bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tillage Effects on Soil Physical Properties and Wetland Rice Yield
Authors: Sharma P. K. , De Datta S. K. , Redulla C. A. 
Published: July 2010

AbstractPuddling is the most common method of land preparation for wetland rice (Oryza sativa L.) in south and southeast Asia. While this method has certain advantages, it is time‐, energy‐, and capitalintensive. The objective of this study was to identify time‐, energy‐, and capital‐efficient tillage techniques for sustained productivity of wetland rice soils. The effects of different land preparation techniques on soil physical properties, root growth, and grain yield of wetland rice (cv. IR36) on two Philippine (IRRI) soils are reported. Bulk density, penetration resistance, and temperature of surface soil layers decreased with tillage intensity. In clay soil (Andaqueptic Haplaquoll with a water table of 0.30 m), the average daily water use (percolation + seepage + evapotranspiration) during a 90‐d irrigation period for zero tillage (dry‐seeded rice) was 37 mm d−1; zero tillage (transplanted rice), 35 mm d−1; minimum tillage, 34 mm d−1; and puddling, 30 mm d−1. The corresponding values for the clay loam (Typic Argiudoll with a water table > 1.2 m) were 393, 501, 263, and 164 mm d−1, respectively. Root‐length density (RLD) at the 0‐ to 0.10‐m depth at harvest was negatively correlated with soil bulk density at transplanting. On the other hand, grain yield was positively correlated with RLD, but negatively correlated with bulk density and soil penetration resistance and was less on zero‐tilled than on tilled plots. For the clay soil, grain yield (two‐season average) with minimum tillage was 26% higher than with zero tillage. for shallow puddling (one‐season data) and puddling, the figures were 33 and 28% higher. The corresponding values in clay loam soil were 36,66, and 56%, respectively. Zero and minimum tillage plots dried faster than puddled plots after they were drained at harvest; surface cracking was higher in puddled plots. In the clay soil and in both seasons, minimum tillage produced the same grain yield as puddling, and in such soil, minimum tillage may be an alternative to puddling, provided weeds are controlled.
Effects of Ozone and Water Stress on Canopy Temperature, Water Use, and Water Use Efficiency of Alfalfa
Authors: Temple Patrick J. , Benoit Larry F. 
Published: July 2010

AbstractOzone (O3) and soil water deficit are two environmental stresses that significantly affect the growth and yield of alfalfa (Medicago sativa L). However, little is known of the responses of field‐grown alfalfa to O3, and the effects of the interaction between O3 and water stress on canopy temperature and water relations of alfalfa have not been previously reported. The objective of this 2‐yr study was to determine the interactive effects of O3 and soil water deficits on canopy temperatures, water use, and water use efficiency (WUE) of alfalfa. Alfalfa (cv. WL‐514) was grown in 30‐3‐ by 5.5‐m plots on Wasco sandy loam (coarse‐loamy, mixed, nonacid, thermic Typic Torriorthents) in Shafter, CA, and was exposed in open‐top chambers to five levels of O3 for 12 h daily, from March to October of 1984 and 1985. Ozone treatments ranged from charcoal‐filtered air (CF) to twice ambient O3 concentrations. Each plot received either normal amounts of irrigation (NI) or 30% less than normal (WS). Canopy temperature‐air temperature differentials (Tc‐Ta) were significantly reduced by water stress an average of 27.9% in 1984 and 44.0% in 1985. Ozone also significantly reduced Tc ‐ Ta by 31% in NI and 37% in WS plots in 1984, but in 1985 O3 had no effect on Tc ‐ Ta. Water use, rate of soil water depletion, or depth of effective rooting zone were not affected by O3, hereas water stress significantly reduced all three. Water use efficiency was significantly reduced by O3, averaging 12% lower in nonfiltered compared with CF plots. The effects of O3 on WUE were attributed to premature senescence and abscission of older alfalfa leaves.
Influence of Chemical Drying Agent and Surfactant on Drying Time and Ruminal Nutrient Digestion of First‐Cutting Alfalfa Hay
Authors: Nocek James E. , Russell James B. , Fallon Janet B. 
Published: July 2010

AbstractDrying agents and surfactants have been used to decrease field drying time of hay; however, little is known about their influence on ruminal digestion. This study was conducted to determine the effect of chemical drying agents (alkaline carbonates, 30 g L−1) or surfactant (actylphenoxypolyethoxyethanol, 0 to 0.164 ml L−1), or both, on field drying time and extent and rate of ruminal nutrient digestibility of alfalfa (Medicago sativa L.) hay. Untreated controls had longer drying times than treatments containing drying agent. Drying agent alone did not influence in situ dry matter (DM) or neutral detergent fiber (NDF) digestibility. Surfactant addition decreased the rate of DM and NDF digestion. Bacterial‐N contamination (fraction of residue N of bacterial origin) increased with time in the rumen for treatments receiving the highest surfactant concentrations. The rate of N digestion was faster when treatments contained drying agent plus surfactant. When examined with in vitro fermentation, surfactant concentrations greater than 0.0005 mL L−1 resulted in a greater than 80% reduction in digestion of filter paper. Surfactant had little effect on soluble starch fermentation, but there was an approximately 50% reduction both of ammonia production and cell protein, if protein hydrolyzate was the substrate. Amylolytic bacteria were less sensitive to the surfactant than cellulolytic species. The surfactant used in this study was inhibitory to rumen microorganisms and decreased the NDF digestion rate of alfalfa hay.
Trifluralin‐Substituted Amide Herbicide Interactions
Authors: Prosch S. D. , Weber J. B. 
Published: July 2010

AbstractSubstituted amide and dinitroaniline herbicides are used to selectively control annual grasses and certain broadleaf weeds in soybean [Glycine max (L.) Merr.]. Often, additional herbicide must be applied to control other broadleaf weed species. The objective of this study was to determine if combinations of selected soil‐applied herbicides could be used to control or suppress the growth in soybean of weeds that cannot be controlled with currently available herbicides. Field trials were conducted in 1982 and 1983 to evaluate the effects of two different application methods of trifluralin [2,6‐dinitro‐ N, N‐dipropyl‐4‐(trifluromethyl) benzenamine] and alachlor [2‐chloro‐ N‐(2,6‐diethylphenyl)‐N‐(methoxymethyl)acetamide] or metolachlor [2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐N‐(2‐methoxy‐1 ‐methylethyl) acetamide] combinations for controlling broadleaf weeds, including morningglory (Ipomoea spp.) and jimsonweed (Datura stramonium L.), in soybean. No significant differences in the control of broadleaf weeds were found between a sequential application and a tank‐mix application of the two herbicides applied as a shallow incorporation. Both herbicide combinations provided good to excellent control of morningglory, and fair to good control of jimsonweed. The control of three Ipomoea species was not significantly different when combinations included either substituted amide. Greenhouse sand culture studies showed significant interaction effects of trifluralin plus alachlor combinations on the growth inhibition of soybean, hemp sesbania [Sesbania exaltata (Raf.) Rydb. ex A. W. Hill], morningglory, jimsonweed, velvetleaf (Abutilon theophrasti Medik), and sicklepod (Cassia obtusifolia L.). Soybean was much less sensitive to the herbicide interaction effects than were broadleaf weeds.
Nitrogen and Mineral Content of Selected Wild and Cultivated Genotypes of Jerusalem Artichoke
Authors: Seiler Gerald J. 
Published: July 2010

AbstractJerusalem artichoke (Helianthus tuberosus L.) can be a weed in pastures and crops or used as silage, but little is known about its N and mineral content and their contribution to forage quality. This study evaluated 19 wild and cultivated genotypes of perennial Jerusalem artichoke for protein and mineral concentrations at various stages of maturity, and compared these to an annual cultivated sunflower (H. annuus L.), ‘Hybrid 894’. The field experiment was conducted on Pullman clay loam (fine, mixed, thermic Torrertic Paleustoll) at Bushland, TX. The 19 perennial genotypes and the commercial sunflower, Hybrid 894, were planted in pure stands. Leaves, stems, and whole plants were evaluated at vegetative, flowering, and fruiting stages to ascertain their nutritive value for ruminants. Crude protein (CP) concentrations of 140 g kg−1 and above occurred in leaves of 11 of 19 genotypes at the vegetative stage. Fifteen of the 19 genotypes had whole plant CP of 60 to 90 g kg−1 at all stages of maturity. Nutritionally adequate amounts of Ca (2− 8.6 g kg−1) were present in leaves, stems, and whole plants of all genotypes at all stages of maturity. Nutritionally adequate amounts of Mg (1 g kg−1) and K (6.5 g kg−1) were present in leaves and whole plants of most genotypes at all stages of maturity. Leaves, stems, and whole plants of most genotypes had suboptimal P (<2 g kg−1) levels for ruminants at all stages of maturity. Nutritionally adequate amounts of CP, Ca, Mg, and P were present in whole seeds of most genotypes. At varying maturity stages, nutrient levels of some artichoke genotypes are comparable to that of cultivated sunflower. Whether Jerusalem artichoke is mixed with other forbs or grasses in a pasture or hay, or whether it is used as silage, it appears to have the potential to provide a satisfactory nutrition level for ruminants.
A Field Technique to Study Root Growth in Peanut
Authors: Kvien C. S. , Schroeder J. , Banks P. A. 
Published: July 2010

AbstractTraditional techniques for the field study of root growth usually require extensive monitoring devices and a large labor force. We have developed a simple field technique to study root growth using the carotene‐inhibiting herbicide, fluridone {1‐methyl‐3‐phenyl‐5‐[3‐(trifluoromethyl)phenyl]‐4(1H)‐pyridinone}. Underground bands (0‐ to 15‐, 20‐ to 35‐, or 40‐ to 55‐cm vertical depth, 5 cm in width) of fluridone were sprayed into location using fan nozzles mounted on a subsoil tine. The experiment was conducted near Tifton, GA, on a Tifton loamy sand (fine‐loamy, siliceous, thermic Plinthic Paleudults). Peanut (Arachis hypogaea L.) seed were hand planted in 3‐m‐long rows at a 23° angle to the band. The horizontal distance from row to fluridone band varied from 0 to 1.2 m. A root growth profile was generated by measuring, three times a week, the horizontal distance from the band to the farthest plant showing leaf bleaching. This technique provided a simple and accurate method for determining root growth patterns in peanut.
Crop Water Stress Index and Yield of Water‐Deficit‐Stressed Alfalfa
Authors: Hattendorf M. J. , Carlson R. E. , Halim R. A. , Buxton D. R. 
Published: July 2010

AbstractThe yield relationship of water‐deficit‐stressed alfalfa (Medicago sativa L.) with the Crop Water Stress Index (CWSI) may be dynamic over the alfalfa harvest period. This investigation was conducted to define the alfalfa yield‐CWSI relationship(s), to test possible advantages of using the CWSI over the canopy‐minus‐air temperature (Tc−Ta) differential, and to combine the yield‐CWSI relationship with a growth function. ‘Apollo II’ alfalfa was grown for 2 yr in 100‐L containers set into the ground and protected from rain by a movable shelter. The soil was a Nicollet silt loam topsoil (fine‐loamy, mixed, mesic Aquic Hapludoll). Treatments were irrigation levels of 112, 100, 88, 77, and 65% field capacity. Five harvests were taken at 7‐d intervals beginning 21 d after an initial clipping. Canopy temperatures were taken daily with an infrared thermometer. A series of exponential yield‐CWSI curves resulted from the sequential harvests. Yield reductions of about 10 and 20% resulted from mean CWSI of 0.05 and 0.10, respectively, over 42‐d periods. The Gompertz growth function was modified for water‐deficit‐stress by combining it with the exponential yield‐CWSI relationship. Vapor‐pressure deficit (VPD) effectively normalized the Tc−Ta data, allowing yield data of the 2 yr to be combined in the yield‐mean CWSI relationship. Yield and Tc−Ta data not normalized for VPD showed clear separation by year for slight VPD differences. Alfalfa yield response to water‐deficit‐stress over time appeared to be adequately described by the combined Gompertz function and the yield‐CWSI (Tc−Ta normalized for VPD) curves.
Germination Requirements of a Perennial Alysicarpus vaginalis Accession
Authors: Singer K. L. , Pitman W. D. 
Published: July 2010

AbstractGermination of a perennial alyceclover [Alysicarpus vaginalis (L.) DC.] accession, which has potential value as a grazing‐tolerant pasture legume for peninsular Florida and some tropical locations, was evaluated for response to seed storage and scarification treatments. Both practical means of enhancing germination and characteristics of germination limitations were considered. A series of experiments evaluated responses to storage time, storage temperature, physical seed coat disruption with sandpaper, and exposure to steam, hot water, and dry heat. Freshly harvested seed failed to germinate regardless of seed treatment. Seed that had been stored for 3 to 8 yr produced rapid, essentially complete germination when scarified with sandpaper. A storage period of approximately 16 wk was sufficient for rapid germination regardless of storage temperature. At 4 wk of storage, a storage temperature of 7°C resulted in higher germination than storage at 24°C. Steam exposure times of from 40 min to 2 h or exposure to 80°C water for 5 to 10 min produced slow germination rates but greater than 60% germination after 56 d. Exposure to dry heat for 6 or 12 h produced poorer results (48% germination at 56 d) than steam or hot water. These heat treatments could have value either where mechanical scarification is not available or in situations where sporadic, early season rainfall creates high pasture establishment risks for seed lots that have been scarified to provide rapid, complete germination. Failure of scarified, imbibed, fresh seed to germinate indicates a physiological limitation to germination. Rapid, essentially complete germination of these seed lots after storage periods of from 16 wk to a number of years indicates that an afterripening period overcomes this limitation. Physical seed coat impermeability or hardseededness is demonstrated by the need for scarification even in seed that has been stored long enough to meet the after‐ripening requirement.
Persistence of Reed Canarygrass Clones in Binary Mixture with Alfalfa and Birdsfoot Trefoil
Authors: Jones T. A. , Carlson I. T. , Buxton D. R. 
Published: July 2010

AbstractCompetitive exclusion of one component of a binary perennial grass‐legume mixture by the other component is common, but the persistence of both components is desired. Fourteen reed canarygrass (Phalaris arundinacea L.) clones, exhibiting a range for drymatter yield (DMY), tiller density, and tiller weight, were grown in alternate‐plant binary mixture with ‘Olympic’ or ‘Baker’ alfalfa (Medicago sativa L.) or ‘Norcen’ or ‘Dawn’ birdsfoot trefoil (Lotus corniculatus L.) under a three‐cut‐per‐year management. The objectives were to determine if reed canarygrass clones and legume cultivars interact for DMY and legume concentration, to determine if the ranking of 14 reed canarygrass clones for legume concentration remained consistent across harvests, to compare the importance of tiller density and tiller weight to reed canarygrass DMY in legume mixtures, and to characterize the changing relationship between DMY of reed canarygrass and companion legumes over time. Alfalfa and birdsfoot trefoil concentrations increased from 266 and 159 g kg−1, respectively, at Harvest 1 (8 June 1983), to 937 and 856 g kg−1, respectively, at Harvest 7 (7 June 1985). Interaction between reed canarygrass clones and legume cultivars generally did not accompany significance of main effects, and ranks for legume concentration among reed canarygrass clonal mixtures stabilized by Harvest 2 (26 July 1983). Thus, it may be relatively easy to characterize reed canarygrass clones for legume compatibility. In mixtures, differences in tiller density among reed canarygrass clones usually accounted for more variation in reed canarygrass DMY than differences in tiller weight. A negative relationship between reed canarygrass DMY and legume DMY was always present. Though legumes increasingly dominated reed canarygrass over time, the rate of increase of their domination slowed as legume concentration increased.
In‐Office Retrieval of Literature with Microcomputers
Authors: Pawlak J. A. , Murray D. S. , Nofziger D. L. , Chun Sei , Reynolds D. B. 
Published: July 2010

AbstractCurrent literature searches or retrieval systems generally require strict appointment schedules with operating personnel and are limited to articles published after 1968. A complete data base and a program for rapidly searching the data base in the convenience of one's office would increase literature retrieval efficiency. A searching program and complete data base for the journals Weeds, Weed Science, and Weed Technology, were developed and combined into a total system named WeedLit. The software requirements include the data base “Citation” and the retrieval program “Litsearch.” Hardware requirements include a computer capable of running MS‐DOS or PC‐DOS with a minimum of 512K bytes of RAM and a fixed disk with 4M bytes of free space for Citation. The data base contains all articles published in Weeds from 1952 to 1967, in Weed Science from 1968 to the present, and in Weed Technology from 1987 to the present. Each article in Citation consists of 10 fields containing information on the journal, author(s), title, year, volume, and page numbers, as well as crop(s), weed(s), pesticide(s), and keyword(s) that are pertinent to the content of the article. The LitSearch retrieval program was written in TurboPascal and is capable of rapidly searching the data base. Searches are conducted through the use of search units, which are composed of the field to be searched, a comparison operator, and the text to be searched for within the specified field. The LitSearch retrieval routine is capable of searching on any combination of up to 12 search units. Output options include three format types that can be directed to the screen, a printer, or an ASCII file. Retrieval times vary with complexity of the search as well as with computer model. Complex retrievals take approximately 6 min to complete on an IBM‐PC but can be conducted in less than 2 min with an AT‐type machine.
Seasonal Leaf Area‐Leaf Weight Relationships in the Cotton Canopy
Authors: Reddy V. R. , Acock B. , Baker D. N. , Acock M. 
Published: July 2010

AbstractSpecific leaf area (SLA), the ratio of leaf area to leaf dry weight, is used in crop simulation models to estimate total leaf area or dry weight. This experiment was designed to study changes in SLA in various parts of a cotton (Gossypium hirsutum L.) canopy throughout the growing season. The main stem of the cotton plant was divided into five‐node segments. Leaf area and leaf dry weight were measured for each segment throughout the growing season. The mean seasonal SLAs for the segments from the bottom to the top of the canopy were 26.2, 25.6, 20.9, 19.4, and 18.1 m2 kg−1. Except for the uppermost segment, SLA increased from 43 to 90 d after emergence (DAE) and declined from 100 DAE. The decline coincided with boll maturation but also with canopy defoliation. It was possible to account for 93% of the variation in SLA for all segments by plotting SLA against light flux density within the cotton canopy. Variations in SLA with time, growth stage, and leaf maturity were small to insignificant when variation due to light flux density was removed. Sampling for SLA should include leaves throughout the crop canopy. Modelers who use SLA to estimate total leaf area or dry weight should determine the relationship between SLA and light flux density for their particular crop.
Corn‐Peanut Intercrop Performance in Relation to Component Crop Relative Planting Dates
Authors: Misbahulmunir M. Y. , Sammons D. J. , Weil R. R. 
Published: July 2010

AbstractA two‐yr (1982 and 1983) field study was conducted to determine the vegetative and reproductive effects of three intercrop treatments on corn (Zea mays L.) SS 335 A hybrid and peanut (Arachis hypogaea L.) ‘Florunner’. Three planting time treatments of corn relative to peanut (2 or 3 wk before, simultaneous, and 2 or 3 wk after) were compared. Sole crops of each species were also established. Initial vegetative growth of peanut was greatest when intercropped with corn planted after peanut. Intercropped corn planted before peanut matured early but, after harvest, did not result in an environment favorable for peanut to compensate for early season growth reductions. Dry weights of intercropped peanut, regardless of relative time of corn planting, were reduced to half or less of those of sole‐crop peanut. Reproductive development of both species when intercropped was generally not affected by relative planting times. Grain yields of intercropped corn were 85 to 90% and 46 to 74% of sole‐crop yields in 1982 and 1983, respectively. Intercropped peanut yielded 33 to 37% and 47 to 49% of sole‐crop yield in 1982 and 1983, respectively. Land equivalent ratios for intercrop combinations were not significantly affected by relative planting times; they ranged from 1.20 to 1.25 and 0.96 to 1.26 in 1982 and 1983, respectively. Corn contributed 69 to 72% and 49 to 62% of total intercrop production in 1982 and 1983, respectively. The results suggest that greatest total productivity in a corn‐peanut intercrop will occur when corn is planted either simultaneously with or earlier than peanut. The highest intercrop peanut yields tended to occur when corn and peanut were planted simultaneously.
Grain Sorghum Yield and Susceptibility to Insects as Affected by Early Season Growth
Authors: Karlen D. L. , Sadler E. J. , Roach S. H. 
Published: July 2010

AbstractVigorous and uniform seedling emergence and growth are considered essential for profitable crop production. The objective of this note is to document the effect of nonuniform growth, apparently caused by differences in planting depth, on the susceptibility of grain sorghum [Sorghum bicolor, (L.) Moench] to Heliothis zea (Boddie) in a production environment. Observations were made within an 8‐ha field near Florence, SC, where differences in productivity among 17 soil map units representing seven soil series classified as Ultisols were being determined. The center two rows of each six‐row planting configuration grew more slowly than and reached the boot and bloom growth stage approximately 7 to 10 d after the outside rows. During early grainfill this delayed growth and development resulted in more than 90% infestation of the center rows by Heliothis zea compared with less than 10% infestation in the outside rows. Differential growth and subsequent Heliothis damage to the crop were similar across all soil map units. Average grain yield was reduced from 3110 to 1640 kg ha−1, apparently because deeper seed placement slowed plant growth and development enough that there was subsequent synchronization between a third generation Heliothis flight and flowering. This demonstrates that nonuniform plant growth and seasonal insect populations can reduce yield by nearly 50% in the Southeastern Coastal Plains.