bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature Effects on Cotton Fruit Retention
Authors: Reddy K. R. , Hodges H. F. , Reddy V. R. 
Published: July 2010

AbstractTemperature is a major environmental factor that affects cotton (Gossypium hirsutum L.) production. Temperatures of 35 to 40°C are frequently observed in cotton‐producing areas. High‐temperature environments are sometimes associated with cotton sterility and boll retention problems; however, there is little specific information available on cotton sensitivity to temperature. We conducted a series of experiments in naturally lit growth chambers where the temperature was accurately controlled so we could measure its effects on cotton fruiting site production, abscission of flower buds (squares), flowers, and bolls. Cotton plants grown from seedlings at 40°C for 12 h d−1 shed all their squares. Plants grown from seedlings in the natural environment, then exposed to daytime temperatures of 30, 35, or 40°C during the fruiting period accumulated 47, 5.7, and <1%, respectively, of their mass as bolls. The time of day when plants were exposed to high temperature did not influence percent boll retention. Number of bolls produced, bolls retained, and percent retention were progressively reduced as time per day at 40°C was increased. Three week exposure to 40°C for 2 or 12 h d−1 resulted in 64 or 0% bolls, respectively, retained on the plants. Cultivars appeared to be similar in sensitivity to high temperature. Cultivars tolerant to short periods of high temperature would probably be more productive in today's environment and increased tolerance to high temperature will be even more essential in a warmer environment.
Theory for Leaf Segment Lengths for Plant Canopies
Authors: Walthall C.L. , Norman J.M. 
Published: July 2010

AbstractLeaves are considered the most important architectural components when studying the interaction of solar radiation with vegetation canopies. Models used in the study of solar radiation interaction with canopies generally assume randomly distributed leaves, with little or no attention to the arrangement of leaves and inter‐leaf gaps. This study was conducted to develop a model to describe the distribution of lengths of overlapping or contiguous leaves along a transect. The model describes the cumulative distribution of leaf segment lengths using a modified form of an equation previously used to describe interleaf gap length distributions. The leaf segment distribution model estimates were tested by comparisons with measurements of simulated physical canopies made of paper labels on clear plexiglass sheets. A comparison of model estimates with measurements of the simulated physical canopy showed generally good agreement. This study demonstrates that the distribution of leaf segment lengths along a transect within a canopy, like that of inter‐leaf gaps, is a function of canopy density and individual leaf dimensions. This is important as the leaf segment length distribution provides a technique for indirect canopy structure determination.
Soybean Seed Quality Response to Drought Stress and Pod Position
Authors: Smiciklas K.D. , Mullen R.E. , Carlson R.E. , Knapp A.D. 
Published: July 2010

AbstractThe effects of drought stress on soybean [Glycine max (L.) Merr.] seed quality may be influenced by morphological plant characteristics and the timing of drought stress. Determinate soybean plants were grown near Ames, IA, to ascertain the influences of the timing and frequency of drought stress and pod position on seed quality (as measured by germination, seedling dry weight, and seed leachate current). Plants were well‐watered (high reproductive load) or drought‐stressed at flowering (R2) to decrease potential seed number (low reproductive load). Subsequent drought stresses were implemented at the full pod (R4), seed formation (R5), and full seed (R6) stages, in addition to a nonstressed treatment. The harvested pods were grouped into the top main stem, bottom main stem, and branch positions for seed quality testing. An R2 drought‐stress (low reproductive load) did not prevent reductions in seed quality from occurring when additional stress was imposed at R4, R5, or R6 plant stages. However, the R2 + R4 stress treatment increased seedling weight by 7% and weight per seed by 12% compared with the R4 drought‐stress treatment. Top main stem seeds were of better quality and greater weight than seed harvested from the bottom main stem or branch positions. Branch or bottom main stem seeds were most sensitive to quality reductions when drought occurred during the R5 or R6 stages. The results indicate that variable seed quality resulting from drought stress can be attributed to the timing of stress and pod position on the plant.
Limpograss Sod Management and Aeschynomene Seed Reserve Effects on Legume Reestablishment
Authors: Chaparro C.J. , Sollenberger L.E. , Jones C.S. 
Published: July 2010

AbstractAeschynomene (Aeschynomene americana L.) is a warm‐season, annual legume that is well adapted to wet habitats. Stands must regenerate from seed each year, so size of seed reserve and management of the associated grass in winter and spring are important. In 1988 and 1989, effects of aeschynomene soil‐seed reserve (simulated by broadcasting known quantities of seed in the pod) and winter‐spring management of a limpograss [Hemarthria altissima (Poir.) Stapf and Hubb.] sod on legume reestablishment were evaluated on Smyrna (sandy, siliceous, hyperthermic Aerie Haplaquods) and Pomona (sandy, siliceous, hyperthermic Ultic Haplaquods) sands. All combinations of three tillage procedures (no disking, disking in spring, or disking in early summer) and two grazing treatments (grass grazed to a 10‐cm stubble or not grazed) were allocated as main plots in a split‐plot arrangement. Subplots were four quantities of seed applied the previous December (20, 60, 180, and 540 kg ha−1). Dry weather in late spring and early summer 1988 reduced grass competition to legume seedlings that had established in April, and grazing had no effect on percentage legume (PCL) in harvested forage. Within each disking treatment, PCL increased linearly with size of seed reserve, but summer disking reduced legume contribution relative to spring and no disking. With near optimal rainfall in 1989, PCL for the grazed swards was three to six times greater than for ungrazed swards. For all disk treatments, PCL increased linearly with size of seed reserve, but spring disking was superior to no disking and summer disking. Results suggest that aeschynomene reestablishment in limpograss is favored by spring disking and grazing limpograss until legume seedlings are 5 to 8 cm tall. Using this management in 1988 and 1989, seed reserves of 25 to 135 kg ha−1 were needed for successful aeschynomene reestablishment.
Seed Germination Response for Eleven Forage Cultivars of Brassica to Temperature
Authors: Wilson R.E. , Jensen E.H. , Fernandez G.C.J. 
Published: July 2010

AbstractSlow germination and poor seedling vigor limit stand establishment of forage Brassica spp. Soil temperature is a major factor influencing both processes. Temperature effects on germination of 11 forage brassica cultivars, comprised of three species plus one hybrid, were studied in an incubator. The species and cultivars tested were turnip (B. rapa L.): Civastro‐R, Polaris, Purple Top, Stubble, and Forage Star; rape (B. napus L.): Emerald, Fodder, and Dwarf Essex; kale (B. oleracea L.): Premier, and Marls Kestral; and the turnip × Chinese cabbage hybrid [B. rapa L. × B. pekinensis (Lovr.) Rupr.]: Tyfon. Germination studies were conducted in the dark at 10 constant temperatures (0, 2, 5, 10, 15, 20, 30, 35, 40, and 50°C). Number of seeds germinated were counted on Day 4 and 14 after planting. Cultivars differed significantly (P ≤ 0.001) for percentage germination on both day 4 and 14 at all temperature treatments except 2 and 40°C. Under the cool temperatures (5 and 10°C), Civastro‐R, Polaris, Purple Top, and Stubble were the earliest germinating cultivars. At the 40°C temperature regime, Marls Kestral initiated germination earlier than that of the other cultivars, but total germination was highest for Polaris. The cultivars Civastro‐R, Polaris, Purple Top, and Stubble could serve as potential parents of a new cultivar because of their ability to germinate rapidly over a wide range of temperatures.
Temperature Effects on Early Season Cotton Growth and Development
Authors: Reddy K.R. , Reddy V. R. , Hodges H.F. 
Published: July 2010

AbstractTemperature is a primary environmental factor controlling growth and developmental rates of plants, yet little specific information is available regarding cotton (Gossypium hirsutum L.) responses to temperature. Information covering a wide range of temperatures would be useful for predicting both developmental and growth rates in cotton. Therefore, an experiment was conducted in naturally lit, temperature‐ and CO2‐controlled cabinets from soon after emergence until 56 d after emergence (DAE). The cabinets were maintained at 20/12, 25/17, 30/22, 35/27, and 40/32°C day/night cycles. Plant heights, number of nodes, and leaf areas were determined weekly throughout the experiment, and dry weight measurements were obtained at three intervals. Mainstem elongation, leaf area growth, and biomass accumulation rates were very sensitive to temperature about 3 wk after emergence. Prior to that time, they were relatively insensitive to temperature. The temperature optimum for stem elongation, leaf area expansion, and biomass accumulation was 30/22°C. Developmental rates, as depicted by number of mainstem nodes produced, number of fruiting branches, and fruiting branch nodes, were not as sensitive to temperatures above 30/22°C as were growth rates. Four times as many fruiting branches were produced at 30/22°C as at 20/12°C; whereas more vegetative branches were produced at low temperatures. All flower buds (squares) abscised from plants grown at 40/32°C. Essentially, all bolls and squares were retained at 30/22 °C while a 10% boll and square loss was observed at 35/27 °C during the early reproductive period. Less time was required for this cultivar to produce squares at any temperature, suitable for growing cotton, than was suggested by previous experiments.
Notes: Data Collection Software for the Psion Organiser II
Authors: Panter D.M. , Allen F.L. 
Published: July 2010

AbstractUsing notebook‐sized computers to record field and laboratory data has become commonplace among agricultural researchers. However, the physical size, mass, and limited battery life of notebook‐sized computers reduce their attractiveness for field data recording. Several manufacturers have developed small, hand‐held computers designed primarily for field data recording, but the cost of many of these systems is prohibitive. Our objective was to develop data recording software for the Psion Organiser II Model XP (Psion PLC, London)1, an inexpensive, calculator‐sized computer with long battery life and nonvolatile data storage capabilities. Our software, named NOTES, is a menu‐driven program written in Organiser Programming Language that accepts both character and numeric data, provides a simple method for recording data variables, and supplies utilities for managing data files. Data can be stored on non‐volatile EPROM modules, making them safe from loss of battery power to the computer. Uploading data files to an RS232‐equipped MS‐DOS computer is automated through a file management utility built into the program and data files are stored on the host computer in ASCII format. This hardware/software system provides an easy to use, inexpensive method to increase the efficiency of recording field and laboratory data while virtually eliminating data loss due to battery failure.
Turf Response to Triazine Carriers as Influenced by Pseudomonas Inoculant
Authors: Peacock Charles H. , DiPaola Joseph M. 
Published: July 2010

AbstractTriazines have potential for use as slow‐release N fertilizers. Their degradation by microbial activity and subsequent N mineralization rate is reduced in less microbially active soils. The objective of this study was to determine the influence of Pseudomonas inoculant on the efficacy of triazine fertilizers. Turf response to ammeline (4,5‐diamino‐1,3,5‐triazin‐2(1H)‐one) and melamine (1,3,4‐triazine‐2,4,6‐triamine) inoculated with a 1, 5, or 10% Pseudomonas sp. bacterial culture was investigated on ‘Tifway’ bermudagrass (Cynodon dactylon L. Pers. ✕ C. transvaalensis Burtt‐Davy) and compared to IBDU (isobutylidenediurea) and urea N carriers. During 2 yr of study, overall turf quality was acceptable for all carriers, but was best for those plots receiving IBDU, ammeline, and melamine/urea (M/U) with quality ranging from 6.9 to 7.7. Turf growth was not influenced by N sources the first year. During the second year, weekly shoot growth was greater from plots receiving ammeline and IBDU compared to melamine and M/U (up to 30%). Addition of inoculant to the melamine lowered turf quality by almost a whole point and weekly shoot growth was as much as 40% greater where no inoculant was added. Turf quality reductions with melamine were inoculant‐rate responsive. Inoculant addition failed to provide a microbially competitive advantage over naturally occurring soil organisms to stimulate increased degradation and N release for turf performance.
Comparison of Cellulase Solutions for Use in Digesting Forage Samples
Authors: Bughrara S. S. , Sleper D. A. , Beuselinck P. R. 
Published: July 2010

AbstractPrepared cellulase solutions from different origins may differ in their relative effectiveness in providing accurate estimates of in vitro dry matter digestibility (IVDMD) of forages. Our objectives were to compare prepared cellulase solutions from different commercial sources with our non‐commercial prepared cellulase solution and evaluate their effectiveness in obtaining meaningful estimates of IVDMD for three grass and three legume species. A total of 46 samples were evaluated from six different forage species including switchgrass (Panicum virgatum L.), big bluestem (Andropogon gerardii Vitman), tall fescue (Festuca arundinacea Schreb.), alfalfa (Medicago sativa L.), birdsfoot trefoil (Lotus corniculatus L.), and lespedeza (Kummerowia striata Thunb.). Significant differences for IVDMD were found among the prepared cellulase solution sources. Correlations between IVDMD estimates using the prepared cellulase solutions and in vitro rumen fermentation ranged from 0.57 to 0.95. The highest correlation (r = 0.95) was observed using a non‐commercial prepared cellulase solution and the next (r = 0.91) was obtained from cellulase procured from Worthington Biochemical Corp (Freehold, NJ). We concluded that the cellulase solution prepared from cellulase obtained from Worthington Biochemical Corp. was an alternative to our non‐commercial source in obtaining estimates of IVDMD.
Potassium/Magnesium Ratio Effects on Aluminum Tolerance and Mineral Composition of Wheat Forage
Authors: Huang J.W. , Grunes D.L. 
Published: July 2010

AbstractKnowledge of cation amelioration of Al toxicity may improve our understanding of differential Al‐tolerance mechanisms among winter wheat (Triticum aestivum L.) forage genotypes, and the causes of tetany in grazing cattle. A solution culture experiment was conducted using two winter wheat cultivars (Atlas 66 and Scout 66), two Al levels (0 and 50 μM), and three K/Mg ratios (0.1, 0.7 and 2.3, on a mol Lc−1 basis). Root dry weights were decreased significantly by Al for Al‐sensitive Scout 66, but not for Al‐tolerant Atlas 66. Increasing the K/Mg ratio in the presence of Al significantly decreased root dry weight, root length, and the root tolerance index for Scout 66, but not for Atlas 66. Shoot and root Mg concentrations were always significantly lower for Scout 66 than for Atlas 66. Without Al, shoot K and Ca concentrations for the two cultivars were not significantly different. With Al, shoot K, Ca and Mg concentrations were depressed more for Scout 66 than for Atlas 66. The K(Ca + Mg) ratios increased significantly in Scout 66 with added Al, thereby causing an increased tetany hazard. Adding Al reduced shoot Cu and Zn concentrations in both cultivars, and Fe and Mn concentrations in Scout 66. Increasing the proportion of Mg in solution increased the Al tolerance for Scout 66, indicating that an appropriate K/Mg ratio is important in selecting for Al‐tolerant wheat cultivars.
Growth and Root Morphology of Corn as Influenced by Nitrogen Form
Authors: Teyker R. H. , Hobbs D. C. 
Published: July 2010

AbstractPublic concern about NO‐3 levels in potable waters, together with improving techniques for maintaining NH4+ availability in soils, has renewed research interest in the effects of N form on crop growth. The effects of NO‐3 versus NH+4 on growth and morphology of juvenile corn (Zea mays L.) were investigated in two experiments. In Exp. 1, 16‐d‐old, solution‐grown plants produced less shoot fresh weight when grown with NH+4 than with NO‐3 nutrition. Root fresh weights were similar, but elongation of the primary root axis and its longest first order lateral was less with NH+4 nutrition. Under NH+4 nutrition, apparent thickness (grams per meter) of primary roots was 54% greater, and the frequency of first order laterals with second order laterals was 65% greater, than under NO‐3 nutrition. In Exp. 2, plants were grown in the greenhouse until 40 d after emergence in a slightly alkaline 3:1 sand:soil mix. Nitrogen (75 mg N kg−1) was supplied as either Ca(NO3)2 or (NH4)2SO4 plus nitrapyrin [2‐chloro‐6‐(trichloromethyl) pyridine]. Ammonium‐grown plants produced 2.3 times the dry matter and had higher concentrations of N in both stems (18.5%) and leaves (27.5%) compared to NO‐3‐ grown plants. Tillering was increased by NH+4‐ nutrition. Apparent root thickness was again greater under NH+4 nutrition, but the difference between N regimes was only 15%. Results indicate that under conditions of course‐textured soils and slightly alkaline pH an enhanced NH+4‐ N regime may be advantageous for growth of corn. Differences in pH regimes between the hydroponic and soil‐based experiments may account for the contrasting results.
Intercropping Sorghum and Pinto Bean in a Cool Semiarid Region
Authors: Carr P.M. , Schatz B.G. , Gardner J.C. , Zwinger S.F. 
Published: July 2010

AbstractIntercropping corn (Zea mays L.) with soybean [Glycine max (L.) Merr.] has been found to yield a greater harvest of total grain protein than a sole crop of corn in northern temperate regions. Similarly, it may be possible to increase the total grain protein yield in regions of lower precipitation with an intercrop of grain sorghum [Sorghum bicolor (L.) Moench] and a pulse crop. Our objective was to determine if sorghum could successfully be intercropped with dry bean (Phaseolus vulgaris L.) to produce a grain for feed. A field experiment was conducted during 1989 and 1990 near Carrington, ND (45°30'N, 99°7'W). Sorghum was established at 16 plants m−2 as a sole crop and intercropped in the same row with pinto bean at three different sorghum to bean plant ratios: 8:1, 4:1, and 2:1. Grain yield of sorghum was not reduced by intercropping at the low (8:1) and moderate (4:1) bean plant densities, but yield was reduced (P < 0.05) at a sorghum:pinto bean plant ratio of 2:1. Yield of pinto bean ranged from 0.22 to 0.70 Mg ha−1, depending on population and annual growing conditions. Grain protein yield tended to increase as bean comprised more of the total plant population, although a significant difference between treatments was not detected. While this investigation demonstrates that sorghum can successfully be intercropped with dry bean, other sorghum‐pulse intercrops might be more advantageous in increasing the total yield of grain protein.
Yield and Yield Component Response of Spring Barley to Fertilizer Nitrogen
Authors: Bulman Patrick , Smith Donald L. 
Published: July 2010

AbstractBarley (Hordeum vulgare L.) is an important cereal crop in eastern Canada, where it is used mainly as a source of energy for monogastric animals. A 4‐yr field experiment was conducted to evaluate the effects of N application on the yield of spring barley. Three cultivars, Cadette, Leger (adapted feed types), and Argyle (unadapted malting type) were grown with 0, 50, 100, 150, or 200 kg N ha−1 applied as ammonium nitrate at seeding. Two other treatments consisted of 100 kg N ha−1 at seeding plus 50 kg N ha‐1 as ammonium nitrate (broadcast) or urea (foliar spray) applied at Zadoks growth stage 50 (spike emergence). Grain yield generally did not respond to N treatments. Separate determination of main stem (MS) and tiller yield components revealed that the lack of response to progressively higher rates of N was due to the stable nature of MS yield components and to the relatively small contribution of tillers to grain yield. Very high levels of N occasionally reduced the grain set and yield of MS spikes. Mean weight per MS grain showed little variation among growing seasons and N treatments. High rates and split applications of N had few significant effects on tiller yield and yield components. Tiller spike densities were consistently low (81–147 spikes per square meter). Tiller spikes produced only 7 to 15 grains, with individual grains weighing 60 to 75% of the weight of MS grains. Previous cropping practices and environmental conditions seemed to affect spike development and grain‐set more than application of fertilizer N.
Model of Integrated Effects of Boron, Inert Salt, and Water Flow on Crop Yield
Authors: Shani U. , Hanks R. J. 
Published: July 2010

AbstractHigh boron concentration in the soil causes yield reduction. Recently, a piecewise linear response curve was applied to describe yield response to B in near steady‐state conditions. However, application of similar curves to field situations where water, B, and other ion contents are transient and nonhomogeneous is limited. The objective of this study was to develop a model for simulation of the integrated effects of B, inert salt, and water on crop yield under field conditions. The model computes water flow in response to irrigation, rain, or evapotranspiration processes and subsequently computes inert salt and B transport. Crop yield is related to soil matric and osmotic potentials and B toxicity. Effects of B toxicity are considered by adapting the steady‐state approach to the transient situation. Field experiments with barley (Hordeum vulgare L.) and corn (Zea mays L.) were conducted on the Utah Power & Light Co. research farm (Huntington, UT). Soil was Penoyer loam [coarse‐silty, mixed (calcareous), mesic Typic Torriorthent]. Line source irrigation was used to obtain different irrigation levels. The effects of B, Salt (mixture of Na, Ca, Cl, and SO4), and B+Salt on yield were studied in barley. The effect of B + Salt was studied also in corn. Measurements and simulations were in close agreement for both crops. Barley yield ranked B + Salt < B < Salt < control. Corn yield ranked B + Salt < control. The B adsorption properties result in less leaching than do those of an inert ion like Cl. The effects of initial and boundary conditions together with the B adsorption characteristics on B concentration in the soil solution and the subsequent yield reduction are presented. This model can serve for an analysis of the long‐term effects of high B and help in understanding the relative effects of available water, inert salt, and B on yields.