bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Planting Date on the Yield and Fiber Properties of Three Cotton Cultivars1
Authors: Bilbro J. D. , Ray L. L. 
Published: July 2010

AbstractFor a number of reasons, cotton (Gossypium hirsutum L.) cannot always be planted at the most optimum time. Because information was needed relative to the effects of different planting dates on the yields and fiber properties of various types of cultivars, we studied for 5 years the responses of three cotton cultivars to planting dates. The planting dates each year were approximately April 20, June 1, June 10, June 20, and June 30.As planting date was delayed, yields, lint percentages, fiber lengths, and micronaire units were reduced, and fiber strength was increased. Fiber elongation was not significantly affected by planting date. Yields, lint percentages, and fiber fineness varied significantly from year to year; and the years × planting date interactions were significant for all measured characters.Averaged over all tests, differences among cultivars were significant for all characters studied. Although the relative performance of the cultivars was rather consistent (nonsignificant mean squares for cultivars × years, and cultivars × planting dates) over the range of environmental conditions encountered, generally the earlier the maturity of a cultivar, the less its yields and fiber properties were adversely affected by late plantings.
Influence of Tillage Depths and P‐Fertilizer Application Rates on the Yields of Annual Cropped Winter‐Grown Wheat1
Authors: Stibbe E. , Kafkafi U. 
Published: July 2010

AbstractBecause of different climatical conditions during the growing season from those of reported experiments in literature and the relatively few data about annual cropped winter‐grown wheat (Triticum aestivum L.) yield response to depth of tillage and to incorporation of previously broadcasted P‐fertilizer, a 2‐year field trial was conducted to evaluate the effects of three tillage depths, 10, 20, and 40 cm; and three P‐fertilizer rates on grain yields and dry matter production. The three P‐fertilizer rates were: no P‐fertilizer, 12 kg P/ha per 10 cm depth of tilled soil, and a flat 60 kg P/ha rate.The field trial had a randomized split plot design with four replications and was simultaneously conducted on two soils of different texture.Grain yields, dry matter production, and P‐uptake over 2 years were not influenced by depths of tillage. Initial development of wheat plants was better on shallow tilled soil. Added P‐fertilizer markedly increased grain yields, dry matter production, and P‐uptake. P‐fertilizer rates based on volume of tilled soil were as effective as the flat P‐fertilizer rate. Dry matter production response to P‐fertilizer was influenced by soil texture, indicating limiting P‐availability with decreasing clay content of soil.From the data obtained it can be concluded that increasing depth of tillage has no significant effect on annual cropped winter‐grown wheat yields and secondly that there is no need to incorporate P‐fertilizer deeper than the top soil layer of 10 cm.Therefore, if plowing a wheat stubble becomes necessary, P‐fertilizer rate can be based on the P‐availability of the sampled top soil layer after plowing and adjusted to the depth of the planned seedbed preparation to keep P‐availability at the recommended level for wheat growing.
Temperature Requirements for Seed Germination in an Annual‐Type Rangeland Community1
Authors: Young James A. , Evans Raymond A. , Kay Burgess L. 
Published: July 2010

AbstractGermination as affected by constant and alternating temperatures was investigated in four species of annual grasses, soft chess (Bromus mollis L.); ripgut (B. rigidus Roth); slender oat (Avena barbata Brot.) and foxtail fescue (Vulpia megalura (Nutt.) Rydb.), and in their replacement forage species, seven cultivars and one naturalized population of rose clover (Trifolium hirtum All.); hardinggrass (Phalaris tuberosa var. stenoptera (Hack.) Hitchc.); and perlagrass (P. tuberosa var. hirtiglumis Bott. & Trobut). Temperature combinations were alternated through a 16 hr (night) and 8 hr (day). All combinations were used for −4, −2, 0, 2, 5, and 5‐degree increments through 40 C. The annual grasses germinated under a very broad range of temperatures above a minimum night temperature of 0 C. The rose clover cultivars germinated at lower temperatures, including subzero C (−4 C and −2 C) alternating with 15 to 25 C day temperatures. Seeds of rose clover from a naturalized population had lower germination at low temperatures and higher germination at high temperatures than the seven cultivars tested. In comparison with the annual grasses and rose clover, the perennial grasses were relatively restricted in the temperature regimes that permitted germination. Interpretation of the ecological significance of the results of monitoring seedbed temperatures during germination periods and the juvenile growth rate of the various species is dependent on the results of this investigation.
An Improved Technique for Making Wedge Grafts in Soybean Plants1
Authors: Sanders J. L. , Brown D. A. 
Published: July 2010

AbstractThe design and use of a grafting block for making uniform and reproducible wedge grafts in soybean (Glycine max (L.) Merr.) plants is presented. The grafting block was prepared from plexiglass measuring 14 ✕ 10 ✕ 1.2 cm. A slot to hold the scion was cut at a 2.5‐degree angle to the face of the block. The slot measured 4 cm in length, 0.3 cm in width, and varied in depth from 0.15 cm at the edge of the block to 0.0 cm at its termination point. The slot enabled a precise positioning of the scion for making the wedge cut. The block was used to successfully produce grafted plants which vary in the number of scions and roots. Six wedge grafts with different top:root ratios are described. The grafting block reduced the time required to make a graft and it gave an increase in the survival percentage of grafts. The uniformity of the wedge graft facilitated the interfacing of the scion‐root stock tissues, resulting in a more rapid recovery and uniform growth of the plant.
Influence of Seeding Dates and Methods on Establishment of Small‐seeded Legumes1
Authors: Fribourg Henry A. , Strand Rodney H. 
Published: July 2010

AbstractA 2‐year study was conducted at three locations to evaluate the interactions between seeding dates and methods on alfalfa (Medicago sativa L.), red clover (Trifolium pratense L.), and birdsfoot trefoil (Lotus comiculatus L.) establishment. Each species was seeded 16 to 18 times at each location. At one site, band and broadcast seeding methods and irrigation treatments were used at each date. Stand counts from randomly‐placed permanent quadrats were used to measure seeding success. Seeding date was critical to legume establishment. April to early May seedings were successful at all locations when weeds were chemically controlled. Acceptable stands were established also from seedings made from May to early June and from late July to early August at some locations. Alfalfa was less sensitive to seeding date than red clover or birdsfoot trefoil. Broadcast seeding was equal or superior to band seeding. One month of supplemental irrigation following seeding sometimes resulted in better stands.
A Cone‐Type Planter for Experimental Plots1
Authors: Peacock H. A. , Futral J. G. , Reid J. T. 
Published: July 2010

AbstractA tool‐bar‐mounted 2‐row cone‐type planter was designed and built to seed experimental cotton (Gossypium hirsutum L.) plots. The unit planters equipped with sword openers, parallel adjustable wings, and split press wheels were fitted with cone‐type seeders, roller chain, and sprockets. Rows ranging from 4.60 to 21.85 m in length and from 50.8 to 101.6 cm in width can be seeded on top of a bed or on a flat seedbed. An endless nylon belt provides raking action in the cone‐type seeder, enhances even distribution of seed into the seed spout, and is the unique feature of our planter which facilitates planting machine‐delinted cottonseed. The plot planter, operated by one person besides a tractor driver, can be attached to any tractor of adequate size that is equipped with a 3‐point hitch.
Effect of Gravel Mulch on Crop Yield1
Authors: Fairbourn Merle L. 
Published: July 2010

AbstractResearch has shown that gravel mulch reduces soil water evaporation rate. A study was established to determine if this mulch material might be used to promote increased crop yields from the precipitation of semiarid regions. Treatments of gravel mulch, cornstalk mulch, and a control of bare soil were used in both laboratory and field experiments to observe their effect on soil water, soil temperature, and plant response. Evaporation of soil water was less and soil temperatures were higher under gravel mulch as compared with a bare soil surface. Increased crop yield on the gravel‐mulch treatment appeared to be due to an interaction of more soil water and higher soil temperature. Bare soil strips for crop rows and annual regeneration of the gravel mulch were necessary management practices to permit both crop production and maintenance of an effective mulch. The study has indicated that gravel mulch not only promotes increased crop yields but also has a potential for mechanized application and maintenance.
Relationship Between Tannin Content of Sorghum Grain and Preharvest Seed Molding1
Authors: Harris H. B. , Burns R. E. 
Published: July 2010

AbstractDeterioration of grain by preharvest seed molding is a serious production problem of grain sorghum [Sorghum bicolor (L.) Moench] in areas where grain maturation occurs during wet seasons when temperatures are high. Differential preharvest seed molding among 49 commercial grain sorghum hybrids in hybrid performance tests conducted at Experiment and Midville, Georgia in 1971 was evaluated. The objectives were to investigate the consistency of hybrid reaction to seed molding and to determine the relationship between preharvest seed molding and seed tannin content. Preharvest seed mold severity was rated visually using an index scale of 1 (no more than a trace) to 5 (severely molded with 30% or more of grains deteriorated). Seed molding among hybrids was consistent at the two locations (r = 0.94**), indicating that the mechanism controlling preharvest seed molding was similar in the two environments. Seed tannin content was strongly correlated with preharvest seed molding indices (r = −0.89** at Experiment and r = −0.92** at Midville). The negative correlations and coefficients of determination indicated that 79 and 85% of the variability among hybrids for seed mold indices at Experiment and Midville, respectively, was due to high seed tannin associated with resistance. Seed molding was not related to time of 50% anthesis (r = −0.12); other factors conditioning resistance to seed molding were not identified.
Spectra of Normal and Nutrient‐Deficient Maize Leaves1
Authors: Al‐Abbas A. H. , Barr R. , Hall J. D. , Crane F. L. , Baumgardner M. F. 
Published: July 2010

AbstractSince the advent of spectral mapping and identification of vegetation by remote sensing methods, information about differences in plant nutrient status has gained prominence. Therefore, we decided to study the reflectance, transmittance, and absorptance spectra of “normal” and six types of nutrient‐deficient maize (Zea mays L.) leaves. Nitrogen‐, phosphorus‐, potassium‐, sulfur‐, magnesium‐, and calcium‐deficient leaves were analyzed at 30 selected wavelengths from 500 to 2,600 nm. The analysis of variance showed significant differences in reflectance, transmittance, and absorptance in the visible wavelengths among leaves 3, 4, and 5, among the 7 treatments, and among the interactions of leaf positions and treatments. Only treatments in the infrared wavelengths produced significant differences.The chlorophyll concentration of leaves in all nutrient‐deficiency treatments was lower than that of leaves in the control. Percent moisture in the S‐, Mg‐ and N‐deficiencies was higher. Positive correlations were obtained (r = 0.7) between moisture content and percent absorptance at both 1,450 and 1,930 nm. Second degree polynomial regression analysis of leaf thickness and leaf moisture content showed that these two variables were significantly and directly related (R = 0.894). Leaves from the P‐ and Ca‐deficient plants absorbed less energy than those from normal plants in the near infrared wavelengths; leaves from the S‐, Mg‐, K‐, and N‐deficient plants absorbed more than the normal.Leaf thermograms were prepared on normal and S‐and N‐deficient leaves. Both S‐ and N‐deficient leaves had higher temperatures than normal leaves.
Air Temperature and Vapor Pressure Changes Caused by Sprinkler Irrigation1
Authors: Kohl R. A. , Wright J. L. 
Published: July 2010

AbstractThe downwind effect of evaporation from sprinkler spray was studied in the field to determine if air temperature and vapor pressure were changed enough to influence plant growth and water use. Wet‐bulb and dry‐bulb temperature profiles were measured upwind and at three distances downwind from a sprinkler lateral before and during sprinkling. Wind‐speed and direction were also measured. Air temperature generally was reduced less than 1 C, and vapor pressure in the air was increased less than 0.8 mb. This amount of change in the air temperature and humidity is not likely to be sufficient to cause any significant change in plant growth or evaporative loss of water.
Tillage Effects on Fallow Water Storage in the Eastern Washington Dryland Region1
Authors: Lindstrom M. J. , Koehler F. E. , Papendick R. I. 
Published: July 2010

AbstractEarly stand establishment of winter wheat (Triticum aestivum L.) is essential for efficient production and erosion control in much of the northwest U.S. dryland wheat region. Stand success depends on efficient storage and retention of winter precipitation and thus, on soil management practices which maximize infiltration and minimize evaporative loss during fallow. In this study fall chiseling (25 cm deep) and disking (13 cm deep) were compared with no tillage with respect to the effect on over‐winter water storage in the low precipitation (24 cm annually) region of eastern Washington. Tillage effects were evaluated during a mild winter with minimal soil freezing and during a cold winter with runoff conditions from rain and snowmelt on frozen soil. Three spring tillages, sweep cultivation (13 or 20 cm deep) or disking (13 cm deep), were superimposed on each of the fall tillages to evaluate effects on oversummer soil water retention, both deep in the profile and in the seed zone. In addition, these tillages were compared with a chemical fallow treatment with no tillage.During the cold winter, fall chiseling increased water storage markedly and disking to a lesser extent as compared with no tillage (8.7 cm increase with chiseling, 2.3 cm with disking), but tillage had no effect during the mild winter. September to May storage as percentage of precipitation for this period was 87, 60, and 50% for chiseling, disking, and no tillage, respectively, for the cold winter, and 62% irrespective of tillage during the mild winter. The increase in water stored during the cold winter by chiseling was attributed to improved infiltration properties of the frozen layer associated with this tillage. Storage efficiency with chiseling was greater during the cold winter as compared with the mild winter largely because of differences in the nature of the precipitation. In the mild winter most precipitation fell as intermittent showers, whereas in the cold winter precipitation events were fewer but each was greater in amount.Oversummer soil water loss (May to September) was not influenced by type of spring tillage; amounts lost ranged from 4 to 9% of the total profile water stored in May. Although oversummer loss increased with increases in total stored water, after the cold winter the amount of stored water in the profile at seeding time was still considerably greater for the plots which received fall tillage. Seed zone water at the end of fallow was generally increased with increase in total profile water content, and was higher where spring tillage was used as compared with chemical fallow.
Effects of Plant Population, Row Spacing, and Relative Maturity on Dryland Corn in the Northern Plains. I. Corn Forage and Grain Yield1
Authors: Alessi J. , Power J. F. 
Published: July 2010

AbstractNarrow rows or equidistant planting of corn (Zea mays L.) has been beneficial in the Corn Belt. The concepts were evaluated at Mandan, N. D., to determine their influence under dryland conditions and in combinations with early‐maturing varieties which partially evade late season drought. The 68 and 85‐day relative maturity hybrids were grown at plant populations of 20,000; 30,000; 40,000; 60,000 and 74,000 plants/ha in 50 and 100‐cm spaced rows for 3 years. In 1968, a “wet” year, row spacing and maturity class significantly affected dry matter production, but only population influenced grain yield. Plant population and maturity class significantly affected grain yield in 1969 and 1970, but only population influenced dry matter in 1969. Interactions were not significant. Later‐maturing corn averaged 12% greater forage yield, but early‐maturing corn produced 19% more grain. Average grain yields increased from 2,600 to 3,070; 3,090; 2,960; and 2,680 kg/ha with progressive increases in population. Grain yield for 50 and 100‐cm rows averaged 2,890 and 2,870 kg/ha, respectively. Number of barren stalks increased and ear weight decreased with increased population. Optimum plant population for grain and forage ranged from 30,000 to 40,000 plants/ha.
Turfgrass Wear Simulator for Small Plot Investigations1
Authors: Shearman R. C. , Beard J. B. , Hansen C. M. , Apaclla R. 
Published: July 2010

AbstractA mechanical turfgrass wear simulator was constructed for small plot investigations. It was developed for use on experimental units as small as 1m2. The wear simulator is operated by an electric motor and is constructed to rotate around a pivotal point with an adjustable diameter ranging from 1.0 to 2.7m. The machine is built of light weight materials in a size and weight so that it can be easily moved by an individual. The wear unit simulates both foot and tire wear on turf.
Response of Three Soybean Strains to Equidistant Spacings1
Authors: Wilcox J. R. 
Published: July 2010

AbstractThree soybean [Glycine max (L.) Merr.] strains were evaluated in approximately equidistant spacings at 14 population densities ranging from 25,000 to 582,000 plants/ha (10,000 to 236,000 plants/acre) over a 2‐year period. The objective was to determine the response of the strains to a wide range of populations at equidistant spacings. Plant height, height of the lowest pod, and lodging increased with increasing plant population. Mature plant weight, seed weight per plant, and the ratio of mature plant to seed weight increased as population decreased. The three strains differed in their response to population density when seed yield was expressed per unit of area. Yields of L15 were most consistent across all populations. Yields of C1421 were most responsive to populations above 281,000/ha, whereas yields of C1477 were most responsive to populations below 83,000/ha. Maximum yields for C1477 and L15 were at 281,000 plants/ha and for C1421 at 456,000 plants/ha. Yield of C1421, which was most sensitive to high populations, did not vary significantly with a 27% increase or decrease in plant population from the optimum. Maturity date and seed size were not affected by changes in population.
Chemical Composition of Agropyron desertorum as Related to Grass Tetany1
Authors: Mayland H. F. , Grunes D. L. , Stuart D. M. 
Published: July 2010

AbstractGrass tetany, a Mg deficiency of ruminants, accounts for significant economic losses to Western cattlemen during the spring grazing period on Agropyron desertorum. This nutritional deficiency may also occur when ruminants graze other temperate grasses, but the soil‐plantanimal factors leading to the problem are not well understood.The objective of this study was to provide definitive data relating seasonal changes in the chemical composition of forage to the occurrence of grass tetany on semiarid grasslands.The field experiment was established on two calcareous soils where grass tetany had previously occurred. Agropyron desertorum forage was harvested from both sites at regular intervals during the spring tetany period in each of 5 years. The forage samples were analyzed for mineral elements, N, total water‐soluble carbohydrates (TWSC), higher fatty acids (HFA), ash alkalinity, and aconitic acid.High levels of N and HFA, which are known from other studies to reduce Mg availability to the animal, coincided with the occurrence of tetany. The low Mg concentrations measured in the forage probably provided only marginal levels of available Mg to the grazing animals. A rapid increase in the ratio of N/TWSC coincided with the onset of tetany, and may be the primary factor which indirectly decreases Mg availability and precipitates the occurrence of tetany. Although the relationship of the protein/energy imbalance to grass tetany has been suggested previously, as far as the authors are aware this is the first time that N/TWSC values obtained during the growing season have been documented in conjunction with the occurrence of grass tetany.
Evaluation of Laboratory Methods for Determining Quality of Corn and Sorghum Silages: I. Biological Methods for Predicting In Vivo Digestibility1
Authors: Schmid A. R. , Goodrich R. D. , Marten G. C. , Meiske J. C. , Jordan R. M. , Halgerson J. L. 
Published: July 2010

AbstractWhile many laboratory procedures have been proposed for estimating feeding quality of perennial grass and legume forages, none have been adequately tested for their potential in predicting quality of corn and sorghum silages. The objective of this phase of a comprehensive study was to assess the value of six biological procedures proposed for predicting forage digestibility of silages of corn (Zea mays L.) and sorghum (Sorghum bicolor (L.) Moench, S. sudanense (Piper) Stapf, and their hybrid).In vivo digestible dry matter (DDM) of 51 corn and sorghum silages (17 in each of 3 years) was determined using sheep in conventional feeding trials.A modified Tilley and Terry (1963) in vitro procedure (T‐T DDM), gave the highest correlations with in vivo DDM (r = 0.83 for corn silages and 0.91 for sorghum silages). A “direct acidification” in vitro rumen fermentation procedure resulted in in vitro DDM which was also highly correlated with in vivo DDM (r = 0.50 and 0.91 for corn and sorghum silages, respectively). Within the corn silages, the correlation between direct avidification DDM and in vivo DDM of 18 entries with high grain percentages was only 0.19, while that for seven entries with low grain percentages was 0.93. Apparently, the combination of large amounts of available carbohydrates in the high grain entries and the phosphate buffer led to erratic growth and digestive action by the rumen bacteria.A 6‐hour rumen fluid fermentation procedure gave DDM values which were 36 to 38% of the T‐T DDM values and were poorly correlated with in vivo DDM. A cellulase‐acid pepsin procedure gave DDM values for both corn and sorghum silages that were 56% of the T‐T DDM values; however, cellulase‐acid pepsin DDM was positively correlated with in vivo DDM of sorghum silages (r = 0.72) and negatively correlated with in vivo DDM of corn silages (r = −0.42).Two procedures that involved the neutral detergent extraction (Goering and Van Soest, 1970) and a 48‐hour rumen fluid fermentation gave in vitro DDM values which were highly correlated with in vivo DDM (r = 0.73 to 0.90).A multiple correlation analysis revealed that little improvement of the simple correlation between specific laboratory procedures and in vivo DDM was attained by combining procedures.We developed simple regression equations to predict in vivo DDM from T‐T DDM and direct acidification DDM for corn and sorghum silages.