bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphorus Translocation Between Small, Non‐Reproductive Tillers and the Main Plant of Maize1
Authors: Russelle M. P. , Schild J. A. , Olson R. A. 
Published: July 2010

AbstractTiller growth and development are generally limited under high plant populations used in modern maize (Zea maysL.) production. The physiological relationship between the main plant and small, barren tillers has not been clarified. Two experiments were conducted to investigate the existence, direction, and relative magnitude of P translocation during different phenological intervals, and to observe the effect of tiller senescence on P translocation. A foliar application of 32P was made at each of three growth stages to the tiller or to the most recently expanded leaf on the main stalk of several maize plants grown hydroponically in the greenhouse. Plants were later separated into tiller, main plant, and roots and were assayed for radioactivity. In a field experiment, foliar applications of 32P were made to tillers of maize grown on a Sharpsburg silty clay loam (Typic Argiudoll, fine, montmorillonitic, mesic) when the main plants were in the 11‐ to 12‐ or 15‐ to 16‐ leaf stage. Aboveground tissue was removed 32 or 33 days after treatment and assayed for radioactivity. Apparent translocation of 32P from main plant to tiller was very small or nonexistent in plants grown in the glasshouse, whereas translocation from tillers to the main plant and roots was substantial. More than 24% of the radioactivity found in the whole plants at sampling had been translocated from the tiller, even though tillers accounted for <0.3% of the total dry weight at the 16‐leaf stage. In the field study, movement of isotope to developing grain from a tagged tiller depended directly on total grain weight and was greater when the tiller did not senesce before sampling. The presence of active, barren tillers may therefore be an important characteristic for reducing maize yield losses where environmental stress limits nutrient absorption and assimilation during late vegetative and early reproductive growth.
Sulfur Accumulation in Tall Fescue, Orchardgrass, and Alfalfa1
Authors: Barney P. E. , Bush L. P. , Leggett J. E. 
Published: July 2010

AbstractSulfur nutrition of forages and its utilization by animals are poorly understood. The availability of S to animals apparently is different among forage species. Sulfur accumulation and distribution were examined in seedlings of tall fescue (Festuca arundinaceaSchreb.), orchardgrass (Dacfylis glomerataL.), and alfalfa (Medicago sativaL.). Seedlings were grown in half‐strength Hoagland's No. 1 solution with or without 0.5 mMSO4added to the nutrient solution. When the seedlings were approximately 1 month old, S accumulation kinetic and pH studies were conducted utilizing 35S‐SO4to measure S accumulation in shoots and roots. Sulfur accumulation in plant parts and accumulation rates were higher in those plants previously grown without SO4than in those plants previously grown with SO4. The differences were due to a greater concentration gradient between the nutrient solution and the plant tissue of those plants previously grown without SO4than those grown with SO4. Apparent SO4, absorption sites or carriers were saturated between 0.05 and 0.5 mMSO4. The SO4absorption mechanism of alfalfa appeared to be different than the SO4absorption mechanism of the grasses because increased solution pH decreased S accumulation by alfalfa, but had no effect on S accumulation by the grasses. The ratio of shoot to root S accumulation per unit dry weight during the experimental period was as much as three times greater in tall fescue than in the other species.
Effect of Applied and Residual P on Double‐Cropped Wheat and Soybean under Conservation Tillage Management1
Authors: Sharpe R. R. , Touchton J. T. , Boswell F. C. , Hargrove W. L. 
Published: July 2010

AbstractIn the Piedmont area of Southeastern USA, the economic advantages of double‐cropped wheat (Triticum aestivumL. Thell) and soybean (Glycine maxL. Merr.) have recently resulted in increased acreage of both crops. In many cases, the rotation is wheat and soybean under conservation tillage management. Many soils in this region of the USA are low in P, and it may be advantageous to raise these soils to the high soil test range before initiating conservation tillage practices. The purposes of this study were to determine if it is necessary to raise low P soils to the high soil test range prior to initiating conservation tillage systems and to determine how long a single high rate of P will maintain yields equal to those obtained with annual or biannual applications. Wheat and soybean were double‐cropped under conservation tillage management on a Cecil sandy loam soil (clayey, kaolinitic Typic Hapludult) from 1978 to 1981. The P treatments were applied as a one‐time application in the fall of 1977. Broadcast rates of P were 0,64, 128,256, and 384 kg ha−1. Two annual P applications of 64 kg P ha−1were also included for comparison of residual soil P and annually applied P. One‐time applications of 128 or more kg P ha−1provided sufficient soil P to maintain soybean yields significantly higher than the zero P application rate 4 years after application. The 128 kg P ha−1treatment also produced consistently good wheat yields for 3 years after application, but the 256 and 384 kg P treatments reduced wheat yields in 1978 due to increased lodging and glume blotch ((Septoria nodorum). The data indicate that a single application of 128 kg P ha−1can maintain wheat and soybean yields for at least 3 years in a double‐cropping conservation tillage system without significantly reducing micronutrient uptake. Phosphorus fertilization increased soil P levels and plant tissue P. Applied P increased extractable soil Zn, but decreased the concentration of Zn, Cu, and Mn in the soybean plant tissue.
Effects of Sulfur and Nitrogen Levels and Clipping on Competitive Interference Between Two Annual Grass Species
Authors: Center D. M. , Jones M. B. , Vaughn C. E. 
Published: July 2010

AbstractAnnual ryegrass (Lolium multiflorumLam.) and soft chess (Bromus mollisL.) are often seeded for increased forage production and erosion control on California annual rangelands. Observations in grazed pastures and small plots indicate that the relative proportions of these two species in the community can be influenced by the application of S and N fertilizers. The purpose of this study was to further define the effects of S, N, and clipping on yield response and interference between these two important annual grassland species. Plants were grown in a greenhouse in unleached pots filled with Josephine loam (fine‐loamy, mixed, mesic Typic Haploxerults). Both species were seeded in monoculture and in a 50:50 mixture at a total density of 2000 viable seed m−2. Treatments were factorial combinations of 0, 10, 20, 30, 40, or 80 mg S kg−1soil at the time of planting and N applied at 10 or 30 mg kg−1soil every 14 days. Onehalf of the pots were clipped to a height of 3 cm every 28 days and the other half were clipped only at the termination of the experiment. Dry matter yield and percent S were measured for all clippings and percent N for the last clipping on the repeatedly clipped pots. Only dry matter production was measured on the pots clipped once at the end of the experiment. Yield and response to S and N of ryegrass was greater than that of brome in all treatments. Yield per plant of ryegrass was greater when grown with brome than in monoculture in both the clipped and unclipped pots. In the clipped pots there was little difference in the yield of brome per plant whether grown in mixture or in monoculture, but under unclipped conditions brome yielded more per plant in monoculture than in mixture. Based on analysis of relative yield totals and relative crowding coefficients no significant competitive interference could be detected in the clipped pots at any S or N level. In the unclipped pots the two species were competing and ryegrass was the better competitor. The nature of the interference was not changed with the addition of S or N. From this it was concluded that at the rates used in this study, the major factor influencing competitive interaction between these two species was light, and S and N levels were not major influencing factors.
No‐Tillage of Grain Sorghum on a Shrinking Clay Soil1
Authors: Gerik Thomas J. , Morrison John E. 
Published: July 2010

AbstractConservation tillage systems, such as no‐tillage, have shown tremendous potential for controlling erosion, yet results in crop growth and yield have varied with location, environment, and soil type. The objectives of this study were to evaluate the effects of no‐tillage (NT) and conventional tillage (CT) on growth and development of grain sorghum (Sorghum bicolorL. Moench) grown on a heavy clay soil in a humid, subtropical climate. The study was conducted over a 2‐year period on an Austin silty clay (fine‐silty, carbonatic, thermic Entic Haplustolls) with grain sorghum grown in rotation with winter wheat (Triticum aestivumL.). Grain sorghum yields did not differ significantly between NT and CT. Soil water contents were not significantly different between the tillage treatments, but there were consistent trends toward more soil water under NT throughout sorghum development each year. The tillage treatments did not have a major effect on soil temperature. Reductions in the leaf area index at panicle initiation noted under the NT treatment, however, were not reflected in differences in grain yield. Therefore, no‐tillage may become an attractive management alternative for areas with similar soil and climatic conditions.
Soybean Seed Growth. I. Timing of Growth of Individual Seeds1
Authors: Spaeth S. C. , Sinclair T. R. 
Published: July 2010

abstractThe seed‐filling duration for whole soybean [Glycine mar (L.) Merr.] plants of indeterminate cultivars is not well defined, because the initiation and termination of rapid dry matter accumulation by individual seeds are sequential, not synchronous. Arbitrary selection of events to delimit duration may not identify durations which are physiologically important. To relate the contribution of individual seeds to whole‐plant seed‐filling duration, the times of initiation and termination of rapid growth were determined for individual seeds at all morphological positions of individual 'Chippewa 64' plants grown under field conditions in Ithaca, N.Y. The soil type was a Hudson silty clay loam (fine, illitic, mesic Glossaquic Hapludalf). Initiation was determined directly by determining the date when the ovule silhouette within intact pods reached a size of 2.5 ✕ 2.0 mm. Termination was defined as the time when cotyledon peripheries changed from green to yellow. Duration of growth of individual seeds was calculated as the time between these two events. Initiation of seed growth progressed sequentially up the stem of plants over periods of more than 21 days in some larger plants. Morphological characteristics other than node number influenced the time of initiation slightly. Seeds on secondary racemes initiated rapid growth 6 to 9 days later than seeds at the same nodes which were located on primary racemes. Seeds ceased growth in a pattern similar to that of initiation but over shorter periods. The long periods for initiation indicate that arbitrarily selected single events are less likely to identify physiologically well‐defined measures of seed‐filling duration.
An Improved Screen‐Cage Design for Use in Plant and Insect Research1
Authors: Lambert Lavone 
Published: July 2010

AbstractLarge screened cages are often necessary for certain types of plant and insect research. Traditionally, the cage frames have been constructed of wood and covered with wire and plastic screen. These cages are very expensive to construct and maintain. To reduce the cost of doing research in screened cages and to improve their serviceability, a 614.4 m2metal frame, screen‐covered cage for inclusion and exclusion of insects was developed. This cage should be of interest to plant breeders and entomologists who work in areas such as host plant resistance to insects, biological control, insect population dynamics, and controlled pollination. The cage is 2.4 m high × 19.2 m wide × 32.0 m long and cost $5450 (1982 prices) including all labor. Cage construction costs spread over the usable life of the cage frame are estimated to be only 44% of those for a wood frame cage. In addition, maintenance costs of the metal frame cage are: only a fraction of those for a wood frame cage.
Quality Changes of Late Summer and Autumn Produced Alfalfa and Red Clover1
Authors: Collins Michael , Taylor T. H. 
Published: July 2010

AbstractLate summer and autumn produced cool‐season grasses have been widely studied as stockpiled forage for pasturage in late autumn and winter. Knowledge of changes in chemical composition and quality of forage legumes during autumn and winter, however, is lacking. The object of this field study was to investigate the quality and chemical composition of late‐summer and autumn produced alfalfa (Medicago sativaL.) and red clover (Trifolium pratenseL.) forage. Samples of alfalfa and red clover grown on a silt loam soil (Typic Paleudalfs) were collected during autumn and early winter of 2 years following cutting at two times in late summer (average dates of 22 August and 8 September). Quality analysis included in vitro dry matter disappearance (IVDMD), N, P, K, Ca, and Mg concentrations in the forage. Nitrogen concentration in red clover forage declined initially after frost and then increased or remained unchanged during the remainder of the sampling period. The decrease in alfalfa N concentration continued throughout the sampling period in 1975 but was similar to the trend for red clover in 1976. The lowest N concentration recorded for either species was equivalent to 17.8 and 17.2% crude protein (CP) for alfalfa and red clover, respectively. In 1975, forage IVDMD declined continuously after frost and reached a minimum of 56.5% for alfalfa and 51.2% for red clover. In 1976, alfalfa IVDMD increased slightly until approximately 30 days after frost and then declined rapidly through 56 days after frost (12 December). The trend of red clover IVDMD in 1976 was similar to that of alfalfa except that the decline in IVDMD began sooner after frost for red clover. In 1976, the lowest IVDMD measured was 68.3 and 58.9% for alfalfa and red clover, respectively. Concentrations of all minerals studied declined during autumn, K being lost most rapidly, P and Mg intermediate, and Ca least rapidly. Averaged over treatments, the loss in K during the sampling period amounted to 77 and 65% of the K present initially compared with losses of 21 and 15% of the Ca during 1975 and 1976, respectively. Results of a 2‐year field study indicate that IVDMD of both alfalfa and red clover declined substantially during late autumn. Nitrogen concentration in the forage, on the other hand, declined initially after frost but then changed little for the remainder of the sampling period. The concentrations of P and Mg in the forage declined to levels below those suggested for several classes of livestock by the end of the sampling period.
Forage Legume Response to Dicamba and 2,4‐D Applications1
Authors: Griffin J. L. , Watson V. H. , Knight W. E. , Cole A. W. 
Published: July 2010

AbstractWeed control options in pastures containing legumes are limited due to herbicide selectivity. A field study was conducted for 2 years in northeast Mississippi on a Leeper fine sandy loam (fine, montmorillonitic, nonacid, thermic Vertic Haplaquept) soil to evaluate tolerance of subterranean (Trifolium subterraneumL.), white (T. repensL.), crimson (T. incarnatumL.), red (T. pratenseL.), and arrowleaf (T. vesiculosumSavi) clovers and vetch (Vicia sativaL.) to dicamba (3,6‐dichloro‐o‐anisic acid), 2,4‐D [(2,4‐dichlorophenoxy) acetic acid], and a 3:l (W:W) mixture of 2,4‐D + dicamba. Stands of all clover species were generally reduced where dicamba at 0.56 kg ha−1and where 2,4‐D + dicamba at 0.42 + 0.14 or 0.84 + 0.28 kg ha−1were applied. Forty‐five days after herbicide application legume yields, with the exception of crimson clover, were reduced at least 24% when treated with dicamba. Yields of all clover species were severely reduced where 2,4‐D + dicamba was applied ranging from 50% for subterranean to 84% for red clover. Subterranean clover yield was not affected and white clover yield was only slightly reduced (28%) where 2,4‐D at 1.12 kg ha−1was applied; yields of other clover species were markedly reduced. Vetch was killed with all herbicides applied. To determine residual activity, bermudagrass [Cynodon dactylon(L.) Pers.] sod was treated with dicamba and 2,4‐D + dicamba 120, 90, 60, 30, and 15 days prior to overseeding crimson and white clover on 1 October. The study was conducted for 2 years on a Leeper fine sandy loam soil. Application time of dicamba at 0.28 kg ha‐1and 2,4‐D + dicamba at 0.42 + 0.14 kg ha−1did not affect crimson or white clover yields measured in mid‐May. However, crimson and white clover yields were reduced an average of 39 and 55% where dicamba was applied at 0.56 and 1.12 kg ha−1, respectively, and 37% when 2,4‐D + dicamba was applied at 1.68 + 0.56 kg ha−115 days prior to overseeding compared to 30 days. Selective broadleaf control can be obtained by using 2,4‐D at 1.12 kg ha−1in pastures containing subterranean and white clover. Dicamba at 0.56 kg ha−1or 2,4‐D + dicamba at 1.68 + 0.56 kg ha−1should be applied to warm‐season grass pasture at least 30 days prior to overseeding in order to avoid residual activity on overseeded legumes.
Predicting Cold Tolerance in Perennial Ryegrass from Subcrown Internode Length1
Authors: Wood G. M. , Cohen R. P. 
Published: July 2010

AbstractThe high value of perennial ryegrass (Lolium perenne L.) for turf and forage is unquestioned; however little use is now made of the species in northeastern United States because of its reputed low cold tolerance. Many new cultivars now available have been selected for increased cold tolerance but remain unproven. This research reports a cold hardiness screening test that can aid in extending the usable range of the species northward. A significant negative correlation was found between subcrown internode length in laboratory−germinated perennial ryegrass seedlings and winter survival of the same cultivars grown in the field (Typic Udipsamments soil). Cultivars with a relatively short subcrown internode length generally had less winter injury than did those with a longer subcrown internode length. A period of only 7 days from seed was required to produce the seedlings for internode measurements. Winter survival data used for correlation with the laboratory test were obtained from 1.2 × 1.8 m replicated field plots for the years 1975 to 1977 and 1980 to 1981. We concluded that the technique could be a valuable supplement to other cold tolerance screening methods.
Skip‐Row Planting and Row Pattern Effects on Virginia‐Type Peanut Cultivars1
Authors: Mozingo R. W. 
Published: July 2010

AbstractSince increasing peanut (Arachis hypogaea L.) production per area of land is a constant goal of researchers, skip‐row planting was an avenue that needed exploring. A 3‐year study was conducted at the Tidewater Research and Continuing Education Center in Suffolk, Va. to determine the effects of two planting patterns, two row patterns, and two cultivars on the yield, value, and grade characteristics of virginia‐type peanut. Planting patterns of solid (all rows planted) and skip‐row (two 0.91 m rows planted and one 0.91 m wide row fallow) were used in a 2 × 2 × 2 factorial arrangement with row patterns of a single row centered in a 0.91 m wide row and twinrows (0.18 m apart) centered in a 0.91 m wide row for the cvs. Florigiant and NC 7. Plots were 3.66 m wide and 10.67 m long with the two center rows harvested for the single row planting and the four center rows harvested for the twin row planting. Soil types for the study were Dragston fine sandy loam (coarse‐loamy, mixed, thermic, Aerie Ochraquults) in 1979, Dragston loamy fine sand in 1980, and an Eunola loamy fine sand (fine‐loamy, siliceous, thermic Aquic Hapludults) in 1981. NC 7 produced a higher percentage of extra large kernels (ELK), sound mature kernels (SMK), total meat (TM) and had a higher dollar value ha−1 than Florigiant. No differences were found between the two cultivars for yield or percentage of fancy size pods (FP). The two row patterns had no effect on yield, value or any grade characteristic. Skip‐row planting produced a significantly (P < 0.01) higher yield and value on a planted hectare basis than did solid planting, while no differences were recorded for any grade characteristic. The highest yield (4599 kg ha−1) and value (2266 dol ha−1) were recorded for NC7 in the twin‐row pattern with skip‐row planting.
Cowpea Response to N Form, Rate, and Timing of Application1
Authors: Beverly R. B. , Jarrell W. M. 
Published: July 2010

AbstractCowpeas [Vigna unguiculata (L.) walp.] grown in California may receive little or no N fertilizer, or as much as 100 kg ha−1 N, usually applied preplant. Research was undertaken to determine whether N management could increase seed yield of furrow‐irrigated cowpeas on a fine‐loamy, mixed, thermic Haplic Durixeralf soil. Treatments included no N fertilizer, 168 kg ha−1 N as ammonium nitrate broadcast preplant, and side‐dressing with two N sources [calcium nitrate or urea‐ammonium nitrate (UAN) solutions] at two rates (56 or 168 kg ha−1 N) applied either at bloom or during podfill. Nitrogen application increased seed yield, with side‐dress application being more effective than preplant fertilization. Side‐dress application at bloom increased yield relative to application during podfill, and UAN produced higher yields than calcium nitrate. The higher rate of side‐dress N did not significantly increase seed yield. Preplant fertilization increased vegetative growth, but shoot dry matter differences disappeared during the reproductive period. Symbiotic N2 fixation decreased and mineral N uptake increased (as indicated by ureide‐N and NO−3 −N concentrations in xylem exudate, respectively) in response to N fertilization. Differences between preplant‐fertilized and control plants for these parameters did not persist through reproductive growth, whereas side‐dress application did cause differences during podfill. The increase in seed yield due to N management did not appear to be explained by increased growth, N accumulation in plant parts, or N supply during podfill. We propose that seed yield increased due to decreased consumption of photosynthates by nodules following inactivation of N2 fixation by N fertilization.