bluuebunny/crossref_metadata_2025_split huggingface dataset:
Day and Night Temperature Effects on Nitrogen and Soluble Carbohydrate Allocation During Early Reproductive Growth in Soybeans1
Authors: Thomas Judith F. , Raper C. David , Weeks Willard W. 
Published: July 2010

AbstractBy altering the timing of reproductive events, temperatures may affect allocation of N and C within soybean [Glycine max (L.) Merrill]. The objective of this study was to determine the changes in partitioning associated with early development of the reproductive sinks. Plants of the determinate cultivar ‘Ransom’ growing in controlled environments were transferred to inductive shortday photoperiods at the V3 stage and grown under 25 combinations of day/night temperatures over a range of day temperatures of 14 to 30 C and night temperatures of 10 to 26 C. Plants from each combination were sampled at 0, 20, 30, and 50 days after the first inductive photoperiod. Plants were separated into leaves, stems, and pods, freeze‐dried, and analyzed for total N and soluble carbohydrates.During the first 20 days after plants were transferred to short days and before pods appeared, increases in rates of accumulation of dry matter, N and soluble carbohydrates in leaves and stems were related to increases in both day and night temperatures. Time of pod appearance was inversely related to temperature. As pod growth became an active sink, accumulation rates of dry matter, N and soluble carbohydrates decreased in leaves and stems, but even at higher temperatures with the greatest rates of pod development, net accumulation of dry matter and N (and soluble carbohydrates in some instances) were measured during the final sampling interval. The most advanced plants at Day 50 were approaching full seed (R6) development stage. Nitrogen and soluble carbohydrate concentrations in leaves and stems were different among temperature treatments at the initial sampling on 20 days after treatments were imposed and before pods had appeared. During the subsequent growth intervals, there were no further variations of N concentration in leaves and stems within temperature treatments in association with stage of pod development through R6. However, concentrations of soluble carbohydrates had begun to decline as the stage of pod development approached R6. These results indicate that until the stage of seed fill, the greatest effect of reproductive growth on N reserves in vegetative tissues may be in limiting the amount of vegetative tissues rather than in net remobilization from these pools.
Effects of Turfgrass on the Establishment of Woody Plants1
Authors: Fales S. L. , Wakefield R. C. 
Published: July 2010

AbstractSuppression of woody plants by grasses has been widely reported; but few studies have investigated the factors responsible for the reduced growth and poor appearance often shown by ornamental trees and shrubs planted in association with turfgrass. This research was undertaken to determine the major factors responsible for this phenomenon.A field study, conducted over two growing seasons, evaluated the growth of flowering dogwood (Cornus florida L.) and forsythia (Forsythia intermedia Spaeth.) planted in established sod (Enfield silt loam soil, Typic Dystrochrept). Treatments included different sized areas of turf‐free space (0.3m2, 0.7m2, and 23.7m2), surface and subsurface placement of fertilizer and irrigation, and two mowing heights (10 cm and 4 cm). Turfgrass significantly reduced the growth of both woody species. Although supplementary fertilizer, applied as a topdressing, failed to benefit the ornamentals, subsurface treatments resulted in considerable increases in growth. Competition for moisture did not appear to be responsible for the observed differences in growth, since maintaining a high level of soil moisture failed to overcome the inhibitory effects of the turfgrass. Competition for N, however, was indicated by results of leaf tissue analysis.A bioassay experiment tested the hypothesis that the competitive nature of turfgrasses involves an allelopathic mechanism. Aqueous leachates of the roots of perennial ryegrass (Lolium perenne L.), red fescue (Festuca rubra L.), and Kentucky bluegrass (Poa pratensis L.) were applied to rooted cuttings of forsythia. Top growth of the forsythia was inhibited by leachates from all three turfgrass species. Root growth was suppressed by ryegrass and red fescue leachates.Results of these experiments indicate that the suppression of woody plants by turfgrasses may involve chemical inhibition as well as direct competition for available N.
Protein and Oil Content of Winged Bean Seeds as Measured by Near‐Infrared Light Reflectance1
Authors: Hildebrand D. F. , Chaven C. , Hymowitz T. , Bryan H. H. , Duncan A. A. 
Published: July 2010

AbstractGrain analyzers are being utilized by plant breeders to estimate the protein and oil content of various agricultural commodities. The method is rapid and inexpensive. Its potential use for the analysis of winged bean [Psophocarpus tetragonolobus (L.) DC.] seed meal was investigated in this study. Simultaneous estimations of protein and oil concentrations in winged bean seed meals made by a near‐infrared light reflectance instrument coupled to an analog computer (grain analyzer) were compared to protein and oil determinations by Kjeldahl and Soxhlet extraction procedures. The correlation between Kjeldahl protein and the grain analyzer values was 0.998. The correlation between Soxhlet extracted oil and the grain analyzer values was 0.995.The 240 winged bean accessions evaluated in this study were obtained from 16 countries. The seed protein contents ranged from 20.7 to 45.9%. The seed oil contents ranged from 7.2 to 21.5%.A centrally located grain analyzer facility should be able to monitor the protein and oil values in winged bean cultivar and breeding trials carried out anywhere in the world.
Forage Production of a Tall Fescue Sod Intercropped with Sorghum ✕ Sudangrass and Rye1
Authors: Belesky D. P. , Wilkinson S. R. , Dawson R. N. , Elsner J. E. 
Published: July 2010

AbstractA multispecies no‐tillage system was designed to produce supplemental forage for year‐round grazing while maintaining a viable tall fescue sod for erosion control. This system offers the potential to improve forage quantity and quality for low yielding tall fescue (Festuca arundinacea Schreb.) pastures in the South. Sorghum ✕ sudangrass hybrid, cv. ‘Pennington's summergrazer’ (Sorghum bicolor L. Moench ✕ Sorghum bicolor L. Moench) (SS hybrid), was seeded into tall fescue sod after the flush of spring growth, and rye (Secale cereale L.) seeded in early October after the end of the summer growing season for 3 consecutive years. Tall fescue sod kill treatments of no kill, 25, 50, and 100% of the surface area were obtained with 0.28 and 0.56 kg paraquat (1, 1'‐dimethyl‐4, 4'bipyridimium ion) per ha. Nine treatments were applied in a randomized block design replicated four times on Cecil sandy loam (Typic Hapludult, clayey, kaolinitic thermic). Phosphorus and K fertilizer was applied to satisfy soil test recommendations, while N fertilizer was applied in split applications across all treatments. Summer forage was harvested and separated by cutting height into tall fescue and SS hybrid, while winter yield was represented by tall fescue or tall fescue plus rye. The higher rate of paraquat gave no significant yield advantage to sod‐seeded species at a given level of tall fescue sod control. A tall fescue sod monoculture yielded 7,405 kg dry matter/ha annually (3‐year average). Inclusion of SS hybrid and rye in the tall fescue system with 50% sod kill increased total average forage yield to 11,115 kg/ha and improved distribution of yield over the year. Sorghum ✕ sudangrass hybrid accounted for 48%, (5,283 kg dry matter/ha) of the average yearly total yield for 50% sod kill. Yearly total forage yields were not significantly different far 50 and 100% levels of tall fescue sod kill seeded with both SS hybrid and rye.Thus, it was feasible to increase and improve distribution of forage yield and provide species diversity, while maintaining tall fescue sod as an integral part of the system.
Estimating Development Stages of Corn from Spectral Data — An Initial Model1
Authors: Badhwar G. D. , Henderson K. E. 
Published: July 2010

AbstractWhen applying remote sensing technology to crop area estimation or crop condition assessment, a knowledge of the crop development stage at the time the remotely sensed data is acquired is important. In addition to historical statistics and weather driven development stage models, remotely sensed spectral data provides a potential tool for estimation of crop development stage. A model based upon spectral data should also provide advantages in terms of simplicity, timeliness, and applicability to areas as small as individual fields.In this investigation, a model for determining development stage of corn (Zea mays L.) from spectral measurements in the four Landsat bands of 0.5 to 0.6, 0.6 to 0.7, 0.7, to 0.8, and 0.8 to 0.11 <m is proposed.Estimated corn development stages using the model were determined from Landsat data acquired over sample areas 01 the U.S. Corn Belt as well as agricultural research plots at the Purdue University Agronomy Farm, West Lafayette, Indiana. The estimated corn development stage using the model was compared to ground observations made with the Hanway scale (1966).Corn development stage estimates made from Landsat data had a correlation of R2 = 0.964 with the ground observed stages, being most accurate at stages earlier than Hanway Stage 6.0 (blister). Analysis of spectral data obtained from corn research plots at Purdue Agronomy Farm revealed that the model worked well with variation in plant population and soil background differences as well as arbitrary division into grain yield levels due to various experimental conditions. For all treatment variations of soil type and plant population and yield groupings, the R2 of calculated vs. observed development stage exceeded 0.95. This model's advantage for remote sensing is that it uses only spectral data and does not require meteorological data such as temperature, precipitation, and daylength. The model can be applied to individual corn fields rather than a general application to a region as large as crop reporting districts (or a state) and was found to work well for fields sampled over a large geographic area.
Date of Planting and Row Spacing Effects on Four Soybean Cultivars1
Authors: Parker M. B. , Marchant W. H. , Mullinix B. J. 
Published: July 2010

AbstractSoil moisture conditions favor April planting of soybeans [Glycine may (L.) Merr.] in the southern USA, but reports have indicated that soybean cultivars were not adapted to April planting. Data are not available on the response of newer cultivars to early and late plantings. Also, reports from the north central USA have indicated that soybeans yield more when planted in narrow (46 cm or less) than in wide (92 cm or greater) rows, but there are conflicting data regarding row width from the southern USA.A 3‐year study was conducted on a Tifton silt loam (fine‐loamy, siliceous, thermic, Plinthic Paleudult) at Tifton, Georgia (31° 28‘ N). ‘Essex’, ‘Davis’, ‘Bragg’, and ‘Hutton’, maturity groups V through VIII, respectively, were planted in narrow (46 cm) and wide (92 cm) rows at 15day intervals from early April to early July.The interval from planting to flowering decreased for Essex and Davis as the planting date was delayed from early April through early July. This relationship occurred for Bragg and Hutton after early May planting. Essex was the earliest flowering and produced the shortest plants among all cultivars within each planting date. Essex was too short for efficient combining.The overall effect of narrow rows vs. wide rows was a yield inuease of 1.2 quintals/ha or 4.2%, but yield response to narrow row planting was not affected by cultivars or planting dates.Highest yields of Essex were obtained from early May planting. The other three cultivars yielded equally well when planted from late April through early June. Yields of all cultivars were lower for early April and early July plantings than for May and early June plantings.May to early June was the optimum planting period for Davis, Bragg, and Hutton for the combined factors of yield, plant height, and seed quality, and none of the cultivars performed well in April planting. However, the late flowering characteristics of Davis, which apparently is responsible for relatively tall plants in April plantings, offers possibilities for use in breeding programs to develop desirable cultivars for April plantings but improved seed quality needs to be combined with other desirable traits.
Effects of N Fertilization and Cutting Schedules on Stockpiled Tall Fescue. I. Forage Yield1
Authors: Collins Michael , Balasko J. A. 
Published: July 2010

AbstractForage stockpiled in situ for winter use provides pasturage during a period of low forage production in midlatitude states of the midwestern and eastern United States. Two experiments were conducted to study the effects of harvest management and N fertilization rates on spring‐summer and autumn‐winter production of tall fescue (Festuca arundinacea Schreb.) forage. Treatments in Exp. I included four N rates; 0, 60, 120, and 180 kg/ha applied as NH4NO3 in split applications of one‐half in March and one‐half in August; three spring‐summer cutting schedules (1) mid‐June only, (2) mid‐May and early July, and (3) early June and mid‐July; and three autumnwinter harvest dates (1) mid‐December, (2) mid‐January, and (3) mid‐February. The soil was a moderately welldrained Lily loam (Typic Hapludults). Regression analysis indicated that the yield of forage available during winter increased as annual N application increased up to 137 kg/ha and 126 kg/ha for mid‐June stockpiling initiation in 1973–1974 and 1974–1975, respectively. The optimum annual N application rate for forage stockpiled beginning in early‐July was calculated to be 197 kg/ha in 1973–1974 and 136 kg/ha in 1974–1975.Stockpiled forage yields decreased from 2.50 metric tons/ha to 2.24 metric tons/ha between December and February averaged over the 2 years of the study. Winter in vitro digestible dry matter yield (IVDDM) decreased during winter.In Exp. II, treatments included four N rates: 0, 75, 150, and 225 kg/ha applied as NH4NO3 at the time of the last summer or autumn cutting which occurred in either early September, mid‐September, or early October. The soil was a Clarksburg silt loam (member of the fine‐loamy, mixed, mesic family of Typic Fragiudalfs). All forage was harvested in late winter. Forage yields during spring and summer increased up to the highest rate of N applied in both seasons. Any delay in initiation of stockpiling in Exp. II resulted in reduced winter yield. Winter yields increased in response to N application. Cutting date in autumn had little influence on forage yields the following spring, but rate of N fertilization did influence spring yield. Increasing autumn N application from 0 to 225 kg/ha increased spring forage production by an average of 2.40 metric tons/ha.
Combined Nitrogen and Vegetative Regrowth of Symbiotically‐grown Alfalfa1
Authors: Fishbeck Kathleen A. , Phillips Donald A. 
Published: July 2010

AbstractFew studies clearly compare N source effects on herbage yield of alfalfa (Medicago sativa L.) grown with Rhizobium over several harvest cycles. Therefore, the effects of combined N on nodulation, growth, N accumulation, and development of alfalfa were studied over four harvest/regrowth cycles with a genotype cloned from the nondormant cv. ‘Dohfari.’ Ramets inoculated with Rhizobium meliloti Dang. strain 102F28 and irrigated with 0,2,8, or 16 mM N provided as NH4NO3, NO3‐, or NH4+ were grown in vermiculite in a naturally illuminated greenhouse in two replicate experiments from March through June and July through October. All combined N treatments enhanced herbage dry weight and total crude protein above the nil N control during the first growth period. The promotive effect of combined N decreased with each harvest until during the fourth regrowth, plants totally dependent on Rhizobium for reduced N produced herbage and crude protein yields equivalent to plants supplied 8 or 16 mM N as NH4NO3. Plants grown with 2mM N, a more reasonable N concentration for the soil solution, were more productive than nil N plants during the first two growth cycles but had no advantage during the third and fourth cycles regardless of the form of combined N used. Nitrate suppressed nodule development more than either NH4NO3 or NH4+. Greater availability of combined N increased the soluble sugar:starch ratio in the root and crown tissues. No significant differences were observed between the two experiments except that plants grown later in the year (July to October) took longer to flower during each regrowth cycle.The data indicate that the Rhizobium symbiosis cannot produce sufficient reduced N for optimum alfalfa growth during the first few harvest/regrowth cycles. During subsequent regrowth cycles, however, plants totally dependent on Rhizobium for N compounds had overcome the period of N‐limited growth and produced as much herbage and crude protein as plants grown with levels of combined N that might be expected under normal field conditions.
IVDMD, Total Sugars, and Lignin Measurements on Normal and Brown Midrib (bmr) Sorghums at Various Stages of Development1
Authors: Hanna Wayne W. , Monson Warren G. , Gaines T. Powell 
Published: July 2010

AbstractReduced lignin concentrations found in brown midrib (bmr) mutants of sorghum, Sorghum bicolor (L.) Moench., have great potential for increasing the in vitro dry matter digestibility (IVDMD) of sorghum forage. The objective of this study was to determine the effects of five bmr mutants on IVDMD, lignin concentration and total sugars of young vegetative forage that would be used for grazing or hay.Forage from bmr 12 and bmr 18 harvested 4 weeks after planting was significantly higher in IVDMD than their normal counterparts in each of the 3 years tested. Three other mutants were not consistently higher in IVDMD indicating a possible environmental interaction. Total reducing and non‐reducing sugars were not related to IVDMD and the bmr mutants did not have a significantly different total sugar concentration than normal types. Four weeks after planting, IVDMD of bmr 12 forage was 7.2 and 5.6 percentage units higher than normal forage for leaves and stems, respectively. The differences observed for the bmr gene should lead to significant improvement in animal performance.
Chloride Effects on Water Potentials and Yield of Winter Wheat Infected with Take‐all Root Rot1
Authors: Christensen N. W. , Taylor R. G. , Jackson T. L. , Mitchell B. L. 
Published: July 2010

AbstractSeverity of take‐all root rot (caused by Gaeumannomyces graminis var. tritici) of winter wheat (Triticum aestivum L.) has been decreased in the Willamette Valley of western Oregon by applying Cl containing fertilizers. Apparent increases in leaf turgor of field grown wheat following spring topdressing with NH4Cl fertilizer suggested that Cl salts affect plant water potential components. Since the growth rate of G. graminis tritici declines with declining water potential, changes in plant water potential could influence the rate of host colonization by the pathogen. Leaf water (Ψ), osmotic (π), and turgor (P) potentials of winter wheat grown in replicated field trials on an Argiaquic Xeric Argialboll, an Aquultic Argixeroll, and a Pachic Ultic Argixeroll fertilized in March with 135 to 140 kg N/ha as (NH4)2SO4 or NH4Cl were measured in May and June to ascertain whether application of Cl salts influences water potential components in wheat. Fresh plant weight at milky ripe stage, grain yield, and grain kernel weight were measured to evaluate treatment effects on yield of wheat infected with take‐all root rot.Applying 342 and 355 kg Cl/ha as NH4Cl reduced π in ‘Yamhill’ and ‘Stephens’ winter wheat leaves measured in May by 4 and 2 bars, respectively. Chloride treatment effects on π generally persisted through June. The slope of the regression of π on percent Cl in leaf tissue at one site was the same as that predicted by the van't Hoff equation indicating that increased symplasm Cl concentration probably accounted for the measured change in π. Leaf water and turgor potentials tended to be lower and higher, respectively, when these parameters were influenced by Cl treatment.Use of NH4Cl fertilizer increased grain yields from 770 to 2,150 kg/ha (11 to 40%) over those obtained with (NH4)2SO4. Fresh weight yield and kernel weight were also increased with NH4Cl fertilization. Application of (NH4)2SO4 plus KCl or NaCl (101, kg Cl/ha) at one site increased grain yield and kernel weights over those obtained with (NH4)2SO4 alone.Results of this study suggest that the susceptibility of winter wheat plants to G. graminis tritici colonization may be reduced by lowering the chemical potential of water in the plant. Because the osmotic potential in wheat plants changes readily with Cl application, fertilization with Cl salts provides an opportunity to actively manage plant water potential components for the express purpose of take‐all root rot suppression.
Aflatoxin Production on Various Popcorn Genotypes1,2
Authors: McMillian W. W. , Widstrom N. W. , Wilson D. M. 
Published: July 2010

AbstractAflatoxin, a metabolite of the ubiquitous fungus, Aspergillus flavus Link, is a chronic contaminant of preharvest corn (Zea mays L.) produced in some areas of the USA. Growing hybrids that sustain relatively low levels of toxin has been suggested as a method of minimizing this potentially serious threat to animal and human health. The purpose of this 3‐year study was to evaluate ears of selected popcorn genotypes for corn earworm, Heliothis zea (Boddie), damage, incidence of greenish‐yellow fungus (GYF) sporulation characteristic of A. flavus Link infections, and aflatoxin contamination levels in the grain. Evaluations were conducted under field conditions in Tifton loamy sand (Thermic, Plinthic Paleudult) and involved 17 popcorn genotypes. Results demonstrated significant differences among popcorns for levels of aflatoxin contamination, fungal infection, and corn earworm damage. A significant interaction between genotypes and years indicated that information from a single year cannot be relied upon to accurately identify host plant genotypes with consistent low aflatoxin levels.