Carbohydrate accumulation and utilization during shoot regrowth after defoliation winter has been studied extensively in most species used as forage. However, recent work suggests that N reserves found vegetative tissues also are important for tolerance hardiness. Results suggest these constitute an alternative source when 2 fixation and/or mineral uptake reduced. 15 labelling experiments indicate a large proportion of herbage is derived from mobilized stem bases or roots to developing...

Leaf elongation rate (LER) in grasses is dependent on epidermal cell supply (number) and duration of elongation. Nitrogen (N) fertilization increases LER. Longitudinal sections from two genotypes tall fescue (Festuca arundinacea Schreb.), which differ by 50% LER, were used to quantify the effects N components mesophyll division. Rate determined using a relationship between length displacement velocity derived continuity equation. was exponential. Relative rates increased 9% with high N, even...

Cold hardiness among zoysiagrass ( Zoysia spp.) genotypes varies, but the physiological basis for cold is not completely understood. The objective of this study was to determine relationship carbohydrate (starch, total soluble sugars, reducing sucrose, glucose, and raffinose family oligosaccharides) proline concentrations with acclimation lethal temperature killing 50% plants (LT 50 ). Thirteen were selected contrasting levels winter hardiness. Plants grown 4 wk 8/2°C day/night cycles a 10‐h...

Understanding differences in herbage yield of alfalfa ( Medicago sativa L.) can be simplified by using components: plants per area; shoots plant; and shoot (YPS). Our objective was to examine the influence plant population on components, morphology, forage quality ‘Vernal’, ‘Hi‐Phy’, Beltsville International Composite 5‐WH alfalfa. Ten‐week‐old seedlings were transplanted 0.9‐m 2 plots at populations 11, 22, 43,97, 172 m −2 early May 1984 1985. Plants clipped late June both years, harvested...

A trend toward early planting of soybean [ Glycine max (L.) Merr.] in Indiana results higher yield, but the limit to which a positive response occurs has not been evaluated. Our objective was determine how affects yield components and seed composition indeterminate planted late March through June Indiana. Three cultivars (Pioneer brand 92M61, Becks 321NRR, 367NRR) were sown at six dates (late June) West Lafayette, IN, 2006 2007. Across cultivars, ranged between 4.24 4.43 Mg ha −1 from...

Abstract Cellulosic bioenergy feedstock such as perennial grasses and crop residues are expected to play a significant role in meeting US biofuel production targets. We used an improved version of the Soil Water Assessment Tool ( SWAT ) forecast impacts on watershed hydrology water quality by implementing array plausible land‐use changes associated with commercial for two watersheds Midwest USA . Watershed‐scale were estimated 13 scenarios, including: Miscanthus × giganteus upland Shawnee...

Root total nonstructural carbohydrate (TNC) has been studied, but little is known about seasonal trends in proteins and other macronutrients legume roots. Our objectives were to determine how winter hardening resumption of growth spring influence (i) concentrations sugars starch, activities amylases; (ii) protein concentration composition, abundance N, P, K. Alfalfa ( Medicago sativa L.), red clover Trifolium pratense birdsfoot trefoil Lotus corniculatus biennial sweetclover Melilotus...

Phosphorus and K fertilization increases alfalfa (Medicago sativa L.) yield stand persistence, but the changes in components as affected by P fertility level are not known. Our hypothesis is that (or) will increase one or more components, those component responses may change with age. The objectives of this field study were to determine impact on forage during initial 3 yr after establishment. Treatments factorial combinations four rates (0, 25, 50, 75 kg ha−1) five 100, 200, 300, 400...

Nonstructural carbohydrates in stem bases are important for regrowth of tall fescue ( Festuca arundinacea Schreb.). The objectives this study were to i) examine changes concentration nonstructural individuals tem base tissues during regrowth; ii) evaluate the relationship between leaf elongation rate (LER) and carbohydrates; iii) estimate degree polymerization (DP) fructans regrowth. Plants grown a controlled environment chamber at 23°C with photosynthetic photon flux density 650 µmol m −2 s...

Leaf elongation rate (LER) of tall rescue ( Festuca arundinacea Schreb.) and other forage grasses is known to be modified by management practices. Our objectives were estimate the influence harvest frequency N fertilization on cell division, elongation, associated cellular changes that collectively result in LER rescue. In two experiments, was estimated, then length epidermal cells measured at 2 mm intervals from base elongating leaf throughout intercalary meristem. Using mature lengths...

Leaf elongation rate is a factor associated with yield per tiller and of canopy development. Elucidation the mechanism by which leaves elongate may assist plant breeders crop managers in optimizing agronomic performance. Our objectives were to locate leaf intercalary meristem tall rescue ( Festuca arundinacea Schreb.) assess relative contribution cell division, rate, mature length rate. Both division occurred an located lignin‐sensitive stain basal 30 mm elongating leaf. Growth rates within...

Abstract The Soil and Water Assessment Tool ( SWAT ) is increasingly used to quantify h y drologic water quality impacts of bioenergy production, but crop‐growth parameters for candidate perennial rhizomatous grasses PRG Miscanthus × giganteus upland ecotypes Panicum virgatum (switchgrass) are limited by the availability field data. Crop‐growth parameter ranges suggested values were developed in this study using agronomic weather data collected at Purdue University Quality Field Station...

Abstract Simulation models for perennial energy crops such as switchgrass ( Panicum virgatum L.) and Miscanthus x giganteus ) can be useful tools to design management strategies biomass productivity improvement in US environments. The Agricultural Production Systems Simulator APSIM is a biophysical model with the potential simulate growth of crops. crop modules do not exist Miscanthus, however, re‐parameterization existing could used these perennials. Our aim was evaluate ability predict dry...

Organic reserves in below‐ground storage organs are generally recognized as indicators of regrowth and persistence potential forages. The objective this experiment was to examine the causal relationships between alfalfa ( Medicago sativa L.) root organic reserves, i.e., nonstructural carbohydrates or N N, soluble protein, vegetative protein (VSP). Variations reserve level induced by cultivar differences (cv. Lodi Europe), length previous period (30 45 d), competitive position for light...

Large differences in winter hardiness exist among alfalfa (Medicago sativa L.) cultivars, but the physiological and molecular bases for these are not understood. Our objective was to determine how raffinose family oligosaccharide (RFO) accumulation steady state mRNA levels galactinol synthase (GaS) roots relate genetic variation survival. A GaS cDNA isolated that possesses over 70% identity with clones from other plant species. Induction of transcripts crowns hardy cultivars occurred within...

Carbohydrate composition changed seasonally in red osier dogwood (Cornus sericea L.) stem tissues. Starch concentration was highest fall and decreased to a minimum midwinter. Coincident with the breakdown of starch fall, there an increase concentrations soluble sugars. Soluble sugars were present Glucose, fructose, sucrose, raffinose predominant both bark wood In early spring, sugar increased. The seasonal interchange between did not simply reflect general quantitative shift balance because...

Forage legumes benefit pastures and hay crops by fixing N, improving seasonal distribution of growth, enhancing animal performance, but their lack persistence is viewed as a major limitation. Stand depends largely on plant in crown-forming perennials that do not spread stolons or rhizomes, seed production, timely germination, seedling survival annuals, biennials, many short-lived perennials. Stolon- rhizome-forming can colonize unoccupied areas if management favorable. Conversely,...

Addition of P and K fertilizer can increase alfalfa ( Medicago sativa L.) yield stand persistence, but the components associated with P‐ K‐induced variation in agronomic performance are not clear. Our objectives were: (i) to determine impact nutrition on productivity a relatively old stand; (ii) which changes forage yield. Treatments were factorial combination four five rates replicated times. Forage harvests occurred times annually. Plant populations determined early December late May each...