bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regrowth and Alcohol Dehydrogenase Activity in Waterlogged Alfalfa and Birdsfoot Trefoil1
Authors: Barta A. L. 
Published: July 2010

AbstractSusceptability of alfalfa (Medicago sativa L.) to waterlogging injury seriously limits its persistance and adaptability. Waterlogging injury and accumulation of ethanol under root anoxia may be causal agents which facilitate or promote infection by Phytophthora megasperma Drechsler zoospores and result in “root rot” of alfalfa.While induction of alcohol dehydrogenase (ADH) and increased root accumulation of ethanol are general characteristics of flood‐intolerant species, these parameters have not been examined in alfalfa and birdsfoot trefoil (Lotus corniculatus L.) which vary greatly in flood tolerance and Phytophthora resistance. The objective of this greenhouse study was to compare the flooding response of alfalfa and birdsfoot trefoil and determine the effect of anoxia on the induction of ADH and accumulation of ethanol in flooded roots of both species.When flooded for 7 days, alfalfa exhibited much more severe shoot injury symptoms (wilted and yellowing leaves), reduced shoot dry weight, reduced shoot and root total nonstructural carbohydrates, and reduced rates of acetylene reduction than trefoil which is Phytophthora resistant. Induction of ADH activity was very rapid and reached similar levels in both alfalfa and trefoil. Flooding for 6 days at 22 C resulted in maximum ethanol concentration in alfalfa after which shoot injury symptoms rapidly developed. However, ethanol concentration in trefoil roots was several fold lower than alfalfa indicating that trefoil may effectively remove ethanol from the roots.
Nitrogen Loss in Conjunction with Transpiration from Rice Leaves as Influenced by Growth Stage, Leaf Position, and N Supply1
Authors: da da Silva P. R. F. , Stutte C. A. 
Published: July 2010

AbstractAn understanding of the fate of the N used or discharged by crop plants is important to cost‐efficient producton. Recent reports from our laboratory show that leaves of several crop and weed species lose volatile N in conjunction with transpirational water vapors. This study has investigated the effects of growth stages, leaf position, transpiration rate, and N supply in relation to rate of this loss on rice (Oryza sativa L.).A pyro‐chemiluminescent method was used to quantify the volatile N loss along with the transpirational water vapors from rice leaves. Calculations, based on collected data, estimate N loss of 14.1 (‘Bonnet 73’) to 15.2 (‘Starbonnet’) kg/ha from plant leaves over a l00day period. Rate of N loss decreased during the period between tillering and 1 to 3 weeks beyond panicle initiation after which it increased as plants progressed to the heading stage. The most recently matured leaf lost N at a higher rate than older leaves. The N concentration in nutrient solution did not affect rate of volatile N loss per unit of leaf area of the most recently matured leaf; however, older leaves supplied with high rates of N lost N at a higher rate than those grown in low‐N medium. Volatile N lost per plant increased with N supply mainly due to higher leaf area and higher N loss rate from older leaves. Quantifying the physiological influences on volatile N loss can help to determine the time for application and the amounts of N fertilizers needed for optimum rice production. Additional
Transpiration Efficiency of Potato1
Authors: Tanner C. B. 
Published: July 2010

AbstractWittwer (1979) recently has stressed the need for information on the number of kilograms of water needed to produce a kilogram of food. The objective of this study was to provide this information for potato, and in particular, to test the general proposal of Bierhuizen and Slatyer (1965) that transpiration efficiency (yield/transpiration) could be described by Y/T = k(e*−e), where k is a physico/physiologically‐based constant and (e*−e) is the average daytime saturation deficit. Regression analysis of 3 years of field data, including periodic yield measurements and daily measurements of transpiration and saturation deficits, shows that during tuber bulking, k = 0.065 ± 0.007 mb for both tubers and total dry matter. This experimental k is in good agreement with a k derived from physiological data for potato. During early vine growth we found k = 0.055 ± 0.006 mb. These k values disagree with data of Rijtema and Endrodi (1970) which yield k = 0.015 mb. Sources of variability in k and the difference between the Wisconsin and Rijtema and Endrodi data are discussed.It is clear that since evapotranspiration is greater than transpiration, ET‐efficiency is less than T‐efficiency; therefore k ≈ 0.065 mb sets an upper limit of potato water‐use efficiency for a given saturation deficit regime. Also potato water‐use efficiency will be higher in humid regions than in semi‐arid regions because of lower saturation deficits, particularly where advection exists.
Hay Yield Determinations of Mixed Swards Using a Disk Meter1
Authors: Baker Barton S. , Eynden Thomas Vanden , Boggess Neal 
Published: July 2010

AbstractEstimates of hay yields are frequently desirable for purposes of measuring fertilizer response, studying effects of management and cultural practices, and determining animal units that can be maintained on forage produced from a given area. Estimates of forage yield can be obtained by cutting and weighing, but the random collection of forage samples for estimating yields is not a viable alternative in some cases. A convenient, quick, and accurate method of determining forage yields in situ would benefit research workers and those involved in commercial and extension agriculture operations.The purpose of this investigation was to determine the suitability of using a disk meter to estimate dry matter yield of mixed swards. A 0.5m2 disk meter was constructed from hardboard paneling, steel pipe, and a flange. Paired disk meter readings and dry matter yields from clipping were taken from 708 swards used for hay production in 1978. Swards consisting of cool season grasses, legumes, and weeds were characterized into 14 categories according to species composition and growth stage. Regression equations were determined for each category from paired disk readings and dry matter yields from clippings. The slopes of the regression lines for the different categories were not significantly different. The coefficient of determination (r2) was 0.82 when using a single regression line for all categories. The points of intercept of the regression lines on the vertical axis for the different categories were different with a definite trend for regression lines for first cutting swards to intercept higher than regression lines for aftermath.The formula which best described the relationship between disk reading and yield was: yield estimate = intercept for category + 183 (disk reading) − 1.73 (disk reading)2. In order to test the disk meter and formula method, yields on 40 swards were determined independently using two methods. The correlation coefficient between sward yields estimated using the disk meter and formula and sward yields estimated using weighed clippings was +92.
Sunflower Cultivar Performance as Influenced by Soil Water and Plant Population1
Authors: Prunty Lyle 
Published: July 2010

AbstractInformation on the yield performance of sunflower (Helianthus annuus L.) as related to a range of soil water potential in the near‐optimum range has not previously been reported. Previous studies of sunflower plant population density effects on yield have lacked agreement. In this study three sunflower cultivars (‘Peredovic’, ‘894’, and ‘Northrup King 212’) were tested for response to soil water potential at Oakes, North Dakota and for response to population density at Carrington, North Dakota (irrigated) and Fargo, North Dakota (dryland). Yield was higher if the soil water potential in the root zone, as measured by commercial tensiometers, was limited to values of ‐20 cbar and ‐40 cbar and was lowered if the root zone water potential was allowed to drop to ‐75 cbar. There was no significant difference in seed yield between populations at thinning of 49,400, 59,300, and 69,200 plants/ha. A comparison of harvest methods at Oakes indicated that a number‐of‐heads harvest method increased yield estimates by 20% compared to an area harvest method. This comparison also showed that the harvest method used did make a significant difference in yield results obtained from the water potential experiment. It is hypothesized that harvest method may have influenced previous sunflower population density experiments similarly.
Growth and Photosynthate Partitioning in Alfalfa Under Eight Temperature‐Photosynthetic Period Combinations1
Authors: Chatterton N. J. , Carlson G. E. 
Published: July 2010

AbstractA characterization of the growth responses of high and low yielding alfalfa (Medicago sativa L.) plants to environmental parameters will provide important information on their yield potential. This experiment was conducted to determine if growth temperature and length of the photosynthetic period mediate the differential herbage yielding abilities of alfalfa genotypes previously selected under field conditions for high and low herbage yield. Twelve genotypes were grown at 20/15, 23/18, 26/21, and 29/24 C day/night temperatures in 10‐hour and 14‐hour photosynthetic periods in controlled environments. Dry weights and total nonstructural carbohydrate percentages were obtained on herbage and root tissues. Carbon dioxide exchange rates were measured using infrared gas analysis on attached leaves and expressed on a per unit leaf area and a per unit leaf dry weight basis. Relatively large herbage yield differences previously observed among the various clones under field conditions were minimized in all treatments when plants were grown in controlled environments where moisture and nutrient stresses were assumed to be minimal. The apparent diurnal accumulation rate of total nonstructural carbohydrates was faster in the herbage of plants grown in short photosynthetic period conditions than in those grown in long ones. Such a relationship suggests an influence on photosynthate partitioning by length of the daily photosynthetic period. We conclude that yield differences observed under field conditions were not necessarily related to differential responses to either temperature or length of the daily photosynthetic period. Furthermore, photosynthesis, as measured by single leaf CO2 exchange rate, was not positively correlated with herbage yield under the various controlled environmental conditions used in this experiment.
Effect of Rhizobium japonicum Inoculant Rates on Soybean Nodulation in a Tropical Soil1
Authors: Smith R. S. , Ellis M. A. , Smith R. E. 
Published: July 2010

AbstractSoybean [Glycine max (L.) Merr.] research and production is expanding in tropical areas. Successful soybean nodulation in a soil free of Rhizobium japonicum is dependent totally upon viable rhizobia from the inoculant. This study examined soybean nodulation as influenced by the rate of applied R. japonicum in a tropical soil without indigenous R. japonicum.Rates of R. japonicum were evaluated with soybeans grown in a field experiment on a Puerto Rican Coto clay (Typic Haplorthox, clayey, kaolinitic, isohyperthermic) lacking indigenous R. japonicum. Eight rates of liquid inoculation were added to the seed furrow at planting and supplied number of R. japonicum from log 2.59 cells/cm row with 10 fold increases through log 9.59 cells/cm row. R. japonicum rates of log 2.59 and 3.59 cells/cm row were not successful in establishing nodulation. Nodule numbers increased with increasing rates of applied rhizobia from log 4.59 up to the highest rate of log 9.59 viable cells/cm. Regression analyses indicated linear relationships between the rate of inoculation with rhizobia and the number of tap root nodules, total number of nodules, and nodule weight/plant. An inverse relationship was observed between weight/nodule and total number of nodules. Inoculation levels above log 5.0 rhizobia/cm were necessary to establish effective nodulation in a R. japonicum free tropical soil.
Fruiting of Upland and Pima Cotton with Different Planting Dates1
Authors: Kittock D. L. , Henneberry T. J. , Bariola L. A. 
Published: July 2010

AbstractInterest in short‐season cotton production is increasing because of late‐season insect problems and, in the West, because of the expense of irrigation. Diverse cultivars of Upland cotton (Gossypium hirsutum L.) and American Pima cotton (G. barbadense L.) were compared at Phoenix, Arizona to evaluate short‐season production using several planting dates in 3 years and three dates of final irrigation in one of the years. The soil was a fine‐loamy, mixed (calcareous), hyperthermic, Anthropic Torrifluvents. Lint yield of Upland cotton was not reduced when planted as late as 7 May, except when irrigation was terminated in mid‐August. In contrast, lint yields of Pima cottons were reduced with each later planting date, except for the earliest planting and latest irrigation and harvest. Plant populations in 2 years had no interaction with planting dates for lint yield. The dates of seedling emergence and dates of early flowering occurred about the same time for Upland and Pima cotton in most plantings and therefore could not account for the differences between species in yield response to dates of planting and final irrigation. The rate of flowering, once started, was much slower for Pima cotton than Upland cotton. ‘Pima S‐5’ reached peak flowering an average of 18 days later than ‘Deltapine 61’ (DPL 61). Weekly lint production far DPL 61 was 4.5 times that for Pima S‐5 in August, twice that of Pima S‐5 in September, but only three‐fifths that of Pima S‐5 in October. Pima strain ‘79–106’ was intermediate between DPL 61 and Pima S‐5 in earliness of lint production. We conclude that Pima cotton requires early planting and nearly full‐season production for highest yield. Early planting is not as critical for Upland cotton, unless early crop termination is planned.
The Interrelationship Among Nutrient Elements Applied to Calcareous Sand Greens1
Authors: Christians N. E. , Martin D. P. , Karnok K. J. 
Published: July 2010

AbstractA field study designed to observe the interacting effects of applied N, P, and K on the growth and quality of creeping bentgrass (Agrostis palustris Huds. ‘Penncross’) was conducted on highly calcareous, experimental, sand greens at Ohio State Univ. in 1977 and 1978. Application rates of N and K ranged from 0 to 10.8 kg/are/year (1 are = 100 m2, 1 kg/are is approximately 2 lbs./1,000 ft2) and application rates of P ranged from 0 to 5.4 kg/are/year. Data were also collected on the effects of applied nutrients on a number of soil test measurements. Potassium test levels ranged from 52 to 252 kg/ha after the 2nd year of the study. Increasing rates of N and K interacted in their effect on K soil test levels. Potassium test level in plots receiving 10.8 kg/K/are/year were 125 kg/ha higher in plots receiving no N than in plots receiving the highest level of applied N. Nitrogen and K were also observed to interact in their effects on tissue growth. At lower levels of applied N, tissue production increased with increasing levels of applied K. At high levels of applied N, tissue growth decreased slightly with increasing levels of K. Evidence is presented which would indicate that Mn may have been limiting to growth at high rates of N and K. Highest tissue chlorophyll content and quality were observed at N application rates of approximately 6 kg N/are/year. This is nearly double the rate normally recommended for greens in temperate regions.
Thatch and Quality of Meyer Zoysia in Relation to Management1
Authors: Dunn J. H. , Sheffer K. M. , Halisky P. M. 
Published: July 2010

AbstractThatch control is a serious management problem in ‘Meyer’ zoysia (Zoysia japonica Steud.), one of the best adapted turfgrass varieties in the upper South. Improved cultural methods would greatly enhance the use and adaptability of Meyer zoysia in this region. The purpose of this study was to evaluate the effectiveness of annual, mechanical thatch removal, two mowing heights, and three N carriers, each applied at two rates of N, in reducing thatch accumulation and improving quality of Meyer zoysia.Vertical slicing reduced the thatch depth by 12 to 18% each year over a period of 5 years. Mowing at 1.9 cm compared with 3.8 cm decreased thatch by 13 to 25% annually over the same period. Thatch was not significantly affected by applications of 0.98 or 2.93/kg N/100 m2 annually with IBDU, (isobutylidene diurea), UF (ureaformaldehyde), or urea.Mowing at 1.9 cm plus mechanical thatch removal almost eliminated “winter injury” in 1976, while zoysia turf with no thatch removal and 3.8 cm mowing was 81% injured. Nematode (Helicotylenchus spp., Tylenchorynchus spp., and Xiphinema spp.) populations were sometimes large in turf showing winter injury but there was no significant correlation of nematode genus or population size with injury. Zoysia mowed at 3.8 cm recovered more slowly following thatch removal than that mowed at 1.9 cm and was infested with Kentucky bluegrass (Poa pratensis L.) which comprised 16% of the turf after 5 years.Thatch depth was not affected by applications of 0.98 or 2.93 kg N/100 m2 IBDU, UF, or urea. Differences in quality and fall color were small in response to N carriers and rate of application. However, UF and IBDU, particularly at the higher rate of N, stimulated henbit (Lamium amplexicaule L.) in winter and early spring when zoysia was dormant.Mowing at 1.9 cm plus annual thatch removal, irrigation, and a moderate rate of N reduces “sponginess” and can produce good quality summer zoysia turf over a period of several years, irrespective of N carrier.
Foliar Fertilizer Damage to Corn Leaves: Relation to Cuticular Penetration1
Authors: Neumann Peter M. , Ehrenreich Yael , Golab Zvia 
Published: July 2010

AbstractFoliar fertilization with N, P, K, and S has been reported to sometimes produce large yield increases in important food crops. However, zero and negative effects on yields are often reported: frequently in conjunction with foliage damage from fertilizer salts. Little is known about the mechanism of burn damage induction or the comparative damaging effects of different fertilizers applied to intact leaves.We have compared the damaging effects of solutions of several N, P, K, and S fertilizers applied to intact corn (Zea mays L.) leaves under controlled conditions. Minor differences in the chemical structure of the fertilizers had large effects on the threshold concentration above which damage was induced. For example, K2HPO4 was damaging at concentrations ≥ 0.05 M whereas KH2PO4 became damaging only at concentration ≥ 0.50 M. Penetration of these two compounds through the intact cuticle occurred at similar rates and was dependent on concentration rather than type of salt. Transfer away from the site of application was slow and significant differences in transfer rate were not observed. We conclude that all osmotically‐active fertilizer compounds can induce plasmolytic damage when sufficiently high concentrations penetrate into the leaf. However, fertilizers such as K2HPO4 and some others with a higher range of solution pH have specific toxic effects which can induce cell and tissue necrosis at relatively low concentrations.
Root Development of Winter Wheat as Related to Tillage Practice in Western Nebraska1
Authors: Wilhelm W. W. , Mielke L. N. , Fenster C. R. 
Published: July 2010

AbstractTillage practices can influence crop root development. Root distributions were determined for wheat (Triticum aestivum L.) grown in a wheat‐fallow rotation during the 1977–1978 winter wheat crop year on an Alliance silt loam (Aridic Argiustoll). The fallow tillage treatments were plow, subtillage, and chemical (no tillage). Each tillage treatment was split into subplots for N application of 0 or 45 kg/ha.Rooting density was determined by washing the roots in soil cores 7.6 cm in diam by 15 cm long extracted to depths of 90, 105, and 120 cm on 28 Mar., 2 May, and 8 June 1978, respectively. After root length was determined, roots were dried and weighed. Soil penetration resistance was determined with depth in the soil by inserting a penetrometer horizontally 4 cm into the soil at vertical intervals of 10 cm from the surface.Root weight was greatest for the chemical treatment (46 mg/dm3) and least for the subtillage treatment (26 mg/dm3). Approximately 62% of the total root mass was in the upper 30 cm of soil with maximum rooting depth greater than 120 cm for all treatments by 8 June 1978. Root development was limited by the alluvial horizon at a depth of about 25 to 40 cm. Visual observations also showed some root resistance by tillage shear plane at 10 cm. Nitrogen fertilization did not significantly change the rooting pattern; however, the N‐by‐tillage interaction for root weight was significant at the second sampling date—the subtillage treatment showed a positive response to added N, while chemical and plow treatments showed a negative response. Wheat yields were not significantly influenced by fallow tillage or N. This indicated that root development occurring above and below the resistant layer was sufficient to supply the plant with its water and mineral needs.
Response of Soybean Plants to High Root Temperature as Affected by Plant Cultivar and Rhizobium Strain1
Authors: Munevar F. , Wollum A. G. 
Published: July 2010

AbstractThis study examined the effect of high root temperatures on nodulation, dinitrogen fixation, and growth of five soybean [Glycine max (L.) Merr.] cultivars associated with either of two Rhizobium japonicum strains of contrasting temperature tolerances.In each of three greenhouse experiments, soybeans growing in pots containing vermiculite were submitted to root temperatures of 28, 33, and 37 C or 28, 33, and 35 C by submerging the pots in thermostatically controlled water baths. In the first experiment, cvs. ‘Hutton’ and ‘Ransom’ were inoculated with either strain USDA 110 or 587, while in the second experiment the same strains were used to inoculate cvs. ‘Gasoy‐17’ and ‘Bragg.’ In a third experiment cvs. Bragg, Gasoy‐17, ‘Lee,’ and Ransom were grown in association with strain 587. Plants were harvested 34 days after germination.The superiority in high temperature tolerance of strain 587 over USDA 110, found in earlier work with cv. Lee, was confirmed for cvs. Gasoy‐17, Hutton, and Ransom. Results with cultivar Bragg were inconsistent for the two experiments in which that genotype was included.The results indicate that soybean genotype influences the response of the symbiotic system to high root temperatures. Gasoy‐17 and Lee appeared to be more tolerant to high root temperature than the other cultivars. That characteristic was enhanced when Gasoy‐17 was associated with the tolerant strain 587. Selection of soybean cultivars with tolerance to high root temperature in symbiotic association with R. japonicum appears to be a feasible alternative to overcome high soil temperature stress and needs to be done in conjunction with strain selection.