bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cultivar ✕ Tillage Interaction of Hard Red Spring Wheat Cultivars
Authors: Hall E. F. , Cholick F. A. 
Published: July 2010

AbstractTillage systems in the spring wheat (Triticum aestivum L.) production areas of the North Central Great Plains are changing to control soil erosion and increase soil water conservation. Therefore, a field study was conducted under three environmental conditions to determine if there was a cultivar ✕ tillage interaction for grain yield, plant establishment, tiller number at boot and maturity, grain volume weight, and plant height. Eighteen adapted hard red spring wheat cultivars were evaluated using two tillage systems, till and no‐till, during 1985 and 1986 on a Beotia silt loam (fine‐silty, mixed, Pachic Udic Haploboroll) and during 1986 on an Aberdeen silt clay loam (fine, montmorillontic, glossic Udic Natriboroll). There was a significant cultivar ✕ tillage interaction for grain yield, with a range from a 9.8% increase to a 11.6% decrease depending on cultivar when examined over all environments. There was a cultivar ✕ tillage interaction for seed weight (P = 0.07) and grain yield (P < 0.05). Stand establishment was superior at all locations in no‐till. Tillering at various growth stages did not explain grain yield differences. This study indicated that selection under no‐till should be considered to more efficiently develop spring wheat cultivars for no‐till production systems.
Water‐Use Efficiency and Light Interception of Semidwarf and Standard‐Height Sunflower Hybrids Grown In Different Row Arrangements
Authors: Zaffaroni Eduardo , Schneiter A. A. 
Published: July 2010

AbstractSemidwarf sunflower (Helianthus annuus L.) may have potential for adaptation in large areas where conventional‐height sunflowers are currently grown. To develop improved production practices for this plant type, a better understanding of light and water use is needed. The objective of this study was to evaluate light interception, water‐use efficiency (WUE), and energy‐use efficiency (EUE) of semidwarf (SD) and standard‐height (SH) sunflower hybrids grown under various row spacings. Field studies were conducted at Prosper, ND during the 1984 and 1985 growing seasons. Row arrangements consisted of (i) conventional rows, spaced 0.76 m apart; (ii) solid seeding, rows spaced 0.38 m apart; and (iii) twin rows, two rows 0.19 m apart on 0.76‐m centers at populations of 35 000, 50 000 and 65 000 plants ha−1. Soil‐water depletion at different levels of the soil profile was similar for both plant types during 1984, but statistically greater for the SH hybrid during 1985. In general, soil‐water depletion was greater under solid seeding both years. Total water use (WU) and WUE were not statistically different between hybrids or among row arrangements in combined analysis across years. In 1985, WUE was statistically higher for the SD hybrid (4.69 kg ha−1 mm−1), as a result of decreased yield in the SD hybrid caused by Sclerotinia head rot (Sclerotinia sclerotiorum). Light interception among treatments was not different in 1984, but in 1985 was higher for sunflower sown at solid seeding and twin rows than in conventional rows. Energy‐use efficiency was not different among treatments in 1984, while in 1985, the SH hybrid had statistically higher values (1.29%). During this year EUE significantly increased from 0.99 to 1.33% as plant population increased.
Infrared Thermometry to Measure single Leaf Temperatures for Quantification of Water Stress in Sunflower
Authors: Nielsen D. C. , Anderson R. L. 
Published: July 2010

AbstractQuantification of water stress by infrared thermometry is routinely done on complete plant canopies to minimize the influence of viewed soil surface. When plants are small or widely spaced, canopies may not be complete. This study was conducted to determine if Crop Water Stress Index (CWSI) values computed from infrared thermometer measurements of single‐leaf temperatures of sunflower [Helianthus annuus (L.) ‘Triumph 566DW’] were correlated with other measures of plant water stress. Plants were grown under an automated rainout shelter and subjected to four water treatments ranging from 0.0 to 100% replacement of evapotranspirational losses. The soil type is a Rago silt loam (fine, montmorillonitic, mesic Pachic Argiustoll). Statistically significant correlations were found between CWSI calculated from single‐leaf temperatures and stomatal conductance, CO2 exchange rate, leaf water potential, transpiration rate, and percent available water in the active root zone. Calculating CWSI from single‐leaf temperatures measured with an infrared thermometer can provide a rapid means of assessing plant water status in incomplete canopies.
Bermudagrass Response to Leaching Fractions, Irrigation Salinity, and Soil Types
Authors: Devitt D. A. 
Published: July 2010

AbstractReuse of wastewater as an irrigation source for turfgrass is becoming a more viable and appealing option in arid environments where competition for good‐quality water is increasing. The objective of this research was to determine the impact that varied leaching fractions, irrigation salinity, and soil types had on root growth and distribution, and fractional water uptake of bermudagrass [Cynodon dactylon (L.) Pers.]. Bermudagrass was grown for a 2‐yr period in large columns packed with three different soil types (sandy loam, silt loam, and clay). Saline water was synthesized and applied at three different salinity levels (electrical conductivities of 1.5,3.0,and 6.0 dS m−1). Irrigations were applied 3 d wk−1 at a rate beyond measured evapotranspiration (ET) to establish three different leaching fractions (0.09, 0.18, and 0.27). The soil salinity (ECe), soil solution chloride (CI−), root density, and volumetric water contents were measured in soil cores taken with depth and time. Dry matter of weekly grass clippings was measured and recorded throughout the 2‐yr period. Plant water status was monitored by measuring canopy temperatures and leaf xylem water potentials. Results indicated that bermudagrass was very tolerant to the range of salinity‐leaching conditions imposed. However, differences were noted by treatments, with the sandy soil showing as much as a 25% yield decrement at the highest salinity level. Salinity of the irrigation water (ECI), rather than soil salinity (ECe), was more highly correlated with most of the soil‐plant‐water relationships observed. Root length density was best described by a hyperbolic function. Only limited success was found in correlating root length density with fractional water uptake. In addition, poor correlations were found between soil salinity with depth and fractional water uptake. These findings indicate that the ability to predict water uptake based on root distribution and/or soil salinity would be poor and that great error might occur in using such an approach in predictive models.
Soil and Tissue Nitrate Tests Compared for Predicting Soil Nitrogen Availability to Corn
Authors: Fox R. H. , Roth G. W. , Iversen K. V. , Piekielek W. P. 
Published: July 2010

AbstractMounting concern about NO3 pollution of the nation's ground and surface waters make accurate N‐fertilizer recommendations increasingly important. A study was initiated in 1984 to determine if presidedress soil or corn stalk (Zea mays L.) NO3 concentrations could be used to predict soil N availability and the need for sidedress N fertilizer. Nitrate concentration was determined in the surface 30 cm of soil and in the lower 10 cm of corn stalks 22 to 37 d after emergence (corn was in the 5‐ to 6‐leaf stage). Eighty‐seven N‐response experiments were conducted over a 4‐yr period in central and southern Pennsylvania. A number of these sites were on fields that had received high rates of manure in the past. Corn stalk NO3 concentration was not an accurate predictor of soil N availability nor of the probability that a site would respond to N fertilizer. The NO3 concentration in the surface 30 cm of soil 4 to 5 wk after emergence was a good indicator of whether a response to sidedress N fertilizer would be attained. The best critical level for separating responsive from nonresponsive sites was 21 mg NO3‐N kg−1. No sites responded to N fertilizer when the soil NO3‐N concentration was greater than 25 mg kg−1. Soil NO3 concentration and soil N‐supplying capability (NSC) at soil NO3 levels below the critical level were not correlated well enough (r2 = 0.34) to use the predicted NSC for adjusting N‐fertilizer recommendations. As a result, the best use of this test in Pennsylvania appears to be in identification of nonresponsive sites rather than predicting N‐fertilizer rates. Use of this test by farmers in Pennsylvania will help minimize the practice of applying “insurance” N when N contributions from manure and legumes in rotations are uncertain.
Chemical Regulation of Alfalfa/Grass Mixtures with Imazethapyr
Authors: Fales S. L. , Hoover R. J. 
Published: July 2010

AbstractGrowth regulators can improve forage grass quality, but they have not been evaluated for quality enhancement with grass‐legume mixtures. A field experiment was conducted for 2 yr to investigate the effects of applications of imazethapyr [5‐ethyl‐2‐(4‐isopropyl‐4‐methyl‐5‐oxo‐2‐imidazolin‐2‐yl) nicotinic acid] on production and quality of alfalfa (Medicago sativa L.) /grass mixtures. Mixtures of alfalfa with either orchardgrass (Dactylis glomerata L.), ryegrass (Lolium perenne × L. multiflorum Lam.), reed canarygrass (Phalaris arundinaceae L.), smooth bromegrass (Bromus inermis Leyss.), or timothy (Phleum pratense L.) were established on a Hagerstown silt loam (fine, mixed, mesic Typic Hapludalf) and were treated with imazethapyr at application rates of 0, 25, 50, and 100 g a.i. ha−1. Results showed first‐harvest mean (mean of rates and grass species) grass crude protein (CP), in vitro dry matter disappearance (IVDMD), and neutral detergent fiber (NDF) of 128,643, and 622 g kg−1, respectively compared with 108, 623, and 654 g kg−1, respectively for controls. Alfalfa was unaffected by treatments. Changes in CP, IVDMD, and NDF concentrations with increasing imazethapyr levels showed significant linear and quadratic components for first harvest in 1986, but showed only a linear trend in 1987 due to reduced effectiveness of the 25 and 50 g ha−1 treatments the second year. Second‐ and third‐harvest quality trends were inconsistent both years. Controls averaged 21% grass at first harvest in 1986 and 37% in 1987, whereas imazethapyr lowered first harvest grass percentage to 13 and 22%, respectively for the 2 yr. In 1986, treated plots showed enhanced grass regrowth at second cutting, but the same was not observed in 1987. Consequently, treatments did not affect seasonal yield in 1986, but resulted in a mean reduction of 0.6 Mg ha−1 in 1987. Where forage quality of alfalfa/grass hay is paramount, imazethapyr may be an effective management tool.
Chemical Regulation of Growth and Forage Quality of Cool‐Season Grasses with the Imazethapyr
Authors: Fales S. L. , Hill R. R. , Hoover R. J. 
Published: July 2010

AbstractForage quality in cool‐season grasses declines rapidly in the spring primarily due to the production of relatively indigestible stem tissue. This study was conducted to evaluate the ability of the plant growth regulator, imazethapyr [5‐ethyl‐2‐(4‐isopropyl‐4‐methyl‐5‐oxo‐2‐imidazolin‐2‐yl) nicotinic acid], to constrain losses in grass quality by reducing rates of neutral detergent fiber accretion and by maintaining levels of crude protein and in vitro dry matter disappearance. In 1986 and 1987 field plots of ‘Pennlate’ orchardgrass (Dactylis glomerata L.), ‘Bison’ ryegrass (Lolium perenne L. × L. multiflorum Lam.), ‘Palaton’ reed canarygrass (Phalaris arundinacea L.), ‘Saratoga’ smooth bromegrass (Bromus inermis Leyss.), and ‘Toro’ timothy (Phleum pratense L.) were treated with imazethapyr, at rates of 0, 25, 50, and 100 g a.i. ha−1. Plots were sampled at weekly intervals for 7 wk after imazethapyr application in the spring. Treated forage averaged between 36 and 71 g kg−1 lower in neutral detergent fiber, between 19 and 44 g kg−1 higher in vitro dry matter disappearance, and between 9 and 20 kg−1 higher in crude protein, depending on the level of imazethapyr applied. Improvements in quality were accompanied by corresponding dry matter yield reductions, which ranged between 0.8 and 2.8 Mg ha−1. Rates at which yield increased or quality decreased as the season progressed were reduced by higher rates of imazethapyr application. Imazethapyr appears to be an effective tool for manipulating the growth and nutritive quality of cool‐season grasses.
Foliar‐Applied Daminozide Effect on the Yield and Tuber Size Distribution of Potato
Authors: Sanderson J. B. , White R. P. , Platt H. W. , Ivany J. A. 
Published: July 2010

AbstractThis study investigated the effects of foliar applied daminozide (butanedioic acid mono 2, 2‐dimethyl hydrazide, Alar 85, Uniroyal Chemical, Inc.) on two potato (Solanum tuberosum L.) cultivars, Kennebec and Red Pontiac, field grown with six replications over 3 yr at Charlottetown, Prince Edward Island, Canada. Four treatments were evaluated in 1985: (i) control, (ii) 0.42 kg daminozide ha−1 applied when largest tubers reached 20 mm, and (iii) 0.85 kg daminozide ha ' applied when largest tubers reached either 20‐min or (iv) 30‐mm stage. The treatments evaluated in 1986 and 1987 were: (i) control, and (ii) 0.85 kg daminozide ha−1 applied when the largest tubers had reached either the 10‐mm, (iii) 20‐mm, or (iv) 30‐mm stage. Daminozide did not significantly affect foliar or tuber disease levels, nor total tuber yield, but an increase of 2.36 t ha−1 in the seed size tuber yield did result from a 0.85 kg daminozide ha−1 application at the 30‐mm tuber size stage. Differences in cultivar responses occurred at earlier tuber size stages. Application of daminozide modified the tuber size distribution of the potato crop, however considering the cost of daminozide, its potential value to seed potato producers is questionable.
Growth Analysis of ‘Florigraze’ Rhizoma Peanut: Forage Nutritive Value
Authors: Saldivar A. J. , Ocumpaugh W. R. , Gildersleeve R. R. , Moore J. E. 
Published: July 2010

Abstract‘Florigraze’ rhizoma peanut (Arachis glabrata Benth.) is a perennial tropical forage legume grown in Florida and the southern Gulf Coast. Two field studies were conducted near Gainesville, FL on Arredondo loamy sands (loamy, siliceous, hyperthermic, Grossaremic Paleudults) in 1980 and 1981. The objective of these studies was to evaluate nutritive value of Florigraze topgrowth as measured by crude protein (CP) and in vitro digestible organic matter (IVDOM). Experiment 1 was an establishment‐year growth analysis study conducted at two sites (years). Experiment 2 was a defoliation‐frequency study (0 vs. 2, 6, and 8 wk) conducted in 1981 on plants that were undisturbed at the 1980 site. Samples were taken periodically during the growing season in both years. In Exp. 1, both CP and IVDOM concentrations were characterized by two‐stage curves, where CP and IVDOM declined linearly (−0.9 and −0.7 g kg−1 d−1) until September, then stabilized at 125 and 610 g kg−1, respectively. Leaves constituted 60 to 80% of top growth in both years. In Exp. 2, CP and IVDOM declined linearly (−0.3 and −1.0 g kg−1 d−1) during the growing season for all defoliation treatments. Decline in percent leaf in the established plants of Exp. 2 was twice that of undisturbed plants in Exp. 1: −0.10 vs. −0.05 percentage units d−1. There was a sampling date × defoliation treatment interaction (P < 0.001) in percent leaf. Values for undefoliated plants were similar to that of Exp. 1, but leaf percentages declined at increasing rates in all defoliation treatments. At four dates in Exp. 1 and three dates in Exp. 2, top growth was separated into leaves and stems for IVDOM analysis. Leaf IVDOM declined linearly (−0.3 g kg−1 d−1), while stem IVDOM declined and then increased slightly from September through December. The data suggested that leafiness can be altered by defoliation management, and in turn, leafiness influences forage nutritive value of Florigraze rhizoma peanut.
Carbon Dioxide and Water Level Effects on Yield and Water Use of Winter Wheat
Authors: Chaudhuri U. N. , Kirkham M. B. , Kanemasu E. T. 
Published: July 2010

AbstractIncreasing levels of atmospheric CO2 may have major effects on yield and water use of winter wheat (Triticum aestivum L.). The objective was to determine the effect of elevated levels of CO2 on grain yield and water use from planting to harvest under two water levels. ‘Newton’ winter wheat was grown in the field under ambient (340 µL/L) and elevated levels (485, 660, and 825 µL/L) of CO2, during three growing seasons, in 16 underground boxes (77 cm long, 37 cm wide, and 180 cm deep) containing a Muir silt loam (finesilty, mixed, mesic Cumulic Haplustoll). Water in half of the boxes was maintained at 0.38 m3/m3 (high water level) and in the other half between 0.14 to 0.25 m3/m3 (low water level). Boxes were weighed in the fall and spring to determine the amount of water use by transpiration. Plastic chambers (121 by 92 by 168 cm) covered the boxes to maintain different CO2 levels. Grain yield of the high‐water‐level wheat grown under ambient CO2 was about the same as the grain yield of low‐water‐level wheat grown at the highest level of CO2 (825 µL/L) (3‐yr means: 725 and 707 g/m2, respectively). Similar results were obtained for yield components (spike number, spike weight, kernels/spike, and kernel weight). High‐water‐level wheat grown with 825 µL/L CO2 transpired more water than low‐water‐level wheat grown under ambient levels of CO2 (3‐yr means: 453 and 370 L/m2, respectively). Under high and low water levels, 29 and 31% less water was required, respectively, to produce a gram of grain when the CO2 concentration was raised from ambient to 825 µL/L. Results show that the water requirement of wheat is reduced by about 30% by elevated (1.4 times present ambient) CO2.
Respiration Measurements of Maize Plants Using a Whole‐Plant Enclosure System
Authors: Berard R. G. , Thurtell G. W. 
Published: July 2010

AbstractField‐portable enclosure systems are useful in assessing the impact of environmental parameters on crop growth rates and yields. These systems are normally designed to measure only one aspect of the C exchange budget, either the incoming (net photosynthesis) or outgoing (respiration) C fluxes. The objective of this work was to enable a whole‐plant enclosure system, originally designed exclusively for field measurements of photosynthesis and transpiration, to be used additionally for respiration measurements. The conversion from photosynthesis to respiration measurement was relatively simple and required minimal modifications to the existing system. The technique basically involved substituting CO2‐free air for CO2 as the gas being injected into the chamber to maintain a constant [CO2] within the chamber. Precise monitoring of air flow rate into the chamber allowed calculation of the whole‐plant respiration rate. Calibration tests indicated that the system was accurate to within <5% of typical respiration rates. Nighttime measurements on the whole maize (Zea mays L.) plants yielded respiration rates typical of those reported in the literature. The system could be left unattended throughout the night during respiration measurements, and could be converted back to daytime photosynthesis measurements within a few minutes. The ability of the enclosure system to provide constant day/night monitoring of whole‐plant C exchange makes it a valuable tool in the study of environmental factors affecting the above‐ground carbon balance of maize plants.
Rice Photosynthesis and Evapotranspiration in Subambient, Ambient, and Superambient Carbon Dioxide Concentrations
Authors: Baker J. T. , Allen L. H. , Boote K. J. , Jones P. , Jones J. W. 
Published: July 2010

AbstractThe current global rise in atmospheric carbon dioxide concentration, [CO2], has stimulated interest in the response of agricultural crops to [CO2]. The objectives were to determine the effects of [CO2] on photosynthesis, evapotranspiration, and water use efficiency of rice (Oryza sativa, L., cv. IR‐30). Rice plants were grown in naturally sunlit, plant growth chambers in subambient (160 and 250), ambient (330), or superambient (500, 660, and 900 μmol CO2 mol−1 air) [CO2] treatments. Photosynthetic light response curves were analyzed to obtain estimates of canopy light utilization efficiency (α) and canopy conductance to CO2 transfer (τ). Estimates of ℵ increased with increasing [CO2] treatment with the greatest increase in the 160 ito 500 μmol mol−1 treatments. Estimates of were more variable tham those for τ and were not different among [CO2] treatments. Photosynthetic rates increased with increasing [CO2] treatment from 160 to 500 μmol mol−1 followed by a leveling off of the response among the superambient [CO2] treatments. Evapotranspiration decreased while water‐use efficiency increased with increasing [CO2]. Shortterm cross‐switching of [CO2] among the chambers revealed a profound adaptive response to long‐term [CO2] growth treatments. Photosynthetic rate, measured at a common [CO2], decreased with increasing long‐term [CO2] growth treatment. The lack of further Photosynthetic response above the 500 μmol mol−1 [CO2] treatment appears to indicate a need to select or screen rice cultivars for increased response to superambient [CO2] in order to more fully take advantage of future increases in global atmospheric [CO2].
Growth Responses, Ion Relations, and Osmotic Adaptations of Eleven C4 Turfgrasses to Salinity
Authors: Marcum K. B. , Murdoch C. L. 
Published: July 2010

AbstractShortages of fresh water, coupled with soil salinization in many areas have resulted in an increased need for salt tolerant turfgrasses. This study was conducted to compare growth and physiological responses of eleven C4 (grasses which utilize the C‐4 carboxylic acid pathway in photosynthesis) turfgrasses to salinity. Grasses were grown in solution culture in a glasshouse, with NaCl added to achieve salinities of 0.7, 10, 20, and 30 dS m−1 (0, 99, 198, and 298 mM NaCl). Grasses were ranked for salinity tolerance according to their relative top growth reductions with increasing salinity. Tolerant grasses included a Hawaii selection of seashore paspalum (Paspalum vaginatum Swartz), two St. Augustinegrasses (Stenotaphrum secondtum Walt.), and manilagrass (Zoysia matrella L.). Bermudagrasses (Cynodon spp. (L.) Pers. Burtt‐Davey) tested were generally less tolerant to salinity. Shoot and root Na and CI concentrations reached very high levels in St. Augustinegrasses, and were relatively high in seashore paspalum and Japanese lawngrass (Zoysia japonica Steud.). In contrast, manilagrass and bermudagrasses maintained low levels of Na and Cl under high salinity which is indicative of ion regulation, due in part to efficient leaf salt glands. Seashore paspalum maintained higher shoot and root K concentrations under high salinity than did other grasses. All grasses adjusted osmotically under increasing salinity. Although St. Augustinegrasses and seashore paspalum accumulated Na and Cl in the shoots to relatively high levels, they maintained much higher tissue water levels than did other grasses, resulting in intermediate sap osmolalities.