bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cotton Production Affected by Row Profile and N Rates1
Authors: Harris C. H. , Smith C. Wayne 
Published: July 2010

AbstractCotton (Gossypium hirsutum L.) production in the Delta of Arkansas requires 150+ days from planting to final harvest. The evolved system for growing cotton includes planting on raised beds with N applied preplant into or under the bed. Maturity delays and associated yield reductions in recent years may have been related to this system. A study was initiated in 1975 to compare four genotypes grown in flat or bedded seedbeds with twice the recommended rate of N and half the recommended rate in order to evaluate the role of salts on seedcotton yield and earliness. The four genotypes represented a range of genetic maturity. A split‐block, split‐plot arrangement of a randomized complete block was utilized and the test site was Calloway silt loam, a fine‐silty mixed, thermic alfisol, located on the Cotton Branch Experiment Station, Marianna, Ark.Observations confirmed the surface drainage advantage of raised seedbeds. Otherwise, row profile contrasts had no effect on yield during any year, and we found no evidence that nitrate salts became concentrated in raised seedbeds, discounting the suggestion that increase in these salts resulted from the raised beds and thus directly delayed maturity.The 134 kg/ha rate of N resulted in higher seedcotton yields than did 34 kg/ha but also delayed maturity as indicated by percent first pick, regardless of row profile. Aborted terminals were shown not to be the cause of delayed maturity with the high rate of N. Genotypes responded to the effects of contour and N equally as indicated by the lack of significant interactions.
Salinity, Irrigation Frequency, and Fertilization Effects on Barley Growth1
Authors: Wagenet R. J. , Campbell W. F. , Bamatraf A. M. , Turner D. L. 
Published: July 2010

AbstractThe response of a grain crop to yield variables such as salinity, soil fertility and irrigation often depends upon the integrated and simultaneous effects of these factors. A greenhouse study was therefore conducted to investigate the interactive effects of water salinity, N and P fertilization, and irrigation scheduling on barley (Hordeum vulgare L.). Three water salinity levels, four N fertilization rates, three P fertilization rates, and three frequencies of water application were imposed on a nonsaline, nongypsiferous, silty clay loam soil (aquic ustifluvent). Dry matter and grain yields, and several yield components were measured. Dry matter and grain yields were reduced with decreasing irrigation frequency (2 to 8 days) and increasing salinity of irrigation water (0.5 to 13.5 mmho/cm). Nitrogen fertilization did not produce greater salt tolerance, and resulted in reduced yield by promotion of tillering at the expense of grain filling. Neither dry matter nor grain yield changed appreciably with increasing P fertilization. Increases in dry matter and grain yield were associated with decreases in the leaching fraction (LF) to a certain limit, then yield declined as LF decreased. The salinity of the soil extract increased noticeably as irrigation water salinity increased. However, frequent irrigation prevented salt buildup.
Labeled Nitrogen Uptake by Drip‐Irrigated Tomatoes1
Authors: Miller R. J. , Rolston D. E. , Rauschkolb R. S. , Wolfe D. W. 
Published: July 2010

AbstractIn order to evaluate the availability of fertilizer N applied by drip irrigation, tomatoes (Lycopersicum esculentum Mill.) were grown in the field for two years on Panoche clay loam (Typic Torriorthents). Labeled fertilizer was banded in the soil and furrow or drip irrigated as well as applied through the drip system to measure the effect of different placements and timing on fertilizer N availability. Some treatments received N only at planting while others received split applications through the drip system at different stages of plant development. Nitrogen (15N depleted) was applied to the center harvest rows while commercial (0.36%15N) ammonium sulfate was applied to the outside rows of each plot. Plants from the center harvest rows were analyzed for total N and isotopic composition. Plant analyses indicated that treatments in which fertilizer N was applied through the drip system, regardless of timing or growth stage, showed higher percent fertilizer N contents during most of the growing season than those of the furrow‐irrigated treatments. The greatest amount of fertilizer N in the plant at any sampling time was 40 to 50% of the total plant N. Only small differences in total tomato yields were observed among treatments, although drip‐applied did appear to enhance tomato fruit maturity. For high efficiency, fertilizer N should be placed carefully with respect to plant roots, taking into consideration the direction of water movement during irrigations.
Soybean Root Morphology and K Uptake1
Authors: Peterson W. R. , Barber S. A. 
Published: July 2010

AbstractWhen roots are grown in media of high mechanical strength, such as in sand rather than solution, root diameter increases. Little is known of how root morphology affects nutrient influx. The objective of this research was to determine if changes in root morphology created by changing growth media affected K influx into the root. Soybean (Glycine max L. Merr.) plants were grown in solution culture and in sand continuously leached with nutrient solution. Both were in a controlled climate chamber. Shoot weights were similar for both treatments. Root weight per pot and root radius were greater )(0.22 vs. 0.17 mm) for sand‐grown plants than for solution grown plants. Root lengths per pot were similar. Increased root radius was due to an increase in radial size of the cortical cells. Radius of the stele was not affected by treatment nor was number of cortical cells in a cross‐section of the root. Imax (maximum influx) for K influx was 55% greater for sandgrown roots than for solutiongrown roots. The Michaelis constant (Km) and the level of K in solution where net K influx was zero (Cmin) were not influenced by treatment. Soybeans had greater root weight when the roots encountered adverse growing conditions. When the data for increased root radius and Imax were used in a mathematical model to predict K uptake, increasing r, from 0.17 to 0.22 mm increased predicted uptake 21% and increasing Imax from 4.6 to 7.1 pmoles cm−2Sec−1 increased predicted uptake 35%.
Daily Patterns of Apparent Photosynthesis and Evapotranspiration in a Developing Winter Wheat Crop1
Authors: Johnson R. C. , Witters R. E. , Ciha A. J. 
Published: July 2010

AbstractHigh temperatures strongly influence apparent photosynthesis (AP), evapotranspiration (ET), and leaf area index (LAI) of winter wheat (Triticum aestivum L.) in semi‐arid regions. Our objectives were to relate temperature and short‐wave solar radiation (SR) to crop AP, ET, and LAI in a field environment. Two aluminum frame chambers covered with mylar plastic and occupying 0.74 m2 of soil surface area were used with infrared gas analyzers to measure AP and ET on ‘Wanser’ winter wheat grown in Ritzville silt loam (Mesic Calciorthidic Haploxerolls). Calculations of AP and ET were made from the respective differences between chamber intake and exhaust CO2 and H2O concentrations.On clear, high SR days, maximum AP declined from 4.2 to 2.9 g CO2m−2hour−1 from stem extension through the watery ripe developmental stage. During that same period, maximum daily ET ranged between 440 and 600 g H2O m−2 hour−1, but did not decline as LAI declined from 2.0 to 1.1. A midday reduction in AP was observed when leaf temperatures (TL) approached 25 C corresponding to high daily values of ET and SR at anthesis, water ripe, and milky ripe stages. Since measurements of ET were over dry soil and assumed to represent plant transpiration, substantial stomatal closure was apparently not responsible for the decline in AP on those days because a concomitant reduction in ET was not always observed. Temperatures that were above optimal for AP most likely caused the midday decline in AP. This interpretation was consistent with water use efficiency (WUE) values, expressed as AP/ET, which were lowest at midday and generally declined as the crop matured.Total daily AP from heading through anthesis (15 days) on clear and partly cloudy days did not decline appreciably (ranging from 30.5 to 32.4 g CO2 m−21 day−1) even though LAI declined 17% during that period. On clear days, high ET was associated with high SR and high temperatures. Temperatures tended to depress AP so that WUE was greater on partly cloudy and overcast days than on clear days at a given developmental stage. Under the climatic conditions of this study, WUE could be increased with early maturing cultivars that avoid the high late season heat load commonly associated with wheat production in this region.
Selection of Concomitant Variates Affecting Regrowth, Yield, and Digestibility in Forage Sorghums1
Authors: Fribourg Henry A. , Creel Rodney J. 
Published: July 2010

AbstractNumerous environmental factors and plant characteristics, and interactions among them and with management practices, affect growth and composition of summer annual forage sorghums (Sorghum bicolor (L.) Moench). Thirty‐eight plant and environment characteristics were estimated concurrently with the dry matter (DM) yield, DM regrowth rate (DM yield/day since emergence or since preceding harvest), and in vitro dry matter digestibility of three cultivars grown in the field on a fine‐loamy, siliceous, thermic Humic Hapludults and subjected to 19 different defoliation regimes in 2 different years. The selection of a subset of the 38 observed concomitant variates could be useful for planning future research. The purpose of this paper is to report on the sequential use of factor analysis and multiple regression techniques to decrease the number of independent variables without appreciable loss in the explanation for variability in the dependent variables. Factor analysis was used first to reduce possibly redundant concomitant variables or select proxy variables for a whole dimension. Fifteen of the original 38 variates were selected. multiple regression was then used to reduce further the concomitant variables to nine variables (days of growth since planting, days of regrowth since previous harvest, height of standing crop, leaf area index (LAI) of whole plant, DM yield of stubble at previous harvest, cumulative precipitation, degree days since previous harvest, percent leaf in DM harvest, LAI of whole plant at previous harvest). Six or fewer of these variates were associated with a large portion of the variability in the three dependent variables.The goal of parsimoniously identifying the variables which affected the dependent variables within a genotype in these experiments was attained. The strategy employed—sequential use of factor analysis and multiple regression for reduction in number of concomitant variables—may have merit for investigations in many agronomic disciplines.
Predicting Cotton Crop Boll Development1
Authors: Wanjura D. F. , Newton O. H. 
Published: July 2010

AbstractCotton (Gossypium hirsutum L.) lint development on the Texas High Plains frequently spans periods of low temperature that reduce yield and quality. We conducted a study in 1977 to 1979 at Lubbock, Texas, to develop a procedure for estimating the level of crop lint maturity at any time after boll setting begins.The procedure includes a model that uses the initiation date for each 1/10 increment of the total crop of bolls and average daily air temperatures. Data generated by the estimating procedure were compared with data on observed crop lint development in the cultivars ‘Paymaster 303’, ‘Paymaster 909’, and ‘Acala 3080’. The observed data were obtained by tagging all blooms initiated by plants in two 3‐m row lengths of each cultivar and measuring boll periods of the permanent bolls.The procedure produced accurate timely estimates for crop lint development and boll opening rate for all cultivars in 1977 and 1978. Observed boll periods in all cultivars were 15% shorter than estimates for the entire crop of bolls in 1979. A likely explanation for the shortened boll periods was that 1979 plants required 2 weeks longer to reach first bloom than 1977 and 1978 plants and were physiologically older. Other researchers have also reported reduced boll periods in “old” cotton plants.
Reflectance Differences Between Target and Torch Rape Cultivars1
Authors: Gausman H. W. , Leamer R. W. 
Published: July 2010

AbstractTo characterize and explain leaf and plant reflectance differences between Target (Brassica napus L.) and Torch (Brassica campestris L.) rape cultivars, laboratory spectrophotometric reflectance measurements were made on leaves of the same age, collected from different nodes, and on leaves of different ages, collected from the same node, for both small (five leaves) and large (nine leaves) Target and Torch plants. Spectroradiometric reflectance measurements were made on Target and Torch plants (four and five leaves, respectively) that were growing in 0.09 m2 soil‐containing flats. Torch's spectrophotometric single leaf reflectance was consistently lower than Target's at the 650‐nm chlorophyll absorption band because Torch's chlorophyll concentration was larger than Target's, which caused more red light absorptance. Spectroradiometric measurements indicated that: (1) wet soil strongly absorbed visible light (500 to 700 nm) so that Target's soil‐containing flat with 60% plant cover had less reflectance than Torch's soil‐containing flat with 75% plant cover, (2) Torch (most foliage) had higher near‐infrared (750 to 1,350 nm) reflectance than Target (least foliage), and (3) the 2,200‐nm wavelength is a candidate band to distinguish Target from Torch. The difference in chlorophyll concentrations between Target and Torch, compared with leaf structural differences, is apparently the most important factor that would affect the infrared color film's tonal response to vegetation in the photographic sensitive region (500 to 900 nm).
The Influence of Irrigation and Rhizobium japonicum Strains on Yields of Soybeans Grown in a Lakeland Sand1
Authors: Mahler R. L. , Wollum A. G. 
Published: July 2010

AbstractUnder existing management technology, Lakeland sands (Typic Quartzipsamments) produce low yields of soybeans [Glycine max (L.)Merr.] in North Carolina. These soils have an available water holding capacity of only 4.0% on a weight basis and as a result require about 2.5 cm of water every 5 to 6 days during the growing season to produce acceptable crop yields. In addition, Lakeland sands usually have extremely low or a totally nonexistent indigenous population of Rhizobium japonicum. Information on irrigation and nodulation effects is needed to make these soils more productive.The objectives of this study were to investigate the influence of irrigation and inoculation with different R. japonicum strains on yields of soybeans grown in a Lakeland sand. The study was conducted at the Sandhills Research Station at Jackson Springs, North Carolina. Additional nonirrigated plots inoculated with strains 31, 110, and 122 were initiated on finer textured North Carolina soils for comparative purposes to the Lakeland sand.Soil moisture treatments included plots not irrigated and plots irrigated each week with 2.5 cm of water. The five inoculation treatments consisted of a set of noninoculated plots and plots inoculated with strains of R. japonicum representing serogroups 31, 76, 110, and 122 at the rate of 50 ✕ 104 cells per cm of soybean row. Numbers of soil rhizobia were monitored throughout the study using a plant infection and MPN technique.Irrigated soybean seed yields were significantly greater when inoculated with rhizobia of either serogroup 110 or 122 than yields from noninoculated but irrigated plots. Inoculation without irrigation did not increase soybean yields. It was also observed that inoculated, irrigated soybeans had greater nodule mass and numbers of nodules than the nonirrigated and/or noninoculated plots. All four serogroups used in the study adequately nodulated soybean roots under irrigation and produced fewer nodules on soybean roots in the nonirrigated plots. On the basis of seed yield, strain ranking from best to worst was: 122>110>31>76. The noninoculated controls yielded higher than serogroup 76 but less than those soybeans in plots inoculated with serogroup isolate 31.
Predicting In‐Season N Requirements of Sugarbeets Based on Soil and Petiole Nitrate1
Authors: Gilbert W. A. , Ludwick A. E. , Westfall D. G. 
Published: July 2010

AbstractCrop quality is a continuing concern of the sugarbeet (Beta vulgaris L.) industry. A carefully managed N fertilizer program can significantly contribute to improved quality. The objectives of this study were to evaluate sidedressing N for correction of mid or late season N deficiencies and to evaluate an approach suggested by Giles et al. to predict the occurrence of midseason N deficiency. This method uses the preplant residual soil NO3− level, preplant N fertilizer rate, and one midseason petiole NO3‐N Concentration in a decay equation to predict the date the petiole NO3‐N level will drop to 1,000 ppm.Field experiments were conducted at two locations in 1975 and two different locations in 1976 in eastern Colorado. The soil at these sites (Argiustolls or Paleustolls) had an alkaline pH (7.7 to 7.9) and contained a wide range of soil NO3‐N (57 to 232 kg/ha) at planting. Rates of preplant N ranged from 0 to 168 kg/ha and a sidedress N rate of 84 kg/ha was applied at different dates between late May and mid‐August. Plant petioles were sampled at approximately 3‐week intervals during the season.Nitrogen deficiency was effectively corrected by sidedressing N through June. Delaying application until after mid‐July resulted in yield loss and frequently depressed sucrose concentration. Purity was not affected by sidedressing N at any location. Maximum sugarbeet quality was associated with petiole NO3‐N concentrations of <2,000 ppm on 1 September. The petiole decay equation of Giles et al. to predict NO3‐N concentrations on this date was reasonably successful. The coefficient of determination for calculated vs. actual NO3‐ decline in half‐life days (t½) was r2 = 0.63. The average t½ error was 6 to 7 days. This approach shows promise for evaluating in‐season N nutrition sufficiently early to correct incipient deficiencies before serious or possibly any yield loss occurs.
Agronomic Evaluation of Cytozyme as a Growth Regulator1
Authors: Ryan J. , Saghir A. R. , Shafyuddin M. , Barsumian A. 
Published: July 2010

AbstractIn recent years, fertilizer costs have spiralled due largely to higher energy costs involved in fertilizer manufacture. This development has underlined attempts to provide alternatives to or supplement fertilizers with cheaper sources, especially in developing countries. Cytozyme is one of several commercially available chemicals purported to have such an effect. This study evaluated the potential of this compound as a growth stimulant for sugarbeet (Beta vulgaris L.) in the field corn (Zea mays L.) and tomato (Lycopersicum esculentum Mill.) in the greenhouse. The chemical was applied to the seed prior to planting, and directly on the soil alone and in combination with conventional organic manures, and with a commercial inorganic compound fertilizer. However, under the conditions of these trials, none of the Cytozyme compounds or a similar material Goe‐mar had any significant effect on the parameters studied. These results question the effectiveness of legislation regarding the use of such materials in agriculture.
A Heat Exchanger for Soil Temperature Control of Potted Plants1
Authors: Robacker D. C. , Flottum P. K. , Erickson E. H. 
Published: July 2010

AbstractA heat exchanger that regulates soil temperature of individually potted plants is described. The device is a water jacket into which a single pot is inserted such that drainage of the potted plant is not restricted. Heat exchange occurs between the soil of the plant and water which circulates through the water jacket. In experiments, heat exchangers connected in series maintained soil temperature within 3 C of a desired value. Advantages and disadvantages of this method of soil temperature regulation are discussed.
Weed Control in Double Cropped Corn, Grain Sorghum, or Soybeans Minimum‐Till Planted Following Canning Peas1
Authors: Ndon B. A. , Harvey R. G. , Scholl J. M. 
Published: July 2010

AbstractDouble cropping involving minimum‐till planting has become popular in many parts of the USA. In Wisconsin, double‐cropping usually includes canning peas (Pisum sativum L.) as the spring crop. Trifluralin (a,a,a‐trifluoro‐2,6‐dinitro‐N,N‐dipropyl‐p‐toluidine) is used for weed control in much of this pea acreage. Since effects of trifluralin residues alone or in combination with subsequent herbicide treatments on summer crops and weeds were unknown, experiments were conducted at the Univ. of Wisconsin Arlington Farm in 1977 and 1978 on a Plano silt loam (Typic Argiudoll, fine, silty, mixed mesic) with 3.5 to 4.0% organic matter. Corn (Zea mays L.), grain sorghum (Sorghum bicolor L. Moench), and soybeans [Glycine max (L.) Merr.] were minimum‐till planted following canning peas grown with or without preplant‐incorporated trifluralin. Effects of two herbicide combinations and an untreated control were compared in each of the summer crops.Trifluralin controlled both broadleaf and grass weeds in canning peas but did not increase shelled pea yield. Average weed growth in corn, grain sorghum, and soybeans following peas treated with trifluralin was reduced 52, 52, and 62%, and average grain yields of corn and soybeans were increased 10 and 28%, respectively, compared with the same crops following untreated. peas. Trifluralin residues reduced grain sorghum stands (44%) and yields (17%).Alachlor [2‐chloro‐2′, 6′‐diethyl‐N‐(methoxymethyl) acetanilide] + atrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine] + paraquat (1,1‐dimethyl‐4,4′‐bipyridinium ion) was more effective in reducing weed growth in minimum‐till corn than alachlor + cyanazine [2‐chloro‐4‐(1‐cyano‐1‐methylethylamino)‐6‐ethylamino‐s‐triazine] + paraquat. There was no significant difference between the two combinations in terms of corn grain yield, however. Alachlor + cyanazine + paraquat following trifluralin in peas resulted in better weed control in minimum‐till corn than a similar treatment applied to corn planted following peas grown without trifluralin. Atrazine + paraquat and 2,4‐D [(2,4‐dichlorophenoxy)acetic acid] + paraquat also provided excellent weed control in grain sorghum, and alachlor + linuron [3‐(3‐4‐dichlorophenyl)‐1‐methoy‐1‐methylurea] + paraquat, and linuron + paraquat provided excellent weed control and increased grain yields in soybeans when both crops were minimum‐till planted after peas treated with trifluralin. Overall, soybeans appeared to be the most successful of the three crops when minimum‐till double‐cropped following peas under southern Wisconsin conditions.