Southern Great Plains of the USA. Two field experiments were conducted to evaluate the effect of the novel endophyte AR542 on the survival of Flecha

Economic Potential of Substituting Legumes for Synthetic Nitrogen in Warm Season Perennial Grasses used for Stocker Cattle Grazing

Stocker cattle grazing warm season perennial grasses is an important economic activity in the southern Great Plains. Substantial increases in the price of nitrogen fertilizer is negatively affecting forage producers’ profitability. Two alternative nitrogen management systems that use annual and perennial legumes have been developed for bermudagrass pastures. The goal of the study is to determine if the legumes systems are more profitable than the conventional practice of applying synthetic sources of nitrogen. Results of the two-year grazing study show that the legume systems could not compete economically with the common practice.economics, grazing, legumes, bermudagrass, nitrogen fertilizer, stocker cattle, Crop Production/Industries, Farm Management, Production Economics,

Transgenic expression of phytase and acid phosphatase genes in alfalfa (Medicago sativa) leads to improved phosphate uptake in natural soils

Alfalfa (Medicagosativa L.) is one of the most widely grown crops in the USA. Phosphate (P) deficiency is common in areas where forage crops are grown. To improve the use of organic phosphate by alfalfa, two Medicagotruncatula genes, phytase (MtPHY1) and purple acid phosphatase (MtPAP1), were overexpressed in alfalfa under the control of the constitutive CaMV35S promoter or the root-specific MtPT1 promoter. Root enzyme activity analyses revealed that although both genes lead to similar levels of acid phosphatase activities, overexpression of the MtPHY1 gene usually results in a higher level of phytase activity than overexpression of the MtPAP1 gene. The MtPT1 promoter was more effective than the CaMV35S promoter in regulating gene expression and extracellular secretion under P-deficient conditions. Measurement of growth performance of the transgenic lines further proved that the best promoter–gene combination is the MtPHY1 gene driven by the MtPT1 promoter. Compared to the control, the plants with high levels of transgene expression showed improved growth. The biomass of several transgenic lines was three times that of the control when plants were grown in sand supplied with phytate as the sole P source. When the plants were grown in natural soils without additional P supplement, the best performing transgenic lines produced double the amount of biomass after 12 weeks (two cuts) of growth. Transgene effects were more obvious in soil with lower pH and lower natural P reserves than in soil with neutral pH and relatively higher P storage. The total P concentration in leaf tissues of the high-expressing transgenic lines was significantly higher than that of the control. The transgenes have great potential for improving plant P acquisition and biomass yield in P-deficient agricultural soils. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11032-011-9628-0) contains supplementary material, which is available to authorized users