bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantification and Classification of Locational Effects on Cotton Cultivar Testing Programs
Authors: Geng Shu , Hu Bingmin , Bassett Dick M. 
Published: July 2010

AbstractMultiple locations are commonly used to evaluate cultivar performance in breeding programs, but the relative contribution of location to cultivar selection is rarely discussed. This paper presents a method by which locational effects can be quantified and classified. Lint yield data of upland cotton (Gossypium hirsutum L.) obtained from the U.S. Regional Cotton Variety Tests between the years 1981 and 1986 were used to quantify four characteristics of the locations which were used in testing cultivars. The four characteristics of the locations are: the ability to discriminate differences among cultivars, consistency in discrimination over years, relative potential productivity, and repeatability of the potential productivity. These characteristics which are estimated from the yield data are used to evaluate the effectiveness of the location in testing cultivars. When the estimates of the characteristics are subjected to cluster analysis, a new basis for zoning the cotton belt for the cotton testing program is revealed. The resulting regions include locations which are different from the regions derived from yield data or derived from cultivars by environmental interactions. Results of this study provide an alternative basis for possible future rezoning of the U. S. Cotton Belt for cultivar testing.
Magnesium, Nitrogen Form, and Root Temperature Effects on Grass Tetany Potential of Wheat Forage
Authors: Huang J. W. , Grunes D. L. , Welch R. M. 
Published: July 2010

AbstractGrass tetany, a Mg deficiency syndrome, is a disorder of ruminants grazing grass or cereal forages under certain environmental conditions. A solution culture experiment was conducted to gain a clearer understanding of the nutritional and environmental factors affecting Mg concentrations in winter wheat (Triticum aestivum L.) forage. Effects of N form (NH4/NO3 in mM—10:0, 5:5, or 0:10), root‐zone temperature (RZT) (10,15, or 20 °C), and Mg supply (0.4 or 4 mM) on growth and mineral composition of winter wheat forage were investigated. Shoot and root yields were highest for the mixed‐N form, and increased linearly with increasing RZT. Increasing the Mg supply significantly increased Mg concentrations, and decreased Ca concentrations, in both shoots and roots. Concentrations of K and Ca, and estimates of total organic acids significantly increased with increasing proportion of NO3. There was no significant effect of N form on shoot Mg concentrations at the high Mg level. However, at the low Mg level, increasing the proportion of NO3 significantly decreased shoot Mg concentrations, producing a forage more likely to cause grass tetany. Ratios of Mg accumulated in shoots to Mg in whole plants were negatively correlated with K concentrations in roots. Correlations with K concentrations in shoots were much lower. Apparently, increasing the K concentration in roots depressed the rate of net Mg translocation from roots to shoots. When Mg in the root zone is low and K is high, increasing the proportion of NO3 may decrease shoot Mg concentration and thus increase the likelihood of hypomagnesemia.
Dry Matter, Nitrogen, Phosphorus, and Potassium Accumulation by Four Cotton Varieties
Authors: Mullins G.L. , Burmester C.H. 
Published: July 2010

AbstractSince the mid‐1940s, varieties and cultural practices have changed for cotton (Gossypium hirsutum L.) grown in the southeastern USA. We believed a more current investigation of dry matter production rates and nutrient uptake patterns was needed for representative cotton cultivars. Field studies were conducted to determine if dry matter production and distribution, and nutrient uptake and distribution are affected by the cultivar of cotton grown under nonirrigated conditions. Four cotton cultivars were compared: Deltapine 90, Stoneville 825, Coker 315, and Paymaster 145. The experiment was conducted on a nonirrigated Decatur silt loam (clayey, thermic, kaolinitic Rhodic Paleudults) and a Norfolk silt loam (fine loamy, thermic siliceous Typic Paleudults). Soil fertility was uniform within a given site. Intact cotton plants were harvested at 14‐d intervals throughout the growing season starting at 15 d after emergence, and separated into leaves, stems, burs, seed, and lint. Total dry matter production averaged 7923 kg ha−1 in 1986 and 7695 kg ha−1 in 1987 on the Decatur soil, and 6726 kg ha−1 on the Norfolk soil in 1986. The four cultivars produced and partitioned dry matter similarly within a location. Differences between locations (soils) were not related to a difference in cumulative heat units. Total N, P and K uptake averaged 128, 17.3 and 106 kg ha−1, respectively. Cotton plants from the study removed an average of 19.9 kg N, 2.5 kg P and 15.3 kg K for every 100 kg lint. Nutrient concentrations and nutrient uptake by a plant part, and total nutrient uptake were not affected by the cotton variety.
Sugarbeet Response to Nitrogen as Affected by Seasonal Irrigation
Authors: Winter S. R. 
Published: July 2010

AbstractSugarbeet (Beta vulgaris L.) responses to irrigation (I) and N have been documented but I by N interactions are less well understood. The objective was to determine if N response is dependent on the amount of seasonal irrigation. Sugarbeet root yield, fresh weight sucrose concentration, and impurities were measured in experiments involving four N rates within three irrigation levels during 1982, 1984, 1986, and 1987 on a slowly permeable Pullman clay loam (fine, mixed, thermic Torrertic Paleustoll). Irrigation by N interactions were not significant in 1982 and 1984 when residual NO3–N was an important N source. Significant I by N interactions for all yield and quality factors were measured in 1986 and 1987, when residual NO3–N was low (87 and 99 kg ha−1, 0‐ to 2.4‐m depth) and NO3–N concentration was greater above than below 0.6 m. Sucrose yield increased an average of 0.54, 1.76, and 2.65 Mg ha−1 in 1986 and 1987 in response to N for irrigation levels averaging 0, 234, and 435 mm, respectively. Sucrose loss to molasses at the N rate needed for maximum sucrose yield averaged 15.2, 14.1, and 13.3 g sucrose kg−1 roots for 0, 234, and 435 mm irrigation levels, respectively. Sucrose loss to molasses averaged 20.1, 16.0, and 14.1 g kg−1 at the highest applied N rate for 0, 234, and 435 mm irrigation levels, respectively, and indicated a potential for serious impurity problems with excess residual or applied N and reduced irrigation.
Impacts of Cropping Intensity on Carbon and Nitrogen Mineralization under No‐Till Dryland Agroecosystems
Authors: Wood C. W. , Westfall D. G. , Peterson G. A. , Burke I. C. 
Published: July 2010

AbstractImposing no‐till and lower fallow frequency on soils previously managed under tilled and frequent fallow systems may alter soil organic C and N concentrations and activity (potential mineralization). This study was conducted to determine the effect of cropping intensity (number of crops/unit time) on surface soil (0‐5 cm) C and N activity after 3.5 yr of no‐till management. The effect was examined across three soil catenas in the West Central Great Plains that were previously managed under tilled and alternate crop‐fallow systems for >50 yr. Production systems included the less intensive wheat (Triticum aestivum L.)‐fallow (WF), and the more intensive wheat‐corn (Zea mays L.)‐millet (Panicum miliaceum L.)‐fallow (WCMF). After 3.5 yr of no‐till, potential C and N mineralization, C turnover, and relative N mineralization were 61,39,36, and 43% greater under WCMF than WF, respectively. Footslope soils had greater potential C and N mineralization than summit or backslope soils, but lower C turnover and relative N mineralization, which was probably due to long‐term accumulation of recalcitrant C and N compounds. Differences in potential soil C and N activity between cropping systems were due to greater surface organic C concentrations under WCMF (mean = 10.88 g kg−1) than WF (mean = 9.60 g kg−1), which were related to cumulative plant residue additions over the 3.5‐yr‐study period (mean = 9.01 and 7.04 Mg ha−1 for WCMF and WF, respectively). It appears that potentially active surface soil organic C and N are very sensitive to change in cultural practices, and are increased by greater cropping intensity under notill management.
Quantitative Method for Analysis of Grain Yield in Rice
Authors: Takami Shinichi , Kobata Tohru , Van Bavel C. H. M. 
Published: July 2010

AbstractCereal crop yields can be substantially reduced when drought occurs during grain filling. A mathematical expression is proposed to describe the effects of drought during the grain‐filling stage of rice (Oryza sativa L.). The expression predicts the grain yield as a function of the total dry matter production during the grain filling with two parameters: potential yield, and amount of mobilizable reserves at anthesis, both to be determined experimentally. The proposed relation states that grain yield equals the potential yield when the total assimilate supply (the amount of mobilizable reserves at anthesis, plus the total dry matter produced during grain filling) is equal to, or greater than the potential yield. Below this level of assimilate supply, grain yield decreases in proportion to the total dry matter produced during grain filling. Drought is assumed to reduce the grain yield through dry matter production alone, without any effects on the potential yield and the amount of mobilizable reserves. The model was tested in an experiment in which the yield response of two different cultivars to six levels of water availability was measured. The theoretical generalization fits the experimental results. The model is useful in predicting the yield response of rice when the crop encounters drought stress during grain filling, provided the two parameters cited above can be measured or estimated at anthesis. It also could serve as a submodel for yield prediction in a mechanistic crop production model.
Evaporation Measurements beneath Corn, Cotton, and Sunflower Canopies
Authors: Villalobos F. J. , Fereres E. 
Published: July 2010

AbstractExperiments were conducted at Cordoba (southern Spain) between 1986 and 1988 to obtain independent estimates of evaporation from the soil (E) and crop transpiration (T) in irrigated corn (Zea mays L.), cotton (Gossypium hirsutum L.), and sunflower (Helianthus annuus L.). Microlysimeters that allowed root exploration were used to estimate E by differential weighing. Cotton and sunflower evapotranspiration (ET) were measured with a weighing lysimeter (3 by 2 by 1.5 m), while corn ET was estimated using a water balance technique. Root density and soil water content inside the open microlysinteters were similar to those measured in the surrounding soil. Estimated E, when the soil surface was wet, varied from 80% of reference ET (ET0) at 0.8 leaf area index (LAI) to 15% when LAI increased to four. A single relationship between E/ET0 and LAI fit the data for the three crops. The estimated E values for periods spanning 30 to 40 d, when LAI increased from 0.7 to 5, was 20 to 27% of measured ET, for an irrigation frequency of 7 to 8 d. The T values, calculated as the difference between ET and E, varied for a given LAI depending on the E level. When the soil surface was dry and E was low, the ratio, T/ET0, in cotton was 1.1 for a LAI of three. If the surface soil was wetted by rain or irrigation, the calculated T/ET0 ratio dropped to 0.58 the 1st d after wetting. The results highlight the interdependence of the E and T processes in the consumptive use of water by row crops.
Ultraviolet and Photosynthetically Active Bands: Plane Surface Irradiance at Corn Canopy Base
Authors: Grant Richard H. 
Published: July 2010

AbstractThe potential increase in ultraviolet (UV) irradiance and potential decrease in productivity of agricultural crops due to stratospheric ozone loss requires knowledge of the characteristics of UV irradiance above and within crops. Little is currently known about the distribution of UV radiation within crops. The objectives of this study were to describe the UV radiation environment with respect to the photosynthetically active radiation (PAR) environment at the base of a corn canopy and relate the differences in measured irradiances to differences in canopy characteristics and differences in the proportion of direct and diffuse radiation in the two wavelength bands. Measurements of the near UV (wavelength band approximately 305‐350 nm) and PAR irradiance on plane surfaces (such as leaves) oriented in a wide range of view zeniths and azimuths were made at the base of a corn canopy in September 1989 at West Lafayette, IN (solar zenith angle 54.6 ± 5°). Comparisons between the transmitted energy in near UV (NUV) and PAR wavelengths through the corn canopy were made using normalized paired irradiance measurements for a plane surface in 737 different view zenith and azimuth orientations. The NUV irradiance decreased more rapidly than the PAR irradiance as either the incidence angle (between the sun and the plane surface normal) or the view zenith angle increased. Results suggest that the corn canopy transmittance of PAR and NUV are similar but the canopy reflectance of PAR is greater than that of NUV.
Nitrogen Use by Tall Fescue and Switchgrass on Acidic Soils of Varying Water Holding Capacity
Authors: Staley T. E. , Stout W. L. , Jung G. A. 
Published: July 2010

AbstractIncreased use of bunchgrasses on acidic soils of the humid Northeastern USA requires more detailed knowledge on the fate of fertilizer N for economic and environmental reasons. A 3‐yr field investigation using 15N‐depleted fertilizer was undertaken to determine the effect of soil water holding capacity (WHC) on the use of soil and fertilizer N by cool‐season (tall fescue, Festuca arundinacea Schreb.) and warm‐season (switchgrass, Panicum virgatum L.) forages. Three sites of varying soil depth provided WHC of 5, 15, and 25 cm. Fertilizer N was applied at 0, 90, and 180 kg ha−1 (split application for tall fescue). Three‐year production averages for Cut 1 switchgrass (mid‐July) were two‐ to three‐fold greater than for tall fescue (mid‐June) on all sites receiving N, and four‐fold greater on the two shallower sites without N. Cut 2 (late‐October) production was nearly equal for both species, with tall fescue averaging 50%, and switchgrass 10%, of Cut 1. Nitrogen concentration of both species generally increased with N rate but not with WHC. Total N uptake (TNU) increased with N rate for both cuts of tall fescue, but only for Cut 1 for switchgrass, on all sites. Percentage of TNU derived from fertilizer N ranged from 23 to 47% for tall fescue and 14 to 39% for switchgrass. Tall fescue and switchgrass recovered from 23 to 31% and 25 to 33%, respectively, of the fertilizer N applied to the two deeper sites. Only on the shallow Klinesville site at the 90 kg N level was there a significant difference in fertilizer‐ N recovery, where switchgrass recovered 31% compared to tall fescue at 19%. Although these results demonstrate relatively low recoveries by both species, the more efficient use of fertilizer N by switchgrass, both in terms of production and recovery, recommend its increased usage at low N rates in the Appalachian Region.
Estimating Turf Biomass, Tiller Density, and Species Composition by Coring
Authors: Lush W. M. , Franz P. R. 
Published: July 2010

AbstractThe methodology for estimating tiller density, turf biomass, and species composition by core sampling was examined in order to establish an objective, quantitative protocol for measuring turf responses to management and for comparing genotypes. Cores were collected from a fine‐textured creeping bentgrass (Agrostis stolonifera L.) turf and an intermediate‐textured turf composed of Kentucky bluegrass (Poa pratensis L.), ryegrass (Lolium perenne L.) and annual bluegrass (P. annua L.). Estimates based on different sampling tools, one rectangular and three round, and different methods of storing cores between collection in the field and processing in the laboratory were examined. It is concluded that the numbers of cores needed to estimate, at a specified level of accuracy, the biomass and tiller density of a turf (or of the most frequently occurring species in a turf) are low enough (e.g. eight to 43 cores of 4.8‐cm diam.) for coring to be a practical way of quantifying the standing vegetation of turfs. Coring is not a good method for estimating infrequently occurring species because of the large numbers of cores required, in this case around 3000. Estimates of tiller density or biomass were biased in cores with a long perimeter relative to their cross‐sectional area by soil entrapment (especially if free water accumulated during storage), and in cores that became desiccated during storage.
Corn‐Weed Interactions with Long‐Term Conservation Tillage Management
Authors: Coffman C. Benjamin , Frank J. Ray 
Published: July 2010

AbstractThe use of monoculture production systems such as continuous corn (Zea mays L.) in conservation‐tillage systems has created a requirement for information concerning crop and weed responses to annual herbicide inputs. The objective of this 5‐yr investigation (1981–1985) was to evaluate weed problems and delineate weed and crop interactions in continuous conservation‐tillage corn as affected by annual herbicide applications. Preemergence treatments contained selected combinations of triazines or a triazine plus alachlor [2‐chloro‐N‐(2,6‐diethylphenyl)‐N‐(methoxymethyl)acetamide]. Preemergence or preplant incorporated herbicide mixtures were applied at common usage rates and compared for their effects on weed cover, weed species stability, and grain production. All plots were essentially weed‐free the first year. Weed cover in most treatments increased significantly by the second year with fall panicum (Panicum dichotomiflorum Michx.) dominating the flora in Years 2 and 3, and smooth pigweed (Amaranthus hybridus L.) dominating in Years 4 and 5. Smooth pigweed reached densities of 85% in several treatments. Fall panicum was the dominant weed in pre‐plant incorporated treatments that contained atrazine [6‐chloro‐N‐ethyl‐N'‐(l‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine] plus a carbamothioate herbicide. Grain yields were negatively correlated with fall panicum densities in the second year in all herbicide treatments. Smooth pigweed densities were negatively correlated with grain yields in the fifth year in all preemergence treatments. Smooth pigweed densities were lower in triazine plus alachlor treatments than in double triazine treatments for the last 2 yr of the study.
Cotton Response to Water and Salinity under Sprinkler and Drip Irrigation
Authors: Meiri A. , Frenkel H. , Mantell A. 
Published: July 2010

AbstractKnowledge of crop response to water is essential for proper irrigation management. The wide‐spread introduction of drip irrigation, together with the increasing use of brackish water for cotton (Gossypium hirsutum L.) has made it necessary to examine how these variables effect its production function. A field study was conducted to determine the interaction of water salinity (3.7–7.8 dS m−1), irrigation method (sprinkler and drip), water amount (230–780 mm), irrigation interval (1–14 d), and plant density (intra‐row spacing of 8 or 12.5 cm) on ‘Acala SJ‐2’' cotton grown on a sandy‐loam loess soil (Calcic Haploxeralf). With sprinkler irrigation, the two‐piecewise curves that describe the yield response to water application differ in slopes, intercepts, and break points for the different salinites and irrigation intervals. The crop used more stored soil water at low salinity, low irrigation amount, and long irrigation interval. When we evaluated crop response to the sum of applied water and amount of stored water used, we found that the intercepts were nearly eliminated and the four slopes were combined, while the break points remained lower for the higher water salinity. The break points determine the water amounts above which other factors become limiting. The response function for drip irrigation had no break point, but had the same slope and intercept as the sprinkler treatments. The common production functions for seed cotton and total dry matter yield were Y kg ha−1 = −26.5 kg ha−1 + 9.21 kg ha−1 mm−1 × Wmm and Y kg ha−1 = −338 kg ha−1 + 21.2 kg ha−1 mm−1 × Wmm, respectively, where Y = yield, and W = sum of seasonal water application plus depletion of stored soil water. Water salinity, irrigation method and frequency, and intrarow spacing did not affect the linear response of seed cotton or dry matter yields to water when factors other than water availability were not limiting.
Temperature Effects on Pima Cotton Growth and Development
Authors: Reddy K.R. , Hodges H.F. , McKinion J.M. , Wall G.W. 
Published: July 2010

AbstractAn understanding of genetic and environmental factors affecting plant growth and development is needed for accurate yield predictions by crop models. At present there is little information about how Pima cotton, Gossypium barbadense L., a species known for its excellent lint quality, will respond to various temperatures. The objective of this experiment was to determine the growth and developmental rates of Pima cotton plants grown at different temperatures. Pima cotton was grown in 20/12, 25/17, 30/22, 35/27, and 40/32°C day/night temperature cycles in sunlit controlled‐environment chambers soon after emergence to 64 d under optimum water and nutrient conditions. Plant heights and mainstem nodes were determined at weekly intervals. Mainstem elongation rates were very sensitive to temperature after about 3 wk following emergence. Prior to that time, the differences were small but measurable. Mainstem node addition rate increased as temperature increased to 40/32°C. The temperature optimum for fruiting branch growth, and square and boll production and retention was 30/22°C. Above 30/22°C, there was an imbalance between vegetative and reproductive growth. Plants became less reproductive at 35/27°C and lost their reproductive ability at 40/32°C. Heat tolerance, as depicted by heat units required to produce first square, is much superior to that reported for Pima, cv. S‐2, but slightly less than Upland cotton, cv. DES 119.