bluuebunny/crossref_metadata_2025_split huggingface dataset:
White Lupin Growth, Yield, and Yield Components in Eastern Canada: Influence of Management Factors
Authors: Faluyi M. A. , Zhang F. , Leibovitch S. , Smith D. L. 
Published: July 2010

AbstractManagement studies are required to assess the full potential of white lupin (Lupinus albus L.) as a grain crop for eastern Canada. A 2‐yr study to quantify the effects of management practices on morphology, yield, and yield components of two large‐seeded white lupin cultivars (Primorski and Ultra) was conducted at the E.A. Lods Agronomy Research Centre of McGill University in Quebec, Canada, on a fertile sandy loam soil and a well‐drained clay loam soil. Treatments included two planting dates, two row spacings (20 and 40 cm), and two cultivars, factorially combined on two soil types in 1991 and 1992. The weather was unusually cool and wet in 1992, while 1991 was more typical of the area. In both years, there were effects on plant growth, yield, and yield components due to soil types, sowing dates, row widths, and cultivars. In 1991, Ultra had 23 and 55% greater seed yield than Primorski on clay loam and sandy loam soils, respectively, whereas yields did not differ between the two cultivars in 1992. Early seeding resulted in greater yields than later seeding in both years, but this effect was larger in 1991 than 1992. Yields were higher when lupin was produced in narrower than wider rows; the effect was more pronounced on a clay loam than on a sandy loam soil. Interactions occurred between lupin cultivars and each of the three management factors (row width, seeding date, and soil type). Overall, an early seeding date in narrow rows is recommended for lupin production in short‐season areas.
Water Stress during Seed Filling and Leaf Senescence in Soybean
Authors: De Souza P. I. , Egli Dennis B. , Bruening William P. 
Published: July 2010

AbstractWater stress during seed filling could reduce soybean [Glycine max (L.) Merr.] yield by accelerating leaf senescence and shortening the seed filling period. Greenhouse experiments were conducted to (i) evaluate the effect of water stress during seed fill on leaf senescence and (ii) determine the potential role of redistributed C and N in moderating the effect of water stress during seed fill. Soybean plants (‘McCall’, Exp. 1; ‘Elgin 87’, Exp. 2) were grown in soil‐filled pots. At the beginning of Growth Stage R6, two levels of water stress were imposed until maturity: daily waterings of 60% (moderate stress) and 30% (severe stress) of the water required to bring well‐watered pots to field capacity. Moisture stress reduced yield by reducing seed size (8–20%) in Exp. 1 and seed number (18%) and seed size (14–32%) in Exp. 2. Moisture stress accelerated leaf senescence, as shown by more rapid declines in leaf chlorophyll and N, and shortened the seed filling period in both experiments. In Exp. 2, a 50% depodding treatment was applied at the beginning of Growth Stage R6. Depodding delayed senescence and physiological maturity. Moisture stress accelerated leaf senescence and reduced seed size on the depodded plants, but the effect was less than on the nondepodded plants. Our results demonstrate that moisture stress during seed filling reduces yield by accelerating senescence and shortening the seed filling period. Increasing the source‐sink ratio may reduce the effect of moisture stress on seed size.
Lentil Green Manure as Fallow Replacement in the Semiarid Northern Great Plains
Authors: Pikul Joseph L. , Aase J. Kristian , Cochran Verlan L. 
Published: July 2010

AbstractGreen manures (GM) may offset inorganic N needs and improve soil quality. Study objectives were to determine effects of green manure on soil‐N fertility, water use, soil quality, and yield of spring wheat (Triticum aestivum L.). On two treatments, lentil (Lens culinaris Medikus cv. Indianhead) was green manured in a green manure‐spring wheat rotation. Lentil was killed by disking (GMMF) or chemicals (GMCF). Additional treatments were annually cropped wheat (AW) in a mechanical fallow (MF) or chemical fallow (CF) sequence. No inorganic N was used on GMMF and GMCF. Experiments were started in 1991 on a Williams loam (fine‐loamy, mixed Typic Argiboroll) near Culbertson, MT. Green‐manure treatments used 56 mm more water than fallow treatments when lentil was grown to lowerpod set. When lentil was killed at full bloom, there were no differences in water use among GM and fallow treatments. There were no differences among treatments in soil water at wheat planting. Wheat yield was 25% less on GM than on MF and CF. Soil NO3‐N (0–0.6 m) was 35% less on GM than MF and CF rotations. There were no differences in soil quality indicators of bulk density, organic C, pH, electrical conductivity, and deep NO3‐N (0.6–1.8 m) among treatments after two cycles of GM. Potentially mineralizable N was 66% greater on GM treatments than on fallow treatments. Short‐term results (5 yr) show that available N limited wheat production more than did soil water on the GM treatments. Soil improvement using green manures may require many additional cropping cycles.
ROOTEDGE: Software for Measuring Root Length from Desktop Scanner Images
Authors: Kaspar Thomas C. , Ewing Robert P. 
Published: July 2010

AbstractOne approach for measuring the length of roots washed from soil samples is to use a desktop scanner to acquire binary images and then use image analysis procedures to determine root length. Normally, this approach requires user‐adjusted exposure thresholding. The objectives of this study were to develop a procedure for obtaining binary images of root samples with a desktop scanner that does not require user‐adjusted exposure thresholding of each image and to test the performance of the newly developed ROOTEDGE program by using images containing single or multiple root segments of corn (Zea mays L.). ROOTEDGE was developed for measuring the length of digitized roots using the edge chord algorithm. It is insensitive to object orientation, has four image‐processing operations, and holds only seven lines of the image in memory. Visual comparisons of digitized images with actual root segments showed that root segments with diameters less than 0.15 mm were not being completely digitized by the image acquisition procedure and were fragmented in the images. The most complete root images were produced by using the highest available scanner resolution and the lowest scanner threshold level for exposure. Using the closing image‐processing operation in ROOTEDGE with a test coefficient of 1 also helped to join fragmented objects within images and improved the correlation of ROOTEDGE measurements to direct measurements. Ratios of ROOTEDGE length measurements to manual line‐intersection length measurements ranged from 0.98 to 0.88 for four corn root samples of different sizes. In general, the ROOTEDGE software and image acquisition system accurately measured corn root length without user‐adjusted exposure thresholding.
Variation among Soybean Cultivars in Dinitrogen Fixation Response to Drought
Authors: Serraj Rachid , Sinclair Thomas R. 
Published: July 2010

AbstractDinitrogen fixation in soybean [Glycine max (L.) Merr.] is especially sensitive to soil drying, and this trait can have important negative affects on yield. An exception to this general response has been the identification of ‘Jackson’ soybean as drought tolerant for N2 fixation. The objectives of this research were to examine the response in additional soybean cultivars of N2 fixation to soil drying under field conditions, and to determine if there is any link between the drought sensitivity among cultivars and the ureide levels in the plants. Two field experiments were conducted to further examine the genetic variation in the sensitivity of soybean cultivars for biomass and N accumulation rates in response to soil drying. Substantial variation among soybean lines was found, and the drought‐tolerance trait was demonstrated again in Jackson. Differences between cultivars in the response of N accumulation to drought stress were associated with differences in petiole ureide concentration found in well‐watered plants. An experiment was conducted in the greenhouse with eight soybean cultivars grown in pots and exposed to drought by soil dehydration over a 2‐wk period. Differences among cultivars in the sensitivity of N2‐fixation rates to soil drying found from measurements of acetylene reduction activity (ARA) in the greenhouse correlated with differences in N accumulation in the field (r2 = 0.86). The tolerance of N2 fixation to drought stress was associated (r2 = 0.84) with maximum ARA in response to changes in O2 concentration around nodules. Among the eight cultivars, there was a significant negative correlation (r2 = 0.73) between the drought tolerance of N2 fixation and ureide concentration in the xylem sap. Ureide levels might be an efficient way to screen large numbers of genotypes for N2‐fixation drought tolerance.
Establishment of Rhizoma Peanut: Interaction of Cultivar, Planting Date, and Location on Emergence and Rate of Cover
Authors: Williams M. J. , Kelly‐Begazo C. A. , Stanley R. L. , Quesenberry K. H. , Prine G. M. 
Published: July 2010

AbstractRhizoma perennial peanut (RPP), Arachis glabrata Benth., has high nutritive value, drought tolerance, and persistence; however, inconsistent establishment success and slow rate of coverage has limited the use of RPP in production systems. The objectives of this study were to determine the effects of planting date (February, April, June, August, and December), location (Brooksville, Gainesville, and Quincy, FL), and cultivar (Florigraze and Arbrook) on emergence (sprouts per square meter at 2 to 12 wk post planting) and rate of RPP cover (percent ground cover at 26, 52, 78, and 104 wk post planting). We also determined the relationship of sprout counts during the emergence period with rate of cover. Number of sprouts per square meter at 12 wk post planting ranged from 0 to >200 and, in most cases, the sprout counts obtained for April, June, August, and December planting dates were lower or equal to those from the February planting date, regardless of location or cultivar. Generally, Arbrook had higher numbers of sprouts per square meter at 12 wk post planting than Florigraze, but this did not translate into higher ground cover ratings at 26 wk. Number of sprouts per square meter was positively correlated with percent ground cover. The highest correlation coefficient (0.69) occurred for the relationship of sprouts per square meter at 12 wk post planting and ground cover at 26 wk post planting; correlations of responses declined from that point as stands aged. Rate of cover was also variable, taking between 26 and >104 wk post planting to reach >60% RPP ground cover. On average, February plantings achieved >60% RPP ground cover 26 wk earlier than any of the other planting dates. This study indicates that establishment times for RPP can be more variable than has been thought. The first criterion for deciding when to plant is the need for reliable soil moisture (from rainfall or irrigation) for 60 to 90 d post planting. Secondly, if there is more than one time of the year that meets this moisture requirement, then the planting date with the longest frostfree period after planting should be chosen.
Evapotranspiration, Yield, and Water Use Efficiency of Corn Hybrids Differing in Maturity
Authors: Howell Terry A. , Tolk Judy A. , Schneider Arland D. , Evett Steven R. 
Published: July 2010

AbstractShort‐season corn (Zea mays L.) hybrids may reduce irrigation requirements and permit earlier harvest. We measured and compared evapotranspiration (ET) of a short‐season (SS, Pioneer 3737) and full‐season (FS, Pioneer 3245) hybrid under full irrigation in 1994 at Bushland, TX, and examined differences in growth, yield, and water use efficiency (WUE). Both hybrids were planted the same day in contiguous 4‐ha fields (each field with a weighing lysimeter to measure ET directly), were irrigated simultaneously until the SS hybrid reached mid grain fill (R5 dent stage), and were managed for high productivity. Harvest was at the normal field‐dried grain water content of 136 g kg−1 for the region. Rainfall was 320 mm; 465 and 577 mm of irrigation was applied to the SS and FS hybrid fields, respectively. Seasonal ET was reduced with the SS hybrid (SS, 673 mm; FS, 802 mm), with the primary reduction after SS anthesis. Peak daily ET rates (some >10 mm d−1) were not affected by hybrid type. Grain yields (dry basis) declined from 1322 to 1130 g m−2, but grain water use efficiency (WUEg = grain yield/ET) was similar across hybrids: SS, 1.68 kg m−3; FS, 1.65 kg m−3. Dry matter (DM) was reduced by >390 g m−2 for the SS hybrid, but DM water use efficiency (WUEd = DM/ET) was identical for the two hybrids, at 3.02 kg m−3. The SS hybrid reached physiological maturity 12 d earlier than the FS hybrid and was harvested 11 d sooner. Leaf area index was >5.5 m−2 m−2 for the FS hybrid, but barely >4 m−2 m−2 for the SS hybrid. The WUEd, WUEg, and peak daily ET rates were not appreciably different for the two hybrids when fully irrigated, although seasonal ET was less with the SS hybrid. A shorter‐maturity hybrid can reduce ET and seasonal irrigation requirement, but it will not reduce the needed irrigation capacity (flow per unit area) by more than 5 to 10%, as that is largely dictated by the near‐maximum daily ET rate needed to avoid soil water deficits and a corresponding yield reduction. With prevailing regional pumping and production costs, the reduced production income with a SS hybrid would be more than six to eight times the saving in irrigation water cost, but this could be offset by higher grain marketing prices with an earlier harvest and by the opportunity for grazing income from a winter wheat (Triticum aestivum L.) double‐crop.
Forage and Nitrogen Yield of Barley—Pea and Oat—Pea Intercrops
Authors: Carr Patrick M. , Martin Glenn B. , Caton Joel S. , Poland W. W. 
Published: July 2010

AbstractBarley (Hordeum vulgare L.) and oat (Avena sativa L.) have been intercropped with field pea [Pisum sativum subsp. sativum var. arvense (L.) Poir.] to increase forage yield and quality. Our objective was to evaluate the effects of two barley and two oat cultivars and seeding rates of cereal—pea intercrop on forage production, crude protein (CP) concentration, and N yield. A field experiment was conducted in 1993 and 1994 under dryland management in both fallowed and continuously cropped, no‐tillage environments. ‘Bowman’ and ‘Horsford’ barley, and ‘Dumont’ and ‘Magnum’ oat, were each sown at 93, 185, and 278 kernels m−2 with ‘Trapper’ pea at 40, 80, and 120 seeds m−2, in all possible rate combinations. The cereal cultivars also were sown alone at 185 kernels m−2. Cultivars developed for forage production (Horsford, Magnum) produced as much or more forage than cultivars developed for grain production (Bowman, Dumont) across sole‐crop and intercrop plots (P ≤ 0.05). Forage yield was unaffected by intercropping when the cereal crop was sown at the sole‐crop or greater rate. Less forage was produced by intercrops when the cereal component was sown at half the sole‐crop rate. Forage yield was not affected by the pea seeding rate, but CP concentration increased with increasing seeding rate of pea in three of four environment‐years. Forage N yield was unaffected by intercropping. These data indicate that the cereal component in barley—pea and oat—pea mixtures should be sown at a sole‐crop or greater seeding rate for maximum forage production. Forage CP concentration can be increased as the relative proportion of pea seed to cereal kernels sown in a mixture is increased, but forage N yield may not be affected, since the cereal component contributes more to yield than the pea component.
Plant Density Effects on Tropical Corn Forage Mass, Morphology, and Nutritive Value
Authors: Cuomo Greg J. , Redfearn Daren D. , Blouin David C. 
Published: July 2010

AbstractTropical corn (Zea mays L.) has potential as a silage crop in doublecrop systems with cool‐season annual grasses in the southeastern USA. In a 3‐yr study conducted in silt loam soils in southeast Louisiana, plots within stands of Pioneer hybrid X304C tropical corn planted at 89 000 plants ha−1 were thinned to achieve harvested plant densities of 44 830, 52 150, 58 130, 65 150, and 72 920, plants ha−1 to to determine the effect of plant density on total forage mass, plant morphology, and forage nutritive value of tropical corn. Total forage mass was greater at higher plant densities than at lower plant densities, but forage mass was not different among plant populations that exceeded 58 130 plants ha−1. Leaf concentration of dry matter did not differ among plant populations and averaged 300 g kg−1. The sum of stem and grain concentrations was similar among treatments and ranged from 622 to 637 g kg−1. Within the stem and grain components, grain concentration decreased and stem concentration increased in an almost one‐to‐one relationship as plant density increased. Forage nutritive value of tropical corn was similar among plant densities. In vitro true digestibility averaged 654 g kg−1 across all plant densities. Increasing forage mass, coupled with stable forage nutritive values, indicates that, until some factor limits production of high‐quality tropical corn silage, high plant densities are desirable. Under the environmental conditions of this experiment, it appears that plant densities of about 58 000 plants ha−1 are optimal.
Simulated Traffic on Turfgrass Topdressed with Crumb Rubber
Authors: Rogers John N. , Vanini J. Timothy , Crum James R. 
Published: July 2010

AbstractTopdressing plays a vital role in turfgrass subjected to traffic. Sand is commonly used for topdressing; under suboptimal growing conditions, however, methods to maintain wear tolerance are limited. There has been recent interest in using crumb rubber from recycled tires as an amendment for turfgrass areas. A topdressing study was initiated in July 1993 to determine the effect of crumb rubber on turfgrass systems subjected to traffic. A factorial randomized complete block design with three replications was implemented with two crumb rubber particle sizes (large, 6.0–2.0 mm; small, 2.0–0.05 mm) and five topdressing rates (0.0, 17.1, 34.2, 44.1, and 88.2 t ha−1) on a 1‐yr‐old Kentucky bluegrass‐perennial ryegrass (Poa pratensis L.‐Lolium perenne L.) stand. In 1993 and 1994, 96 passes were made with a Brinkman traffic simulator. Surface hardness characteristics measured were peak deceleration, time to peak deceleration, and impact duration. The small crumb rubber size was more effective in increasing impact time periods than the large crumb rubber, but had no effect on peak deceleration values. Shear resistance values decreased by as much as 40% as crumb rubber volumes increased in 1993, but were increased by 20% in 1994 after rubber particles had settled to the soil surface. There was generally an increase in turf cover under traffic as crumb rubber rates increased above 34.1 t ha−1, and the small crumb rubber was more effective in 1993. Our results suggest that crumb rubber can alter surface characteristics and increase wear tolerance of turfgrass exposed to traffic.
Scales 2: Computer Program to Convert among Developmental Stage Scales for Corn and Small Grains
Authors: Harrell Dorothy M. , Wilhelm Wallace W. , McMaster Gregory S. 
Published: July 2010

AbstractProducers and agronomists need crop developmental scales that are easy to use, universally accepted, and accurate. Development of such a scale requires correlation of stages among scales currently in use and correlation of developmental patterns among crops. A computer program for converting among staging systems is a useful tool in developing new staging systems with wider applicability. The BBCH scale (BASF‐Bayer‐Ciba‐Geigy‐Hoechst) has been proposed as a prototype of a universal scale. We have added the BBCH scale to our scale conversion program for wheat (Triticum aestivum L.) and developed a similar conversion program for corn (Zea mays L.), based on correlations reported in the literature. SCALES 2 provides a tool to translate among several widely used scales for corn and small‐grain development, and can be used to develop familiarity with the various scales.
Wheat Yields, Nitrogen Uptake, and Soil Moisture Following Winter Legume Cover Crop vs. Fallow
Authors: McGuire Andrew M. , Bryant Dennis C. , Denison R. Ford 
Published: July 2010

AbstractLong‐term use of fallow in dryland wheat (Triticum aestivum L.) systems can increase erosion and decrease soil fertility. One possible solution is to grow a green manure crop during the fallow period. To evaluate the short‐term effects of substituting a winter legume green manure for fallow in a 2‐yr wheat rotation, a series of experiments were conducted in the Sacramento Valley of California from 1994 to 1996. Soil water content, inorganic soil N, and yield of fertilized wheat after fallow were compared with those of unfertilized wheat following a woollypod vetch‐field pea [Vicia villosa Roth subsp. varia (Host) Corb.; syn. V. dasycarpa Ten.‐Pisum sativum] green manure crop. Supplemental experiments (1995–1996) compared unfertilized wheat following (i) fallow with incorporation of legume biomass imported from another plot, (ii) growth and incorporation of green manure plus supplemental legume biomass from another plot, or (iii) growth of a legume crop with removal of aboveground biomass. Soil water content after a green manure crop was 6.6 cm less than after fallow in 1994 (to the 90‐cm depth), but only 1.5 cm less in 1995 (to 150 cm). During the wet winter of 1995–1996, fertilized wheat plots after fallow had higher inorganic soil‐N levels than unfertilized plots following a green manure crop, but wheat yields were similar. Where a green manure crop was grown and incorporated, there was no wheat yield response to additional legume biomass. Similarly, without a green manure crop, there was no yield difference between fertilized plots receiving 112 vs. 28 kg N ha−1. Results could be different in drier years or in soils with lower N fertility, but the data indicate that possible long‐term yield benefits of green manuring are not necessarily preceded by lower short‐term yields.