bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Length of Cut and Leaf Surface Treatments on Digestibility of Fresh Forage1
Authors: Monson Warren G. , Burton Glenn W. 
Published: July 2010

AbstractDigestibility of leaves of pearl millet, napiergrass, and bermudragrass was increased by several treatments. After 48 hours in rumen fluid, average dry matter losses from leaves cut to lengths of 2.5, 1.2, .6, and .3 cm were 17.1, 25.9, 30.6, and 42.8%, respectively. When leaves were pressed on a rough surface or abraded with sand paper to break the cuticle, average dry matter losses were from 2.5 to 5 times (mean = 3.2) the losses from intact leaf sections. Increasing the cut surfaces or rupturing the cuticle enhanced the digestion of fresh forage by rumen micro‐organisms.
Growth and Composition Responses of Soybeans to Some Growth Regulators1
Authors: Basnet B. S. , Paulsen G. M. , Nickell C. D. 
Published: July 2010

AbstractSome growth regulators studied for morphological and yield effects on soybeans [Glycine max (L.) Merr.] have not been studied for chemical compositional effects, particularly under Great Plains conditions. The objective of this study was to compare morphological aud mature seed compositional responses of 11 growth regulators.Eleven growth regulators of various modes of action were applied at two rates to foliage of soybeaus at one‐tenth bloom stage to study their effects on plant growth and seed composition. The desired rate of each growth regulator was applied in 1 liter of water containing 0.02% (v/v) polyoxyethylene sorbitol monolaurate as a surfactant per plot.Morphological characteristics responded more than did the chemical constituents, oil and protein, to the growth regulators. Responses were changes in the node number subtending the first pod, number of branches, and number of pods per plant. The antiauxin triiodobenzoic acid reduced plant height, node number, and node number subtending first pod; and increased branching and pod set. None of the growth regulators, however, increased yield when compared to no treatment. Although none of the regulators appeared useful by itself for commercial soybean production, some might have a role under stress conditions or combined with other regulators.
Nitrogen Nutrition and Yield Relations of Nugaines Winter Wheat1
Authors: Laopirojana Pojanee , Roberts S. , Dawson M. D. 
Published: July 2010

AbstractA nitrogen rate study was undertaken to determine the potential utility of the critical nutrient concept as a guide to N fertilization of winter wheat (Triticum aestivum L.), as part of a more extensive soil fertility investigation in western Oregon. This work on wheat was prompted by the need for a suitable diagnostic technique for determining more precisely the optimum levels of available N. Only limited information exists on the applicability of the critical nutrient concept or on critical levels of plant N in winter wheat, particularly the semidwarf types.Top grain yield was reached after N application of 140 kg/ha, but there were no significant yield differences over the range from 84 to 224 kg/ha. Plant NO3‐N values in leaves and shoots at tillering, jointing, and boot stages of growth were increased significantly by the highest N increment of 224 kg/ha compared to the next lower N rate. In contrast to grain yield, the highest values for total N percentage in plant shoots at all the later growth stages and dry matter yield at the soft dough stage were obtained with the highest rate of applied N, which also produced the highest values for plant NO3‐N. Semidwarf wheat utilized the high N rate more efficiently for dry matter production than for grain yield, and high N fertility also increased grain protein percentage.A graph of grain yield vs NO3‐N concentration in plant leaves at jointing showed a definite peak in grain yield at approximately 500 ppm NO3‐N in the leaves. Additional applied N very readily increased leaf NO3‐N considerably above 500 ppm and caused a slight, insignificant drop in grain yield. These results suggest the applicability of the critical nutrient concept to semidwarf wheat, and provide justification for additional work to establish more precisely the critical level for NO3‐N in wheat.
Influence of Seed Size and Depth of Planting on Seedling Emergence of Two Milkvetch Species1
Authors: Townsend C. E. 
Published: July 2010

AbstractThe relationship between seed size and seedling emergence was studied in cicer milkvetch (Astragalus cicer L.) and falcatus milkvetch (A. falcatus Lam.). Three sizes of seed of each species were planted at 1.3‐, 2.5‐, and 3.8‐cm depths in both the greenhouse and the field. The three seed sizes were designated as large, medium, and small. Sterilized soil was used in the greenhouse. Plantings were made at Ft. Collins and Akron, Colo, in fallowed soil.In both the greenhouse and the field there were significant differences among depths of planting for seedling emergence. In the field, seedling emergence was influenced by soil moisture conditions at planting time and by subsequent precipitation. Usually, the optimum average planting depth under such variable conditions was 2.5 cm for both species. Shallower seeding would be satisfactory, however, if the soil surface was moist at planting time. Seedling emergence was good from all three depths in the greenhouse and was much better than in the field.In the greenhouse, seedling emergence from the large seeds was significantly better than from the small seeds for cicer milkvetch. Differences among seed sizes for seedling emergence, however, were slight and nonsignificant for falcatus milkvetch.The relationship between seed size and seedling emergence was variable for both species at both field locations. In two of four studies with each species a significantly greater number of seedlings was obtained from the large seeds than from the small seeds. The variability was attributed to soil moisture conditions. In general, there appeared to be more promise of improving seedling vigor through selection for large seeds in cicer milkvetch than in falcatus milkvetch.
Effect of Levels of Soil Potassium, Fertilizer Potassium, and Season on Yield and Ear Leaf Potassium Content of Corn Inbreds and Hybrids1
Authors: Gallaher Raymond N. , Parks W. L. , Josephson L. M. 
Published: July 2010

AbstractThree corn (Zea mays L.) genotype groups including: inbreds T101, T105, T1ll, T115; their six possible single cross hybrids; and three double cross permutations were grown on a Hartsells loam soil at four rates of K fertilization for 3 years to evaluate their K requirements. The hybrids responded to higher rates of K fertilization than the inbreds. However, the leaf K values for the inbreds should be greater than the 1.5% critical level of hybrids for maximum yields. Seasonal variation in rainfall, temperature, and sunlight caused large differences in yield and ear leaf content of K. A quadratic regression model was fitted to yield of corn and percent K content of the ear leaf for each genotype group. Results indicated that the model would be more useful in accounting for variation in yield and K concentration for double‐cross hybrids than for single‐cross hybrids or inbreds. The linear effect of fertilizer K accounted for more yield and ear leaf K content differences than any other factor studied.
Effect of High Rates of N, P, K Fertilizer on Corn (Zea mays L.)1
Authors: Powell R. D. , Webb J. R. 
Published: July 2010

AbstractThis experiment was conducted to observe the effects on corn (Zea mays L.) grown on soils which received annual applications of fertilizer at rates above those normally recommended. Annual applications of high rates of N, P, and K fertilizer to Clarion‐Webster Soil Association soils in central (Ames) and north central (Kanawha) Iowa planted to corn produced variable yield results. Incremental rates of N, P, and K fertilizers up to 1,344, 504, and 1,008 kg/ha, (1,200, 450, and 900 lb/a), respectively, were applied annually for 3 consecutive years. The grain yields were analyzed statistically using analyses of variance and regression techniques. Three regression functions, a second order quadratic, a logarithmic to the base e, and a square root function were used to estimate the response surfaces and compared for goodness of fit. The yields were the dependent variable and the applied fertilizer nutrients were the independent variables.It was observed that the logarithmic function fitted the data best in all three years at both sites. A second order quadratic yield prediction equation was developed which included independent variables for fertilizer N, K, N2, interactions of N with soil p, K with soil k and K with soil pH, a variable for soil n supplying power and a variable for measuring climatic influences. Increases in yields resulted from N fertilization. Yield decreases the final year were attributed to high salt concentrations and acid soil reactions. The surface soil pH decreased at a rate of 0.05 pH units per 112 kg/ha (100 lb/a) of N and yields decreased the final year as salt concentrations increased. Yields decreased at N rates above 224 kg/ha (200 lb/a) at the Ames site and above 448 kg/ha (400 lb/a) at the Kanawha site.
Relationships Between Dry Matter Yields and Concentrations of Zn and P in Young Corn Plants1
Authors: Terman G. L. , Giordano P. M. , Allen S. E. 
Published: July 2010

AbstractYield‐Zn or P concentration relationships were studied in corn (Zea mays L.) grown in several greenhouse pot experiments conducted to compare various rates and sources of Zn and P on soils deficient in these nutrients, Such relationships are important in proper interpretation of plant analysis results. The usual result was for corn forage yields to increase at a minimum Zn concentration of 7 to 9 ppm in the dry forage until P or other growth factor became limiting. Then yields leveled off and Zn concentrations increased at sufficiently high levels of applied Zn. Similarly, yields increased at a minimum P concentration near 0.10% until Zn or other growth factor became limiting; P concentrations then increased. Critical concentrations in the dry corn forage were estimated to be about 14 ppm of Zn and 0.14% P.
Influence of Seedling Age at Transplanting on Rice Performance1
Authors: Sanchez P. A. , L. N. Larrea 
Published: July 2010

AbstractWith the advent of high‐yielding rice (Oryza sativa L.) varieties on the cost of Peru, the question arose as to how these short‐statured plant types react to delays in transplanting, a common situation in the field because of uncertain water supply. A field experiment conducted in Lambayeque, Peru evaluated two short‐statured varieties, ‘IR8’ and ‘IR5,’ with the tall, traditional ‘Minabir’ variety at transplanting dates from 30 to 105 days after seeding and at three seedbed growth rates. IR8 produced the highest grain yield (12.0 tons/ha) when transplanted at 30 days after seeding. Yields decreased linearly at the rate of 125 kg/ha per day of delayed transplanting beyond 30 days. Minabir showed less‐pronounced yield decreases up to 75 days after seeding. Slowing seedbed growth of IR8 through water and N stress produced significant yield increases when transplanted at 75 and 90 days after seeding. Delayed transplanting reduced plant height and dry matter production, caused flowering shortly after transplanting in some cases, and decreased panicle production and the number of fertile grains per panicle. Seeding density had no effect on yields. The experiment showed that the short‐statured plant types are more sensitive to delays in transplanting than the tall ones, but that the new varieties can outyield the tall varieties when transplanted up to 90 days after seeding.
A Simple, Inexpensive Watre Bath for Precise Temperature Control
Authors: Spomer Louis A. 
Published: July 2010

AbstractA simple, inexpensive water bath for precise laboratory temperature control is described. The bath was constructed from common materials at an actual cost of less than $35. Bath temperature is maintained slightly above ambient by a large volume mercury‐toluene thermoregulator and mechanical heat proportioner. This apparatus has maintained 20 C with maximum short fluctuations of ± 5 × 10−4 C and drift of + 2 × 10−3 C day−1 for continuous periods up to 25 days.
Effect of Delayed Thinning on Sorghum Growth and Yield1
Authors: Clegg Max D. , Maranville Jerry W. 
Published: July 2010

AbstractAn experiment was conducted to determine if a delay in thinning would adversely affect growth and yield of grain sorghum [Sorghum bicolor (L.) Moench]. Results showed that thinning should be performed as early as possible, preferably before plants reach 7.5 cm in height. Yield was reduced when thinning was delayed until plants were 15.0 cm to 23.0 cm in height. Stem diameter was reduced and seed size was increased when thinning was delayed until the plants had reached a height of over 31 cm. We suggest that when a delay in time of thinning is anticipated, planting to a desired population based on reliable laboratory germination tests may be preferable.
Carbon Dioxide and the Photosynthesis of Field Crops: A Metered Carbon Dioxide Release in Cotton Under Field Conditions1
Authors: Harper L. A. , Baker D. N. , Box J. E. , Hesketh J. D. 
Published: July 2010

AbstractThe benefits of increased carbon dioxide concentration in enclosed plant environments are well known, but there has been only limited experimentation with increasing carbon dioxide on a field scale. The purpose of this study was to artificially enrich a cotton (Gossypium hirsutum L.) crop with carbon dioxide using a known release rate and to determine the variation in canopy carbon dioxide concentration with respect to meteorological conditions.Carbon dioxide was metered into the crop canopy while concentrations of carbon dioxide and other meteorological parameters in and above the canopy were measured. The crop had a leaf area index of 2.34, and the crop surface was aerodynamically rough. Turbulence caused considerable short‐term fluctuation in concentrations, but concentrations of 450 to 500 ppm at three‐fourths plant height were maintained with a release rate of 222.6 kg/ha/hour (198.6 Ib/acre/hour). Photosynthetic recovery of applied carbon dioxide was calculated from data obtained in the crop during its release and from data describing its behavior in a semiclosed plexiglass chamber just before the carbon dioxide release. Calculated recoveries ranged from 7 to 33% over a range of solar radiation levels from 205 to 1,095 W/m2. The release produced unexpectedly high carbon dioxide concentrations 4 m above the soil surface (due to vertical movement), and these concentrations varied little with windspeeds up to 200 cm/sec at the 150‐cm level. The daily net photosynthate production increased by an estimated 35%.
Germination of Dormant and Nondormant Rescuegrass Seed on the Thermogradient Plate1
Authors: Larsen Arnold L. , Montgillion Dorothy P. , Schroeder Eltora M. 
Published: July 2010

AbstractDormant and nondormant rescuegrass (Bromus catharticus Vahl.) seed were tested on the two‐way thermogradient plate to make a comprehensive comparison of their germination responses to alternating and constant temperatures within a range of 5 to 35 C. Nondormant seed germinated within 1 week at a constant temperature near 30 C and within 4 weeks over most of the temperatures above 15 C. Dormant seed did not germinate at constant temperatures. Moderate germination of dormant seeds was obtained at 4 weeks with alternating temperatures. Imbibition of dormant seed on 0.2% KNO3‐moistened blotters improved germination slightly. Clipping off the distal end of the caryopsis of dormant seed produced substantial germination at 3 weeks, but only at alternating temperatures. The combination of KNO3 and clipping resulted in a germination response by dormant seed at almost the same temperature range favorable for germinating nondormant seed.
Potassium Rate and Source Influences on Yield and Composition of Bromegrass Forage1
Authors: Laughlin Winston M. , Martin Paul F. , Smith Glenn R. 
Published: July 2010

AbstractObjectives of the study were to determine K rate and source optima for bromegrass (Bromus inermis Leyss.) and effect of treatments on uptake and balance of K and other nutrient elements. A 2‐year field study compared six rates of two K sources on bromegrass grown on a K‐deficient area. Dry matter yields were determined and the forage analyzed for N, P, K, Ca, Mg, AI, Ba, B, Fe, S, Sr, Cu, Zn, and Mn concentration.Each K rate increased K concentration of each cutting both years and decreased the Ca and Mg percentages. KCI increased K percentages, but had little effect on forage color, yield, or mineral uptake. Potassium sulfate increased both yields and mineral uptake. All K2SO4 rates eliminated the yellow foliage color. Each K increment of this K source increased the K and S percentages and uptake.Results indicate that both K and S deficiencies were present. Of the applied N, P, K, and S brome foliage removed 70 to 194%, 36 to 76%, 109 to 155%, and 19 to 95%, respectively.
Phosphorus Availability of Some Philippine Rice Soils as Affected by Soil and Water Management Practices1
Authors: Sanchez P. A. , Briones A. M. 
Published: July 2010

AbstractIt is well established that flooding increases the availability of soil P to rice (Oryza sativa L.). Very little is known, however, on the influence of native soil P status or the type of water management used on the growth and P uptake of this crop. Also, the interaction between these two factors is unknown. In order to clarify these relationships, two greenhouse experiments were conducted on six representative Philippine lowland rice soils. The results indicate that the beneficial effects of flooding to rice vary with the level of available soil P, as measured by P uptake. In soils of high P availability, no differences were observed when rice was grown under constant flooding, on a partially oxidized profile or when flooding was delayed from 15 to 35 days after seeding. The latter two treatments produced lower yields and P uptake in comparison to constant flooding in soils of moderate to low P availability. When severe water stress occurred, rice growth, yield, and P uptake drastically decreased in all soils regardless of P availability. Puddling flooded soils has no effect on rice yields or P uptake at harvest regardless of soil P availability. Puddling unflooded soils severely decreased growth and responses to applied P when severe soil shrinkage took place. The benefits of flooding on P uptake by rice depend both on the available P level and the type of water management used.
Laboratory Evaluation of Quality in Subtropical Grasses: II. Genetic Variation Among Hemarthrias in In Vitro Digestion and Stem Morphology1
Authors: Schank S. C. , Klock M. A. , Moore J. E. 
Published: July 2010

AbstractIn vitro organic matter digestion (IVOMD) was studied in selfed progeny from four introductions of Hemarthria (limpograss) and in hybrids between two stoloniferous diploid lines. This grass genus occurs naturally in swampy areas of Africa, Asia, and South America, but introductions were not successfully introduced into the U.S. until 1964. Genetic improvement of the Hemarthrias was considered feasible because of their ability to persist under flooding, drought, and freezing temperatures. Information on the in vitro digestion of the limpograsses would also benefit long‐range plant breeding objectives by indicating relative differences between lines. IVOMD was significantly higher in a coarse‐stemmed tetraploid line from Africa than in any of the diploid lines studied. The stoloniferous diploid lines from Transvaal, Africa were intermediate in digestion but not significantly different from each other. F1 hybrid plants obtained from these two diploids were also intermediate in IVOMD. The least digestible Hemarthria studied was a bunch‐type, diploid introduction from Argentina. IVOMD at 5 weeks regrowth ranged from 54.3% in the Argentine diploid to 68.4% in the African tetraploid. In mature plants, IVOMD of the Argentine diploid averaged 38.5%; the African diploids, 56%; and the tetraploid, 66%. Studies of stem morphology revealed that the combined percentage area of vascular bundles for each cross section area was inversely related to IVOMD, indicating that structural differences can greatly reduce the digestibility of a grass.
Effects of Method of Harvest on Flue‐Cured Tobacco Part II. Chemical Components1
Authors: Brown G. W. , Terrill T. R. 
Published: July 2010

AbstractTobacco (Nicotiana tabacum L.) is subject to modification of chemical characteristics by alteration of production practices. If a suitable product can be provided for the tobacco manufacturers, utilizing the once‐over harvest approach, a much simpler and relatively less expensive harvesting machine could be developed and production costs could be markedly reduced.Normal and once‐over methods of harvesting flue‐cured tobacco were evaluated for effects on the chemical characteristics of cured leaves. All plants were topped to 12, 16, or 20 leaves per plant. Stalk position data were compared within the three topping heights.Lesser percentages of total N and total N‐soluble and a lower pH were evident in leaves grown in 1968 than those produced in 1969. As topping height was increased from 12 to 20 leaves per plant, percentages of total N, total N‐soluble, nicotine, and water‐soluble acids in the leaves decreased, while reducing sugars increased. These chemical changes were attributed to utilization of equivalent amounts of nitrogen for the development of greater number of leaves. Higher concentrations of total N, total N‐soluble, nicotine, and water‐soluble acids were recorded for leaves harvested by the normal method than when all leaves were removed in one harvest. Undoubtedly, overmature bottom leaves and immature top leaves, associated with the once‐over method, influenced the average chemical composition for the whole plant.The nitrogenous constituents and water soluble acids increasel in leaves from bottom to top stalk positions except for percent alpha amino nitrogen. The pH of leaves decreased from bottom to top stalk positions. Overmature bottom and immature top leaves from the once‐over harvest contributed to difference in chemical composition of leaves at the upper and the lower stalk positions. When all leaves were harvested at one time, only bottom and top leaves appeared to be different in chemical composition from those presently being used by the tobacco trades.
Use of Potassium‐40 as an Evaluator of Animal Response in Grazing Trials1
Authors: Clark J. L. , Matches A. G. , Thompson G. B. 
Published: July 2010

AbstractOur objective was to evaluate techniques for measuring the response of cattle grazing four pasture systems. The techniques employed were the use of the Whole Body Counter to measure potassium‐40 (40K) of animals to predict body composition, visual condition scores, and body weight. The condition score is a subjective score placed on the animal to estimate the amount of external flesh. Pasture systems were composed of orchardgrass (Dactylis glomerata L.) and tall fescue (Festuca arundinacea Schreb.) for spring grazing and the round baled hay plus regrowth of orchardgrass‐Korean lespedeza (Lespedeza stipulacea Maxim.) and tall fescue for summer grazing.Composition of gain was not influenced by pasture systems, and there was no change in condition score or FFB over the season. Approximately 66 to 74% of the gain was FFB and the remaining 26 to 34% represented body fat and gut content. There were no significant differences (P ≤ .05) in gain due to pasture systems. Since the estimation of body composition using 40K can be obtained without slaughtering the test animals, we believe the Whole Body Counter has much potential as a research tool in grazing research.