bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Exchangeable Sodium on the Yield and Chemical Composition of Raya (Brassica juncea L.)1
Authors: Singh S. B. , Chhabra R. , Abrol I. P. 
Published: July 2010

AbstractLarge sodic areas of India are being brought under cultivation using gypsum as an amendment and by appropriate agronomic practices. Raya (Brassica juncea L.) is an important oilseed crop of the area, but virtually nothing is known about its tolerance to exchangeable Na. This study examined the effect of varying the exchangeable Na percentage on the yield and chemical composition of raya that was cultivated in the field. Raya was grown on plots that had been treated with graded doses of gypsum and subsequently cropped. At the time of planting, the soils (Aquic Natrustalfs) had attained ESP's of from 2.6 to 50.6 in the 0 to 15 cm layer and 20 to 90 in the 15 to 30 cm layer. Plant samples were analyzed and the oil content of seeds was estimated. Soil was analyzed for exchangeable Na and other chemicals. We found out that an ESP of more than 23 delayed germination, emergence of flowers and pods, but enhanced maturity. Grain and oil yield were significantly reduced above an ESP of 23.The decrease in the grain yield was associated with a Na content of 0.28% and a Ca:Na and K:Na of 3 in the stem at maturity. Sodium increased and Ca decreased with an increase in ESP; there was no effect on P and Mg content of the different plant parts. Potassium content at early stages of plant growth decreased with increase in ESP but was unaffected at maturity. Increasing soil ESP, in the range studied, did not affect the Fe, Mn, Zn, and Cu content of different plant parts.
Effect of Exchangeable Sodium on the Rate and Pattern of Water Uptake by Raya (Brassica juncea L.) in the Field1
Authors: Acharya C. L. , Sandhu S. S. , Abrol I. P. 
Published: July 2010

AbstractSodium can adversely affect crop growth, and the mechanism by which roots obtain water in sodic soils needs further study. Effect of exchangeable Na (ES) on the rate and pattern of water withdrawal by roots of irrigated raya (Brassica juncea L.) was studied in aquic Natrustalfs soils in a field experiment. Root water extraction was measured by monitoring the change in water content and the flux divergence with time in the soil profile. Flux divergence was calculated from the knowledge of the hydraulic conductivity vs. water content relations established in the field for different percent of ES soils and the hydraulic gradients obtained in situ during crop growth. Both the rate (Rz) and pattern of water withdrawal from the soil profile by the roots were significantly affected by the amount of Na in the surface and subsurface layers. The Rz measured in soil having ES of 38% in the 0 to 15 cm layer was 0.141 cm day‐1 compared to 0.233 cm day−1 in soil with ES of 4%. In high ES soil 78% of Rz came from the 0 to 15 cm layer and the layers below 30 cm did not show any change in water content. In low ES soil 0 to 15 and 15 to 30 cm layers contributed about 77% of the total Rz and water extraction by the roots was apparent to the 60 cm depth.
Response of Kleingrass and Buffelgrass to Herbicides1
Authors: Bovey R. W. , Baur J. R. , Merkle M. G. , Bashaw E. C. 
Published: July 2010

AbstractKleingrass and buffelgrass are sometimes difficult to establish in the field from seeding because of poor seedling vigor and severe competition from weeds. Greenhouse studies were conducted to evaluate the tolerance of kleingrass (Panicum coloratum L. ‘Selection 75’) and buffelgrass (Cenchrus ciliaris L. ‘Nueces’) seedlings to nine herbicides applied pre and postemergence at rates of 0, 0.28, 0.56, 1.12, and 2.24 kg/ha. Herbicides investigated were atrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine], ametryn [2‐(ethylamino)‐4‐(isopropylamino)‐6‐(methylthio)‐s‐triarine], prometryn [2,4‐bis(isopropylamino)‐6‐(methylthio)‐s‐triazine], and propazine [2‐chloro‐4,6‐bis(isopropylamino)‐s‐triazine]; linuron [3‐(3,4‐dichlorophenyl)‐l‐methoxy‐l‐methylurea], pendimethalin [N‐(lethylpropyl)‐3,4‐dimethyl‐2,6‐dinitrobenzenamine], alachlor [2‐chloro‐2',6'‐diethyl‐N‐(methoxymethyl)acetanilide], metolachlor [2‐chloro‐N(2‐ethyl‐6‐methylphenyl)‐N‐(2‐methoxy‐l‐methylethyl)acetamide], and propachlor [2‐chloro‐N‐isopropylacetanilide].Kleingrass and buffelgrass were grown in a 1:1:1 Houston black clay (Udic Pellustert): sand: peat moss mixture in small pots. Five to 10 plants were typically grown in each pot with five replications (pots) per treatment. All herbicides were sprayed in water at a spray volume of 93.5 L/ha. Herbicide injury counts were made by visually estimating percent desiccation and/or dead plants per pot 14 days after treatment.Kleingrass seedlings were tolerant to preemergence sprays of propazine up to and including 0.56 kg/ha. All other herbicides and rates applied preemergence were phytotoxic to emerging kleingrass. At the early postemergence stage, kleingrass tolerated rates up to and including 2.24, 0.56 and 0.28 kg/ha of propazine, propachlor and metolachlor, respectively, but did not tolerate other herbicides included in the study. Response of buffelgrass to pre and postemergence applications of propazine was similar to kleingrass. Buffelgrass, however, tolerated early postemergence sprays of propachlor and atrazine at 0.28 and 0.56 kg/ha; pendimethalin and alachlor at 1.12 kg/ha each; and metolachlor at 2.24 kg/ha. Propazine was the only herbicide that showed promise for both preemergence and postemergence applications in kleingrass and buffelgrass.
Extractant Color as a Factor in Grain Sorghum Tannin Analysis1
Authors: El Tuhami M. K. , Cummins D. G. , Burns R. E. 
Published: July 2010

AbstractMethods of tannin analysis for sorghum [Sorghum bicolor (L.) Moench] depending on color reaction, such as vanillin hydrochloric acid (VHCl) and modified vanillin hydrochloric acid (MVHCl), have not accounted for the color of the extract due to various pigments before adding the test reagents. The objective of this study was to determine how much this original color intensity affects the apparent level of tannin in the plant material. Tannin in the extract was estimated by the traditional VHCl method. The original color of the extract (without reagents) was measured after adding methanol to the extractant and using methanol as 100% transmittance standard. The amount of tannin in the grain, milk, dough, and mature stages of 20 single cross sorghum hybrids was estimated. Results from the VHCl method compared to correction for extractant color showed that the original color of the extractant before adding the reagents for color development had a significant effect on the measured tannin levels. The amount of tannin measured after correcting for extractant color was significantly lower than that measured by VHCl. The corrected method showed that the amount of unmeasured pigments differed with maturity, location, hybrid, and year. The corrected method produced lower standard errors and coefficients of variation than the VHCl method, and the corrected method probably produced the most accurate estimation of astringent tannins.
Tolerance of Soybean Genotypes to Metribuzin1
Authors: Eastin E. F. , Sij J. W. , Craigmiles J. P. 
Published: July 2010

AbstractMetribuzin [4‐amino‐6‐tert‐butyl‐3‐(methylthio)‐as‐triazin‐5(4H)‐one] controls several troublesome weeds in soybean [Glycine max (L.) Merr.], but may result in excessive soybean injury. Previous research has shown differential soybean cultivar responses to metribuzin. Sixteen determinate soybean genotypes, including the new cultivar ‘Dowling,’ and several genotypes whose tolerance have not been reported previously, were evaluated in a greenhouse for their response to 0.3, 0.6, and 1.1 kg/ha metribuzin applied preplant incorporated. Ts 72‐6, ‘Forrest,’ ‘Davis,’ ‘Hutton,’ Dowling, ‘McNair 800,’ and Ts 74‐23, were moderately tolerant; ‘Dare,’ PI 200492, ‘Pickett 71,’ ‘Bossier,’ and ‘Ransom,’ were moderately sensitive; and ‘Semmes,’ ‘Hampton 266A,’ ‘Tracy,’ and Ts 74‐34, were sensitive to the use rate of 0.6 kg/ha when evaluated 2 weeks after planting. Increased rates of metribuzin resulted in increased injury within a given genotype. Metribuzin should not be used for weed control when sensitive cultivars are being grown.
Effect of Rowspacing on Yield of Spring Planted Austrian Winter Field Pea1
Authors: Heneise H. K. , Murray G. A. 
Published: July 2010

AbstractAustrian winter field peas [Pisum sativum spp. arvense (L.) Poir.] are usually planted in the fall on 18 cm row spacings. Winter damage, cold soils, and soil‐borne diseases reduce vigor of fall planted peas more than spring planted peas. Spring planted peas escape winter damage and cold soil problems and have more resistance to some of the soil borne diseases. This study was undertaken at two locations to determine the influence of row spacings on yield of spring planted Austrian winter field pea. Row spacings were 18 cm between rows, 36 cm between rows, and alternating spacings of 18 and 36 cm between rows. ‘Fenn’ peas planted on 18 cm row spacings averaged 29 and 43% more seed than peas planted on 18‐36‐18 and 36 cm row spacings, respectively. Weed competition did not significantly influence seed yield of spring planted Fenn peas at any row spacing or location. Vine dry weight of peas planted on 18 cm rowspacings at mid‐season and harvest was significantly higher than vine dry weight of peas planted at other rowspacings, regardless of weed control treatments. Vine dry weight at harvest was also highest for peas that had been weeded regardless of rowspacing. Spring planted Austrian winter peas yielded about one‐third to one‐half as much as fall planted winter peas in independent studies.
Soybean Response to Indigenous Rhizobia as Influenced by Cultivar Origin1
Authors: Nangju D. 
Published: July 2010

AbstractMany investigators believe that when grown for the first time, the soybean [Glycine max (L.) Merr.] nodulates poorly unless inoculated with Rhizobium japonicum. However, in Nigeria the cultivar ‘Malayan,’ which originated from Indonesia, has nodulated quite well with indigenous strains of Rhizobium. We chose cultivars originating from Southeast Asia and from the USA and compared parameters associated with effective nodulation when these cultivars were grown with and without inoculation with Rhizobium japonicum. Seed inoculation with Nitragin‐S inoculant did not significantly improve nodulation, growth, amino‐N stem exudate, and yield of the Southeast Asian cultivars Malayan, ‘Orba,’ and ‘TGm 686.’ In contrast, the American cultivars ‘TGm 294‐4‐2371,’ ‘Bossier,’ and ‘Jupiter’ nodulated poorly without inoculum, and showed increases in growth of 36 to 47% and seed yield of 40 to 97% when inoculated. However, the American cultivars generally have better agronomic characteristicsa and higher yield potential than the Southeast Asian cultivars. It is, therefore, important to combine the desirable characteristics of these two distinct groups of soybean cultivars in the breeding program to develop improved cultivars suitable for and adapted to tropical environments.
Iron Use Efficiency in Grain Sorghum Hybrids and Parental Lines1
Authors: Esty James C. , Onken Arthur B. , Hossner L. R. , Matheson Richard 
Published: July 2010

AbstractGrain sorghum [Sorghum bicolor (L.) Moench] response to iron stress appears to be somewhat different from other species (e.g. release of less reductant and fewer H+ ions into solution), and, while it is apparently genetically controlled as in other species, it may not be as simply inherited. In this study, three grain sorghum hybrids and their parental lines were screened in nutrient culture in order to make preliminary assessment of heritability of Fe use efficiency, to evaluate the screening technique and to investigate the relationship of P and Fe accumulations to Fe use efficiency in these hybrids and parental lines. The seedlings were grown in a greenhouse on a complete nutrient solution at pH 6.5 until the plants were sufficiently large for experimental use. Subsequently, they were transferred for 7 days to either a modified Hoagland‘s No. 1 or Steinberg‘s solution with Fe, P, ammonium, and nitrate concentrations being varied. The plants were visually ranked for Fe use efficiency based on Fe deficiency symptoms, P and Fe concentrations in the top two leaves were determined and the pH of the nutrient solutions was monitored.Results obtained from screening the sorghum parental lies and F, hybrids indicated varying degrees of Fe use efficiency. Hybrid ATx 378 X RTx 2536 was classed most efficient in Fe utilization and RTx 7000 was classed most inefficient. Heterosis for Fe efficiency was observed when line ATx 378 was combined with lines RTx 2536, RTx 7000 and RTx 415. However, the efficiency of the two latter hybrids was not as good as ATx 378 X RTx 2536. Parental line RTx 2536 had a higher Fe efficiency ranking than the other three restorer lines. The inheritance of the Fe efficient trait appears to be dominant or over‐dominant in nature. Chemical analyses in this work, show that a negative, apparently linear, correlation exists between P and Fe concentrations in the top leaves of the sorghums studied.
A Weighing Lysimeter for Use in Isolated Field Areas1
Authors: Heatherly Larry G. , McMichael B. L. , Ginn L. H. 
Published: July 2010

AbstractA weighing lysimeter was designed for and used in field areas not equipped to accommodate instrumentation requiring a power supply or constant maintenance for accurate operation. A hanging crane scale, which held the lysimeter box, remained responsive and accurate throughout a season of field installation. The only maintenance requirement was that of periodically leveling the suspended box by adjusting turnbuckles installed at each corner. Seasonal water loss data were obtained from lysimeters planted with cotton (Gossypium hirsutum L.) and soybeans [Glycine max (L.) Merr.]. These data are comparable to other lysimeter water use data for these two crops obtained at other locations.
Close‐Grown Tobacco: Yield, Alkaloids, and Sugar Content by Stalk Position1
Authors: Campbell C. R. , Chaplin J. F. , Johnson W. H. , Miner G. S. 
Published: July 2010

AbstractFlue‐cured tobacco (Nicotiana tabacum L.) produced in a close‐grown system may offer an alternative to use of synthetic smoking materials. In order to develop optimum production and handling practices for this system, information is needed on the chemical and physical contents of the harvested material.Tobacco (‘Sp C‐28’) was produced in a close‐grown system with varying plant populations (45,448, 90,896, 136,344 plants/ha), N‐rates (84, 168, 252, 336 kg/ha), top ping (topped vs. nontopped), and row spacings (equidistant vs. twin). The research was conducted at the Oxford Tobacco Research Station on a Durham loamy sand (fine loamy, siliceous, thermic, Typic Hapudult). Yield, total alkaloids, and reducing sugars of lamina, midrib, and stalk from the upper, middle, and lower thirds of cured plants were compared.One‐third of the total plant weight was in each stalk position. The upper third of the close‐grown plant contributed most to total lamina weight and total alkaloid level. The proportion of lamina in the upper stalk position was higher in plants that were topped or when plant population was increased above 45,448/ha but it deoreased when N‐rate was increased above 84 kg/ha. Total alkaloid concentration was highest in the upper stalk position and in lamina. Increased plant population resulted in decreased total alkaloids in the middle stalk position. Topping and increasing N‐rate resulted in higher total alkaloids in all stalk positions. Reducing sugar content was approximately the same for all three stalk positions but highest levels in lamina and midrib were found in the upper two‐thirds of the plant. Reducing sugar concentrations were highest in stalk. Plant population had no significant effect on reducing sugar content but increased N‐rate lowered concentrations in the lower stalk position.Results indicate that agronomic practices offer a means for altering the physical and chemical content of closegrown tobacco.
Irrigation Regime and Honeybee Activity as Related to Seed Yield in Alfalfa1
Authors: Goldman A. , Dovrat A. 
Published: July 2010

AbstractSeed yields of alfalfa (Medicago sativa L.) vary capriciously in time and space. This variation seems mainly caused by the delicate interplay between plant factors monitored by soil moisture availability and the obligate tripping requirement of alfalfa flowers by pollinators. The object of this study was to quantify the main effects and interactions between water application to the alfalfa field and tripping by honeybees, to identify mechanisms which affect the seed yield and to suggest indices for their quantitative evaluation. A wide array of conditions differing in soil moisture and in tripping level was established in the sprinkler‐irrigated field. Observations were made on flowering and pod set of the plants and on the pollinating behavior of the bees.High water rates decreased seed yield. A moderate rate, applied at mid‐flowering to a relatively dry soil, markedly increased seed yield; the effect diminished toward the beginning of the end of flowering. The effect of water application depended also on the degree of tripping.The tripping pressure of honeybees (ie., their propensity to trip alfalfa flowers) was found to be inconsistent and seems to depend mainly on the availability of competing pollen sources. Dry and wet plots were equally welltripped under high tripping pressure and were neglected under low tripping pressure. Under moderate tripping pressure, pollen bees were attracted to dry plots earlier in the morning and in greater numbers than to wet plots, resulting in a higher percentage of tripped flowers, but the total number of tripped flowers was higher in the wet plots.Death of stem apices and a decrease in the rate of node formation were identified as mechanisms which regulate the duration and intensity of flowering and pod set.
Dinitrogen Fixation (C2H2) by Established Forage Grasses in Texas1
Authors: Weaver R. W. , Wright Sara F. , Varanka M. W. , Smith O. E. , Holt E. C. 
Published: July 2010

AbstractEfficient forage production by grasses requires an input of fertilizer nitrogen. Fertilizer N applications substantially increase the cost of forage production. Development and management of a biological N fixation system for forage grasses would greatly increase forage production efficiency. As a first step toward development of such a system, a survey was undertaken in the subtropical region of Texas to determine the rates of biological N fixation naturally occurring in the rhizosphere of native and introduced forage grasses. The acetylene reduction method was used to estimate potential rates of biological N fixation. During 3 years, 463 soil cores were collected, of which 13% produced ethylene when exposed to acetylene. In the third year of the survey, 216 cores were collected, of which 21% reduced acetylene to ethylene when tested immediately after sampling, and 70% showed activity after a period of regrowth in the greenhouse. Only samples extrapolated to fix N at rates exceeding 0.5 kg/ha/100 days were classified as active. The most active rhizosphere samples were extrapolated to fix N at rates of 33, 26, 20, and 20 kg/ha/100 days for Cynodon dactylon (L.) Pers., Paspalum urvillei Steud., Brachiaria sp., and Andropon gerardi Vitman respectively. These high rates indicate that under the proper environmental conditions a potential exists for agronomically significant rates of biological N fixation to occur in the rhizosphere of forage grasses.
Defoliation Effects on Regrowth, Nodulation, and Nitrogenase Activity at Anthesis with Hairy Vetch1
Authors: Lynd J. Q. , McNew Ronald W. , Odell George V. 
Published: July 2010

AbstractPasture legumes present a great potential to increase productivity of pastures. Little information is now available concerning quantitative evaluation of symbiotic N fixation with pasture legumes such as hairy vetch (Vicia villosa, Roth).Results from 3 years of study are summarized to determine the influence of defoliation and regrowth on tillering, nodulation, and nitrogenase activity (C2H2 reduction) at anthesis with ‘Madison’ hairy vetch inoculated with Rhizobium legumimsarum Frank, ATCC 10314. Plants were grown in a siliceous thermic Psammentic Paleustalf (Eufaula) of pH 6.1. Peak nitrogenase activity of field grown plants occurred at anthesis about 250 days after emergence. Highly significant increases in tillering resulted with three defoliations at 45, 90, and 180 days along with increased nodule fresh weight, nodule numbers, and nitrogenase levels. Abundant large cluster nodule types occurred on root systems of most plants regardless of defoliation treatment. Significant correlations were apparent for nitrogenase levels with top weight, number of tillers, nodule weight, and number of nodules for plants receiving the threedefoliation treatment. Nodule number was significantly correlated with top weight. Nodule number and nodule weight were negatively related probably due to an influence from frequent large nodule cluster development. No significant correlations were apparent with the nondefoliated plants. Multiple regressions indicated nitrogenase levels were influenced in decreasing order by nodule weight, tillers, top weight, and nodule number with R2 = 0.775, C.V. = 29.1% P < 0.001. The pot culture technique used may be adapted for nondestructive evaluations with repotted plants utilized for plant breeding and further symbiotic N fixation research.
Reflectance of Wheat Cultivars as Related to Physiological Growth Stages1
Authors: Leamer R . W. , Noriega J. R. , Gerbermann A. H. 
Published: July 2010

AbstractCrop yield predictions are based on a comparison between the rate of growth of the current crop and the normal crop‐calendar. Remotely sensed reflectance data provide an indication of the amount of plant growth. In this investigation, we followed the seasonal changes in reflectance of three cultivars of wheat (Triticum aestivum L.) as related to their physiological development. Reflectances over the 0.45 to 2.50‐µ/m wavelength intervals were measured with a ground‐based spectroradiometer between planting and maturity of wheats planted on Hidalgo sandy clay loam (Typic Calciustolls) soil in south Texas. After plants covered about 25% of the ground area, all reflectance curves had the characteristic shape for vegetated surfaces. Wheat plants seldom reach the eight leaf layers required for infinite reflectance in the near‐infrared plateau (0.75 to 1.35 µ/m) wavelengths. Consequently, reflectance at these wavelengths were closely related to stage of physiological development as long as the plants were developing leaves, regardless of their rate of maturity. Dwarf, early Mexican cultivars (‘Anza’ and ‘Penjamo’) that were not daylength‐sensitive progressed through physiological stages more rapidly than did a tall, later maturing, daylength‐dependent cultivar (‘Nadadores’). Reflectance in the near‐infrared plateau increased as plants of all cultivars developed physiologically until they reached Feekes growth Stage 9. Growth Stage 9 represents the stage at which the last ligule has appeared and the plant goes into the booting stage. The lower leaves began to turn brown, lose chlorophyll, and mature, resulting in a decrease in the number of actively reflecting leaf layers with a consequent decrease in reflectance within the near‐infrared plateau wavelengths. Reflectance at other wavelength bands are not sensitive to the stage of physiological growth. Knowledge of the stage of plant development through a crop season will improve the accuracy of yield predictions made prior to harvest.