bluuebunny/crossref_metadata_2025_split huggingface dataset:
Straw and Tillage Management Practices in Soybean‐Wheat Double‐Cropping1
Authors: Sanford J. O. 
Published: July 2010

AbstractManaging straw residue in wheat (Triticum aestivum L.)‐soybean [Glycine max (L.) Merr.] double‐cropping systems can be a problem, and many management systems are currently being used. Type of tillage used is, to some extent, determined by the straw management practice. In this study, five tillage‐straw management practices were studied on Brooksville silty clay (fine, montmorillonitic, thermic Aquic Chromudert) for 4 years. Only 3 years' data are reported, however, since all treatments failed 1 year because of extreme drought. Objectives were to determine effects of tillage‐straw management practices on (a) stand establishment, growth and yield of double‐cropped soybeans, (b) surface soil organic matter content, and to (c) compare costs and net returns of the wheat‐soybean systems and the monoculture soybeans.In 1 of 3 years when rain did not soon follow planting, preparing the soil by disking, whether the straw was burned or not, resulted in reduced germination and growth. During 1 year, germination was adversely affected when the straw was shredded and left on the soil surface. Yields were highest and most consistent when soybeans were no‐till seeded into the burned stubble, but these yields did not differ from systems where straw was burned followed by conventional tillage or where straw was shredded followed by no‐till planting. The average soybean yield was 29% less for the best double‐crop practice than for monoculture soybeans (1,370 kg/ha vs. 1,927 kg/ha). Wheat yields averaged 3,384 kg/ha and were not affected by the tillage‐straw management practices. Excluding a year in which all double‐crop systems failed, all double‐crop systems except where the wheat straw was incorporated in land preparation gave greater economic returns than monocrop soybeans. The double‐crop system in which straw was burned followed by no‐till seeding and cultivation, gave the greatest average net return.
Potato Irrigation Requirements in a Hot Climate Using Sprinkler and Drip Methods1
Authors: Shalhevet J. , Shimshi D. , Meir T. 
Published: July 2010

AbstractPotato (Solanum tuberosum L.) is a heat‐ and drought‐sensitive crop, which in hot climates usually requires large water applications for optimum production. Irrigation water in Israel is both limiting in quantity and high in price; thus it is critical to know the water requirement of the crop, as well as how to improve irrigation efficiency. Field experiments were conducted in the Negev (arid) region of Israel on a Typic Camborthid soil to determine the water production functions of potatoes (‘Desiree’) under drip and sprinkler irrigation. Irrigation treatments were based on Class A pan evaporation. The linear production functions relating total yield in metric ton ha−1 to seasonal water application depth (W) in cm were, for sprinkler irrigation: Y = ‐23.5+1.19W, and for drip irrigation: Y = −12.8+1.14W. Similar total maximum yields were obtained with about 8 % less water with the drip as with the sprinkler method (not statistically significant). A single production function for both methods described the yield of marketable tubers: Y = −40.0+1.28W. These functions apply in the relative water application range (water applied over Class A pan evaporation) of 0.3 to 1.0, at which point the function reaches a plateau. Yield was reduced by 12% as soil water potential in the 0 to 0.6 m depth increment changed from −20 to −29 J kg−1 for sprinkler irrigation. Under drip irrigation the soil could dry to −40 J kg−1 without yield reduction, as long as the water supply was adequate. This was explained by the higher root concentration under drip than under sprinkler irrigation.
Establishment and Nodulation of Arrowleaf Clover1
Authors: Rich P. A. , Holt E. C. , Weaver R. W. 
Published: July 2010

AbstractWe need information on effects of planting depths and inoculation methods on stand, nodulation, and early plant development for establishing temperate, small‐seeded annual legumes. Arrowleaf clover (Trifolium vesiculosum Savi ‘Yuchi’) plantings from uninoculated and water or commercial sticker inoculated seed were made at depths of 0, 10, 25, and 40 mm with and without irrigation immediately following planting, on a Udertic Haplustoll soil. Seedling and nodule numbers, and biomass (plant top and root weights) were determined in eight environmental periods. Regression testing and curve fitting of unequal planting depth increments and plant trait measurement were made with a special set of orthogonal polynomial coefficients. Nodulation maximums were at greater planting depths (19 and 22 mm) than seedling number maximums (6 and 10 mm) in early and pooled irrigation blocks, respectively. Number of plants and nodules per plant were optimum at the balanced compromise depth of 13 mm and in a range of 10 to 30 mm for early irrigation. With pooled irrigation or simulated dryland planting the balanced compromise point was 16 mm and the range 10 to 25 mm for optimizing planting depths. Surface or 40 mm depths were hazards to establishment of the small‐seeded legume, and its rhizobium. Pelgel sticker significantly increased nodulation over water sticker and the untreated check with early irrigation at 0 and 10 mm planting depths, but in all irrigation treatments nodule numbers were increased by pelgel sticker only in plantings at 10 mm depth. Biomass and plant number were significantly correlated under both early and delayed irrigation treatments (0.95 and 0.98, respectively) due to poor growth environment.
Magnesium Uptake by Tomato Plants as Affected by Mg and Ca Concentration in Solution Culture and Plant Age1
Authors: Schwartz S. , Bar‐Yosef B. 
Published: July 2010

AbstractMagnesium deficiency of tomato (Lycopersicon esculentum Mill.) plants grown under glass and in the field is widespread. Deficiency may occur because of interference in Mg uptake by various cations or from diminishing rates of uptake resulting from root aging. To investigate the interrelationship of Ca and Mg uptake by tomato plants and the dependence of uptake on plant age, a solution culture study with various Mg and Ca concentrations (CMg, CCa) was conducted. From solution depletion measurements of Ca and Mg during 2 to 3‐day periods, net cation flux (Fmax) and Michaelis‐Menten uptake rate coefficients were estimated for various plant ages (18 to 21, 34 to 37, and 80 to 83 days) and solution composition. Enhanced CCa (2.5 vs. 1 meq/L) decreased Fmax and KM of Mg. This effect was attributed to stimulation by Ca of selective ion uptake (related to KM) and a competitive effect on carrier sites which reduced Fmax. Increased CMg values had no appreciable effect on Fmax of Ca but they enhanced KM, especially during early growth (18 to 21 days). The flux of Mg uptake decreased with plant age. Between Days 21 and 83, Fmax, was reduced from 68 to 17.5 µeq Mg g fresh root−1day−1, while KM values under the same conditions increased from 0.55 to 1.2 meq/L. Similar changes with time characterized the Fmax and KM values for Ca. Root and canopy growth rates were appreciably retarded at CMg of 0.05 or CCa of 0.1 meq/L, relative to those at higher Mg and Ca concentrations. At the initial appearance of deficiency symptoms, Mg and Ca concentrations in the shoots were 0.13 and 0.11%, respectively.
Radiative Transfer in an Array of Canopies1
Authors: Norman J. M. , Welles J. M. 
Published: July 2010

AbstractTheories describing radiative transfer in plant canopies are very well developed for canopies approximating full cover. However, for canopies of partial cover such as orchards, wide‐row crops or widely spaced individual plants, no general theory exists. This paper contains a description of a general radiative transfer model that is capable of accommodating nearly any canopy structure. The plant canopy is approximated by an array of ellipsoidal subcanopies that may be equally spaced, randomly spaced, or spaced in any manner desired. Ellipsoids were chosen because of the infinite variety of shapes that they can approximate. All of the foliage of any individual subcanopy is contained within the confines of its ellipsoidal subcanopy, and assumed to be statistically distributed within the subcanopy volume with respect to location, foliage angle, and foliage area per unit of subcanopy volume. The radiative transfer model includes attenuation of direct beam and sky diffuse radiation, multiple scattering for visible and near‐infrared wavelength, and emission for thermal wavelengths. When the subcanopies overlap extensively, the predictions from the general ellipsoidal model approach the predictions from one‐dimensional models applicable to canopies of full cover. Predictions from this three‐dimensional model are compared with cross‐row measurements in a corn canopy. In addition, sunfleck area and sunlit‐leaf area comparisons are made between this three dimensional model and a one dimensional model for a developing corn canopy.
Cotton Cultivar Response to Mepiquat Chloride1
Authors: York A. C. 
Published: July 2010

AbstractThe effects of mepiquat chloride (1,1‐dimethylpiperidinium chloride) on cotton (Gossypium hirsutum L.) growth and yield have been widely studied but few studies have investigated cultivar response to this plant growth regulator. Since the response to a pesticide or a plant growth regulator may vary among cultivars, a knowledge of cultivar response to that chemical is an important consideration when developing recommendations for its use. A 3‐year study was conducted in eight environments to determine if 14 cultivars respond differently to mepiquat chloride. Cultivars evaluated were ‘Coker 304’, ‘Coker 310’, ‘Coker 315’, ‘Coker 420’, ‘Deltapine 41’, ‘Deltapine 55’, ‘Deltapine 70’, ‘McNair 220’, ‘McNair 235’, ‘Rex 713’, ‘SC 1’, ‘Stoneville 213’, ‘Stoneville 506’, and ‘Stoneville 825’. Mepiquat chloride at a rate of 49 g/ha increased lint yield 10 to 28% in three environments and decreased yield 5% in one environment. Earlier maturity was usually observed. Plant height was reduced 11 to 26%, and reductions in plant height were closely correlated with final height of the untreated cotton. Mepiquat chloride increased both boll weight and seed weight 3 to 10%, and slightly increased fiber length. The effect on micronaire was variable, but in most environments there was a small reduction. There was little to no effect on number of seed per boll, fiber strength, and fiber length uniformity. Lint percent was decreased 0.4 to 0.8% in most environments as a result of the increased seed weight. There were no mepiquat chloride by cultivar interactions for lint percent, fiber length, boll weight, seed weight, number of seed per boll, number of bolls produced, plant height, or maturity. Cultivar by mepiquat chloride interactions for yield, micronaire, fiber strength, and fiber length uniformity were observed in only one environment. All observed mepiquat chloride by cultivar interactions were small and, considering the infrequency of occurrence, were probably not of practical significance. This study indicated that cultivar selection should not be a consideration in deciding whether to apply mepiquat chloride.
Corn Growth Response to Temperature and Photoperiod I. Seedling Emergence, Tassel Initiation, and Anthesis1
Authors: Warrington I. J. , Kanemasu E. T. 
Published: July 2010

AbstractThe efficient breeding and selection of corn (Zea mays L.) genotypes for different climatic regions requires a quantitative understanding of the plant's developmental responses to environmental factors such as temperature and photoperiod. This information is also essential if reliable and meaningful crop simulation models are to be developed. Plants of two corn hybrids, XL45 and W346 were grown in controlled environments under 18 day/night temperature combinations ranging from 16/6 to 38/33°C (12‐h photoperiod) and under three photoperiods (12,14, and 16 h) at two selected temperatures (constant 18 and 28°C). Data defining the temperature response curves, including the minimum and optimum temperature limits, for germination and emergence and for the development periods from sowing to tassel initiation and sowing to anthesis were obtained. A minimum temperature of 9°C was predicted for germination and emergence, and a requirement of 62.5 degree‐days was determined for this growth stage. The optimum temperature was approximately 30°C. Minimum temperatures of 8 and 7°C were determined for tassel initiation and anthesis, respectively, and the optimum temperature for both was 28°C above which the development rates declined. These temperature limits compared with minima and maxima of 10 and 30°C, respectively, used in most current heat‐sum methods. Between the limits of 7 and 28°C, the number of degree‐days required to reach tassel initiation and anthesis were, respectively, 208 and 736 for hybrid W346, and 245 and 816 for XL45. Tassel initiation occurred at approximately one‐third of the time between sowing and anthesis when calculated either on the basis of heat‐sums (degree‐days) or from calendar‐days under the steady‐state temperature conditions used. An increase in photoperiod lengthened both the time between sowing and tassel initiation and that between tassel initiation and anthesis in a similar, almost equal, manner for both cultivars. Sensitivity to the photoperiod response was not altered by temperature.
Design of a Large Dual – Structure Rainout Shelter1
Authors: Upchurch D. R. , Ritchie J. T. , Foale M. A. 
Published: July 2010

AbstractIn locations subject to rainfall during the cropping season, a rain excluding device must be employed to impose water stress for drought studies. A rainout shelter facility that covers 0.09 ha has been constructed for plant water stress research in central Texas. The shelter consists of twin structures connected to a single drive system and linking cable. The dual structures, which move together to cover the plot, incorporate permanent side and end walls thereby completely excluding driving rain. Minimum ground clearance of the wall allows some air movement under the closed shelter. Wind loading during shelter movement is neutralized as the structures move in opposite directions. The shelter is clad with fiberglass transmitting 70% of global radiation which allows continuing energy interception by the crop when the plots are covered. Movement of the building is controlled by a tipping bucket rain gauge, a local manual switch, and through telephone answering equipment connected electronically to the drive motor. The position of the building may be checked and changed by telephone. The sheltered area is large enough for replicated experiments with a satisfactory range of treatments. Several features have contributed to the successful operation of this shelter which is larger than any described previously.
Moisture Deficits and Grain Sorghum Performance: Drought Stress Conditioning1
Authors: Garrity Dennis P. , Sullivan Charles Y. , Watts Darrell G. 
Published: July 2010

AbstractThe exploitation of drought stress conditioning responses in field crops may enable substantial water savings in limited irrigation. We analyzed the effectiveness of stressing grain sorghum [Sorghum bicolor (L.) Moench] to varying degrees prior to the grain‐fill period in inducing a drought stress conditioning response during grain fill. A line source sprinkler system was used to apply two sets of treatments on the three sorghum hybrids in a field study conducted on a sandy soil (Typic Ustipsamment): Gradient irrigation (G) applied throughout all growth stages (GGG), or full irrigation (I) during the vegetative and reproductive periods, followed by gradient irrigation during the grain‐fill period (IIG). Large differences in total dry matter (DM) production and grain yields were observed due to different timings or magnitudes of water stress during grain fill (IIG) or throughout the growing season (GGG). However, the harvest index remained the same regardless of stress treatment. A substantial mobilization of stored assimilates from the stem to the grain was observed (up to 73% of grain weight) on the IIG treatment. The stress adjustment of hybrid RS 626 was significant enough to be of practical importance. Grain yields for the GGG and IIG were the same. Much greater seasonal soil water depletion occurred in the GGG than in the IIG treatment, while soil water extraction during grain fill was similar between the two treatments, although the IIG began this stage with a full profile. Dry matter and grain weight were much less sensitive to seasonal evapotranspiration (ET) deficits in the GGG treatment than in the IIG treatment, but seasonal water‐use efficiency in the GGG treatment was substantially higher. All hybrids had the same water‐use efficiency (WUE) in DM and grain production during the grain fill period. Hybrids, NB 505 and NC + 55X tended to escape the effects of grain fill stress by earlier maturity. Leaf area and canopy temperature comparisons suggest that they were not as physiologically sensitive to drought stress as hybrid RS 626 when stress was imposed with a prior conditioning stress. The results indicate that the magnitude of a drought stress conditioning response may be substantial, but will depend on the genotype used, the phenological timing of the treatment, and the irrigation regimen employed.
Laboratory and Field Evaluations of Sorghum for Response to Aluminum and Acid Soil1
Authors: Duncan R. R. , Clark R. B. , Furlani P. R. 
Published: July 2010

AbstractPlant responses in controlled environments (greenhouse and growth chamber) should relate to field plant responses if laboratory screening methods are to be used effectively for the improvement of plant tolerances to soil stress conditions. Eight acid soil susceptible and tolerant sorghum [Sorghum bicolor (L.) Moench.] genotypes were compared for dry matter production, element uptake, and visual plant stress symptoms under field stress (Georgia) and artificially‐induced Al‐toxic nutrient solutions (Nebraska). Sorghum was grown on three soil types (Typic Rhodudults, Fragiaquic Paleudults, and Typic Hapludults) and at three levels of Al (0, 46, 93 µmol L−1) in nutrient solution. Net seminal root lengths were used to evaluate plants for Al tolerance in the laboratory. The objectives of this study were to compare sorghum genotype responses when plants were grown under both field and laboratory conditions to determine genotypic differences and to better quantify Al and acid soil tolerance screening techniques. Among the genotypes studied, SC0283 was the most tolerant to acid soil field stress conditions and was also the least affected by Al toxicity conditions in nutrient solutions. NB9040 was susceptible to acid soil field conditions, exhibited considerable tolerance to medium levels of solution Al, and was susceptible to high levels of solution Al. Tolerance or susceptibility to Al among the sorghum genotypes was influenced by the level of the acid soil stress condition. Manganese toxicity probably affected plant responses in the field. Genotype responses to Al‐induced stress conducted in the laboratory and to acid soil stress conducted in the field showed similar responses when the screening parameters for each environment were quantified. The susceptibility response of NB9040 was equivalent at 93 µmol L−1 Al (32 µmol L−1P) in solution and pH 4.4 to 4.8 for the three soils used in this study.
Effect of Sample Preparation and pH on the Cation Exchange Capacity of Thatch1
Authors: Danneberger T. K. , Turgeon A. J. , Peck T. R. 
Published: July 2010

AbstractWhere it develops excessively, the thatch layer may serve as the primary medium supporting the growth of a turfgrass community. Since little is known about the edaphic properties of thatch, the purpose of this study was to determine the effect of sample preparation and pH on the cation exchange capacity (CEC) of thatch. Samples were obtained from a Kentucky bluegrass (Poa pratensisL. cv. Merion) lawn using a cork borer with an inside diameter of 15 mm. The CEC was measured using both undisturbed samples and ground samples passing through a 40‐mesh screen. The effect of pH was determined at pHs of 2.5,3.5,5.0,6.0,7.0, and 8.0; results were analyzed by linear regression. No significant differences were observed due to grinding of the thatch samples; however, variation in CEC occurred depending upon the saturation solution used. The CEC expressed on an undisturbed volume basis was considerably lower than that based upon sample weight. A threefold increase in CEC occurred over a pH range of from 2.5 to 8.0.
Rapid Method For Measuring Kernel Density1
Authors: Wessel‐Beaver L. , Beck R. H. , Lambert R. J. 
Published: July 2010

AbstractA rapid, accurate, and reproducible method for measuring corn kernel density is needed if selection for density in a breeding program is to be effective. Comparisons of two methods involving the Archimedes principle for measuring corn (Zea maysL.) kernel density included: 1) water displacement in a graduate cylinder and 2) a cage of kernels submerged in a tared water container resting upon a balance. Sixty samples of opaque‐2 corn (45 kernels each with densities from 960 to 1250 kg m‐3) were analyzed. The cage method required 67 vs. 136 min/60 samples for kernel volume measurements and was more repeatable (r = 0.94** vs. r = 0.67**). The coefficients of variation for the two methods and the two analysts ranged from 4.9 to 5.6%. The cage method is rapid, accurate and reproducible.
Persistence and Recovery of Rhizobium japonicum Inoculum in a Field Soil1
Authors: Ellis W. R. , Ham G. E. , Schmidt E. L. 
Published: July 2010

AbstractInoculation of soybean (Glycine max L.) rarely increases seed yields in fields where this crop has been previously grown. The inability of the inoculum strain to persist in soil could be a factor in this poor response. The persistence of the inoculant strain Rhizobium japonicum USDA 110 was followed for 56 weeks in a field soil (Typic Haplaquoll) using a fluorescent antibody technique. Statistically significant increases in the population of R. japonicum strain USDA 110 in soil were observed for the first 7 weeks after inoculation. When USDA 110 was applied at 2 × 106 cells g−1 soil the population of this organism in soil reached 1 × 107 cells g−1 soil 1 week after inoculation; a value significantly higher than observed in other inoculation and fertilization treatments. The population observed for the uninoculated control varied nonsignificantly from 6 × 104 to 2.6 × 105 cells g−1 during both growing seasons. No significant differences due to inoculation were observed for seed yield, or total aboveground N in either year. Even though the soil population was increased significantly, inoculation of strain USDA 110 at high rates produced no significant alteration in strain distribution in the nodules of soybeans in either year. Rhizobium japonicum strain USDA 110 was observed mostly in doubly infected nodules with strain USDA 123 which may have minimized the effect of strain USDA 110 on N2 fixation and seed yield.