bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Soil Mineral N Levels and Inoculation on Nodulation, Nitrogenase Activity, and Grain Yield of Pigeon Pea1
Authors: Quilt P. , Dalal R. C. 
Published: July 2010

AbstractSince pigeon pea [Cajanus cajan L. (Millsp.)] has a considerable potential as a tropical legume, intensive research in the Caribbean is being undertaken with a view to increase production. There is a scarcity of information on the effectiveness of Rhizobium of the pigeon pea to fix atmospheric N and to meet the N needs of the crop. Moreover, conflicting results have been reported on the effect of fertilizer N on grain yield, presumably because of variable mineral N levels in soil. Therefore the present investigation was designed to study the effect of changes in soil mineral N levels (brought about initially by incorporation of coconut fibre and bagasse with soil at the rate of 25 metric tons/ha each) and five Rhizobium strains (two local, UWI 10004 and UWI 10013, and three exotic, iCPE(a), CB756 and CIAM/1001) on nodulation, nitrogenase activity and grain yield of the crop. Greenhouse and field experiments were conducted on a River Estate Loam, a fluventic eutropept, at the University Field Station, Trinidad. The results showed that the incorporation of coconut fibre and begasse reduced soil mineral N levels through immobilization and led to early nodule formation and nitrogenase activity. Although the incorporation of coconut fibre increased plant shoot weight after 14 weeks growth, that of bagasse immobilized so much mineral N (from initial level of 50 ppm N to 6 ppm N at 7 weeks after application) that plants were N starved. The dry pod yield was increased by all Rhizobium strains. However the grain yield was significantly increased by the exotic strains, iCPE(a) and CIAM/1001. Thus, by manipulating soil mineral N levels and by using effective Rhizobium strains, the pigeon pea grain yields can be increased.
Influence of Supplemental Irrigation and Pre‐Sowing Soil Water Storage on Wheat1
Authors: Singh N. T. , Singh Rachhpal , Mahajan P. S. , Vig A. C. 
Published: July 2010

AbstractWater stress at certain physiological stages of growth reduces crop yields. The magnitude of water stress and the associated plant response depend upon the initial water content of the soil profile and the timing of additional input of water. A study was conducted to find out the influence of pre‐sowing profile water storage and the timing of supplemental irrigation on wheat (Triticum aestium L.) grown on Fatehpur loamy sand, a Typic Ustochrept. The storage levels were 25, 30, and 35 cm water in the 180 cm profile corresponding to approximately 15, 20, and 25‐cm of available water. The supplemental irrigation was applied at crown root initiation, boot, and grain development stages. Plant height, leaf area index, and number of tillers significantly increased with increase in the amount of profile stored water. The average grain yield increased from 26.1 to 33.1 q/ha when initial water storage increased from 25 to 35 cm. The increase in grain yield between the 25 and 30 cm storage levels was 0.80 q/ha per cm of additional storage, but with further increase in storage level from 30 cm to 35 cm, the increase per cm of additional water declined to 0.60 q/ha. The surface soil at crown root initiation dried to a water content of about 5%. The supplemental irrigation applied at this stage resulted in a maximum grain yield of 36.4 q/ha. Water use increased with increase in initial water storage in the soil and with the earliness of supplemental irrigation. Water use efficiency increased from 28.9 to 34.5 kg/ha per an water with an increase in the initial profile stored water from 25 to 35 cm. This study shows that in soils with water storage around 20 cm/m and substantial loss of soil water occurring early in the season, maximum yield of wheat is obtained when a supplemental irrigation is applied at the crown root initiation stage.
Seasonal Changes in Organic Acids, Water‐Soluble Carbohydrates, and Neutral Detergent Fiber in Tall Fescue Forage as Influenced by N and K Fertilization1
Authors: Hannaway David B. , Reynolds John H. 
Published: July 2010

AbstractThe seasonal trends of the major energy‐supplying constituents in tall fescue (Festuca arundinacea Schreb.) affect performance of beef cattle in the southeastern U. S. since this grass is usually grazed nearly year‐round.Concern has been expressed about the effect of fertilization on tall fescue that would be grazed during the late winter and early spring when incidence of grass tetany is highest. The objective of this research was to determine the effect of N and K fertilization on three major organic constituents: organic acids, water‐soluble carbohydrates (WSC), and neutral detergent fiber (NDF) in tall fescue. The seasonal trends of these constituents were evaluated in relation to the eriod of incidence of grass tetany in the late winter and early spring, and to seasonal forage quality. Forage was sampled monthly in two 1‐year field experiments near Knoxville, Tennessee, on a thermic, Typic Paleudults soil. The freeze‐dried forage was analyzed for ash alkalinity, an estimate of total organic acids, as well as for WSC and NDF. Fertilization treatments reported are 0 and 112 kg N/ha for the first year and 0 and 168 kg K/ha for the second year. In the first year, N generally increased organic acids but in the second year, K generally decreased them. The most pronounced peaks for organic acids were in spring and summer. The seasonal change in organic acids did not appear to be enough to influence incidence of grass tetany. Nitrogen and K fertilization effects on WSC and NDF generally were not significant. Peaks of WSC occurred in early spring and fall with levels generally higher in the cooler months. The peak of NDF coincided with stemmy material in May. Levels of NDF were generally higher in the warmer months. Highly significant negative correlations between WSC and NDF in both years were the most salient relationships found. These negative correlations are probably the reason for the general impression that fast‐growing fescue forage is associated with incidence of grass tetany. The months with high NDF and low WSC were those in which tall fescue digestibility is usually lowest. The benefit from increased yields with N fertilization would have to be considered in relation to the possible increased incidence of tetany from increased N, K, and organic acid levels.
Growth of Subterranean Clover in a Range Soil as Affected by Microclimate and Phosphorus Availability. III. Comparative Growth of Subterranean and Rose Clovers at Cold Soil Temperatures1
Authors: Raguse Charles A. , Taggard Kenneth L. 
Published: July 2010

AbstractThe biological yield potential of winter annual range legumes is influenced by the timing of rainfall adequate to ensure germination. If rains are late, the establishment phase of growth must occur at cold soil and air temperatures. On low‐P soils, this combination of abiotic factor constraints can limit symbiotic N fixation.We conducted three controlled‐environment experiments to compare the seedling growth of rose clover (Trifolium hirtum All., ‘Hykon’) and subterranean clover (T subterrateum L., ‘Mt. Barker’, hereafter referred to as subclover) on a P‐deficient soil (Sobrante‐Las Posas association), simulating winter conditions of cold soils and low light. Comparative growth responses, especially intraplant dry matter partitioning and nodulation, were observed for several soil P availability levels.A sunlit phytotron provided a common shoot environment of seasonal (fall/winter) ambient light intensity and photoperiod, with a programmed smooth diurnal temperature cycle of 20 C maximum and 5 C minimum. Three independently‐controlled water baths maintained soil temperature experiments at a constant 5 C, a constant 10 C, and a diurnal 5 C to 10 C alternation. Phosphorus levels were 0, 45, 90, and 180 kg/ha equivalents. Growth intervals (5 ± 0.5 trifoliolate‐leaf stage), varied between 58 and 114 days.Leaf area of subclover was greater than that of rose clover, and responded more to increasing P levels. Leaf areas tended to increase with higher soil temperatures. Nodule weight was positively correlated with leaf area; nodule weight:leaf area regressions suggested that nodule development was adequate at 5 C and that nodule development was primarily related to time rather than to morphological development of the shoot. Nodule weights were similar for the two species, and low at 0 P.The results suggest that while the practical soil threshold temperature for overall growth is near 5 C, some intraplant growth processes may proceed, but only at adequate, availability levels of mineral nutrients. These relationships may be particularly important where range annual legumes are being introduced as part of a more general range improvement program.
Effects of Premature Defoliation and Plant Kill on Germination of Cottonseed1
Authors: Minton Earl B. , Wanjura D. F. , Bilbro J. D. 
Published: July 2010

AbstractPerformance data on cottonseed (Gossypium hirsutum L.) harvested from plants following premature defoliation and premature plant kill are limited. The objective of this study was to determine the effects of premature defoliation following adverse weather, hand defoliation, and premature plant kill (plants cut off at the soil line and dried rapidly in the greenhouse) at different dates in the fall on germination of cottonseed. The seed were stored for several weeks in the laboratory at about 30% relative humidity and 21 C before they were germinated at alternating 20 to 30 C and at a constant 18 C. Means for germination percentage, germination rate index (GRI), and coefficient of velocity of germination (CVG) were separated by Duncan's multiple range test. Reduced germination and GRI were obtained with seed harvest from plants that set fruiting following late season irrigation, premature defoliation following low temperatures, leaf removal by hand, and prematurely killed in September. Premature plant kill in October increased germination when compared to 50 and 100% leaf removal by hand and the check (no leaves removed). Germination was similar for seed harvested from plants with 50% leaf removal and the check. Removal of all leaves had the most adverse effect on the performance of cottonseed. The lowest CVG was obtained from plants left intact in the field. Seed from a determinant cultivar appeared to be affected less than seed from an indeterminant one.
Relative Effectiveness of Several Mn Sources on Virginia‐Type Peanuts1
Authors: Hallock D. L. 
Published: July 2010

AbstractRecently, Virginia farmers have experienced more cases of Mn deficiency in peanuts (Arachis hypogaea L.). More information was needed concerning the relative effectiveness of various commercial sources of Mn and methods of application on peanuts. Several sources of Mn were sprayed, broadcast, or banded on peanuts in 1975 and 1977 under conditions where considerable chlorosis typical of Mn deficiency was prevalent both years in a sandy Aquic Hapludult, pH 6.5.Peanut yields in 1975 averaged 3,915 kg/ha where sources of Mn were sprayed on foliage. Soil‐applied (band or broadcast) sources averaged 3,385 kg/ha. Check plot yield was 2,620 kg/ha. Highest yields were obtained from the Sequestrene treatment (Chelate, 0.45 kg/ha Mn) followed closely by the Manzate 200 (C4H6MnN2S4, 1.1 kg/ha Mn) Sorba‐Spray Mn (MnSO4, 0.19 kg/ha Mn) and Manganese sulfate treatments (3.36 kg/ha Mn), each sprayed three times except Manzate (4 sprays). Five other products where the Mn source was either MnSO4, MnO, or both also were included.Sources in 1977 included only Man‐Gro (MnSO4), Manganese sulfate, and Dithane M‐45 (C4H6MnN2S4), but combination treatments with Mn banded on the row and sprayed on foliage were included. Average yields obtained from soil‐only (broadcast or banded), combination soil and foliar, and foliar‐only treatments were 2,640 kg/ha, 2,720 kg/ha, and 2,820 kg/ha, respectively. The check plot yielded 2,035 kg/ha. Highest yields were obtained from 4.48 kg/ha of Mn as MnSO4 in three sprays (2.24 kg/ha in first spray), whereas the yield from a broadcast treatment (44.8 kg/ha) of Mn was nearly as high. Drought probably limited yield potentials particularly in 1977.
Corn Response to Foliar Application of Dinoseb1
Authors: Hicks D. R. , Lueschen W. E. , Ford J. H. , Nelson W. W. , Overdahl C. J. , Evans S. D. , Peterson R. H. 
Published: July 2010

AbstractFoliar application of dinoseb (2‐sec‐butyl‐4‐.6‐dinitro phenol) has been reported to increase the grain yield of corn (Zea mays L.) The objective of our work was to evaluate the response of dent corn hybrids adapted to the northern region of the Corn Belt to foliar applications of dinoseb. Several rates of dinoseb were evaluated on corn grown at two locations for 4 years.Dinoseb with a surfactant was applied as a foliar spray at the rate of 190 to 238 liters/ha. In 1974–73, dinoseb rates evaluated ranged from 0 to 70 g a.i./ha and were applied 2 weeks prior to tassel ing. 1974–73 one rate (12.5 g a.i./ha) of dinoseb was applied when the unemerged tassel was 1.3 or 17.8 cm in length. Three hybrids of differing maturity were planted on two dates for the test. Grain yield and ear or kernel moisture percentages were determined for all experiments. Tasseling and silking dates, test weight, barrenness, and 100‐kernel weight were recorded in some experiments.In general, grain yields were not statistically affected by dinoseb foliar application. Yield differences were small and in many cases the numerical difference between dinoseb treated and nontreated plots was negative. Percent moisture at harvest, tasseling and silking dates, kernel test weight, 100‐kernel weight, and barrenness were not statistically affected by foliar application of dinoseb. The lack of a significant yield increase, the low mean response, and the inconsistent response do not support foliar application of dinoseb to enhance corn grain yield.
Physiological Maturity in Soybean1
Authors: TeKrony D. M. , Egli D. B. , Balles J. , Pfeiffer T. , Fellows R. J. 
Published: July 2010

AbstractA visual indicator of physiological maturity (maximum dry seed weight) in soybean [Glycine max (L.) Merrill] would be useful to researchers and soybean producers. Experiments were conducted utilizing two cultivars in the greenhouse and six cultivars in the field to characterize the color of soybean seeds and pods at physiological maturity. In greenhouse experiments where plants were exposed to 14CO2 as they neared maturity, it was found that the 14C content of the seed decreased as the yellow coloration of the seed coat increased. Practically no 14CO2 was recovered from yellow seeds, regardless of the color of the pod, suggesting that the seed stops importing assimilates and is physiologically mature when it is completely yellow (free of green color). Normally, yellow seeds were found only in yellow or brown pods. The respiration rate of seed, measured as CO2 evolution, declined rapidly as the seedcoat began to turn yellow and reached a low level when the seed were completely yellow at a seed moisture content of 55 to 60%.Physiological maturity of an entire plant, estimated from dry seed weight data in the field, occurred when 26% of the seed were yellow and 35% of the pods were yellow or brown. The seed moisture content ranged from 54 to 62%. The date of physiological maturity estimated in the field was slightly early in comparison to complete physiological maturity (all seed completely yellow) due to the sampling variation associated with estimating dry seed weight and the variation in pod maturity on an individual plant.The data suggest that the occurrence on the main stem of one normally colored mature pod per plant represents a useful and acceptable indicator of physiological maturity, even though all the pods or seed were not completely yellow at this stage of development.
Dry Weight and Leaf Area Production Rates of Irrigated Determinate Soybeans1
Authors: Scott H. D. , Batchelor J. T. 
Published: July 2010

AbstractQuantitative measurements are needed to determine the effects of irrigation on production rates of dry matter and leaf area of soybeans [Glycine max. (L.) Merr.]. A field experiment was conducted on a Typic Albaqualf (Crowley silt loam) and a Vertic Fluvaquent (Kobel clay) for three seasons. The objectives were to evaluate dry matter and leaf area production and to use growth analysis techniques to quantify these growth rates for irrigated (I) and nonirrigated (N) soybeans. Growth analysis parameters computed include crop growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), leaf weight ratio (LWR), and specific leaf area (SLA). Little or no plant response to irrigation was found during the wetter than normal season in 1974. Differences in plant growth due to soil moisture regime were obtained in the two dry seasons (1975 and 1976). These differences initially were found during late vegetation and early bloom growth stages in both leaves and stems on or near the same date. Generally, the irrigated soybeans accumulated greater amounts of dry matter and leaf area and had higher seed yields than did the nonirrigated soybeans.Values of crop growth rate for I and N soybeans increased to a maximum during late July and early August of 1974 and declined thereafter. Similar results were found with the I soybeans in 1975. The period of maximum CGR corresponded to late vegetative and early reproductive growth. The maximum CGR of the N soybeans was found at mid‐August during 1975, the season when rainfall deficits were observed. This period of maximum CGR corresponded to mid‐podfill growth stages.Values of relative growth rate, net assimilation rate and leaf area ratio were highest during early vegetative growth and decreased as the season progressed. Generally, in a given year the I soybeans had greater values of the growth parameters during reproductive stages. The decline of LAR of the N soybeans during 1975 was attributed to the decrease in leaf weight ratio during vegetative growth and to the decrease in both LWR and specific leaf area during reproductive growth. The greater LAR values of the I soybeans during reproductive growth was due to the longer period during which the assimilates were converted to leaf area production.
Elongation of Wheat Leaves Exposed to Several Levels of Matric Potential and NaC1‐Induced Osmotic Potential of Soil Water1
Authors: Sepaskhah A. R. , Boersma L. 
Published: July 2010

AbstractLeaf elongation is a major indicator of plant growth. It is partly controlled by turgor potential which, in turn, is affected by soil water potential and/or by the osmotic potential of the soil water. This study was conducted to determine the interaction of osmotic potential of Soil water induced by NaCl (0, −4, −8, and −12 bars) and soil matric potential induced by carbowax 4000 (−0.3, −2.5, −5.0, and −7.5 bars) on the turgor potential and elongation rate of leaves of 2‐week‐old wheat seedlings (Triticum aestivum L.). Relationships between rate of leaf elongation and leaf turgor potential and rate of leaf elongation and leaf water potential at all combinations of the experimental variables were obtained. Seedlings of spring wheat (Triticum aestivum L. ‘Fielder’) were grown in a Xerollic Durargids loam soil separated from the surrounding nutrient solution by a semipermeable cellulose‐acetate membrane. The rate of leaf elongation of the 2‐week‐old plants, growing in a walk‐in growth room, was measured at 24‐hour intervals with a ruler. Turgor potential of leaves was obtained as the difference between leaf water potential measured with a pressure chamber apparatus and osmotic potential of leaf cells measured with a thermocouple psychrometer.At the matric potential of −0.3 bars, where cell dehydration does not occur, accumulation of salt in the leaves at osmotic potentials of −4, −8, and −12 bars appeared to increase the turgor potential of leaf cells. Under moderately low to very low soil water potentials of −2.5 to −7.5 bars combined with low osmotic potentials of the soil water, leaf water potential decreased more strongly than could be counteracted by osmoregulation through a decrease in the osmotic potential of the cell; consequently, the turgor potential decreased as the osmotic potential of soil water decreased. We found significantly different linear relationships between rate of leaf elongation and turgor potential and between rate of leaf elongation and leaf water potential at the experimental osmotic potentials of the soil water. The “gross extensibility” and threshold turgor potential of the leaves were different at the various osmotic potentials of the soil water, ranging from 5.29 to 2.01 μm/min‐bar and from +0.33 to +1.33 bars, respectively. The rates of leaf elongation decreased at an accelerated rate as the osmotic potential of the soil water decreased. Leaf elongation ceased at leaf water potentials of −18.2, −20.7, −24.4, and −29.7 bars at osmotic potentials of the soil water of 0, −4, −8, and −12, respectively. The toxic effects of NaCl on metabolic processes of cell wall extension have been discussed.
Phosphorus Response of Maize Grown on Alfisols of Southern Nigeria1
Authors: Kang B. T. , Osiname O. A. 
Published: July 2010

AbstractPhosphorus plays an important role for food crop production in the forest zone of tropical Africa but very little information is available on the phosphate requirement for maize production there. Field trials were, therefore, conducted with maize (Zea mays L.) at two locations on Alfisols in southern Nigeria to investigate the P response and the residual effect of applied P. The experimental sites were recently cleared from fallow and the vegetation was removed after land clearing.On the Egbeda soil (Oxic Paleustalf), which is derived from basement complex rocks, five seasons of maize croppings were done from 1971 to 1973 using a split‐plot design with three replications. Four periods of fresh P applications (major and minor seasons 1971 and major and minor seasons 1972), formed the main plots and each of these fresh P applications consisted of five P rates (0, 26, 52, 78 and 104 kg P/ha) which made up the sub‐plots. Maize culture T2A ✕ TZB was planted at a spacing of 75 ✕ 25 cm (53,300 plants/ha). The minor season maize received supplementary irrigation. On the Alagba soil (Oxic paleustalf) which is derived from sedimentary rocks, five P rates (0, 20, 40, 80, and 160 kg P/ha) were compared using a randomized complete block design with four replications. Phosphate was broadcasted as single superphosphate and incorporated in the soil to the various treatments. The residual effects of applied P were followed up at both locations. With removal of fallow vegetation following land clearing, significant responses to P applications were observed at both locations. The P requirement for obtaining significant yield increases was not very high, ranging from 26 to 52 kg P/ha depending on season and location.Higher yield response to P was observed during the main season (April to July) than during the minor season (August to November) planting. At both locations significant residual effects of applied P was observed on maize yield and Bray P‐1 soil test levels. On the Egbeda soil it was possible to build up and maintain adequate amounts of extractable P for two to three maize crops with one addition between 52 to 104 kg P/ha.Good relationship was observed between maize grain yield and Bray P‐1 test values on the Egbeda soil. The critical Bray P‐1 test values was estimated to be about 14 ppm P. Results of incubation studies showed that under laboratory conditions 2.5 to 3 ppm of fertilizer P was required to increase the Bray P‐1 test level by 1 ppm for the Egbeda and Alagba soils respectively. Under field conditions for the Egbeda soil the P rate required was estimated to be 3.5 ppm P.The critical P in the ear leaf was estimated at 0.3% P. High rate of P application was shown to depress the Zn status in the ear leaf.