bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Aerial Environment and Soil Water Potential on the Transpiration and Energy Status of Water in Wheat Plants1
Authors: Yang S. J. , de Jong E. 
Published: July 2010

AbstractWater stress is an important factor limiting wheat (Triticum aestivum L.) growth on the Canadian prairies. To determine the effect of evaporative demand and soil water potential on transpiration and leaf water status, Thatcher wheat was grown under four combinations of air temperature and relative humidity in a loam and a clay soil. Transpiration rate, leaf water potential, leaf water content, and soil water potential were determined. The relationship between transpiration rate and soil water potential depended on evaporative demand and soil texture. The decline in the transpiration rate from its maximum commenced at higher soil water potentials under conditions of higher evaporative demand and was more gradual on the clay than on the loam soil, presumably due to the higher capillary conductivity of the former. Permanent wilting occurred at soil water potentials of —20 to —25 bars on the loam soil and at —45 to —50 bars on the clay soil. At these potentials the capillary conductivities of both soils were about equal. Resistance to Water flow in the plant decreased with increased temperature, while changes in relative humidity had no consistent effect. The total resistance to water movement in the plant and the soil increased with decreasing soil water potential and decreasing air temperature. The relationship between leaf water potential and relative water content was affected by aerial environment and soil texture.
Water Use by Sugar Beets in a Semiarid Environment as Influenced by Population and Nitrogen Fertilizer1
Authors: Moraghan J. T. 
Published: July 2010

AbstractLittle information is available concerning the utilization of soil moisture by sugar beets (Beta vulgaris) under dryland conditions in a semiarid environment. The influence of population (26,400 and 70,700 plants/ha) and N fertilizer (0, 56, 112, and 224 kg N/ha) on water use by sugar beets under such conditions was studied. The growing season was characterized by long periods with little precipitation, and extensive use was made of stored soil moisture to a depth of at least 183 cm. The higher population and N fertilizer treatments increased water use by approximately 9.5 and 3.5%, and yield of sucrose by approximately 20 and 15%, respectively. The leaf area index was increased percentage‐wise much more markedly by both treatments. During the growing season the greatest effect of increasing population on water use was most evident in the deepest depths from which moisture was being utilized. The sugar beets apparently utilized soil nitrate to at least 152 cm.
Depletion of Nitrate Reductase Activity in Response to Soil Leaching1
Authors: Long R. C. , Woltz W. G. 
Published: July 2010

AbstractNitrate leaches readily from sandy soils. To test the sensitivity of nitrate reductase (a substrate‐inducible enzyme) as an indicator of nitrate leaching and restoration, low, normal, and high N treatments were imposed on young tobacco (Nicotiana tabacum L.) plants grown on a Durham sandy loam soil (Typic hapludult). Subsequent treatments imposed were soil leaching with and without a later application of replacement fertilizer. Plants were sampled at frequent intervals to determine the rapidity of changes in tissue nitrate concentration and nitrate reductase activity. Tissue nitrate concentration decreased within 24 hours after leaching in all N treatments in 1968. Nitrate reductase activity was decreased in the low and normal N treatments. The addition of replacement fertilizer resulted in increased nitrate reductase activity in the low and normal N treatments within 24 hours.
Influence of Salinity on Fe, Mn, and Zn Uptake by Plants1
Authors: Mass E. V. , Ogata Gen , Garber M. J. 
Published: July 2010

AbstractThis investigation was conducted to determine the influence of salinity on the uptake of Fe, Mn, and Zn by plants during the period of rapid vegetative growth. Relatively few data are available on the micronutrient status of salt‐stunted plants. Tomato (Lycopersicon esculentum Mill. ‘Heinz 1350’), soybean (Glycine max L. ‘Kanrich’), and squash (Cucurbita pepo ‘Golden Summer Crookneck’) were grown in the greenhouse in half‐strength Hoagland‘s solution salinized with 0, 25, 50, 75 and 100 meq NaCl/liter. Concentrations of Fe and Zn increased in the roots and tops of each species with increasing ambient levels of NaCl. Manganese concentrations increased in tomato and soybean tops but decreased in squash tops. Concentrations of Mn in the roots of tomato and squash were reduced at all salt levels, but they increased in all but the 100 meq/liter treatment in soybean. The changes in contents as a function of salinity were in the order of twofold or less and all were significant at the 5% level or better. Although the vegetative growth of the plant tops was depressed 45% or more by the highest saline treatment, the concentrations of these micronutrients in the tissue remained within the physiological limits necessary for normal plant growth. The influence of NaCl on the contents of Ca, Mg, K, Na, and Cl in the plant tops was comparable to that found in other investigations of salinity effects on plant mineral composition.
Corn for Silage as Influenced by Hybrid Maturity, Row Spacing, Plant Population, and Climate1
Authors: Cummins D. G. , Dobson J. W. 
Published: July 2010

AbstractMost research on corn (Zea mays L.) silage production has been conducted in the northern United States and results do not necessarily apply to growing conditions in the South. Therefore in 1968 and 1969, corn was grown in the Piedmont (elevation 282 m) and Mountains (elevation 584 m) of Georgia to determine the influence of hybrid maturity row spacing, plant population, and climate on silage dry matter yields, percentage ears, leaves, and stalks, and in vitro dry matter digestibility (IVDMD). An early and late maturing hybrid was grown in 51 and 102 cm rows with 49‐, 68‐, and 86,000 plants/ha in the Piedmont, and a late maturing hybrid was grown in the Mountains in 61, 76, 91, and 107 cm rows with 30‐, 45‐, 59‐, and 74,000 plants/ha.In the Piedmont, yields were not significantly different for the early and late maturing hybrids, significantly higher in 51 than 102 cm rows (11.9 vs 11.3 mt/ha), and increased significantly as populations increased from 49‐, 68‐, to 86,000 plants/ha (10.5, 11.6, to 12.3 mt/ha). In the Mountains yields were not significantly different for row spacing, and increased significantly as populations increased from 30‐, 45‐, 59‐, to 74,000 plants/ha (17.7, 21.1, 24.4, 26.0 mt/ha). As populations increased from 49 to 86,000 plants/ha at the Piedmont location, ear content decreased from 55 to 45 percent and stalk content increased from 27 to 32 percent. This resulted in significantly lower IVDMD at 86‐, than 68,000 plants/ha (63 vs 65.8 percent). In the Mountains as populations increased from 30‐ to 74,000 plants/ha, less change in ear (57 to 53 percent) and stalk (16 to 18 percent) content was observed with no change in IVDMD with varying papulations. Row spacing did not influence IVDMD at either location. These differences in response to management of corn grown for silage between these locations were attributed to more evenly distributed rainfall and lower temperatures at the Mountain location, and should be somewhat comparable to production response at average northern and southern locations.
Autumn Cutting Effects on Alfalfa Yield and Persistence in Alabama1
Authors: Mays D. A. , Evans E. M. 
Published: July 2010

AbstractThe research described herein was conducted to test the hypothesis that alfalfa (Medicago sativa L.) can be cut in September or early October in the southern United States without detrimental effects.‘Williamsburg’ and ‘Dupuits’ alfalfa were planted at Muscle Shoals, Ala., in September 1963. From 1964 through 1966, 10 fall cutting regimes were imposed on the alfalfa. In 1967 residual yields were taken and stand densities were determined. Root carbohydrate analyses were made at the last autumn harvest and at 2‐week intervals until mid‐December each year.Autumn cutting treatments had a greater effect on subsequent first harvest than on total yields. Total yields and stand density in 1967 showed that Williamsburg was quite tolerant to all cutting schedules and could safely be harvested in September or early October. The best yields and persistence of Dupuits were obtained where no fourth cut was taken. Date of third cut and consequent interval differences between the third and last cut affected subsequent growth and persistence of both varieties.Root carbohydrate levels were slightly depressed for 2 to 4 weeks following harvest. However, the magnitude of fluctuation was much less than is usually reported. Carbohydrate levels did not drop from mid‐December to mid‐March.It was concluded that a well‐adapted alfalfa variety could tolerate a wide range of fall managements in the climate typified by north Alabama.
Effectiveness of Two Nitrification Inhibitors for Anhydrous Ammonia Under Irrigated and Dryland Conditions1
Authors: Cochran V. L. , Papendick R. I. , Woody W. M. 
Published: July 2010

AbstractPotassium azide (KN3) and 2‐chloro‐6‐(trichloromethyl) pyridine (N‐Serve) were evaluated as nitrification inhibitors for anhydrous NH3 field applied on irrigated and nonirrigated Ritzville silt loam and on nonirrigated Naff silt loam in eastern Washington. Formulations of KN3, N‐Serve in liquid NH3, or NH3 alone were applied to fallow soil in midsummer at a rate of 90 kg N/ha. Irrigations were 15 cm of water sprinkler applied 1 day or 2 weeks after fertilizer application, and 10 to 15 cm of water each time at 4, 8, and 13 weeks after NH3 application. The NH3 retention zone was sampled for NH+4 and NO−3 periodically through December for the Naff soil and through February for the Ritzville soil. Both KN3 and N‐Serve effectively inhibited nitrification of the applied NH3 on nonirrigated Ritzville soil when temperature and soil moisture were favorable for rapid nitrification. However, KN3 was completely ineffective following irrigation or, for the Naff soil, after rainwater penetrated below the retention zone 2 weeks after N application. Where irrigated 1 day or 2 weeks after fertilization application, all of the applied N had disappeared from the initial NH3 retention zone in the Ritzville soil in 8 to 13 weeks for both NH3 alone and NH3 + KN3. Results with the Naff soil for these applications were similar to results with the irrigated Ritzville soil. By contrast, N‐Serve effectively suppressed nitrification under leaching and nonleaching conditions.For the Ritzville soil, total N uptake by the wheat (Triticum aestivum L.) crop for different rates of fertilizer application followed the order of NH3 + KN3 > NH3 + N‐Serve > NH3 alone, but grain yields with NH3 + inhibitor were not different from yields with NH3 alone. For the Naff soil there was no N‐uptake or grain‐yield response to N rates, and thus no response to the inhibitors.
Accumulated Heat Units for Classifying Corn Hybrid Maturity1
Authors: Mederski H. J. , Miller M. E. , Weaver C. R. 
Published: July 2010

AbstractPrevious studies comparing the accumulated heat unit (AHU) method with the calendar day method for classifying corn (Zea mays L.) hybrids with respect to maturity do not clearly show the superiority of the AHU method over the calendar day method. They appear to have two limitations: (1) the range of climatic conditions under which the studies were conducted was not broad enough to elicit wide variation in the rate of occurrence of plant development and maturity, and (2) the studies were truncated at silking because the time interval from silking to maturity was assumed to be constant.The objective of the study herein was to determine, under a wide range of climatic conditions, whether AHU methods are superior to the calendar day method for classifying the maturity of corn hybrids and predicting the occurrence of phenological events. For a particular corn hybrid grown under a range of climatic conditions, the number of calendar days between any two phenological events may vary widely but the AHU should be constant.Four plantings of three corn hybrids were made at weekly intervals at seven widely dispersed locations in Ohio in 1969 and 1970. Calendar days and AHU, calculated by six methods, were determined from planting to tasseling and silking, and from planting to 40, 35, 30, and 25% kernel moisture and black layer formation.The coefficients of variation of AHU and calendar days to a particular phenological event for each of the three hybrids were determined on the pooled data from the four planting dates and seven locations for each of 2 years.The differences in coefficients of variation among the six AHU methods were relatively small. However, as a group, the AHU methods were about half as variable as the calendar day method for classifying corn hybrid maturity. The data indicated that the AHU method of classifying corn hybrids was superior to calendar days.
Hydrocyanic Acid Potential of Black Cherry Leaves1
Authors: Smeathers Dan M. , Gray Elmer , James John H. 
Published: July 2010

AbstractBlack cherry (Prunus serotina L.) leaves have been reported to be a cause of hydrocyanic acid poisoning of livestock. It has been widely accepted that cherry leaves must be wilted before they are toxic to cattle.A study was conducted during the 1971 growing season at Bowling Green, Kentucky to determine the level of hydrocyanic acid potential (HCN‐p) in black cherry leaves and to ascertain the effect of wilting of leaves on HCN‐p.Average HCN‐p of fresh leaves from six black cherry trees was highest (2472 ppm) in the spring and decreased rather consistently during the growing season. Average HCN‐p was high in fresh leaves and was intermediate and low in leaves air‐dried for 24 and 48 hours, respectively. A negative relationship was found between level of HCN‐p and dry matter percentage. There were no consistent differences among the six cherry trees for HCN‐p of leaves.These results indicate that wilted leaves should be safer than fresh leaves for cattle consumption.
Reaction of Tall Fescue to Frequent Summer Nitrogen Applications1
Authors: Hallock D. L. , Wolf D. D. , Blaser R. E. 
Published: July 2010

AbstractThe postulation that tall fescue (Festuca arundinacea L. var. ‘Ky. 31’) might tolerate and respond more favorably to higher rates of N in summer if applied frequently in small increments was studied at Holland, Va. from 1966 to 1970. Weekly N applications of up to 56 kg/ha, May through August each year, and one application of 168 kg/ha each March, totalling 1,120 kg/ha by September 1, thinned stands of tall rescue by only 30%. Rates of N up to 22.4 kg/ha per week increased density of stands.Annual dry matter yields increased from 41 to 110 q/ha as N rates increased up to 39.2 kg/ha per week. Yields from the May harvests were highest with generally lower yields in successive cuttings taken every 4 to 6 weeks through September. Nitrogen content was lower in the May cuttings than in succeeding cuttings. Generally, protein concentrations increased in the summer cuttings as the rate of N increased to 22.4 kg/ha per week, above which no increase occurred. Nitrogen uptake by fescue increased from 90 to 375 kg/ha as weekly N rates increased from 0 to 56 kg/ha. The proportion of N removed in rescue forage relative to that applied was highest (61%) from 5.6 kg/ha per week of N and lowest (33%) from 56.0 kg/ha per week of N.Use of tall rescue may be feasible as a vegetative cover for disposal of high N waste if applied frequently in small increments.Soluble carbohydrate concentrations in the stubble probably were not low enough (7%) to influence regrowth and stand survival appreciably.
Quantitative Soil Moisture Use in Corn Grown Under Conventional and No‐tillage Methods1
Authors: Hill Jerry D. , Blevins R. L. 
Published: July 2010

AbstractExperiments conducted at the University of Kentucky during 1969, 1970, and 1971 compared corn (Zea mays L.) production under conventional and no‐tillage systems. The presence of a killed‐sod mulch in the no‐tillage plots almost eliminated the loss of moisture by direct evaporation from the soil surface during the early growing period, but after a full crop canopy had developed, losses from both production methods were about equal. Water loss from the soil during the full‐canopy period was compared with open pan evaporation to determine the rate of loss under varying levels of soil moisture deficiency.The average soil moisture deficiency during the period from about 3 weeks before to 6 weeks after silking was related to final grain yield, and a simple linear relationship indicated that each additional cm of water available to the plant increased yields by about 559 kg/ha. The relationship was tested on regional yield data for the years 1954 to 1968. Soil moisture status was simulated from precipitation and temperature data observed during the growing season by using the Palmer Crop Moisture Index method. The variation in predicted and observed yield follow each other very well, with a linear correlation coefficient of 0.81.
Cutting Management of Sericea Lespedeza for Forage and Seed1
Authors: Hoveland C. S. , Anthony W. B. 
Published: July 2010

AbstractSericea lespedeza (Lespedeza cuneata (Dumont) G. Don.) is being utilized for pasture to a greater extent than in previous years in the southeastern United States, yet information is lacking on the response of this species to frequent and close defoliation. ‘Serala’ sericea was harvested under various management systems in central Alabama for 3 years to determine the effect on forage yield and quality, seed yield, persistence, and root reserves. Harvesting was begun on April 21 each year and terminated in June, August, or October. Forage yields were highest, over 9,000 kg/ha, when sericea was cut at 9‐week intervals until August or October. Cutting at 6‐week intervals reduced forage yields 41% and 53%, respectively. Clipping at a 4‐cm stubble height reduced forage yields below that of a 10‐cm stubble for the 3 or 6‐week cutting intervals, but had no effect at the 9‐week interval. Seed yields were higher, over 600 kg/ha, when one hay harvest was removed to leave a 10‐cm stubble than when cut more frequently. Seed production was responsive to stubble height of forage cut early in the season. Frequent cutting and a short stubble height reduced new shoot development and root reserves but did not affect stands. Digestible dry matter (DDM) of forage was similar for a given treatment throughout the growing season. DDM was slightly lower for forage when cut at 9‐week intervals than at 3 or 6‐week intervals but was unaffected by stubble height.
Length‐Width Method for Estimating Leaf Area of Rice1
Authors: Palaniswamy K. M. , Gomez K. A. 
Published: July 2010

AbstractThe length‐width method for estimating leaf area has been evaluated with traditional Indica and Japonica rices (Oryza saliva L.); the leaves of modern semidwarf rices, however, are quite different in shape. We therefore evaluated the length‐width method using 11,356 leaves taken from 2 semidwarf varieties grown under 3 fertilizer levels for 2 crop seasons. Measurement of length alone was unsatisfactory. The use of length times maximum width, however, was found satisfactory under most test conditions except at 30 days after transplanting and at maturity. In other cases, leaf area could be determined from K(L ✕ W), where L is the leaf length, W is the maximum width of the leaf, and K is 0.73 for dry‐season crops and 0.75 for wet‐season crops. This method is unbiased; estimates should have no more than 5% error.
Persistence and Yield of 10 Grasses in Response to Clipping Frequency and Applied Nitrogen in the Allegheny Highlands1
Authors: Jung G. A. , Balasko J. A. , Alt F. L. , Stevens L. P. 
Published: July 2010

AbstractThis research was undertaken to assess the influence of harvest schedules and fertilization on the persistence and productivity of four warm‐ and six cool‐season grass species under minimal temperature and moisture stresses. The grasses were clipped three, five, or eight times during each of 2 years. The first clipping each year was taken on April 26, May 7, or June 10 and aftermath clippings were taken at 21‐, 35‐, or 55‐day intervals, respectively. Ammonium nitrate was applied in three equal applications during each growing season. A total equivalent of 168 or 336 kg/ha was applied to each plot. Persistence of Kentucky bluegrass (Poa pratensis L.), tall fescue (Festuca arundinacea Schreb.), orchardgrass (Dactylis glomerata L.), and Timothy (Phleum pratense L.) improved as clipping frequency was increased from three to eight cuts per year, especially at the high rate of N. Reed canarygrass (Phalaris arundinacea L.) and smooth bromegrass (Bromus inermis Leyss.) stands were better if clipping was less frequent. Stands of bermudagrass [Cynodon dactylon (L.) Pers.], indiangrass [Sorghastrum nutans (L.) Nash], big bluestem (Andropogon gerardi Vitman) and switch‐grass (Panicum virgatum L.) had deteriorated badly after 2 years, regardless of treatment. Orchardgrass was the most productive species overall and was least affected by the clipping and fertilizer treatments.Dry matter yields of grasses in the second harvest year were differentially influenced by clipping and nitrogen fertilizer (3‐factor interaction = P < .005). At the high rate of N, orchardgrass, reed canarygrass, and smooth bromegrass yields were highest with three clippings, tall fescue and timothy yields were highest with five clippings, and Kentucky bluegrass yields were highest with eight clippings. At the low rate of N all species, except Kentucky bluegrass and timothy, produced highest yields with three clippings. Timothy yields were highest with five clippings, and clipping frequency had little effect on bluegrass yields.Yields were reduced most by infrequent clipping at the high rate of N (Kentucky bluegrass, tall fescue, timothy) and by frequent clipping at the low rate of N (all species except bluegrass).Persistence and yield distribution responses to clipping and nitrogen fertilizer were different from those commonly reported for lower elevations and were attributed to less temperature and moisture stress. Management requirements for warm‐season grasses differ from those for cool‐season grasses and need to be studied in more detail.