bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Mechanical Impedance on Rice Seedling Root Growth1
Authors: Kar S. , Varade S. B. 
Published: July 2010

AbstractThe influence of bulk density and the strength of lateritic sandy loam soil of Kharagpur on root growth of rice (Oryza saliva) seedlings was studied under controlled conditions. Rice (‘Taichung Native‐1’) seedlings were grown for 14 days in soils compacted to different bulk densities in painted galvanized iron cylinders. Water and nutrient requirements were met through nutrient solution.Maximum rice root growth and penetration occurred when the soil bulk density and penetration pressure were 1.6 g cm− 3 and 36 kg cm− 2, respectively. Lower bulk densities resulted in poor root growth, whereas subsequent increase in bulk densities above 1.6 g cm−3 decreased root growth. A penetration pressure of 72 kg cm− 2 was found to be critical for rice root penetration and growth. Rice root growth under saturated conditions is more significantly related to bulk density than to strength of the soil.
Preservation of Soil Samples for Inorganic Nitrogen Analyses1
Authors: Nelson D. W. , Bremner J. M. 
Published: July 2010

AbstractAnalysis of soils for inorganic forms of N is complicated by the fact that the amounts of these forms of N can change significantly during transport, pretreatment and storage of soil samples. Studies of the effects of several pretreatments and storage conditions on the inorganic N contents of 10 Iowa soils indicated that storage at —5 C in an airtight container is a satisfactory method of preserving field‐moist soil samples for inorganic N analyses. Storage at this temperature did not cause a significant change in the exchangeable ammonium N, nitrate N, or fixed ammonium N contents of the soils studied (the average change after storage at −5 C for 9 months was 0.1 ppm for exchangable ammonium N, 0.8 ppm for nitrate N, and 0.3 ppm for fixed ammonium N). Air‐drying at 22 C increased the inorganic N contents of most of the soils studied, with the average increase 4.2 ppm for exchangeable ammonium N, 1.7 ppm for nitrate N, and 4.4 ppm for fixed ammonium N. Oven‐drying at 55 C resulted in a slightly larger increase in exchangeable ammonium N (average, 5.1 ppm) than did air‐drying at 22 C, and drying at 22 C in ammonia‐free air caused a smaller increase in exchangeable ammonium N (average, 1.9 ppm) than drying at the same temperature in laboratory air. Storage of air‐dried soils in paper bags for 9 months led to marked increases in their inorganic N contents, with the average increase 10.2 ppm for exchangeable ammonium N and 5.5 ppm for fixed ammonium N. Only small increases in exchangeable ammonium N, nitrate N, and fixed ammonium N contents were observed when air‐dried soils were stored in stoppered bottles.
Competition Between Phosphate and the Plant for Fe from Fe2+ Ferrozine1
Authors: Brown J. C. 
Published: July 2010

AbstractMuch has been written about how phosphate accentuates Fe deficiency in plants; but little attention has been given to the genotype of rootstock as a controlling factor in Fe uptake. The important role of the plant was studied in these experiments.Competition between phosphate, the plant, and ferrozine for Fe in nutrient solution was examined. Feinefficient and Fe efficient varieties of soybeans [Glycine max (L.) Merr.] (Lycopersicon esculentum Mill.) were used as test plants because they differ, respectively, in their ability to tolerate P and to reduce Fe3+ to Fe2+ at the root. Within 2 days after adding 16 ppm of P to the nutrient solution, only about 10% of the Fe2+ferrozine was colorimetrically detected in solution. The Fe was removed from Fe2+ferrozine, and it appeared in the solution as a suspension of iron‐phosphate. Phosphate was dominating the system for Fe. Four days later, the plants developed Fe deficiency (Fe stress). Fe‐efficient plants responded to Fe stress by releasing more H+ into solution and reducing more Fe3+ to Fe2+ than was reduced by Fe‐inefficient plants. As this occurred, Fe2+ferrozine reappeared in solution. The Fe‐efficient plants now dominated the system for Fe. On day 17 (final harvest), the green top leaves of Fe‐efficient HA soybeans contained 86 ppm of Fe, whereas the chlorotic top leaves of Fe‐inefficient PI soybeans contained only 36 ppm Fe. In the latter, phosphate still dominated the system for Fe because the reducing capacity (Fe3+ to Fe2+) of the Fe‐inefficient plants was not great enough to overcome the effects of phosphate.
Interaction of Temperature and Salinity on Sugar Beet Germination1
Authors: Francois L. E. , Goodin J. R. 
Published: July 2010

AbstractBecause high temperatures and soil salinity adversely affect sugarbeet (Beta vulgaris L.) germination in the southwestern United States, the interaction of temperature and salinity on germination was studied by a modification of the standard blotter technique. The interaction was highly significant. Salinity had little effect on germination at 10 C and 15 C but was increasingly inhibitory as temperature increased from 25 C to 40 C. Germination was maximum at 25 C, with low salinity, and almost completely inhibited at 45 C with all salinity levels. Of the four varieties studied, ‘US‐H2,’ ‘US‐H6,’ ‘US‐H8,’ and ‘HH‐5,’ germination of the US‐H2 variety was most sensitive to salinity over the 30‐C to 40‐C range.
Influence of Tree Root Competition on Growth Response of Four Cool Season Turfgrasses1
Authors: Whitcomb Carl E. 
Published: July 2010

AbstractTrees and turf are important elements in most landscaped and recreational areas. However, must turf research has been conducted in full sun far removed from trees. This study was initiated to determine the competitive ability of four cool season grasses subjected to three competition treatments beneath tree shade: (1) silver maple (Acer saccharinum L.) roots, (2) honeylocust (Gleditsia triacanthos L.) roots and (3) no tree roots. A connecting pot technique was used to maintain light intensity nearly uniform over tree shaded pots with and without tree roots. A fourth competition treatment was located in full sun separate from all trees.Kentucky bluegrass (Poa pratensis L.) clipping yields were more affected by tree roots than the other three grasses. Effect of tree roots on perennial ryegrass was intermediate. Red fescue (Festuca rubra L.) and Poa trivialis responded similarly with or without tree roots suggesting a strong competitive ability. However, all Poa trivialis treatments with tree roots later became diseased.Tree roots in some way reduced growth and vigor of most grasses even when water and nutrients were maintained at optimum levels. In addition to direct competition, biochemical inhibition (allelopathy) may be involved.
Nutritive Value Estimates in Apomictic Lines of Buffelgrass (Cenchrus ciliaris L.)1
Authors: Lovelace Dale A. , Holt E. C. , Ellis W. C. , Bashaw E. C. 
Published: July 2010

AbstractThe cell wall content of a forage and the digestibility of the cell wall determine to a large extent the digestibility of the forage. A study was conducted with buffelgrass (Cenchrus ciliaris L.) to determine whether cell wall digestibility differences among lines are related to components of the cell wall or the total cell wall content. Seven lines of buffelgrass were evaluated in an in vivo digestibility study. Leaf, stem, and whole plant samples of 15 lines were evaluated at two harvests in an in vitro digestion study. Significant differences in dry matter digestibility were detected among lines in both the in vivo and in vitro studies. About 66% of the variation in digestibility was associated with the digesibility of cell wall. Correlations of digestibility with various cell wall components or component ratios were not sufficiently high to be of significance for prediction purposes.There were no differences among lines in in vitro dry matter digestibility of leaves, but there were for stems and whole plants. Differences in digestibility of cell wall were obtained for leaves, stems, and whole plants. Experimental lines differed in agronomic characteristics such as rhizome development, density, seed production, and color, but no significant correlations of these variables with digestibility could be shown. The most useful procedure for screening buffelgrass plants for quality seems to be in vitro dry matter digestibility with an associated neutral detergent fiber determination, whereby both cell wall content and cell wall digestibiity could be estimated.
Rice Response to Zn in Flooded and Nonflooded Soil1
Authors: Giordano P. M. , Mortvedt J. J. 
Published: July 2010

AbstractZinc deficiency in rice (Oryza sativa L.) has only recently been diagnosed. Although most Zn studies have been conducted on flooded rice, comparative data concerning the availability of Zn under upland and flooded soil conditions is needed. Therefore, rice (var. ‘Bluebelle’) was grown hi greenhouse pots on flooded and moist, limed Crowley sil (pH 7.5). Phosphorus, as concentrated superphosphate, was applied at rates of 20 and 200 ppm and Zn as ZnSO4, was applied at rates of 1, 4, and 16 ppm. Dry matter production and P uptake of immature plants were doubled and uptake of Zn was up to five times as great when the plants were grown on flooded rather than moist soil. The Zn concentration in the tissue decreased at the high P rate on moist but not on flooded soil. The percentage recovery of fertilizer Zn by the crop was greater from flooded than moist soil, especially at the high P rate.Mixed and surface applications of Zn were comparable for flooded rice, whereas middepth placement (8 cm below soil surface) was less effective. Both surface and middepth placements were less effective than mixing under nonflooded soil conditions. Results of laboratory studies indicated that the mobility of Zn applied as ZnSO4 was comparable in flooded and moist soil. The amount of DTPA‐extractable Zn tended to be higher in moist than in flooded soil. This suggests that DTPA may not provide a reliable measure of Zn availability in flooded soils and that differences in Zn uptake may be related to root distribution or some other physiological or morphological characteristic of rice roots growing in moist or flooded soil.
Evaluation of a Sorghum Seed Treatment to Prevent Injury from Acetanilide Herbicides1
Authors: Eastin E. F. 
Published: July 2010

AbstractThe effects on sorghum [Sorghum bicolor (L.) Moench, ‘RS 626’] stand of alachlor [2‐chloro‐2',6'diethyl‐N‐(methoxymethyl) acetanilide] and acetochlor [2‐chloro‐N‐(ethoxymethyl)‐6'‐ethyl‐o‐acetotoluidide] were studied with and without 1,8‐naphthalic anhydride as a seed protectant. If sorghum could be protected from injury from these acetanilide herbicides, they could be used for the control of seedling johnsongrass [Sorghum halepense (L). Pers.], which are serious weeds in this crop. It was concluded that, under the conditions of the test, the anhydride seed treatment provided little protection and the anhydride alone was as injurious to the sorghum as herbicidal rates of the herbicides.
A Sorghum Planter for Small Experimental Plots1
Authors: Wiseman B. R. , Johnson R. , Widstrom N. W. , McMillian W. W. 
Published: July 2010

AbstractA sorghum [Sorghum bicolor (L.) Moench] planter was fabricated to replace hand planting and to facilitate economical and uniform seeding of small experimental plots. Four basic units were used in constructing the planter, which seeds rows ranging from 2.84 to 6.35 m in length and 50.8 to 100.6 cm in width. In addition to more uniform seed placement, planting time was reduced by more than 50%.
Effect of Dry Season Drought on Uptake of Radioactive Phosphorus by Surface Roots of the Oil Palm (Elaeis guineensis Jacq.)1
Authors: Forde St. C. M. 
Published: July 2010

AbstractThe hypothesis that the feeding roots of the oil palm (Elaeis guineensis Jacq.) die back because of the effects of pronounced dry season drought in Nigeria was tested using radioactive 32P as a tracer to study P uptake as influenced by different levels of soil moisture. Two trials were carried out in 1964 and 1965, respectively, with the three treatments being: (A) no irrigation during the dry season and 32P applied in solution to the soil; (B) one irrigation of 50.8 mm of water shortly before application of 32P; and (C) irrigation at the rate of 50.8 mm of water per palm per week throughout the dry season and 32P applied to the soil. Leaf samples were taken and the activity of 32P was determined. In both trials the uptake of 32P in treatment C was significantly higher than either treatment A or B and supported the hypothesis that the lower activity was caused by the dieback of the absorbing roots during the dry season drought.
Relationships Among Black Layer Formation, Grain Moisture Percentage, and Heat Unit Accumulation in Corn1
Authors: Daynard T. B. 
Published: July 2010

AbstractTwo field experiments were conducted near Guelph, Ontario in both 1969 and 1970 with the objectives of (i) studying the relationship between grain moisture percentage and black layer development and (ii) examining the effect of environment on the length of the interval from planting or silking to black layer formation in corn (Zea mays L.). The first experiment involved 10 adapted commercial hybrids planted in early May at a plant population of 70,000 plants/ha. The second study concerned three commercial hybrids that were planted at a plant population of 55,000 plants/ha on each of four dates in 1969 (May 14 and 23, and June 5 and 13) and four dates in 1970 (May 6 and 20, and June 1 and 8). For both experiments records or measurements were taken of the date of 50% silking, 50% black layer, grain moisture percentage at 50% black layer, and final yield. Weather records were used to compute the number of accumulated heat units, by either the Ontario Corn Heat Unit (OCHU) or the 10‐ to 30‐C Growing Degree Day (GDDHU) systems, from planting or midsilking to 50% black layer.Among adapted hybrids planted in May percent grain moisture at black layer varied from 30 to 37. For two hybrids planted on June 13, 1969 and June 8, 1970, black layers developed “prematurely” at a grain moisture of 39 to 42%. This premature black layer formation was an apparent consequence of cool weather during the week prior to black layer development.Delayed planting resulted in a decrease in number of days from planting to midsilking, and an increase in number of days from mid‐silking to maturity (50% black black layer). Delayed planting resulted in an increased number of accumulated heat units from planting to midsilking, and a decreased heat unit accumulation from midsilking to maturity, by either the OCHU or GDDHU system. As a result, the number of accumulated heat units from planting to maturity was only slightly reduced by delayed planting date. The two systems were of comparable precision and were superior to number‐of‐days per se in characterizing the length of the interval from planting to midsilking, but not from midsilking to maturity.Because of its ease of detection, black layer development can serve as a useful end‐point for characterizing corn hybrids as to their relative maturity and their adaptability to various localities. Present results suggest that there are significant problems, however, in the wide‐scale use of black layer development for this purpose.
Quantitative Removal of Major Nutrients by Three Pasture Grasses1
Authors: Duell Robert W. , Trout J. Richard 
Published: July 2010

AbstractOn the premise that fertilizer needs might be better understood if plant removal were known, the yield of N, P, and K was recorded for 15 harvests of field plots over 3 years. Tall fescue (Festuca arundinacea Schreb.), Kentucky bluegrass (Poa pratensis L.), and orchardgrass (Dactylis glomerata L.) plots were replicated times and were split to receive annual applications of A, 224‐98‐186 (kg/ha of N‐P‐K) half in spring, half in summer); B, 224‐0‐0 (scheduled as A); and C, 112‐49‐93 (spring only).In individual harvests these grasses frequently differed in yield; percent N, percent P, and weight of N, P, and K removed. Combined analyses (five harvests/year for 3 years) confirmed differences among species in yield and percent N and P; in weight of elements removed by species, however, only the lower quantity of P removed by Kentucky blyuegrass was significantly different, averaging 50% less than the other grasses.The decrease in K removal from NH4NO3 at 224‐0‐0 vs 224‐98‐186 was greater than decreases in removal of N, P, or dry matter. Seasonal and annual decreases in K were consistent.When element removal was calculated as annual yield ✕ mean percentage of the element rather than the sum of the products of plot yield ✕ plot composition, significantly lower mean values for N and K (4.2 and 5.0% lower, respectively) were obtained. N and K percentages were significantly correlated with DM yields. Phosphorus percentage values did not correlate with DM yields. The discrepancy between the actual weight of P removed (by a grass at a fertilizer treatment in a given year) and the short‐cut calculation might be either positive or negative; a comparison between such extreme values would lead to large errors.
Use of the Thermogradient Plate as an Aid in Determining the Relative Vigor of Sweet Corn (Zea mays L.)1
Authors: Cole D. F. 
Published: July 2010

AbstractEighteen lots of sweet corn seed (Zea mays L.) were germinated on a one‐way thermogradient plate to establish a relative index for seed vigor. This index is based upon the rate and total germination over a temperature range of 13 to 43 C. Differences between lots were maximum 2 days after planting. The rankings after 4 and 7 days were the same. Significant correlations were obtained between the vigor index established with the thermogradient plate and data from percent emergence at 25, 35, 15:25 C in a controlled environment and rapid aging of 0, 4, and 7 days. The significant correlations indicate that the thermogradient plate can be used to detect differences in seed vigor of different lots of sweet corn in 4 days.
Acid Detergent Method for Reduction of Tannin Interference in Determining Lignin of Sericea Lespedeza
Authors: Donnelly E. D. , Wear J. I. 
Published: July 2010

AbstractApparent lignin was determined on stems and leaves of high‐ and low‐tannin sericea lespedeza (Lespedeza cuneata [Dumont] G. Don) by two methods. One method by which tannin, other acid‐soluble material, and protein are removed by detergents gave lower and more realistic lignin values than the conventional (H2SO4) method. Tannin was associated with high apparent lignin values when determined by the latter method. Genetic differences in lignin content among normal (high tannin) sericea lines and varieties were found, indicating that varieties lower in lignin than present ones can be developed.
Response of an Al‐Tolerant and an Al‐Sensitive Genotype to Lime, P, and K on Three Atlantic Coast Flatwoods Soils1
Authors: Long F. L. , Langdale G. W. , Myhre D. L. 
Published: July 2010

AbstractAluminum toxicity, calcium deficiency, and a complex of other unidentified factors contribute to the poor productivity of Atlantic Coast Flatwoods soils that occupy more than 100,000 km2 in the southern U.S. Our objective was to investigate the response of aluminum‐sensitive ‘Suregrain’ oats (Avena sativa L.) and aluminum‐tolerant ‘Starr’ pearl millet [Pennisetum typhoides (Burm. f)] lime, phosphorus, and potassium on Bladen, Leon, and Lakeland soils. Results of a series of pot experiments using four or more rates each of dolomitic limestone, monocalcium phosphate, and potassium chloride were used to calculate response surfaces and yield isoquants. Eightytwo to ninety‐five percent of the variation in yield was explained by lime, P, and K variables. Phosphorus was the most critical growth‐limiting factor for plant growth and response to P depended on lime and K levels.
Differential Phytotoxicity of Several Dinitroaniline Herbicides1
Authors: Murray D. S. , Santelmann P. W. , Greer H. A. L. 
Published: July 2010

AbstractResearch was conducted to compare the relative phytotoxicity of trifluralin (a,a,a‐trifluro‐2,6‐,dinitro‐N,N‐dipropyl‐p‐toluidine) with several analogues, and to establish an indices for comparing alternative structural substitutions. GR50 and visual injury values were used to evaluate relative phytotoxicities. There appeared to be a direct correlation between phytotoxicity and selected structural changes on the dinitroaniline ring. The dinitroaniline ring substitutions in order of decreasing phytotoxicity to bioassay indicator plants were substitutions in the one and five positions, one only, and four only. Least phytotoxic was the combined one and four position substitution on the ring.
Effect of Porous Rootzone Materials Underlined with Plastic on the Growth of Creeping Bentgrass (Agrostis palustris Huds)1
Authors: Ralston D. S. , Daniel W. H. 
Published: July 2010

AbstractRecent developments in plastic barrier placement under compacted sand for regulated availability and retention of water (PURR‐WICK Rootzone) raises questions of duration of availability. Creeping bentgrass (Agrostis palustris Huds) was studied under putting green conditions when grown on replicated 1‐m2 plastic‐lined plots containing dune sand, mortar sand, calcined clay, diatomaceous earth, and peat. Soil was not included in any of the rootzone mixtures because of its inherent structural instability. In 1968 and 1969, some infiltration rates exceeded 150 cm/hr and all were greater than 7 cm/hr, therefore, water movement was considered ample.The relative ability of the material in plots to retain moisture was measured by allowing the plots to dry‐down for 15 days between rains during August 1968 and for 17 days during July 1969. No irrigation was added to any plot until turf showed severe wilt. Bentgrass on plots containing the finer fractions of the dune sand, diatomaceous earth, various mixtures of sand, calcined aggregates, and peat did not require water for either period.Comparison of the dune sand treatments with and without subsurface irrigation showed that a constant moisture level could be maintained in the subirrigated plots. Depth ranged from 20 to 50 cm with 40 cm proving ample.