bluuebunny/crossref_metadata_2025_split huggingface dataset:
Leaf Production and Growth Rates of Exotic Cottons1
Authors: McMichael B. L. , Jordan W. R. , Quisenberry J. E. , Dilbeck R. E. 
Published: July 2010

AbstractAn understanding of the growth and development of diverse nonflowering photoperiodic (long‐night) exotic cottons (Gossypium hirsutum L.) differing in traits associated with drought tolerance is needed before this material can be fully utilized in genetic selection programs. Therefore, glasshouse studies were conducted in 1980 to relate previously observed differences in dry matter production to differences in leaf morphology and development. Ten exotic and two commercial cotton lines were investigated at Lubbock; three of the exotic cottons were also grown in another study at Lubbock and at Temple, TX. Plants were grown in a commercial growing medium in the Lubbock experiments and in an Amarillo fine sandy loam soil (fine‐loamy, mixed, thermic, Aridic Paleustalfs) in the Temple experiment. The number of mainstem nodes was counted in the first experiment at Lubbock; in the second experiment the number of mainstem leaves was counted and harvested for dry weight, and total leaf number, total number of nodes, and total leaf area were recorded at 30,44,58,72, and 86 days after planting. Similar measurements were made at 44 and 56 days after planting at Temple. Leaf initiation rates varied significantly, from 0.35 to 0.29 leaves per day, among the exotic cottons in the first experiment, and significant differences occurred between the two locations. The development of leaf area, total dry matter accumulation, rate of dry matter production per unit leaf area, leaf size and total leaf number differed significantly among strains that had similar leaf initiation rates. Observed differences between greenhouse and field‐grown plants at Lubbock indicated a strong environmental influence on the relationships between the growth parameters. Leaf area was directly correlated with dry matter production for all strains. The development of and increase in leaf area, however, was strain‐specific and depended on either increased leaf numbers or increased leaf size.
Tillage for Control of Volunteer Proso Millet and for Production of Sorghum1
Authors: Robinson Robert G. 
Published: July 2010

AbstractProduction of proso millet (Panicum miliaceum L.) results in volunteer plants the following year. This research was conducted to determine if primary tillage influences the population density of volunteer proso and the persistence of the volunteer problem in five subsequent crops of sorghum [Sorghum bicolor (L.) Moench]. Following proso harvest, eight tillage treatments were repeated on the same plots for 5 years on Typic Hapludoll soil at Rosemount, MN. Treatments included moldboard or chisel plowing in the fall or spring, rototilling in the spring, moldboard or chisel plowing in the fall followed by rototilling in the spring, and zero tillage. Seed production of proso and other weeds was prevented for 5 and 3 years, respectively. Proso and annual weed numbers ha−1 were determined from repeated counts made shortly after emergence in permanent 1‐m2 quadrats. Most (80%) of the total proso emergence occurred the 1st year after proso harvest, but 17, 2, and 1% occurred in the next 3 years, respectively. Although moldboard plowing gave the most 1st year control, proso was a potential major weed for 4 years following annual moldboard plowing in the fall and for only 3 years following the other tillage treatments. Most proso plants emerged in May, 10% emerged in June, and only 3% later. Moldboard plowing gave the most control of annual weeds other than proso. Highest grain sorghum yields followed moldboard plowing or rototilling in March or April or moldboard plowing in the fall followed by rototilling in April or May.
Fungicide Effects on Thatch Depth, Thatch Decomposition Rate, and Growth of Kentucky Bluegrass1
Authors: Smiley R. W. , Fowler M. Craven , Kane R. T. , Petrovic A. M. , White R. A. 
Published: July 2010

AbstractDevelopment of improved management strategies for controlling thatch on tuifgrasses is limited by an incomplete understanding of thatch biology. Mechanisms whereby fungicides cause thatch to accumulate in turfgrass were investigated, by evaluating the influences of fungicides on rates of tissue production and thatch decomposition. Fourteen fungicides, one nematicide, and five mixed‐fungicide programs were applied repeatedly (up to nine times annually), over a 4‐yr period, to a field‐grown Kentucky bluegrass (Poa pratensisL.) turf on a soil of the fine, illitic mesic family of Glossoboric Hapludalfs. Measurements were made of thatch depths, root and leaf clipping weights, shear strength of sod, and decomposition rates for thatch implanted into the turfs. Compounds that caused thatch to become deeper (p= 0.05) than in the nontreated control included benomyl, cadmium succinate, fenamiphos, iprodione, and mancozeb. Treatments in which these pesticides were used were characterized by sod shear strengths greater (p= 0.05) than in the control. Thatch accumulations were related mostly to the amounts of roots in the surface 4 cm. None of the studied fungicides significantly (p= 0.10) reduced the apparent rate of thatch decomposition. Fungicides in this study therefore appeared to induce thatchiness in Kentucky bluegrass by increasing the rates of root and rhizome production and not by reducing the rate of litter decomposition.
Nitrogen Utilization of Corn Under Minimal Tillage and Moldboard Plow Tillage. I. Four‐Year Results Using Labeled N Fertilizer on an Atlantic Coastal Plain Soil1
Authors: Meisinger J. J. , Bandel V. A. , Stanford G. , Legg J. O. 
Published: July 2010

AbstractCrop responses and N uptake of corn (Zea maysL.) grown with moldboard plow tillage (PT) and minimal tillage (MT) were measured in a 4‐yr field experiment on a Mattapex silt loam soil (finesilty, mixed, mesic, Aquic Hapludult) near Salisbury, MD (Atlantic Coastal Plain region). Labeled ammonium sulfate or ammonium nitrate (15N depleted) was applied annually to the entire area (74 m2) of each plot at five N rates ranging from 0 to 180 or 270 kg N ha−1. Corn dry matter yield, N content, and isotope composition were determined in the entire plant at the 11 to 12 leaf stage and at silage harvest, as well as in the corn grain at maturity. Below 135 kg N ha−1, dry matter yields, total N uptake, and fertilizer N (FN) uptake were greater with PT than with MT, but with 180 kg N ha1−1there was either no difference between the tillage systems or MT was greater than PT. Fertilizer N additions had no consistent or practically significant effect on soil N (SN) uptake. At 135 kg N ha−1, average crop FN recoveries were 62% for PT and 53% for MT, but this difference decreased with increasing N rate until both tillage systems averaged about 53% recovery at 180 kg N ha−1. Average SN uptake was greater with PT culture than with MT culture, averaging 76 kg N ha−1and 59 kg N ha−1, respectively. The crop N requirement of corn was about 17 kg N ha−1greater for MT corn than PT corn due to a 10% greater yield of total dry matter with MT. Corn grown with MT required about 68 kg more FN ha−1than PT, due to a lower uptake of SN and a greater crop N requirement. A lower uptake of N on MT plots during the second half of the growing season suggests (i) a greater net mineralization of N on PT plots and/or (ii) a greater loss of N via leaching and/or denitrification on MT plots. A nitrogen concentration of about 11 to 12 mg N g−1in the silage total dry matter, or about 15 mg N g−1in the grain, can be used as an approximate value for N sufficiency. However, these values should be considered broad guidelines since significant deviations were observed in individual years.
Tillage for Sunflower Control and for Annual Canarygrass and Fieldbean Production1
Authors: Robinson Robert G. 
Published: July 2010

AbstractSunflower (Helianthus annuusL.) is a major weed in crops that follow sunflower. This research measured the population density of volunteer sunflower and performance of annual canarygrass (Phalaris canariensisL.) and fieldbean (Phaseolus vulgarisL.) following tillage treatments of moldboard plowing, chisel plowing, rototilling, or zero tillage repeated on the same plots for 5 yr. Tillage plots, on Typic Hapludoll soil at Rosemount, MN, were divided into subplots of annual canarygrass planted between 26 March and 30 April and fieldbean planted between 21 and 25 May. Less than 1% of the volunteer sunflower achenes survived more than 1 yr in the soil, but tillage and planting date determined whether sunflower remained an important weed for 0,1, 2, or 3 yr. Sunflower was a major weed the first year after sunflower; however, the problem could be avoided by planting after mid‐June in soil not tilled in the fall. Moldboard plowing, which buried 82% of the achenes over 10 cm deep, gave the best but not adequate control the first year. Zero tillage or chisel plowing in the spring eliminated sunflower as an important weed after 1 yr, regardless of planting date. Chisel plowing in the fall or moldboard plowing in the spring tended to prolong the sunflower problem beyond 2 yr. Weed control in both crops was poorest following zero tillage. Moldboard or chisel plowing in the spring resulted in highest average yields of fieldbean. Highest yields of canarygrass followed moldboard plowing.
Nodulation of Dry Beans by Commercial and Indigenous Strains of Rhizobium phaseoli1
Authors: Weiser G. C. , Grafton K. F. , Berryhill D. L. 
Published: July 2010

AbstractSuccessful nodulation and seed yield increase of dry bean (Phuseolus vulgarisL.) is not often observed after inoculation with Rhizobium phaseoliin the bean production region of North Dakota and Minnesota. A 2‐yr field study was conducted to assess nodulation by indigenous soil strains and commercial strains 127K12b, 127K44, and 127K81‐3 of R. phaseoliin the dry bean cultivars ‘Fleetwood’, ‘Pindak’, ‘UI‐114’, and ‘Upland’. Inoculation with the commercial strains, compared with uninoculated controls, did not increase seed yield; however, nodule number and nodule fresh weight were influenced. Strain 127K12b produced more nodules, more total nodule tissue, and larger nodules than other commercial or indigenous strains. The cultivar UI‐114 had more nodules, total nodule tissue, and larger nodules regardless of inoculum sources. The effect of individual inoculum strains did not vary between years, but was cultivar‐specific for nodule characteristics. Inoculation with commercial strains resulted in significantly greater nodule numbers, nodule tissue, and larger nodules relative to indigenous soil strains.
Uniform Travel Speed for Manually Propelled Sprayers and Spreaders1
Authors: Wolf D. D. , Edmisten K. L. 
Published: July 2010

AbstractAccurate application of solutions from sprayers and of granules from spinner spreaders requires a known constant speed of travel. Use of a commercially available pocket‐size audio metronome is described to aid the operator in maintaining a desired speed. The metronome was powered by a 9‐V battery and was carried in a shirt pocket. The tempo of the metronome was adjusted so that the operator traversed a known course length in a specified time period. For example, 24 s to traverse 26.8 m would be equivalent to 4 km h−1. The tempo set by the metronome varied depending on the stride length of the operator. Coefficient of variation with metronome pacing was 1.7% and without the metronome was 3.7%. A method for calibrating walking speeds using a metronome is described.
Critical Evaporative Demands for Differential Stomatal Action in Peanut Grown in Narrow and Wide Row Spacings1
Authors: Erickson P. I. , Stone J. F. , Garton J. E. 
Published: July 2010

AbstractInduced stomatal closure behavior of irrigated peanut (Arachis hypogeaeL. cv. Comet, a bunch type) as related to row spacing and evaporative demand has been previously demonstrated as real and repeatable. The objective of this research was to determine the magnitude of evaporative demand that induced stomatal closure in narrow‐row plantings. Stomates in wide rows tended to show far less closure on the same days. The differences were not noted on days with low evaporative demand. Concurrent measurements of net radiation, dry‐ and wet‐bulb temperature, and horizontal wind velocity were made every 15 min. Estimates of environmental evaporative demand were made. No distinct peak or cumulative evaporative demand levels were found that separated stomatal differential action days from nonaction days. However, analysis of the cumulative advective energy component of cumulative evaporative demand showed a threshold above which stomatal closure responses were noted. This threshold was 8.5 MJ m−2. Further detailed analysis of the factors involved in the cumulative advective energy component indicated stomatal closure was dominated by neither horizontal wind velocity, integrated over time, nor integrated vapor pressure deficit.
Planting Season and Harvest Date Effects on Dry Matter Production and Nutritional Value of Brassicaspp. in the Southern Great Plains1
Authors: Rao S. C. , Horn F. P. 
Published: July 2010

AbstractBrassicaspp. may serve as high‐quality forage crops in parts of the Southern Great Plains when most warm‐ and cool‐season forages are unproductive. Field studies were conducted to assess the forage (shoot and/or root) yields, crude protein (CP), and digestibility (IVDMD) of turnip root crops (Brassica rapaL., ‘Purpletop’, ‘Cyclon’, ‘Frisia ’, and ‘Tyfon’; a Chinese cabbage × stubble turnip hybrid) and leafy‐stem crops [‘Winfred’ rape (B. napusL.) and ‘Merlin’ kale (B. oleruceaL.)] at different harvest dates. All six Brassicaswere established on a Dale silt loam soil (fine‐silty, mixed, thermic, Pachic Haplustoll) in September 1982 and 1983 (fall) and March 1983 and 1984 (spring) under dryland conditions. Shoot dry matter (DM) production for root crop cultivars was highest 85 and 95 days after planting in fall and spring, respectively. The greatest total plant DM yield was produced by Cyclon in the fall and Purpletop in the spring (7.4 and 7.6 Mg ha−1, respectively). Cyclon and Tyfon produced 0.7 Mg ha−1more shoot DM, whereas Purpletop and Frisia produced 0.4 to 0.9 Mg ha−1more root DM during their maximum DM production period. In early harvests, DM yields of kale were less than those of rape, but after 90 days growth, yields were similar (7.0 Mg ha−1). Shoot CP levels of root crops averaged 220 g kg−1and were about 25 to 60 g kg−1greater than root levels. The IVDMD of mots ranged from 670 to 840 g kg−1and were approximately 60 to 120 g kg−1higher than values for shoots. Levels of DM, CP, and IVDMD for all cultivars were similar or better in fall growing season and did not decline as rapidly compared with spring. Cyclon and Purpletop have the potential to provide high yields of high‐quality forage during the forage deficit periods of Southern Great Plains.
Experimental Test of a Model of Water Uptake by Soybean1
Authors: Radcliffe D. E. , Phillips R. E. , Egli D. B. , Meckel L. 
Published: July 2010

AbstractMechanistic models of soil water uptake have differed in the form of the water uptake term of Richard's equation. One of the most widely used uptake terms is that proposed by Hillel et al., although a detailed study comparing predicted soil water contents with those observed experimentally has been lacking. The purpose of this work was to develop a model that would test the accuracy of this water uptake term on a seasonal basis at various levels of water stress. Simulated soil water contents were compared with water contents observed biweekly in a 3‐yr field experiment that included three moisture treatments: irrigated, normal rainfall, and plastic covered. When a longitudinal resistance was included, 69 to 88% of the predicted soil water contents fell within the 95% confidence limits of the observed values from the irrigated and normal rainfall treatments in 3 yr. In the plastic‐covered treatment, however, only 17 to 49% of the predicted water contents were within the confidence limits. We conclude that the uptake term is accurate under normal and well watered conditions, but not under severe water‐stress conditions. Sensitivity analysis showed that the model was sensitive to net radiation, LAI, and rainfall and insensitive to hydraulic conductivity and root density.
A Compact Continuous Flow and Constant Level Solution Culture Renewal System1
Authors: Callahan L. M. , Engel R. E. 
Published: July 2010

AbstractResearchers need a practical, compact, and versatile continuous flow and constantly renewed nutrient culture system. Therefore, such a system for plant growth in nutrient culture was developed and tested. Numerous individual culture jars can be supported by a single solution reservoir and distributor jar. Solution flow throughout the system is automatic with only the reservoir unit needing manual replacement or resupply. The level of solution in culture jars can be fixed easily and maintained rellably by adjustment of the air inlet tube in the reservoir jar. Each culture jar can be regulated for drainage and aeration. A compact aeration system adapts to the entire unit.
Mobilization of Nitrogen‐15 from Vegetative to Reproductive Tissue of Peanut1
Authors: Kvien C. S. , Weaver R. W. , Pallas J. E. 
Published: July 2010

AbstractA field experiment was conducted to gain a greater understanding of vegetative N mobilization in the peanut (Arachis hypogaea L.) during the pod filling period. Vegetative tissue was labeled with foliarly applied 15NH4SO4 prior to initial pod set and mobilization of the incorporated 15N into various plant parts was then followed from initial pod set until harvest. We concluded from our analysis of individual plant parts that a portion of the 15N label moved out of all vegetative plant parts. Nitrogen concentration (g N kg−1 plant tissue) and 15N enrichment in the vegetative portion of both ‘Florunner’ and ‘Tamnut 74’ declined continuously until the optimum harvest date. The decline of 15N enrichment in the foliage over time was matched by a continuous increase in 15N by the developing fruit.
Photoperiod Effect before and after Flowering on Branch Development in Determinate Soybean1
Authors: Board J. E. , Settimi J. R. 
Published: July 2010

AbstractPrevious research indicated that restricted branch development was a factor associated with soybean [Glycine max (L.) Merr.] seed yield reductions at late planting dates in the southeastern United States. The present studies were conducted to outline the progress of branch development at different planting dates and to determine the role of photoperiod in branch restriction at late planting dates. In field studies, eight cultivars were planted at early April (nonoptimal), mid‐May (optimal), and mid‐June (nonoptimal) planting dates in 1982 and 1983 at Baton Rouge, LA (30°N Lat), on an Olivier silt loam (fine‐silty, mixed, thermic Aquic Fraguidalf) soil. Plants were sampled throughout the season for total branch length and number of branches. Photoperiod studies were conducted at the Phytotron, North Carolina State University, Raleigh, NC. Plants were subjected to combinations of preflowering and postflowering daylength simulations of optimal and late planting dates to determine photoperiod effects on branch development. Field results demonstrated that approximately two‐thirds of total branch length and number of branches were produced between growth stages R1 and R5 and that the period from R1 to R5 declined with each delay in planting. Reduced total branch length and number of branches at late planting dates were associated with fewer days from R1 to R5, while reduction at early planting dates occurred because of short plants. Data from the photoperiod study showed that shorter R1 to R5 period and the associated reduction in branch number, total branch length, and branch node number were photoperiodically induced phenomena. Both preflowering and postflowering daylength regimes at a late planting date were involved in these events.
Phaseolus vulgaris Growth in an Ammonium‐Based Nutrient Solution with Variable Calcium1
Authors: Fenn L. B. , Taylor R. M. , Horst G. L. 
Published: July 2010

AbstractField observations of tests where Ca was added with urea fertilizers have suggested a synergistic effect on plant growth beyond that expected from Ca control of NH3 volatilization and the nutritive effect of Ca. A study was designed to test the hypothesis that Ca stimulates NH4 absorption by plants. Greenhouse experiments were conducted with Phaseolus vulgaris (Great White Northern bean) in quartz sand with 5% CaCO3 to determine the effects of variable Ca concentration on plant growth in an NH4‐based nutrient solution. Ammonium absorption increased with increasing Ca to 13 mmol L−1, as indicated by decreasing NH4 concentration in the leachate, and increased plant growth. Tissue N was unchanged as solution Ca concentration increased. Potassium accumulation in the plant behaved much like N, whereas the Ca level increased with increasing solution Ca concentrations.
Seedling Vigor of Selected Alysicarpus Accessions1
Authors: Taylor S. G. , Baltensperger D. D. 
Published: July 2010

AbstractAlyceclover [Alysicarpus vaginalis (L.) DC.] is a tropical legume considered to have poor seedling vigor. This characteristic often leads to difficulties in establishing new pastures. Ten Alysicarpus breeding lines were evaluated for early seedling growth and compared to common alyceclover. Field experiments in 1984 and 1985 at Gainesville, FL, on Arredondo fine sand (loamy, siliceous, hyperthermic Grossarenic Paleudult) detected a high degree of variation among genotypes for seedling vigor as measured by mean plant dry weights 3 and 6 weeks after planting. One line, FL‐3, was consistently more vigorous than common alyceclover. Several other lines (FL‐1, FL‐2, FL‐5, FL‐6, and FL‐11) were equal to or slightly less vigorous than the common type. Four lines (FL‐4, FL‐7, FL‐9, and FL‐10) had an unacceptable level of vigor. Within this collection of germplasm, there was a high correlation between seed weight and plant weight (r = 0.62 – 0.79). Visual ratings of seedling vigor taken 4 days after germination were also highly correlated with plant weights (r = 0.57 – 0.93). Seed weights and visual seedling vigor ratings may be useful characteristics for preliminary screening in future work. Broad‐sense heritabilities for plant dry weights were high (68–77%), indicating that seedling vigor may be under the control of genetic systems. It is suggested that improvement of alyceclover seedling vigor could be made via selection.