bluuebunny/crossref_metadata_2025_split huggingface dataset:
Yield and Quality Losses Due to Alfalfa Weevil1
Authors: Liu Beverly W. Y. , Fick Gary W. 
Published: July 2010

AbstractEvaluation of management practices to control the alfalfa weevil (Hypera postica Gyllenhal) requires quantitative knowledge of the effects of insect defoliation on yield and quality of alfalfa (Medicago sativa L.). Measurements were made in 1971 when the uncontrolled population peaked at 2.7 larvae stem−1 and in 1972 when the peak was 1.1 larvae stem−1. With weevils chemically controlled, a three‐cut system gave seasonal dry matter yields of 10.1 and 10.5 metric tons ha−1 in 1971 and 1972, respectively, whereas weevil infested plots yielded 8.4 and 10.0 metric tons ha−1, respectively. Corresponding yields for two‐cut systems were lower at 6.4 and 9.1 metric tons ha−1 for non‐infested plots and 7.7 and 8.6 metric tons ha−1 for infested plots. In vitro true digestibility (IVTD) and crude protein (CP) percentages of leaves were reduced during peak larval feeding with the higher population of 1971. Weevil defoliation did not have a significant influence on leaf percentage or on the quality of the total herbage, apparently because stem growth was also retarded. However, yield of quality components was reduced. The greatest effect for a single harvest was in the second cut of the three‐cut system where feeding occurred in the early stages of regrowth. Total seasonal yield reductions in 1971 were highly significant for IVTD and CP, and significant for leaves. Losses for these components were 1.4, 0.3, and 0.8 metric tons ha−1, respectively,in the three‐cut system. Yields and quality tended to be higher in the two‐cut system when weevils were not controlled because of reduced lodging in late cut alfalfa and renewed growth when larval activity subsided. With the lower weevil population of 1972, there was no significant effect of weevil feeding on any of the measured yield and quality parameters.
Spotted Response of Overseeded Ryegrass to Sulfur‐Coated Urea1
Authors: Volk Gaylord M. 
Published: July 2010

AbstractSulfur‐coated urea (SCU) shows excellent potential as a controlled‐release N source for turfgrasses, but highly spotted appearance has always resulted during 3 years of tests in which SCU was used as an early application on winter ryegrass (Lolium perenne L.) overseeded on verticut bermudagrass (Cynodan sp.). Darker green spots 5 to 15 cm in diam constituted 20 to 50% of the surface area, with lighter green grass between the spots. The spots became smaller and the contrast greater as the season progressed. Chlorphyll content determined by methanol extraction of fresh grass was 8.5 mg/g on dry grass basis in representative darker green spots vs. 6.6 mg/g for lighter green interspot areas. Apparently, in the absence of retentive thatch, the large round SCU pellets were readily moved by sprinkler irrigation and rainfall, and concentrated into zones of stability. Poor initial distribution and mower pickup were not determining factors. Where effective thatch is lacking some means of incorporation sufficient to anchor the pellets should be devised.
Fertilization, Nutrient Composition, and Yield Relationships in Irrigated Spring Wheat1
Authors: Gardner B. R. , Jackson E. B. 
Published: July 2010

AbstractWheat acreage in Arizona has increased tenfold since the introduction of high yielding semidwarf spring wheats (Triticum aestivum L.). Because of the higher yield potential of these wheat cultivars, many growers have applied more fertilizer without evidence that these semidwarf spring wheats require more nutrients. This study was initiated to evaluate the effect of N and P fertilization on the growth and yield of semidwarf spring wheat and to develop a workable tissue test to determine the nutritional status of the wheat plan.Tissue samples for chemical analysis were taken from uheat plants in three different field experiments. These experiments consisted of 1) six rates of N and three rates of P, 2) six rates of N and six wheat cultivars, and 3) six rates of N and three wheat cultivars.The NO3‐N concentration in the lower 5 to 8 cm of the stem indicated the N status of the wheat plant. Minimum levels of NO3‐N for different stages of growth were established for Southwestern Arizona conditions. In two experiments excessive N decreased yields slightly when compared to sufficient levels of N. The main effects of N on grain yield components were to increase the number of heads/unit area, increase the number of seeds/ head, and decrease the weight of individual seeds. The total N content in the grain increased with increased N applications. Determination of P in the lower portion of wheat stems was not found to be suitable for indicating the P status of the crop.
Copper Industrial Byproducts for Improving Iron Deficient Calcareous Soils1
Authors: Ryan J. , Stroehlein J. L. 
Published: July 2010

AbstractLaboratory and greenhouse experiments were conducted to evaluate an iron‐rich surplus by‐product (“jarosite”) from a copper refining process as Fe fertilizer. Combinations of H2SO4, which is a by‐product from copper smelting, with “jarosite” were studied in order to see if the iron solubility would be increased. Acidification of the “jaroste” greatly enhanced Fe solubility. As the “jarosite”/H2SO4 ratio increased from 1:1 to 7:1, the amount of the material solubilized as Fe decreased from approximately 12 to 2%. At ratios wider than 7:1, negligible amounts of Fe dissolved. At “jarosite”/H2SO4 ratios < 1, Fe solubility increased but the end product could not be handled as a conventional pelleted or powdered fertilizer.In greenhouse experiments using sorghum (Sorghum bicolor ‘Double Dwarf Yellow Sooner’) in an Fe‐deficient calcareous soil, the 2:1 mixture of “jarosite”/H2SO4 was significantly more effective than either “jarosite” or H2SO4 alone in terms of increasing plant growth and chlorophyll content. The mixture compared favorably with conventional inorganic and chelated sources of Fe. Varying the ratio of “jarosite”/H2SO4 from 1:1 to 5:1 resulted in no differences in yield. Particle size of the mixture influenced plant growth. The < 1 mm fraction was most effective, the 1 to 2 mm and 2 to 6 mm fractions gave similar yields and the 6 to 12 mm fraction was least effective. Post‐harvest analysis of the cropped soil showed that the “jarosite”/H2SO4 mixture significantly increased the levels of DTPA‐extractable Fe.
Transmittance of the Multifoliolate Leaf Characteristic into Non‐Dormant Alfalfa1
Authors: Brick M. A. , Dobrenz A. K. , Schonhorst M. H. 
Published: July 2010

AbstractVariation in leaf morphology and canopy architecture in alfalfa (Medicago sativa L.) has received comparatively little attention despite the importance of the leaf in photosynthesis and nutritive value of the forage. The multifoliolate leaf characteristics presents a potential mechanism whereby quality and leafiness can be changed. This investigation was designed to study the penetrance of the multifoliolate trait into ‘Mesa‐Sirsa,’ a non‐dormant trifoliolate cultivar.Hand and bee‐pollinated reciprocal crosses were made between a trifoliolate (tf) Mesa‐Sirsa clone and four multifoliolate (mf) alfalfa clones to determine if genes for the mf trait could be transmitted and expressed in the F1 generation. Specific leaf weight and internode length were studied in the F1 generation of controlled handpollinated crosses.The multifoliolate characteristic was effectively transmitted in both hand and bee‐pollinated experiments with an average expression of 33%. Expression of the mf trait among progeny of the four multifoliolate clones ranged from 8 to 47%. Average specific leaf weight was consistently higher in the mf progeny compared to the tf progeny, however, these differences were not significant expect in progeny of Mesa‐Sirsa × mf 2. Average internode length varied significantly among crosses and between the tf and mf progeny of crosses MS × mf 1 and MS × mf 2. The multifoliolate clones used in this study had the normal tetraploid complement of 32 chromosomes.The multifoliolate characteristic is an easily transmittable trait and through careful selection could be used to improve the leafiness and canopy architecture of nondormant alfalfa.
Histological and in vitro Digestion Study of 1‐ and 4‐Week Stems and Leaves From High and Low Quality Bermudagrass Genotypes1
Authors: Hanna Wayne W. , Monson Warren G. , Burton Glenn W. 
Published: July 2010

AbstractAnatomical information is limited on changes occurring with age of the forage and differences due to genotype affecting in vitro dry matter digestibility (IVDMD). Since this type of information would be ot value to those concerned with the production and use of forage, two bermudagrass, Cynodon dactylon (L.) Pers., clones with high IVDMD values (Coastcross‐1 and P.I. 293603) and two clones with low IVDMD values (P.I. 291715 and P.I. 291719) were studied histologically. No histological differences were observed in either the stems or leaves between the high‐ and low‐quality bermudagrass of the same age. The formation of a band of thick‐walled cells in the stem at 4 weeks of age more than doubled the percentage of anatomical components resistant to 72 hours of rumen fluid digestion and reduced IVDMD values by up to 44%, as compared to 1‐week‐old stems. The percentage of anatomical components resistant to digestion in the leaves and IVDMD values of leaves remained relatively the same in 1 and 4‐week‐old samples of a specific clone. This indicates that reduction in quality with age of bermudagrass forage is due mainly to changes occurring in the stem. The vascular bundles (except phloem), parts of the epidermal cells, and the thick‐walled cells in 4‐week‐old stems were resistant to digestion. The higher IVDMD values of the high‐quality bermudagrasses appear to be due to a larger soluble fraction and more digestible cell wall. No anatomical differences were observed between the high and low quality genotypes to account for the differences in IVDMD values.
Seed Production and Stand Regeneration of Bigflower Vetch, Vicia grandiflora var. kitaibeliana W. Koch, Grown with Cool‐Season Forage Grasses1
Authors: Templeton W. C. , Taylor T. H. , Wyles J. W. , Woolfolk P. G. 
Published: July 2010

AbstractResearch has shown that bigflower vetch, Vicia grandiflora var. kitaibeliana W. Koch, possesses a number of desirable characteristics as a forage plant. A deterrent to its use, however, is seed shattering, as the pods ripen. Also, no information concerning seed production potential of the species is available. Experiments were conducted, therefore, to gain information on seed production and the effect of spring cutting on seed yields and to explore the potential for regenerating stands from natural reseeding.Two essentially identical field experiments were conducted in which bigflower vetch‐grass mixtures were uncut or cut one to three times in spring prior to harvesting vetch seed. Residual productivity and botanical composition of the swards were determined in a single spring cutting the year after seed harvest.Early‐spring cutting of vetch‐grass mixtures markedly increased vetch seed production, with the most beneficial treatments resulting in clean‐seed yields of ca 600 kg/ha. The most intensive cutting treatments and cutting late in spring either almost or completely prevented seed production.A third experiment, under pasture conditions, involved bigflower vetch and several other legumes seeded into mixed grasses and managed to favor natural reseeding or to deter it, and three levels of N fertilizer. Sheep were used to graze the plots during a 5‐year period.Deferment of grazing in spring or early sumnmer to allow seed production and encourage natural reseeding of legumes increased the legume component of the pastures and sheep‐grazing days obtained from bigflower vetchgrass mixtures but not from other legume‐grass associations. Bigflower vetch‐grass, with the vetch allowed to reseed naturally, was as productive as grass receiving 112 kg N/ha/year.The data indicate that once an adequate reservior of bigflower vetch seed is in the soil, satisfactory stands can be regenerated for at least 2 years without intervening seed production.
Growth and Mineral Composition of Rice at Various Soil Moisture Tensions and Oxygen Levels
Authors: Patrick W. H. , Fontenot W. J. 
Published: July 2010

AbstractThe better growth of rice in a flooded soil as compared to an upland soil has been attributed to the reducing conditions caused by submergence. No study has been carried out, however, in which the effects of the soil moisture status has been separated from the effect of the oxidation‐reduction conditions of the soil.In the study reported here, the effect of soil oxidation‐reduction conditions on early growth and mineral composition of lowland rice (Oryza sativa L. ‘Saturn’) was determined by growing plants in artificially packed soil columns maintained under different soil moisture tension and oxygen conditions. Since soil aeration is largely governed by the moisture status of the soil, this study was designed to separate these effects by subjecting the rice plant to different aeration conditions while at the same time attempting not to limit moisture supply. In one experiment different redox conditions were established by maintaining soil columns at soil moisture tensions ranging from 0 to 80 cm during growth of the plants. In a second experiment plants were grown at soil oxygen levels of 0, 3, 8, and 12% while soil moisture was maintained at 10 cm moisture tension. Vegetative growth of rice was greater under reduced conditions than under oxidized conditions in both experiments. The P concentration of the plant was much higher under reduced conditions than under oxidized conditions. Reduced conditions increased the solubility of P, Fe, and Mn in the soil although no consistent effect of reducing conditions on plant uptake of Fe and Mn was observed.
Nitrogen Nutrition and Yield of Sugarcane as Affected by N‐Serve1
Authors: Prasad M. 
Published: July 2010

AbstractVery few experiments have been conducted to evaluate N‐Serve [2‐chloro‐6‐(trichloromethyl) pyridine] formulated with N fertilizer for sugarcane (Saccharum officirarum L.). N‐Serve when fomulated with N‐fertilizer increased sugarcane yields in the Philippines and in Louisiana but failed to do so in Puerto Rico and in Mauritius. In view of the relatively few experiments conducted with N‐Serve for sugarcane and the conflicting nature of the results, a pot experiment in drums and a field experiment were conducted to study the effect of N‐Serve formulated with solid ammonium sulfate (AS) on sugarcane (‘HJ 5741’) yield, leaf N content, tillering, and on soil N. In the pot experiment two soils, a clayey loam (Typic Tropaqualfs) and a loamy sand (Aquoxic Tropudults) were used combined with a high and low irrigation treatment. There were two rates of AS with and without N‐Serve. A control treatment was also included. N‐Serve was applied at 2.5% of the weight of AS. In the field experiment on a sandy clay (Typic Tropaqualfs) there were three rates of AS with and without N‐Serve. A control treatment was also included. N‐Serve was applied at a flat rate of 24 liters/ha.In the pot experiment N‐Serve increased the yield of sugarcane and leaf N‐content at the low rate of N application. However, N‐Serve reduced yields in the loamy sand soil at both rates of N under low irrigation. N‐Serve was effective in inhibiting nitrification at least up to 6 weeks in all four combinations but it was less effective in the loamy sand soil under high irrigation. High percentage of N in the leaf of the N‐Serve treatments reflected the higher efficiency of N fertilizer with N‐Serve. In the field experiment N at 103 kg/ha with N‐Serve gave yields almost equal to 206 kg/ha without N‐Serve. Nitrification was inhibited up to 12 weeks at N‐Serve application with low rate of N in the field. As in the drum experiment, the efficiency of the N‐fertilizer (as reflected by higher percentage N in the leaf) was improved with N‐Serve applications, especially with lower rates of N.
Effects of Gibberellic Acid on the Cool Season Regworth of Two Tropical Forage Grasses1
Authors: Whitney A. S. 
Published: July 2010

AbstractAlthough the tropical grasses are very productive in Hawaii and elsewhere, their production at subtropical latitudes or elevations is often limited by seasonally low‐temperatures. The feasibility of overcoming low‐temperature effects by applying gibberellic acid (GA3) was therefore evaluated over a 4‐year period on swards of kikuyugrass (Pennisetum clandestinum Hochst. ex. Chiov.) at two sites and pangola digitgrass (Digitaria decumbens Stent) at one site.Significant responses to 62 g GA/ha were obtained in all experiments over the range of N‐fertilization tested (68–180 kg N/ha). Over a 4‐year period, the average response of kikuyugrass to GA under a clipping regime was 1260 kg dry matter (DM)/ha. The average response to ammonium sulfate (at N rates ≥ 68 kg/ha) was 15 kg DM/kg N. Average pangola responses were 1450 kg DM/ha from GA treatment and 10.5 kg DM/kg N. In some cases, the GA responses could not be duplicated by higher levels of N fertilization.GA applied on the date of clipping was as effective as GA applied 2 weeks later, but under some conditions, GA was less effective in increasing (DM) production once regrowth entered the boom portion of the regrowth curve. Growth retardation subsequent to the GA response occurred in clipped plots but not in plots which were left unclipped or were defoliated by 2 weeks of grazing.GA treatment appears to be feasible for increasing production of kikuyugrass and pangola during the cool season. The responses were enhanced by a moderate level of N‐fertilization, and the full‐season responses from single applications of GA were better under grazing than under clipping. The GA‐treated forage was stemmier and thus less completely consumed by grazing animals, however.
Morphology and Growth of Bahiagrass at Three Rates of Nitrogen
Authors: Sampaio E. V. S. B. , Beaty E. R. 
Published: July 2010

Abstract‘Pensacola’ bahiagrass, Paspalum notatum Flugge, is an important grass in the tropics and subtropics, including large areas in the southern part of the United States. Bahiagrass grows by adding new phytomers each with a bud, internode, node, leaf sheath, and blade and usually a root on each tiller growing at the terminal end of horizontal stolons. Rate of phytomer generation and growth/tiller determines forage production and an understanding of phytomer production and component longivity is essential for its effective management. N fertilization influences tiller numbers and possibly rate of phytomer generation and growth. This greenhouse investigation was concerned with rate of tillering and phytomer production and component growth/tiller over 90‐day growth periods when fertilized with 0, 100, and 300 kg/ha of N.Tiller initiation in bahiagrass was relatively slow, and over the 90‐day period each original tiller produced one new tiller when no N was applied and three new tillers when 300 kg/ha N was applied. New leaf (phytomer) production ranged from 9.5 to 9.8/tiller for the 90 day period; total phytomer production was not influenced by N fertilization level. Leaves lived for 54 to 60 days and on N fertilized treatments leaf blades were slightly wider but no longer than were leaf blades on unfertilized treatments. N fertilization tended to accelerate phytomer development for 40 days following application and to delay it for the following 50 days as compared to that of the no N check.
Response of Three Hard Red Winter Wheat Cultivars to Four Planting Arrangements1
Authors: Ketata H. , Edwards L. H. , Morrison R. D. 
Published: July 2010

AbstractAs new and morphologically different wheat cultivars are developed, altered cultural practices may be required to obtain optimum performance from a particular cultivar. This study compared the relative responses of three contrasting hard red winter wheat cultivars (Triticum aestivum L. em Thell.) under four planting arrangements. Cultivars studied were ‘Triumph 64,’ ‘Sturdy,’ and ‘Parker.’ A split plot experimental design was employed with cultivars as main plots and planting arrangements (two row spacings and two drilling patterns) as subplots. Characters investigated were grain yield, tillers/unit area, kernels/spike, kernel weight, test weight, plant height, maturity, and protein content of the grain. The cultivars differed significantly for all characters except grain yield. Tiller count was significantly affected by row spacings and drilling patterns while kernels per spike was significantly influenced by row spacings. Planting arrangements did not induce significant responses in any of the remaining characters. A significant cultivar by spacing interaction was noted for test weight and a significant cultivar by drilling interaction was noted for plant height. The results of this experiment indicate that planting arrangements may influence yield components and other characters in the wheat cultivars studied. However, the optimum planting arrangement for increased yield could not be determined.
Leaching of Phosphate and Selected Cations from Sandy Soils as Affected by Lime1
Authors: Chaiwanakupt Pornphimol , Robertson W. K. 
Published: July 2010

AbstractIt is important to determine if and to what extent P moves through some acid sandy soils and, in view of the high cost of fertilizer P and the problems associated with pollution of ground water, what can be done to prevent or reduce the movement when it occurs.Segmented columns, 25 cm in length and 5 cm in diam., were used to study P leaching in five mineral and one organic soil. A total of 25 or 50 cm H2O was passed through the columns, containing soil from various depths, after treatment in the top 2 cm with 0 to 600 ppm P tagged with 32P. Phosphorus and other ions were measured in the leachates and at the end of the leaching period in 5 cm segments of the soil columns. For those soils where leaching of P occurred, lime effects on its reduction were investigated by repeating the experiment with the addition of Ca(OH)2 at rates to supply 0 to 800 ppm Ca in the soil.Movement of P from the column was nil in Red Bay fine sandy loam but occurred for the other soils as follows: Leon fine sand > Oldsmar fine sand > Eustis loamy fine sand > Lakeland fine sand > Tomoka muck. Leaching was positively related to rates of applied P and negatively related to rates of applied P and to the level of organic matter, Fe and Al contents, pH, and rate of liming. The degree to which these factors affected leaching varied with the soil as well as the location in the profile from which the sample was collected.Leaching of K, Ca, and Mg occurred in all soils. The amount was generally related to the CEC or the levels present in the extractable form before the leaching began. Leaching of Fe and Al was determined only on soils where P leaching was appreciable. These ions generally leached with P but there was a direct relationship between leached and 0.1 N HC1 extractable ions. These data are of value in evaluating and determining P and lime requirements.