bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fertilization of Native Grass and Weeping Lovegrass1
Authors: McMurphy W. E. , Denman C. E. , Tucker B. B. 
Published: July 2010

AbstractYield responses by native range to fertilization has often been disappointing in the tall grass prairie, and the results were confounded by changes in species composition. This study evaluated the response to N and P fertilizer by monocultures of three native species ‘Kaw’ big bluestem (Andropogun gerardi Vitman), ‘Caddo’ switchgrass (Panicum virgatum L.), and indiangrass [Sorghastrum nutans (L.) Nash] and an introduced grass, weeping lovegrass [Eragrostis curvula (Shrad.) Ness].Rates of N fertilizer were 0, 45, 90, and 180 kg/ha in all combinations with P at 0 and 40 kg/ha. Forage production, crude protein, fertilizer N recovery, stand longevity, and soil fertility changes were evaluated.Excellent forage yield responses to N fertilization were obtained from the native species in monoculture. Switchgrass and weeping lovegrass were the most productive species at 180 kg N − 40 kg P/ha, but had different seasonal production. All native grasses produced one flush of growth and very limited regrowth when compared with weeping lovegrass. Indiangrass had significant reductions in stand at 90 kg N and 180 kg N/ha and was the first species each year to show visual symptoms of drought stress. Severe lodging of big bluestem at 180 kg N/ha limited its potential. Fertilizer N recovery of all species was most efficient at the 90 kg N − 40 kg P/ha treatment being 52 to 66% for native grasses and 84% for weeping lovegrass. Soil tests revealed P accumulations with P fertilization, decreased soil pH associated with N fertilizer and soil K changes in relation to forage removal.The native species have some characteristics which limit their potential for use in fertilized meadows.
Responses of Dry Beans to Varying Nitrogen Levels1
Authors: Edje O. T. , Mughogho L. K. , Ayonoadu U. W. U. 
Published: July 2010

AbstractDry beans (Phaseolus vulgaris L.) are poor nitrogen fixers; therefore, nitrogen fertilizers are recommended for even reasonable production. We studied the effects of six levels of nitrogen (0, 40, 80, 120, 160 and 200 kg/ha) on determinate dry bean yields for 2 years.Seed yields increased significantly in both years with increasing rates of N. Average yields were 2,150, 2,704, 3,048, 3,147, 3,366 and 3,779 kg/ha, respectively, for the six rates of N indicating that higher rates of N might have produced greater seed yields. Yield components (yield/plant, pods/plant, seed/size) also increased with increasing N. Percent crude protein and crude protein yield were closely related to the amount of N applied. Leaf area index, canopy height, canopy width, plant height, and pod length were significantly affected by the amount of N applied; however, addition of N had no appreciable effect on specific leaf area and leaf area ratio. Nitrogen increased dry matter production but had no effect on the distribution of dry matter. At 50 days from planting, dry matter was highest in leaflets (47.7%) followed by stems (28.9%) and was least in flowers (1.2%).
Resistance to Water Transport in Rice Plants1
Authors: Tomar V. S. , Ghildyal B. P. 
Published: July 2010

AbstractRice (Oryza sativa L.) is grown either in continuously flooded “lowland” soils or under rainfed conditions in “upland” soils. The objective of the study was to determine whether there are differences in resistance to water transport between plants grown in flooded and non‐flooded soils. This information may be useful in understanding the plant‐water relations under two cultural practices.In a greenhouse, rice variety ‘IR‐8’ was grown under flooded and 0.33 bar soil suction for 45 to 50 days. The resistance to water transport in different plant parts and in the whole plant was measured by a transient flow method. The effect of an increased air saturation deficit from 15 mb to 45 mb on transpiration rate and on leaf water potential was studied in a controlled environment chamber.The resistance to water transport in the non‐flooded plants was nearly twice as high as in the flooded plants. The non‐aerenchymatous roots of non‐flooded plants had about 17 times more resistance than aerenchymatous roots of flooded plants.The gradient between leaf and soil water potential increased markedly when plants were exposed to high air saturation deficit; however, the transpiration rate remained almost constant.These studies indicate the existence and development of large resistances to water transport in rice plants.
An Improved, Rapid, Field Method to Measure Photosynthesis with 14CO21
Authors: Naylor D. G. , Teare I. D. 
Published: July 2010

AbstractRecognizing a need for a rapid, accurate, one‐man technique for comparing photosynthesis rates in fields, we developed one based on the application of a short pulse of air containing 14CO2 over an enclosed leaf (a modification of Shimshi technique) and subsequently determining CO2‐uptake by measuring radioactivity in the enclosed area. The system contains a solenoid on‐off, air‐flow switch driven by an electronic timer, which eliminates human error in judging exposure times, and a miniature photosynthesis chamber designed to ensure adequate ventilation. The 14CO2‐exposed leaf samples were digested in an organic solubilizer for scintillation counting. Exposure times of 15 to 20 sec produced optimum photosynthetic rates for wheat (Triticum aestivum L.), soybean (Glycine max (L.) Merr.), and sorghum (Sorghum bicolor (L.) Moench); however, optimum gas flow rates varied with crops. Soybean required a higher flow rate for optimum photosynthesis than wheat, sorghum, or corn (Zea mays). Photosynthetic rates measured by the 14CO2 technique compared well with rates we observed with infrared gas analysis. Sampling time is short and the system is portable and rugged. If consistent exposure time and flow rates are used, the technique can be valuable for comparing photosynthetic rates between genotypes or among various treatments in an experiment.
Row Spacing and Potential Productivity in Sugarcane1
Authors: Bull T. A. 
Published: July 2010

AbstractSugarcane (Saccharum spp. hybrid) has been reported to respond only slightly to reduced interrow spacing. However, commercial cultivars are released after 10 to 15 years selection at a single row spacing and would be expected to be suited to that particular spacing. To determine if sugarcane has the genetic potential to exhibit increased productivity at high stalk populations, the performance of unselected seedlings was compared with that of commercial cultivars at several planting densities (2.6 to 32 setts/m2) and interrow spacings (25 to 140 cm). Comparisons were made over a 2‐year period in small scale field trials and in pot culture.Reduction of the interrow spacing from 140 to 50 cm significantly increased the yield of some cultivars in an irrigated field trial. The superiority of close row spacing treatments was maintained when the ratoons were grown under natural rainfall.About 7% of an unselected seedling population planted at high density (32 setts/m2) in pot culture performed better than commercial cultivars planted at the same or lower (5 setts/m2) density. Clones which gave superior yields at high planting density were not significantly better than other seedling or commercial clones when grown at conventional planting density. Consequently, exploitation of increased productivity due to reduced interrow spacing should involve selection at the row spacing adopted.
Wheel Traffic on Regrowth and Production of Summer Annual Grasses1
Authors: Fribourg Henry A. , Overton Joseph R. , Mullins James A. 
Published: July 2010

AbstractWheel traffic is known to affect soil characteristics, seed germination and seedling emergence, and has been observed to damage stubble of plants harvested for greenchop. The objective of this study was to measure the gross effects of the passage of tractor and wagon wheels on the regrowth of ‘Sudax SX‐11’ sorghum [Sorghum bicolor (L.) Moench] and ‘Gahi‐1’ pearlmillet [Pennisetum americanum (L.) K. Schum]. Four experiments were conducted during the 1969–71 period at two locations on silt loam soils. Wheel traffic consisted of passing a front (152‐mm wide) and a rear (315 or 396‐mm wide) wheel of a medium‐sized tractor (1,745 or 2,190 kg) over the grass stubble after a greenchop harvest. One year, a 1360 kg wagon followed the tractor. Dry matter regrowth of both grasses was decreased by traffic. The reduction was sometimes 15 to 20%, often 30%, and occasionally 50%. The greatest reduction could be attributed to the first wheel passage, additional traffic having less effect than the first. These results indicate that reducing the number of wheel tracks across a field, either by the use of matched equipment or planned traffic patterns, could lead to greater efficiency of production of summer annual grasses for greenchop.
Growth of Sorghum and Soybeans in Picloram‐treated Soil1
Authors: Bovey R. W. , Miller F. R. , Baur J. R. , Meyer R. E. 
Published: July 2010

AbstractPicloram (4‐amino‐3,5,6‐trichloropicolinic acid) residues in soil may occur as a result of weed control practices on cropland and injure subsequent crops. This study was conducted to determine how soil residues of picloram affected the growth and dry matter production of sorghum (Sorghum bicolor (L.) Moench) ‘Topland’ and soybeans (Glycine max (L.) Merr.) ‘Hill’ grown in soil at various time intervals after picloram had been applied.The potassium salt of picloram was applied at 1.12 kg/ha and incorporated by disking into a Wilson clay loam soil 1½, 3, 6, 7, 12, 14, 16, 19, and 26 months before planting of sorghum and soybeans in the Spring of 1972 and 1973. Soil, sorghum, and soybeans were analyzed for picloram content at time of harvest. After maturing, crop plants were counted and harvested by clipping two rows, 4.1 m long at the soil level in each plot. Plants were weighed and oven‐dried for dry matter determination. Germination tests were conducted with harvested sorghum seed.Sorghum was grown on picloram‐treated soils 12 months after application without reduction in plant numbers, dry matter production, flowering, or germination. No picloram was detected in sorghum seed (immature and mature) produced by plants seeded 6 or 12 months after application of herbicide to the soil. Because soybeans were sensitive to small amounts of picloram in the soil, they should not be grown in a picloram‐treated clay soil for at least 2 years after application. Earlier planting risks possible reduction in stand and dry‐matter production in situations similar to this study.
Winter Mulch Covers, Spring Vigor, and Subsequent Growth of Agrostis1
Authors: Evans G. E. 
Published: July 2010

AbstractThe potential use of mulches to reduce winter injury of turfgrasses (Agrostis spp.), and the associated adverse effect upon incidence of snow mold (Typhula sp.) raised the question of whether these materials in combination with recommended and elevated fungicide rates would have an effect upon vigor. Accordingly, a study of the effects of several mulches and fungicide levels upon spring vigor and subsequent growth of three bentgrasses was conducted in the field over a 6‐year period.In 5 of 6 years Agrostis tenuis ‘Holfior’ produced highest clipping yields in nonmulched, nonchemically treated plots, Agrostis tenuis ‘Highland’ produced lowest clipping yields. Doubling the recommended rate of fungicide did not significantly increase clipping yield.Straw mulch reduced clipping yield markedly for all cultivars regardless of fungicide level. Black plastic in combinations with recommended fungicide rates, resulted in only slight reduction of clipping yield. Clear and perforated clear plastics were the best mulches of those treated, although highest clipping yields occurred in years of low snow mold incidence. The “greenhouse” effect of these mulches is believed responsible for much of the observed yield differences.In 5 of 6 years, Agrostis palustris ‘Penncross’ produced greatest clipping yields prior to July 10, after that highest yields were produced by Holfior.
Reaction of Maize Hybrids and Inbreds to Southern Corn Leaf Blight1
Authors: Hallauer Arnel R. , Martinson C. A. 
Published: July 2010

AbstractThe southern corn leaf blight (SCLB) epidemic of 1970, caused by Bipolaris maydis (Nisikado) Shoemaker, race T, decreased yield of maize (Zea mays L.) 15% nationwide. Use of Texas male‐sterile cytoplasm (T) in the production of hybrids was an important factor in the severity and spread of SCLB. Some information, however, indicated that some T‐cytoplasm lines showed more tolerance to SCLB infection than others in 1970. Our primary objective was to determine the effects of SCLB infection on inbred lines that had shown a differential reaction to SCLB in T cytoplasm. Inbred lines and hybrids produced among the inbred lines were evaluated.Nine inbred lines and 144 reciprocal single crosses produced on normal (N) and T cytoplasm were artificially infected and compared in greenhouse seedling and field tests for reaction to SCLB. Data also were obtained in the field tests for yield and five other agronomic traits.Correlations of the greenhouse tests with the field tests for SCLB infection were 0.56* (* significant at the 1% level) for the inbred lines and 0.65* for the single crosses. On the average, the inbred T‐cytoplasm lines averaged 8.4% less than those on N cytoplasm; B67TRfRf, however, was 55.3% lower yielding than its N counterpart. The effects of SCLB infection on yield for the T‐cytoplasm single crosses were greater than for the inbred lines. The 72 T‐cytoplasm single crosses averaged 19.9% less yield than the 72 N‐cytoplasm single crosses. Yield losses using hybrids produced on T cytoplasm ranged from 13.4% for B68 × Mol7 to 37.2% for B67 × W64A; B68 and Mol7 were classified as relatively resistant and B67 and W64A as being susceptible to SCLB in T cytoplasm. Our results show that inbred lines express different levels of reaction to SCLB infection in T cytoplasm.
Herbicidal Effects of Tebuthiuron and Glyphosate1
Authors: Baur J. R. , Bovey R. W. 
Published: July 2010

AbstractThese studies were conducted to gain a better understanding of the differences in activity of two new herbicides with three commonly used herbicides with regard to their effects on growth, phytotoxicity and germination. This information is necessary for the further evaluation of the new compounds. New herbicides N‐[5‐(1,1‐dimethylethyl)‐1,3,4‐thiadiazol‐2‐yl ]‐N,N′dimethylurea (tebuthiuron) and N‐(phosphonomethyl)glycine (glyphosate) were compared with 1,1′‐dimethyl‐4,4′‐bipyridinium ion (paraquat), alkanolamine formulation of 2,4‐dichlorophenoxyacetic acid (2,4‐D), and 7‐oxabicyclo[2.2.1.] heptane‐2,3 dicarboxylic acid (endothall). Growth and phytotoxic effects were evaluated on cowpea [Vigna unguiculata (L.) Walp.] and sorghum [Sorghum bicolor (L.) Moench] seedlings. Germination effects were studied on seed of sorghum, cowpea, and wheat (Triticum aestivum L.)Greenhouse grown seedlings of cowpea (10 to 12‐days old) and sorghum (25 to 28‐days‐old) were treated by applying 100 μ1 aqueous solution of the test compounds to one unifoliolate leaf of cowpea or to the partially unfurled true leaf of sorghum. Rates ranged from 1.4 to 1,434 μg/plant depending on the herbicide. Evaluation of phytotoxic and growth responses was made 10 to 12‐days post‐treatment. In cowpea, the growth response was determined by measuring the length of the first internode. In sorghum, fresh weight served as a measure of the growth response. Cowpea phytotoxicity was determined on percent dead plants per six‐plant replicate. For sorghum, phytotoxicity was measured as percent desiccation/ plant. Absorption times were determined by washing treated seedlings at intervals for a 6‐hour period. All experiments were repeated six to eight times with each treatment being replicated six and 10 times, cowpea and sorghum respectively.The order of decreasing effectiveness of the five herbicides for growth and herbicidal effectiveness for cowpea and sorghum was paraquat, glyphosate, tebuthiuron, 2,4‐D, and endothall. Endothall‐glyphosate mixtures were synergistic in inhibiting growth of cowpea. Endothalltebuthiuron mixtures were generally synergistic in killing and inhibiting growth of sorghum.Absorption of growth‐inhibiting levels of all five herbicides occurred within the first 60 min. of exposure. Phytotoxic levels of tehuthiuron, paraquat, and endothall were absorbed within 5, 30, and 60 min, respectively. Glyphosate showed rapid action and resistance to removal by washing.Glyphosate and tebuthiuron had little inhibitory effect on germination of sorghum, wheat, or cowpea. Paraquat severely inhibited germination of all three species; endothall and 2,4‐D inhibited only cowpea.
Weanling Meadow Vole and Dairy Cow Responses to Alfalfa Hay1
Authors: Shenk J. S. , Barnes R. F. , Donker J. D. , Marten G. C. 
Published: July 2010

AbstractWeanling meadow voles (Microtus pennsylvanicus) have been suggested as a bioassay of the feeding value of forage. To test the relationship between vole and ruminant intake and performance, six alfalfa (Medicago sativa L.) forages were fed to dairy cows and weanling voles. The six forages represented early and late‐harvested hay in 3 consecutive years. The dairy cow rations consisted entirely of forage, vole diets contained 70% forage. Intake and production responses for both animal species were higher with feedings of early‐cut hay than of late‐cut hay. Multiple regression analyses showed that the neutral detergent fiber and protein concentration of the forages were important factors in the observed responses of each animal species. A linear equation was calculated that accounted for 91% of the variation in milk production from vole weight gain. The study supports the theory that weanling vole may provide useful information about the feeding value of forage for the ruminant animal.
Calculation of Rate of Nutrient Uptake by Growing Roots1
Authors: Khasawneh F. E. 
Published: July 2010

AbstractEquations are presently available to calculate the rate of nutrient uptake by growing roots. They can be used to estimate an average rate of uptake by the entire root system, but they fail to give specific information on uptake by a unit segment of root or on the effects of aging and morphological changes of such a segment on its capacity for uptake. This paper gives a theoretical analysis of the process of nutrient uptake by a growing root system. The objective of this analysis is to derive equations that would give such specific information. A frequency distribution function is used to partition root systems into a continuum of age groups, each possessing a rate of uptake that is a function of the age of that group. Equations are derived that utilize time‐series measurements of root length and nutrient accumulation in the plant. These derivations are used to calculate parameters of nutrient uptake related to two properties of the root system: (i) the rate of nutrient uptake of a unit segment of root and the manner by which this rate changes with aging and (ii) the rate of nutrient flux into the entire root system as a function of time.
Predicting Sugarbeet Dried Petiole NO3‐N by Using Fresh Petiole Juice1
Authors: Halvorson A. D. , Hartman G. P. , Reule C. A. 
Published: July 2010

AbstractThe amount of time required for petiole NO3‐N analysis by established procedures limits the practical application of petiole testing as a tool for sugarbeet (Beta vulgaris L.) management in Montana and other short growing season areas. This study was conducted to determine if fresh petiole juice NO3‐N could be used to predict dried petiole NO3‐N, thereby reducing analysis time.Petiole juice NO3‐N was significantly correlated (r = 0.985) with dried petiole NO3‐N when the NO3‐N concentration was determined by steam distillation. Expressing the juice petiole NO3‐N concentration on a dry weight basis slightly improved the correlation (r = 0.994).To accurately determine petiole NO3‐N concentrations using petiole juice, water content should be considered; but for routine testing and practical purposes, water content differences caused by seasonal and/or soil N fertility levels could possibly be estimated or disregarded without serious error in data interpretation.The petiole juice method of determining petiole NO3‐N concentration requires less time, equipment, expense, and space than other established procedures.
Responses of Bermudagrass to Salinity
Authors: Ackerson R. C. , Youngner V. B. 
Published: July 2010

AbstractBermudagrass (Cynodon spp.) are salt‐tolerant grasses valuable for forage and turf. Experiments were conducted to determine specific responses to increasing salinity to provide a basis for breeding of more salt tolerant, agronomically desirable strains. The cultivar ‘Santa Ana’ (Cynodon hybrid) was grown in solution cultures containing increasing levels of NaCl and CaCl2 or K2SO4. Dry weight of tops decreased while dry weight of roots and total nonstructural carbohydrate concentrations of crowns, but not roots, increased with increased salinity of the culture solution. Net photosynthesis rates were not affected by high levels of NaCl and CaCl2 or K2SO4, although leaf water and osmotic potentials were decreased. Increased concentrations of Na+ and Ca2+ were observed in tops and roots corresponding with decreased concentrations of K+ and Mg2+ when NaCl and CaCl2 were used in the culture solution. When K2SO4 was used to adjust the solution osmotic potential, K2 concentrations were increased in tops and roots while Ca2+ and Mg2+ were decreased. Salinity tolerance of bermudagrass may be facilitated by shunting of photosynthate from top growth to root growth and carbohydrate storage, osmotic adjustment through ionic substitution and redistribution, or increased concentration of organic acids in the cell sap.
Performance of Bigflower Vetch Seeded into Bermudagrass and Tall Fescue Swards1
Authors: Templeton W. C. , Taylor T. H. 
Published: July 2010

AbstractBigflower vetch, Vicia grandiflora var. kitaibeliana W. Koch, is a self‐regenerating winter‐annual legume which has several excellent agronomic characteristics. It has never been used extensively in pasture programs, however, and little information on it is available in the literature. Two field experiments were conducted on a Typic Paleudults, clayey, mixed, mesic soil (Maury silt loam) to study vetch establishment, productivity, and ecological behavior when seeded into established swards of bermudagrass, Cynodon dactylon (L.) Pers., and tall fescue, Festuca arundinacea Schreb.Vetch was broadcast by hand into a bermudagrass sod in fall and covered with a rototiller‐type sod scarifier (contravator). Red clover and various N treatments were included for comparison. Four different sod treatment‐seeding method combinations were used for planting into fescue and two N levels on the grass were also tested. The bermudagrass trial was repeated for 3 years and the fescue one twice. Seeding vetch into bermudagrass increased weed‐free dry‐matter production from 2,770 to 6,490 kg/ha (3‐year avg.). In terms of dry‐matter productivity, vetch‐grass mixtures were more productive than either bermudagrass or tall fescue receiving 100 kg N/ha. Planting vetch into a short sward of tall fescue was superior to planting in accumulated growth when the seed were not covered, but with tillage to cover the seed height of grass was unimportant. Seed coverage was less beneficial when the seedings were made into a short sward than when planted in tall herbage.Vetch grew rapidly in spring and in bermudagrass exerted severe competition against winter annual weeds. With tall fescue the better seeding methods resulted in first‐growth harvests equal or superior in yield to those of tall fescue receiving 100 kg N/ha and herbages containing 48 to 70% vetch.Owing to its ease of establishment and competitive abilities with established grasses it is concluded that bigflower vetch would be useful as a pioneer legume for grassland improvement and for use in permanent pastures where conventional seeding methods are impractical.