bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atrazine Tolerance in Warm‐Season Grass Seedlings1
Authors: Bahler C. C. , Vogel K. P. , Moser L. E. 
Published: July 2010

AbstractAtrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine] effectively controls many annual weeds in established warm‐season range grasses but can damage some of these grasses in the early seedling stage. This study determined the relative atrazine tolerance of seedlings of selected warm‐season grasses and evaluated the effectiveness of a greenhouse bioassay for seedling atrazine tolerance in range grasses. Seed of ‘Pathfinder’ switchgrass [Panicum virgatum L.], ‘Nebraska 54’ indiangrass [Sorghastrum nutans (L.) Nash], ‘Butte’ side‐oats grama [Bouteloua curtipedula (Michx.) Torr.], an experimental blue grama ‘PMK 1483’ [ B. gracilis (H.B.K.) Lag ex Steud], ‘Plains’ bluestem (Bothriochloa ischaemum var ischaemum (L.) Keng), ‘Caucasian’ bluestem [B. caucasica (Trin.) C.E. Hubbard] ‘Blaze’ little bluestem [Schizachyrium scoparium (Michx.) Nash], and a Nebraska experimental prairie sandreed [Calamovilfa longifolia (Hook) Scribn.] were planted in the greenhouse in a 1:1 soilsand mixture that contained 0,1,2, or 3 mg kg−1 atrazine. Seed lots from one cycle of field selection for atrazine tolerance of indiangrass and side‐oats grama were included. A field study was also conducted on a silty clay loam (Typic Argiudoll) and on a loamy sand (Udic Haplustoll) site using little bluestem, blue grama, prairie sandreed, Caucasian bluestem, and Plains bluestem. Survival ranking at 3 mg kg−1 atrazine, in the greenhouse, was: Caucasian bluestem = switchgrass > Plains bluestem > prairie sandreed > indiangrass (check) = indiangrass (cycle 1) > side‐oats grama (cycle 1) = side‐oats grama (check) = blue grama. Atrazine also reduced height in the surviving seedlings. Height reduction in did not appear to be related to seedling survival. Greenhouse data correlated closely with the loamy sand site. because the bioassay used a soil‐sand mixture. Excellent stands of Plains and Caucasian bluestem were obtained on the silty clay loam site at all atrazine rates. The bioassay was an effective screen to separate grasses with differing atrazine tolerances.
Growth Characteristics of Oriental Tobacco as Affected by Cultivar and Type1
Authors: Lolas P. C. , Galopoulos A. , Sficas A. G. 
Published: July 2010

AbstractOriental tobacco (Nicotiana tabacum L.) grown in Greece is classified commercially into three types: a) Aromatic, b) Neutral, and c) Taste. Although growth characteristics of flue‐cured and burley tobacco have been extensively studied, very little work has been done on oriental tobacco. Two cultivars of each of the three oriental types were grown in field plots replicated three times for 3 years. Data obtained at 0, 20, 30, 40, 60, 85, and 105 days after transplanting were: dry weights of roots, stalks, leaves, and inflorescences; plant heights; number of harvestable leaves; relative growth rate; and absolute growth rate. The types and cultivars differed significantly in their growth rates, and patterns after 60 days from transplanting. Generally, cultivars within the same type were not significantly different. All of the measured growth characteristics followed the sigmoid growth curve with the period of rapid growth being from 30 to 60 days after transplanting. Aromatic cultivars were fast growing, early maturing, and low in total dry matter. Taste cultivars, on the other hand, were slow growing, late maturing, and high in total dry matter. Neutral cultivars were intermediate. In all three types, leaves comprised about 40%, stems 25%, roots 18%, and inflorescences 17% of the total plant dry matter. It is concluded that the critical growth period for oriental tobacco cultivars and types is, as for flue‐cured and burley, 30 to 60 days after tansplanting.
Honey Bees as Pollinators for Hybrid Cotton Seed Production on the Texas High Plains1
Authors: Vaissière Bernard E. , Moffett Joseph O. , Loper Gerald M. 
Published: July 2010

AbstractThe production of hybrid cotton (Gossypium hirsutum L.) seed on a large scale requires the use of an economical and reliable agent for pollen transfer. In 1980, five commercial fields of cytoplasmicgenetic male‐sterile (A‐line) and male‐fertile maintainer (B‐line) cotton were grown on a thermic Torrertic Paleustolls soil on the Texas High Plains. To test the ability of the honey bee [Apis mellifera L. (Hymenoptera: Apidae)] for pollinating A‐line cotton, colonies were placed along the sides of three fields. In the two fields (14 ha; 15.5 colonies/ha, and 24 ha; 13.2 colonies/ha) where honey bee colonies were distributed along at least three sides of a field, the seed cotton yield of the A‐line was not significantly different from that of the B‐line, so that, when grown under a similar environment and with adequate pollen transfer, the A‐ and B‐lines produced equal yields of seed cotton. In the 24‐ha field, uniform pollination was achieved. In a third field (15.2 ha; 7.5 colonies/ha) where hives were located along only one edge, however, the A‐line seed cotton yield was 30% less than that of the B‐line and pollination was not uniform. In two other fields (4.0 and 1.4 ha, respectively) where no honey bees were provided, the A‐line yielded 79% less seed cotton than the B‐line in one case and 91% less in the other. Results demonstrated that pollen was transferred by honey bees, and the transfer efficiency depended upon the number and distribution of the colonies. On the other hand, pollination was highly variable and less than adequate when only native pollinators were present.
Pneumatic Applicator for Uniform Distribution of Dry Fertilizer on Small Plots1
Authors: Varvel G. E. , Severson R. K. 
Published: July 2010

AbstractUniform distribution of dry fertilizer materials on small plot areas has been a problem for many years because most of the equipment has been developed for field application. Recent developments of pneumatic herbicide and fertilizer application equipment have been made which allow uniform distribution of these materials over various size areas. These developments made components available which were used to construct a small‐plot applicator to broadcast or inject dry fertilizer. This applicator accurately and consistently metered and distributed three fertilizer materials which varied in particle size. The use of air to distribute the fertilizer also permits various applicator widths with the same machine.
Nitrogen Nutrition and Yield of Seedling Alfalfa as Affected by Ammonium Nitrate Fertilization1
Authors: Eardly B. D. , Hannaway David B. , Bottomley P. J. 
Published: July 2010

AbstractNitrogen fertilization of seedling legumes is a controversial management practice intended to provide an N source to the plant prior to the development of N2‐fixation activity. Field experiments were conducted in 3 consecutive years (1980,1981, and 1982) to evaluate the effect of ammonium nitrate (NH4NO3) at establishment on nodulation, acetylene reduction (AR), percentage herbage N, and dry matter yield of 10‐week‐old seedling alfalfa (Medicago sativa L. cv. Apollo). The soil at the field site was a Woodburn silt loam, a member of the fine‐silty, mixed, mesic Aquultic Argixeroll. The soil contained 8 to 12 mg kg−1 of available soil N. Six rates of NH4NO3‐N were applied preplant in 1980 and nine rates were applied preplant in 1981 and 1982 (0‐224 kg N ha−1) in a randomized complete block design. Data from the 1980 experiment suggested that the native population of Rhizobium meliloti Dang. was ineffective in N2 fixation. This was confirmed by effectiveness tests of native strains of R. meliloti in 1981. In 1982 an inoculation variable was added in a factorial treatment combination to examine the effects of NH4NO3 fertilization on the N nutrition and yield of both effectively and ineffectively nodulated alfalfa. Results from the three field experiments indicated that only plants which were ineffectively nodulated exhibited substantial increases in herbage yield and Kjeldahl N concentration in response to the “NH4NO3 applications. All rates of NH4NO3 fertilization decreased nodulation in a curvilinear response. For example, application of 45 kg N ha−1 reduced both nodulation and AR by 45% at 10 weeks (early bloom) regardless of rhizobial effectiveness. Nitrogen fertilization also increased weed competition in 1981 and herbage nitrate levels in 1982.
Wheat Performance Using No‐Tillage with Controlled Wheel Traffic on a Clay Soil1
Authors: Gerik Thomas J. , Morrison John E. 
Published: July 2010

AbstractWheat (Triticum aestivum L.) is frequently grown in rotation with summer annual crops. These crops are usually grown in widely spaced rows that can easily adapt to controlled‐traffic management, but high soil strengths prevent crop establishment into controlled‐traffic lanes, eliminating one or more rows of wheat. Wheat can compensate (within limits) for lost cropping area, but the effect of no‐tillage culture with controlled traffic is not known. We conducted this study to compare two tillage systems, conventional and no‐tillage with controlled traffic, on grain yield and yield components of wheat. It was conducted over a 3‐year period on an Austin silty clay (fine‐silty, carbonatic, thermic Entic Haplustolls). The no‐tillage treatment confined all wheel‐induced compaction to controlled traffic zones at 2‐m intervals. Crop residues were destroyed completely by repeated tillage and wheel traffic occurred randomly under the conventional tillage treatment. Hard red winter wheat (cv. Sturdy) was grown in rotation with row crops that were subjected to the same tillage and wheel traffic practices. Rows were spaced 20 cm apart in each tillage system, but two rows were deleted in the traffic zones of the no‐tillage treatment, resulting in 20% less cropped area. Plants on rows adjacent to the controlled‐traffic zones compensated for the absence of wheat within the traffic zones during years of adequate precipitation (1981 and 1983) by producing more tillers and grain than plants in rows within the no‐tillage treatment and those grown under conventional tillage. Drought in 1982 significantly lowered tillering and grain yields under no‐tillage. The study established that wheat can be grown using no‐tillage with controlled traffic. Wheat should be grown with no‐tillage controlled‐traffic technology where drought is minimized or as a component of a total management system where yield increases from alternative crops and/or lower production costs are primary issues.
Stomatal Closure Behavior Induced by Row Spacing and Evaporative Demand in Irrigated Peanuts1
Authors: Stone J. F. , Erickson P. I. , Abdul‐Jabbar A. S. 
Published: July 2010

AbstractPeculiar stomatal action has been suggested as one causal factor for observed differences in water use between peanuts (Arachis hypogaea L.) grown in narrow and wide rows. This study was designed to characterize stomatal action in narrow‐ and wide‐row plantings on a Udic Argiustoll soil. Measurements of stomatal diffusive resistance (Rs) and leaf‐water potential (Ψw) were made daily at half hour intervals on irrigated peanuts grown in narrow‐row (NR) and wide‐row (WR) spacings during periods of flowering to pod development in 1979,1981, and 1982. Measurement days were classified as low, moderate, and high evaporative demand days according to respective daily meteorological conditions. In both NR and WR treatments the relationship between Rs and Ψw was generally linear. On certain days, however, NR‐Rs increased to much higher values earlier in the afternoon at a given Ψw than WR‐Rs. The effect was most pronounced on high evaporative demand days and was never noted on low evaporative demand days. Data for 3 years reveal the NR stomatal closure effect was real and repeatable.
Agronomic and Economic Response of Three Tropical Legumes to Lime and Phosphorus in an Acid Infertile Spodosol1
Authors: Snyder G. H. , Kretschmer A. E. , Alvarez J. 
Published: July 2010

AbstractNumerous potential benefits have been cited for the inclusion of tropical legumes in pastures, but few commercial successes have been realized. Information is needed on even the most basic aspects of tropical legume culture. The study herein was designed to determine rates of lime and P for maximum yield of three tropical legumes, and to estimate the rates resulting in maximum economic return under field conditions. An acid infertile Spodosol was amended with lime up to 4000 kg ha−1 and P up to 80 kg ha−1. Equations relating herbage yield during the first 2 years of growth to rates of lime and P were developed. All three legumes (Aeschynomene americana L., Macroptilium atropurpureum Urb., and Desmodium heterocarpon DC.) responded positively to both lime and P. Maximum yield of Desmodium was obtained at lime and P rates of 2740 and 75 kg ha−1, respectively. Maximum calculated herbage yields of Aeschynomene and Macroptilium were obtained at lime and P rates somewhat in excess of maximum treatment levels. An economic analysis that considered hay as the produced product revealed that maximum economic returns occurred at lime and P rates only slightly lower than those for maximum yield. Considering protein as the product, for all three legumes lime and P rates of approximately 3000 and 75 kg ha−1 produced maximum yield and maximum economic return.
Biomass and Sugar Yield Response of Sweet Sorghum to Lime and Fertilizer1
Authors: Soileau John M. , Bradford B. N. 
Published: July 2010

AbstractSoil fertility requirements for sweet sorghum [Sorghum bicolor (L.) Moench] as an alcohol fuel crop have not been well defined. The primary objective of this study was to determine the biomass and sugar (% Brix ✕ extracted juice) yield response of sweet sorghum to N‐P‐K and lime. The study was conducted for 2 years on a Wynnville silt loam (fine‐loamy, siliceous, thermic Glossic Fragiudult) soil in the Cumberland Plateau region of northern Alabama. Experimental design was a split‐plot with 0 or 8 Mg ha−1 dolomitic limestone and combinations of 0, 45, 90, or 180 kg ha−1 N, 30 or 90 kg ha−1 P, and 40 or 120 kg ha−1 K. Liming significantly increased yields of fresh and dry biomass, grain, and juice sugar extracted from stalks. The lime also greatly reduced exchangeable soil Mn and Al and increased Mg and decreased Mn concentrations of the biomass. Due to the dominant effect of lime and other interactions, biomass and juice sugar yields were not consistently related to applied N, P, or K. In nonlimed soil, biomass and sugar yields decreased with high N in the presence of low P‐K, but not with high P or K. This suggests an acidity ✕ P and/or K interaction related to toxicity of soil Mn and/or Al. In the limed soil the maximum dry biomass and sugar yields occurred with 180‐90‐120 (1981) or 90‐90‐120 (1982) kg ha−1 N‐P‐K, however yields from some treatments with lower levels of N, P, or K were often not significantly different at the 0.05 level. Inherent soil acidity and related Mg deficiency must be corrected to obtain maximum response of sweet sorghum to fertilization in Wynnville and associated soils of the Cumberland Plateau region.
Temperature Effects on Germination of Birdsfoot Trefoil and Seombadi1
Authors: Hur S. N. , Nelson C. J. 
Published: July 2010

AbstractForages are often planted in soils that are not at the optimum temperature for germination. Therefore, it is important to know the temperature range of germination and the temperature effect on germination rate. Our objective was to evaluate the time course of seed germination of ‘MO‐20’ birdsfoot trefoil (Lotus corniculatusL.) and seombadi (Dystaenia takesimanaKitagawa), a member of the Umbelliferae family, using germination chambers at constant temperatures of 3,6,9,12,15,20,25, and 30 °C. Final germination of both species was highest at 20 °C. Time to radicle emergence of birdsfoot trefoil decreased as temperature increased. Seombadi seeds germinated only between 12 and 25 “C with little temperature influence on time to radicle emergence. Birdsfoot trefoil showed a linear relationship between germination temperature and the reciprocal of time to reach 50% of final germination, but there was no relationship for seombadi, suggesting factors other than temperature were controlling the response. Base temperature for germination of birdsfoot trefoil was calculated to be 4.7 °C. Germination rate of birdsfoot trefoil showed a marked increase between 9 and 12 °C, suggesting an Arrhenius response, Le., an abrupt change in effect of temperature.
Rhizobium japonicumNodular Occupancy, Nitrogen Accumulation, and Yield for Determinate Soybean Under Conservation and Conventional Tillage1
Authors: Hunt P. G. , Matheny T. A. , Wollum A. G. 
Published: July 2010

AbstractNitrogen fixation and accumulation are important facets of soybean (Glycine maxL.) production. Three determinate soybean cultivars were grown on a Norfolk loamy sand (Typic Paleudult) with either conservation or conventional tillage. Plots were split for inoculation with strain 3I1b 110 of Rhizobium japonicum. Dinitrogen fixation was estimated by the difference between total shoot N for nodulating and nonnodulating ‘Lee’ isolines, and net N returned to the soil was estimated by the difference in dinitrogen‐fixed N and seed N. Drought was significant the first year; only 19.5 cm of rain fell during the podfill period. Rainfall and soil water were adequate the second year. Tillage, cultivar, and inoculation did not consistently affect the percentage of nodules formed by particular rhizobial strains, individually, but specific treatment combinations significantly affected nodular occupancy by certain strains. Inoculated ‘Coker 338’ had the highest shoot total N accumulation in both years; however, the difference between years overshadowed tillage, cultivar, or inoculation effects. For the 2‐y period, percentages of N supplied by N2fixation were estimated to be 58 to 67% and 49 to 65% under conservation and conventional tillage, respectively. Yields generally did not differ significantly for tillage or inoculation; however, Coker 338 soybean was lowest in seed yield even though it had the highest total N accumulation in the shoots. Estimates of net N returned to the soil varied more between years than between tillage treatments; values ranged from 14 to 40 kg ha−1in 1980 and 57 to 123 kg ha−1in 1981.
Cut‐Off, Break‐Over, and Defoliation Effects on a Determinate Soybean Cultivar1
Authors: Malone S. R. , Caviness C. E. 
Published: July 2010

AbstractExtensive research has been conducted on the response of indeterminate soybeans [Glycine max(L.) Merr.] to different types of plant damage, but information on the effect on determinate growth types is limited. This research compared the responses of a determinate soybean cultivar to different intensities of cut‐off, break‐over, and defoliation at five stages of plant growth. The experiments were conducted on a Captina silt loam (fine silty, mixed, Typic Fragiudnlt) during 1981 and 1982 at Fayetteville, AR. Plants were cut off at the point that removed half fresh weight and defoliated below the cut, broken over at the point that divided the aboveground fresh weight in half and defoliated below the break, or completely defoliated. Treatments were applied to 33,66, or 100% of the plants at growth stages V10, R2, R3, R4, and R5. Yields generally were not reduced when 33% of the plants were treated. The cut‐off treatments generally caused greater yield reduction than break‐over or defoliation; defoliation generally caused a greater yield reduction than breakover when 66 or 100% of the plants were damaged. Yield reductions were greater when treatments were imposed at progressively later growth stages. Cut‐off and defoliation influenced seed weight and date of maturity more than break‐over, especially when all plants were treated. Seed weight was reduced when yield reductions were severe, but the loss in seed weight did not account for all the yield loss. Maturity was delayed up to 2 weeks by treatments at R2, R3, and R4, and hastened by treatments at R5.
Yield and Quality of Tobacco Grown with Supplementary Irrigation1
Authors: Orphanos P. I. , Metochis Chr. 
Published: July 2010

AbstractPresently in Cyprus, tobacco (Nicotiana tabacumL.) is grown under supplementary irrigation with water high in CI. The present study sought to investigate the irrigation/yield relationship and the attendant concentration of CI and other constituents in the leaves. In three experiments in which one to six irrigations were tested, maximum evapotranspiration (ET) determined by the soil water balance method was reached 40 to 50 days after planting, and equaled evaporation from a screened Class A pan. The ET started declining just before the first leaf harvest, even though soil water was adequate. However, since soil water became limiting soon afterwards, the course of potential ET could not be followed. From the second leaf harvest until the end of the season, ET was very low (< 1 mm/day). Fresh yield increased from 12 Mg/ha with 60 mm irrigation to 28 Mg/ha with 360 mm irrigation, the highest amount tested. In contrast, dry matter yield only increased from 2.3 to 4.2 Mg/ha, respectively. Moreover, midrib material increased from 20% with 60 mm irrigation to 30% of the total leaf dry matter with 300 mm irrigation. Concentration of CI for the whole leaf increased from about 2% with 60 mm irrigation to 3% with 300 mm irrigation (disregarding the last sampling). Concentration of K decreased from 4 to 2% between the first and the third harvest and in one experiment it tended to increase with irrigation. Leaf P increased from about 0.1 with 60 mm irrigation to 0.2% with 180 mm irrigation. The burn rate of laminae, determined in one experiment, increased with irrigation, even though CI also increased.
Effect of Duration and Type of Natural Weed Infestations on Soybean Yield1
Authors: Jackson Lucinda A. , Kapusta George , Schutte Mason Dolores J. 
Published: July 2010

AbstractThe time of weed removal from a crop may be as important as the extent of removal. A 4‐yr field study was conducted at two locations each year to define the extent of soybean [Glycine max(L.) Merr.] yield and population reduction occurring from the presence of natural weed populations. Soil types were Typic Ochraqualfs and Typic Albaqualfs. ‘Williams 79’ soybeans were planted at approximately 30 seeds m− 1of row using 76‐cm spacing between rows. Grass, broadleaf, or grass plus broadleaf weeds were allowed to interfere 0, 1, 2, 3, or 4 weeks, or all season (control), prior to their removal. Weed populations in the control plots ranged from 16 to 148 plants m−2in 1981 and increased to 104 to 1172 plants m−2in 1984. Allowing grass, broadleaf, or grass plus broadleaf weeds to interfere with soybeans for up to 4 weeks did not reduce soybean yields under ample soil moisture conditions. However, under drought conditions or extremely high weed infestations, yield losses with 4 weeks of interference were observed. No differences were found between the competitive effects of grasses or broadleaves on soybean yield with 4 weeks or less of interference. Significant yield reduction occurred every year at both locations when grass plus broadleaf weeds interfered all season. Yield reductions from all‐season grass‐only or broadleaf‐only weed interference occurred most years, but were dependent on location, weed density, and environmental conditions. Soybean populations were reduced where weeds were most dense and were associated with yield decreases.