bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Water Deficit at Different Growth Phases of Peanut. I. Yield Responses1
Authors: Rao R. C. Nageswara , Singh Sardar , Sivakumar M. V. K. , Srivastava K. L. , Williams J. H. 
Published: July 2010

AbstractThe response of a peanut (Arachis hypogaeaL.) cultivar Robut 33‐1 to drought stress imposed at different growth stages was studied during the post‐rainy seasons of 1980–1981 and 1981–1982 on a medium deep Alfisol at ICRISAT Center, India. Irrigation amount was varied to three levels for each of the following phases: (i) emergence to maturity, (ii) emergence to the start of peg initiation, (iii) from the start of flowering to the start of seed growth, and (iv) from the start of seed growth to maturity. The amount of water applied (stress intensities) during these phases was varied using line‐source irrigation, but the crops otherwise were irrigated uniformly at regular intervals. The greatest reduction in kernel yield occurred when stress was imposed during the seed‐filling phase. Decreased irrigation during the early phase increased the pod yield relative to the fully irrigated control treatment by 19% during the 1980–1981 and by 13% during the 1981–1982 growing seasons. Lowest pod yields resulted from severe stress from emergence to maturity. The evapotranspiration‐yield relationships showed a strong interaction with timing of drought.
Aluminum Toxicity Effects on Growth and Nutrient Composition in Wheat1
Authors: Ohki K. 
Published: July 2010

AbstractAluminum toxicity is frequently the limiting factor to crop production in acid soils. The diagnosis of Al toxicity for a specific wheat (Triticum aestivumL.) cultivar could be simplified by tissue analysis. Greenhouse studies were undertaken to determine the critical Al toxicity level for the cultivar ‘Stacy’ and tissue nutrients affected by Al status. Wheat plants were grown in 10 levels of Al (0, 1.9, 3.7, 9.3, 18.5, 37.1, 74.1, 148, 222, and 297 µMAl) in nutrient solution for 28 days. Aluminum toxicity reduced top dry weight, root dry weight, plant height, tiller numbers, and top/root dry weight ratio. Aluminum concentrations in the blade and stem tissues were low (maximum of 0.3 mmol kg−1in Blade 1, the most recently developed leaf with a developed ligule) and were linearly related to Al in nutrient solution. Aluminum is not readily accumulated in Stacy wheat. The critical Al toxicity levels, defined as the Al concentration in the tissue associated with a 10% decrease from maximum top dry weight due to toxicity, were 0.12 mmol kg−1in Blade 1 and 0.08 mmol kg−1in the whole plant. Knowing these tissue values, one may be able to detect Al toxicity from similar uncontaminated tissue from the Stacy cultivar sampled in the field. Using washed Blade 1 would be preferable to using the whole plant because soil contamination would be minimized. Aluminum toxicity decreased all elemental concentrations in Blade 1 and whole plants. With the exception of P and K in Blade 1, the decreases in elemental concentrations were related by either a linear or quadratic regression.
Screening for Low Fertility Tolerance among Peanut Cultivars1
Authors: Branch W. D. , Gascho G. J. 
Published: July 2010

AbstractBecause of expansion of additional hectareage onto marginal soil types and the economical need to reduce production inputs, differential genetic responses to lower fertility practices need to be sought within crop species. During 1981 through 1983, tests were conducted to evaluate 24 peanut (Arachis hypogaeaL.) cultivars under low soil fertility. The Tifton loamy sand (fine‐loamy, siliceous, thermic Plinthic Paleudult) location selected for the experiment is a typical soil for peanut production in this area; however, this particular site had a 3‐yr mean pH of 5.3 with 10, 25, 69, and 19 mg kg−1P, K, Ca, and Mg, respectively (Mehlich I). Significant differences were found among the cultivars for yield and grade under these specific environmental conditions. ‘Early Runner’, ‘Florunner’, ‘Tifrun’, ‘Southeastern Runner 56‐15’, and ‘Tifspan’ were considered the most tolerant to low soil fertility based on total sound mature kernel yield. No meaningful relationship was found between yield and any singular soil or tissue nutrient concentration.
Planting Date Effects on Seedling Development of Perennial Warm‐Season Forage Grasses. I. Field Emergence1
Authors: Hsu F. H. , Nelson C. J. 
Published: July 2010

AbstractSlow establishment of perennial warm‐season forage grasses is a problem in their utilization to improve animal production in summer when cool‐season grasses are less productive. A field experiment was conducted to determine temperature effects on field emergence, estimate base temperature required for emergence in the field, and provide insight toward optimum planting dates for warm‐season perennial forage grasses. Big bluestem (BB) (Andropogon gerardiiVitman), Causasian bluestem (CB) [Bothriochloa caucasica(Trin.) C. E. Hubb.], indiangrass (IG) [Sorghartrum nutans(L.) Nash], switchgrass (SG) (Panicum virgatumL.), and an annual species, crabgrass (CG) [Digitaria sanguinalis(L.) Scop.] were compared in a split‐plot field experiment with five replications. Unchilled seeds of each species were planted at approximately 2‐week intervals in a Mexico silt loam soil (fine, montmorillonitic, mesic Udollic Ochraqualf) near Columbia, MO from early April to late June in 1982 and 1983. Emerging seedlings were recorded frequently. The logistic function was used to fit the emergence data. No emergence data were obtained for CG since natural emergence also occurred. Maximum emergence percentage was obtained following planting on 30 Apr. and 2 June 1982, and 6 and 16 May 1983. Indiangrass had the highest emergence percentages of pure live seed with 38 and 51% in 1982 and 1983, respectively, followed by SG, BB, and CB. Survival percentage of emerged seedlings averaged about 90%, but was reduced to near 70% on late plantings when soil dried out rapidly. Entries with high emergence percentages also had their highest emergence rates (ER) at Et50(time to reach 50% of final emergence). Corrected ER index and ER50(reciprocal of Et50) were closely correlated (r= 0.99, P<0.01). Both are good indices for evaluating speed of emergence. However, ER50is based on actual measurements and has more agronomic significance and biological meaning. Base temperatures required for emergence in 1982 were estimated as 9.4, 9.9, 10.8, and 11.4 °C for IG, BB, SG, and CB, respectively. For 1983 temperatures were 10.0, 10.8, 10.4, and 9.5 °C, respectively. The data suggest optimum planting dates for these species between late April and mid‐May to maximize emergence percentage and reduce risks of high temperature and soil moisture stress.
Cassava‐Cowpea and Cassava‐Peanut Intercropping. I. Yield and Land Use Efficiency]1
Authors: Mason S. C. , Leihner D. E. , Vorst J. J. 
Published: July 2010

AbstractCassava (Manihot esculenta Crantz) is commonly intercropped with cowpea [Vigna unguiculata(L.) Walp] or peanut (Arachis hypogaeaL.) in the tropics. Little is known about how intercropping these species influences efficiency of land use and yields. Cassava, cowpea, and peanut were grown as sole crops and as intercrops on a Typic Dystropept soil at Santander de Quilichao, Colombia in 1981 and 1982. The objective of this study was to determine land use efficiency, yield, and yield components for cassava, cowpea, and peanut grown in intercropping and sole cropping systems. Cassava yields were reduced 2.3 to 4.7 Mg ha−1when intercropped with cowpea or peanut, except in 1982 when intercropped with cowpea. Cassava yield reductions due to intercropping were associated with the production of 1.5 to 3.9 fewer storage roots per plant than were produced by sole cropped cassava. When intercropped with cassava, cowpea seed yields were reduced from 3195 to 2170 kg ha−1in 1981, and from 2227 to 1328 kg ha−1in 1982. Averaged across years, peanut seed yield was reduced from 2099 to 1293 kg ha−1. Cowpea and peanut yield reductions due to intercropping were associated with the production of approximately 3.5 fewer pods per plant. Even though yields of component crops were reduced by intercropping, the cassava‐cowpea and cassava‐peanut intercropping systems resulted in 15 to 35% greater land use efficiency for the 11‐month growing season than resulted from the sole cropping systems. This is of importance in developing countries where available per capita arable land is low.
Plant Population Density Effects on Seed Yield of Birdsfoot Trefoil1
Authors: McGraw R. L. , Beuselinck P. R. , Ingram K. T. 
Published: July 2010

AbstractLittle is known about the effects of plant population density (PPD) on birdsfoot trefoil (Lotus corniculatusL.) seed production. Our objective was to ascertain the effects of a wide range of PPDs on seed yield and yield components of birdsfoot trefoil. ‘Norcen’ and ‘Viking’ birdsfoot trefoil were transplanted into the field at Roseau and St. Paul, MN in 1981 and 1982, respectively. An experimental design was used which provided 19 PPDs from 1.6 to 61 plants/m2. The Roseau soil was a Glyndon silt loam (coarse‐silty, frigid Aeric Calciaquoll) and the Rosemount soil was a Waukegan silt loam (Typic Hapludoll). Plants were sampled individually when the majority of their pods were brown. Forage yield, seed yield, seed yield components, and harvest index were measured on each plant. Seed yield/m2and forage yield/m2had asymptotic diminishing‐returns relationships to PPD. Forage yield/m2increased about 200% as PPD increased from 1.6 to 61 plants/m2. The PPD at which forage yield/m2reached 90% of its total change was 26.5 plants/m2. Seed yield/m2increased about 75% as PPD increased from 1.6 to 61 plants/m2. The PPD at which seed yield/m2reached 90% of its total change was 19.0 plants/m2. Seed yields were adjusted in response to increasing PPD by reductions in all yield components. Umbels per plant was most responsive to PPD, pods per umbel and seeds per pod had intermediate sensitivity to PPD, and seed mass showed the least change in response to PPD. Harvest index decreased as PPD increased, indicating that seed yield/m2increases were smaller than forage yield/m2increases as PPD increased. Plant population densities required for optimum seed production are less than those required for optimum forage production; thus, lower seeding rates may be used in establishing seed production fields.
In situ Nitrate Assimilation in Winter Wheat: Peduncle Injection with Nitrogen‐15‐Nitrate at Anthesis1
Authors: MacKown C. T. , Van Sanford D. A. 
Published: July 2010

AbstractNitrogen accumulation and assimilation following anthesis in winter wheat (Triticum aestivumL.) depends on the level of soil nitrate and the availability of carbon substrates to support plant transport and assimilation functions. Spike and peduncle nitrate assimilation was investigated by injecting at anthesis 100 µmol 15N‐nitrate (99 atom % 15N) into the hollow peduncles of field‐grown (Typic Paleudalf soil) winter wheat (‘Doublecrop’). Dry weight changes in vegetative and reproductive culm parts and N assimilation and partitioning were followed at 5‐day intervals until maturity, 40 days after anthesis (DAA). Between 10 and 25 DAA, accumulation of spike dry matter and N increased to 56 mg day−1and 79 µmol day−1. Over 80% of the injected 15N‐nitrate was absorbed through the peduncle cavity walls within 5 DAA. Differential utilization of endogenous nitrate and injected 15N‐nitrate or dilution of the injected 15N‐nitrate by soil derived nitrate was observed. Peduncle nitrate atom % 15N decreased from 90.6 (0 DAA) to 54.4 (10 DAA). Within 5 DAA, 50% of the recovered excess 15N was partitioned to the spike. In contrast, 20 DAA elapsed before 50% of the total spike N accumulated after anthesis was acquired. Only a small portion of the total excess 15N in the culm was recovered in the flag leaf (3%) and culm below the peduncle (2%). Collectively, these results indicate that the rapidly absorbed 15N‐nitrate was not incorporated uniformly with peduncle N, but the absorbed 15N was readily transported to the spike. Although the relative contribution of nonleaf components to assimilate soil‐derived nitrate absorbed after anthesis is not indicated, it is clear that the spike and peduncle have a considerable in situ capacity to assimilate nitrate immediately following anthesis.
Water Use Efficiency in Soybean Pubescence Density Isolines— A Calculation Procedure for Estimating Daily Values'1
Authors: Clawson K. L. , Specht J. E. , Blad B. L. , Garay A. F. 
Published: July 2010

AbstractDaily trends of water use efficiency (WUE) throughout a growing season are seldom, if ever, reported. In this paper a method for calculating daily WUE from growth analysis data coupled with weekly estimates of water use from soil moisture measurements are made for near‐isogenic dense and normal pubescent lines of 'Harosoy' and 'Clark' soybean [Glycine mar (L.) Merr.]. Data were collected during a 2‐yr field study at Mead, NE. The soil at this site is classified as a Typic Argiudoll. Evapotranspiration rates (ET) were lower in both dense pubescent isolines compared with the normal isolines, but differences were significant only for the Harosoy cultivar. Peak ET rates in 1980 were 4.7, 4.3, 5.8, and 4.8 mm day−1for the Clark normal, Clark dense, Harosoy normal, and Harosoy dense isolines, respectively. The highest WUE per unit ground area (WUEgand per unit leaf area (WUEg) was observed in the dense pubescent Harosoy isoline. This was the result of a higher crop growth rate and a lower ET in this isoline. Average mid‐season WUEgand WUEgvalues were, respectively, 1.4 and 0.25 g dry matter (kg H2O)−1day−1greater for the dense Harosoy isoline than for the normal isoline. No effect of pubescent density on WUE in the Clark isoline was observed. The interaction of dense pubescence as indicated by results of our study illustrate the need to establish the effect of the dense pubescent gene in cultivars into which it is introduced.
Alternative Establishment Methods for Wheat Following Soybean1
Authors: Griffin James L. , Taylor Richard W. 
Published: July 2010

AbstractA majority of wheat (Triticum aestivumL.) planted following soybean [Glycine max (L.) Merr.] in Louisiana is planted using conventional seedbed preparation. Delayed harvest of soybean due to late maturity or adverse weather may eliminate the option of planting a winter wheat crop. Field studies were conducted in southwest Louisiana on a Crowley silt loam (fine, montmorillonitic, thermic Typic Albaqualf) soil from 1980 to 1984 to compare various seeding methods for wheat following soybean. Planting methods included: (i) conventional seeding, (ii) overseeding at 50% soybean leaf defoliation (early overseeding), (iii) overseeding presoybean harvest, (iv) overseeding post‐soybean harvest, and (v) no‐till seeding in soybean residue. Wheat overseeded early was planted 16, 27, and 23 days prior to the other treatments in 1980, 1981, and 1983, respectively. Averaged over years, percent ground cover at approximately 100 days after early planting and at maturity was highest where wheat was overseeded early and lowest where it was seeded conventionally. Early season plant height averaged over years for wheat overseeded early was 21% greater than wheat overseeded preharvest, postharvest, and no‐till, and 47% greater than wheat seeded conventionally. Plant height at maturity was similar for all seeding methods. Yield obtained from wheat overseeded early was 14% higher than yields of the other treatments. Wheat yield was similar where wheat was seeded conventionally and no‐till. Differences in yield among the treatments were not reflected in wheat spike density or 500‐seed weight. Overseeding wheat in standing soybean and no‐till planting in soybean residue are viable alternative planting methods compared with conventional seedbed preparation. The earlier planting would allow wheat to establish more rapidly in the fall. Both overseeding and no‐till planting would be advantageous in a wet fall or where potential soil erosion would prohibit seedbed preparation.
Liming Rate and Method in Relation to Forage Establishment—Crop and Soil Chemical Responses1
Authors: Koch D. W. , Estes G. O. 
Published: July 2010

AbstractMany fields, because of slope and rockiness, are not suited to conventional seeding. However, the no‐tillage methods of establishing perennial forages preclude the incorporation of lime. The objective of this experiment was to evaluate the response of perennial forages seeded without tillage to surface‐applied lime. A long‐term study was conducted on a Penichuk fine sandy loam (loamy‐skeletal, mixed, mesic Dystric Eutrochrept) in which alfalfa (Medicago sativa L.)‐orchardgrass (Dactylis glomerata L.) and birdsfoot trefoil (Lotus corniculatus L.)–timothy (Phleum pratense L.) mixtures were seeded conventionally and without tillage. Nine months prior to seeding, lime was broadcast at 0, 4.5, and 9.0 Mg ha−1, incorporated for conventional seedings, and left on the surface for no‐till seedings. Soil pH prior to initiating the study was 5.6. In comparison with incorporated lime and conventional establishment, surface liming and establishment without tillage resulted in less vigorous forage seedlings and slower establishment. There was no difference in seedling density with liming or seeding method. Yields of legumes and total forage the seeding year were greater with incorporated than with unincorporated lime. In succeeding years, however, annual yields and 6‐yr total yields from 4.5 Mg ha−1 lime rates were not significantly different due to liming method. Over the long term, there was a yield advantage to incorporation of lime at the 9.0 Mg ha−1 rate. Rates of 9.0 compared with 4.5 Mg ha−1 of surface liming did not speed pH adjustment with depth, and after 6 yr pH had increased to a depth of only 10 cm. Birdsfoot trefoil–timothy was more productive than alfalfa‐orchardgrass without lime, but less responsive to lime. The highest rate (9.0 Mg ha−1) of incorporated lime increased alfalfa‐orchardgrass yields the year of establishment, but similar rates of surface‐applied lime did not produce a yield response until the fourth year.
Defoliation Effects on Forage Dry Matter Production of a Perennial Ryegrass–Subclover Pasture1
Authors: Motazedian Iraj , Sharrow Steven H. 
Published: July 2010

AbstractWhile many authors have reported the effects of either varying defoliation intensity or of varying defoliation interval on pasture dry‐matter production, both intensity and frequency of defoliation have rarely been simultaneously applied over a range of values in such a way that their interaction can be evaluated. The objective of this study was to quantify the response of pasture dry‐matter yield to simultaneous changes in defoliation intensity and frequency over a range of values. Effects of defoliation treatments on dry matter production were evaluated on a perennial ryegrass (Lolium perenne L.)–subclover (Trifolium subterraneum L.) hill land pasture growing on a Ultic Haploxeroll soil near Corvallis, OR. A combination of four defoliation intervals (clipped every 7, 21, 35, or 49 days) and three stubble heights (70, 55, and 40 mm of stubble remaining after defoliation) were applied during the 1980, 1981, and 1982 growing seasons, respectively. Total annual dry matter production in all 3 yr increased as defoliation interval increased from 7 to 49 days between defoliation events. Effect of stubble height on dry matter yield was apparently influenced by forage plant type and sward species composition. When the pasture was dominated by erect‐growing ryegrass in 1980, more dry matter was produced when 70 mm of stubble remained after defoliation; but when the more prostrate subclover dominated the sward in 1982, it yielded more with 40 mm of stubble. The results of this experiment suggest that short‐duration grazing systems, which provide long periods of nonuse for pasture regrowth, should result in more dry matter production than does continuous grazing.
Turfgrass Thatch Components and Decomposition Rates in Long‐Term Fungicide Plots1
Authors: Smiley R. W. , Fowler M. Craven 
Published: July 2010

AbstractThatch management procedures are an important component of high‐intensity turfgrass management programs. Some fungicides used for controlling turfgrass diseases are known to increase the accumulation of thatch, but the thatching tendency in response to applications of most fungicides is unknown. Three new fungicides and three previously studied fungicides were applied to Poa pratensis L. turfgrass seven times annually for 6 yr. The soil was a silty clay loam (Glossaquic Hapludolf). At another location, three applications each year were used in a similar study on a sandy loam (Typic Dystroshrept). Measurements were made of thatch depths, soil and thatch pH, physical composition of thatch (roots + leaf remnants, crowns, rhizomes, and mineral soil), selected microbial populations, and the decomposition rates for cellulose and thatch implanted into the turf (buried litter bag technique). Seven applications of benomyl or iprodione per year caused thatch to become deeper (p = 0.05) than in the untreated turf; however, three applications per year did not. Increased thatch accumulation did not occur with cycloheximide, metalaxyl, propiconazol, or triadimefon. None of the fungicides significantly reduced the decomposition rate of buried thatch, or altered the thatch pH or microbial composition. Iprodione and benomyl increased the overall amounts of recognizable tissue in the thatch matrix. Results of this study support the hypothesis that fungicides influencing thatch accumulation are likely to do so by increasing the rate of tissue production without changing the rate of tissue decomposition.
Growth Regulator Effects on the Composition of Seed of Five Peanut Cultivars1
Authors: Mozingo R. W. , Steele J. L. , Young C. T. 
Published: July 2010

AbstractSince composition of the seed of peanut (Arachis hypogaea L.) is an important quality factor, the effect of the plant growth regulator, succinic acid 2,2 dimethylhydrazide (SADH, sold under the trade name Kylar), on seed composition needed investigation. Field tests were grown in Martin County, NC, on a Norfolk loamy fine sand (fine‐loamy, siliceous, thermic Typic Paleudult) and in Suffolk, VA, on an Eunola loamy fine sand (fine‐loamy, siliceous, thermic Aquic Hapludult) in 1981 and 1982. Peanut seed from treated and untreated plots of the cultivars ‘Florigiant’, ‘NC 6’, ‘NC 7’, ‘VA 81B’, and ‘NC 8C’ at each location were evaluated for fatty acid distribution, iodine value (IV), oleic/linoleic (O/L) ratio, percentage of extra large kernels (ELK), and arginine maturity index (AMI). Application of SADH in 1981 reduced the linoleic acid percentage and IV and increased the oleic acid percentage and O/L ratio. In 1982, SADH application led to significantly lower linoleic acid percentage and IV in all cultivars except VA 81B, and significantly increased the O/L ratio for Florigiant, NC 7, and NC 8C. Similar O/L changes were not significant for NC 6 and VA 81B. NC 7 had the greatest number of significant changes in composition percentages with decreases in palmitic, linoleic, arachidic, eicosenoic, behenic, and lignoceric acids, and an increase in oleic acid in seed of plants treated with SADH. The AMI values were lower for all cultivars and ELK percentage was higher for Florigiant and NC 6, indicating more mature seed, with SADH treatment. Thus, from the results of this 2‐yr study, the application of SADH to reduce foliage growth also affected the ELK, AMI, and fatty acid distribution of seed from several peanut cultivars.