bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Plant Density on Two Varieties of Kenaf in the Georgia Piedmont Region1
Authors: Massey John H. 
Published: July 2010

AbstractKenaf (Hibiscus cannabinus L.) is being investigated as a prospective new annual paper pulp crop. ‘Everglades 71’ and ‘Guatemala 4’ kenaf were grown in 50‐cm rows to study the effect of plant densities of 6.6, 8.8, 13.2, and 26.2 plants/m2 on stem yield, stem diameter, and plant height. Stem yield of Everglades 71 was higher in 1 of 3 years, but with 3‐year averages, varieties did not differ in any characteristic studied. Stem yield at 26.2 plants/m2 was higher than at other densities in 1 of 3 years. Basal stem diameter decreased as plant density increased, but plant height was not affected.The results of this experiment indicate that to avoid excessive plant branching at low densities and lodging of small plants at high densities, an intermediate plant density might be preferable.
Internal Leaf Water Status and Transport of Water in Rice Plants1
Authors: Tomar V. S. , Ghildyal B. P. 
Published: July 2010

AbstractRice (Oryza sativa L.) is generally grown continuously submerged in lowland soils and under rainfed conditions in upland soils. The objective of this study was to relate transpiration rate and leaf water potential to relative water content. This information may be useful in predicting the effect of soil moisture stress on growth and yield.Rice variety ‘IR‐8’ was grown in the greenhouse for 50 to 60 days under submergence and N⅓ bar soil matric potential, and then allowed to wilt.The pressure potential of leaves approached zero at a total water potential of about −19.5 bars, corresponding to 0.33 relative water content. Leaves experienced a change in cell elasticity at about 3 bars pressure potential and −10 bars total water potentialTranspiration rate decreased with leaf water potential, but it was independent of depletion of soil moisture content above 0.21 and 0.18 for plants grown in submerged and unsaturated soil conditions, respectively. These moisture contents correspond to −0.8 bar and −2.0 bars matric potential. Further depletion in moisture content of both soil moisture regimes resulted in a marked decrease in leaf water potential and in transpiration. Trans. port of water in the rice soil‐plant system was affected more by plant factors under flooded conditions than under unsaturated soil conditions.
Effect of Cercospora Leaf Spot of Peanuts on Forage Yield and Quality and on Seed Yield1
Authors: Cummins D. G. , Smith D. H. 
Published: July 2010

AbstractEpidemics of Cercospora leaf spot reduce the forage and seed yield of peanuts (Arachis hypogaea L.). The purpose of this study was to determine the effect of different levels of control of Cercospora leaf spot disease on defoliation, forage yield, quality, mineral composition, and seed yield of peanuts. Adapted peanut cultivars were grown according to recommended management practices in the Coastal Plain Region of Georgia during 1971 and 1972. Three foliar fungicides (benomyl 50W, chlorothalonil 75W, and copper‐sulfur dust) were compared with an unsprayed control. Fungicides were applied on a 14‐ day schedule, with five applications in 1971 and six applications in 1972. Benomyl and chlorothalonil gave significantly better control of Cercospora leaf spot than copper‐sulfur dust as evidenced by reduced defoliation. Copper‐sulfur dust was superior to the unsprayed control. As a consequence of disease control (very little defoliation), forage yields, in vitro digestibility, protein content, and seed yields were higher, and forage fiber content was lower. Higher calcium levels in forage were associated with good disease control in both years; Mg, Mn, Fe, Al, and Mo were higher in only 1 year. These differences between years could have been due to the use of different peanut cultivars. Several elements (P, B, Zn, Sr, Ba and Na) were not changed as a result of leaf spot control in either year. During both years, potassium decreased with control of leaf spot. Higher levels of Cu were observed in the forage treated with copper‐sulfur dust in both years. Thus, control of Cercospora leaf spot in peanuts was accompanied by an increase in yield and quality of forage and yield of seed, and levels of control achieved were highly correlated with yield and quality.
Influence of the Nitrogen Fertility Level on Tricholoma Fairy Ring Development in Merion Kentucky Bluegrass (Poa Pratensis L.)1
Authors: Beard J. B. , Vargas J. M. , Rieke P. E. 
Published: July 2010

AbstractHigher application rates of water soluble nitrogen stimulated the development of fairy rings (Tricholoma sordidum Fr.) in a mature ‘Merion’ Kentucky bluegrass (Poa pratensis L.) turf. The stimulation occurred in plots receiving 3.9 kg or more of nitrogen per are applied annually. Although the increase in Tricholoma fairy ring development was associated with a general decrease in the soil pH, the response was attributed to the more direct effect of the nitrogen fertility level.
Carbon Dioxide Uptake by Wide‐Row Grain Sorghum Computed by the Profile Bowen Ratio1
Authors: Allen L. H. , Hanks R. J. , Aase J. K. , Gardner H. R. 
Published: July 2010

AbstractA method for computing CO2 uptake by an irrigated crop of wide‐row grain sorghum (Sorghum bicolor (L.) Moench, var. ‘RS‐610’) was devised from measured profiles of temperature, water vapor, and CO2 over the crop. The crop Bowen ratio, β and the ratio of photochemical heat flux density of carbon dioxide fixation to latent heat flux density, α, were determined from profiles of points, rather than from just two points. We call this method the profile Bowen ratio. The parameters α and β were used with the energy balance equation to compute the flux density of CO2 to the crop as a function of solar radiation, which itself was a function of time of day. CO2 flux density plotted as a function of solar radiation (or time of day) was lower at the highest radiation loads (midday) than at 1000 or 1400 hours. The lower CO2 flux density at midday may be the result of more mutual leaf shading in this crop geometry at high solar elevation angles. The CO2 flux density curve also showed concave curvature at the radiation loads concomitant with early morning and late afternoon hours when much of the solar energy was penetrating to ground in this east‐west row crop. Finally, computed daily CO2 fluxes were reasonably close to the CO2 equivalent of dry matter accumulation rates plus estimated respiration.
Emergence and Yield of Beans Planted with a Seed‐Orienting Planter1
Authors: Hayden C. W. , Bowers S. A. 
Published: July 2010

AbstractRecent observations from an unrelated bean (Phaseolus vulgaris L.) field experiment indicated a possible relationship between emergence and seed orientation. To test the benefits of a “lay flat” orientation, a furrow opener was developed that horizontally orients bean seeds at uniform soil depths. Beans planted through this furrow opener emerged through the soil crust sooner and in significantly greater numbers than did those planted with a standard two‐disk furrow opener. Oriented and un‐oriented plantings of dry and snap beans did not differ in final total emergence. Nevertheless, early snap bean yields were greater from the seed‐oriented plots. Increased yield was due to earlier emergence, and uniform depth of planting. On uncrusted soil, seed orientation did not significantly increase dry bean yield.
Energy Balance Comparisons of Wide and Narrow Row Spacings in Sorghum1
Authors: Chin Choy E. W. , Kanemasu E. T. 
Published: July 2010

AbstractA sorghum (Sorghum bicolor L. Moench.) canopy has been described as a wick; hence, its evapotranspiration would depend to a large extent on its energy supply. The objective of this study was to determine the effect of row spacing on the energy balance of sorghum.Measurements were made on wide (0.92 m) and narrow (0.46 m) spaced rows of sorghum with equal linear plant density (12 plants/m). Evapotranspiration (lysimeter), net radiation, and soil heat flux were measured. Sensible heat flux was obtained as a residual in the energy balance. Seasonal evapotranspiration was about 10% more from wide row than from narrow row sorghum. High rates of evapotranspiration were maintained on wide row sorghum by row advection during the first part of the growing season and large‐scale advection during the latter part of the growing season. This study suggests that sensible heat and, consequently, evapotranspiration can be reduced by narrow row spacing in sorghum.
Differential Iron Absorption Efficiency of Peanut (Arachis Hypogaea L.) Cultivars Grown on Calcareous Soils1
Authors: Hartzook A. , Karstadt D. , Naveh M. , Feldman S. 
Published: July 2010

AbstractThe commonly observed chlorosis of plants grown on calcareous soils often has been treated effectively by use of iron chelates. Genetic variability for efficiency of utilization of iron on such soils has also been found. Three inefficient commercial cultivars and five efficient experimental cultivars of peanuts (Arachis hypogaea L.) were compared under treated (Fe EDDHA) and untreated conditions for yield and market quality of pods. The gain in yield for chelate treatment ranged from 22 to 210% for the commercial cultivars but only 8 to 18% for the efficient cultivars. Yields of untreated efficient cultivars were comparable to those of treated inefficient ones, suggesting that use of the former would be economically preferable.
Analysis of Sampling Errors with Traversing Radiation Sensors in Corn Canopies1
Authors: Sinclair T. R. , Desjardins R. L. , Lemon E. R. 
Published: July 2010

AbstractA traversing system with a fast responding, photocell light sensor was used to measure mean irradiance in corn (Zea mays L.) canopies. Data were recorded by digital and analog recorders to analyze the sampling problems with a moving sensor. Sampling rates of once every 4 seconds for a row‐planted crop and once every 8 seconds for a uniformly planted crop were required to yield satisfactory mean irradiance values from a fast responding sensor. In addition, sensors with time constants at least as long as 8 seconds could be used to measure mean irradiance. Therefore, we recommend that the sampling rate for a traversing sensor in a maize leaf canopy be at least as frequent as the time constant of the sensor, but in any case the sampling rate does not need to be any more frequent than once every 4 seconds.
Effect of Inoculum Rate on Competitive Nodulation of Glycine max L. Merrill. II. Field Studies1
Authors: Weaver R. W. , Frederick L. R. 
Published: July 2010

AbstractTo provide a scientific basis for predicting successful competitive nodulation of soybeans (Glycine max L. Merr.) by Rhizobium japonicum, the quantitative relationship between soil and inoculum rhizobia, in nodule formation, was determined in the field. Soybean seeds were planted at a rate of 1 seed/2.5 cm of row and were inoculated with up to 3.3 ✕ 1038 R. japonicum cells/2.5 cm of row. Field plots were grown on six soils in Iowa having a range of soil rhizobia populations of 1.2 ✕ 101 to 2.3 ✕ 105/g of soil. Numbers of nodules on tap and lateral roots of soybeans grown on soils containing fewer than 12 rhizobia/g were increased when inoculation rates exceeded 3.3 ✕ 104 cells/seed. Neither numbers of nodules nor total nodule mass was increased by inoculation of soybeans grown on soils containing more than 1 ✕ 103 rhizobia/g. When an inoculation rate of 3.3 ✕ 106 rhizobia/seed was used on soybeans grown in soils with fewer than 12 rhizobia/g and in soils with approximately 1 ✕ 103 rhizobia/g, the inoculum strain produced, respectively, 65% and 35% of the nodules. From our results it may be predicted that if the inoculum rhizobia are to form 50% or more of the nodules an inoculum rate of at least 1,000 times the soil population (per g soil) must be used. Commercial inoculants in the United States probably are not supplying adequate numbers of rhizobia for successful competitive nodulation of soybeans grown on land previously cropped to soybeans.
Flowering Behavior and Seed Development in Four Desmodium Species1
Authors: Chow K. H. , Crowder L. V. 
Published: July 2010

AbstractA knowledge of flowering behavior and seed production would be helpful in formulating intra‐ and interspecific breeding programs of Desmodium species. Selections of D. canum (Gmel.) Schin. and Thell., D. intortum (Mill.) Urb., D. sandwicense E. Mey., and D. uncinatum (Jacq.) DC. were grown in controlled environments and in the glasshouse at Ithaca, New York to investigate plant response to photoperiod and to study ovule and seed development.D. sandwicense was day‐neutral. D. intortum and D. uncinatum flowered under short days of less than 12 hours. D. canum needed at least 12 hours to induce flowering under artificial light of 21,520 lux (2,000 ft‐c). The species is considered day‐neutral, however, since profuse flowering occurred under natural light of 15.2 hours and since it flowers under shorter days in tropical and subtropical areas. The four species had perfect flowers borne on indeterminate racemes. Anthers of D. canum dehisced in midafternoon with 14 to 15.2 hours of light in the glasshouse. Under 11 hours of light the other three species dehisced 6 to 8 hours before the end of the dark period in the growth chamber. A tripped flower wilted quickly and the standard petal folded over the stigma within 1 hour. Without pollinators, flowers generally did not trip, but seed set exceeded 50%.After fertilization, the ovule length:width ratio increased rapidly for 4 to 6 days, then declined as broadening occurred. The epicotyl, hypocotyl, and cotyledons became visible within 5 days. At 17 days after pollination seed coats became impermeable on drying of seeds. Before the seed reached maximum weight at about 28 days, 90% or more had hard seed coats. Seed were viable 20 days after fertilization when scarified, and germination rapidly increased thereafter to about 30 days. There was no dormancy period when seed were properly scarified.
Selection for Seedling Vigor in Astragalus cicer L.1
Authors: Townsend C. E. 
Published: July 2010

AbstractThe use of cicer milkvetch (Astragalus cicer L.) as a forage legume is restricted because of relatively poor seedling vigor. If sufficient variation exists within the species for seedling vigor, it may be possible to improve this character through a breeding program. Therefore, the objectives of this study were to determine (1) the variability in speed of seed germination and total germination in the laboratory at two alternating temperature treatments, 5–20 C and 15–25 C; (2) the variability in speed of seedling emergence and total emergence in the greenhouse and field; and (3) the relationships among these characters. About 80 polycross progenies, representing 3 basic breeding populations, were evaluated. The populations comprised polycross progenies selected for superior, average, and below‐average vigor. Highly significant differences existed among progenies for speed of seed germination and seedling emergence over all environments. Simple correlation coefficients between the various characters generally were significant, but of a relatively low predictive value. There is a great need for a laboratory technique that will give a reliable measure of seedling vigor under field conditions. Variation among progenies for seedling vigor was large enough to indicate that improvement can be made in cicer milkvetch for this character.
Crested Wheatgrass Yields as Influenced by Water Conservation Practices1
Authors: Bleak Alvin T. , Keller Wesley 
Published: July 2010

AbstractEvaporation of water Irom the soil surface is a major economic loss to the western United States, because water is the primary limiting factor in plant growth on arid and semiarid rangelands. ‘Nordan’ crested wheatgrass (Agropyron desertorum (Fisch. ex Link) Schult.) planted in rows 1.1 m apart; the effect on total herbage yield of a gravel mulch, a sheet metal “mulch,” close rows of grass, and cereal grain seeded between the grass rows was determined for a 2‐year period. Some treatments received different rates of N fertilizer. Sheet metal between the rows, covering 86% of the land surface, increased mean 2‐year yield about 112% over clean cultivation (check). A gravel mulch 1.5 cm deep increased mean yield about 16%. Close rows of grass and cereal grain between the grass rows also increased total yield. Benefit from nitrogen at 22, 44, or 66 kg/ha per year was minor. Benefit from the mulches was greater the second year than the first.
Early Growth of Grain Sorghum as Related to Manganese Nutrition1
Authors: Ohki K. 
Published: July 2010

AbstractInfluence of Mn nutrition on sorghum [Sorghum bicolor (L.) Moench.] was investigated to determine the effects of Mn on early growth and define Mn deficiency symptoms under controlled conditions of nutrient solution culture in the greenhouse. Sorghum plants were grown in the greenhouse in nutrient solution containing eight Mn levels from O to 4,000 μg Mn/liter with all other essential nutrients supplied at adequate levels.Growth retardation determined from plant height measurements resulted prior to the development of visible Mn deficiency symptoms. In addition to the usual Mn deficiency symptoms of interveinal chlorosis, symptoms on sorghum Dekalb ‘BR 64’ included brown‐reddish pigmented bands in interveinal areas following chlorosis. Under slight Mn stress conditions, Mn deficiency symptoms decreased hi severity from young to older leaves.
Decontamination of Surface Soil Containing Strontium‐901
Authors: Haghiri F. 
Published: July 2010

AbstractThe effectiveness of “Dresinol‐40,” “Dresinol‐205,” and “Vinsalyn‐100 Emulsion” materials for immobilizing 00Sr(00Y) adsorbed by soil surface in a form not available to plants was examined. These materials appeared to form a satisfactory crust with soil particles. Spray application of the emulsion material reduced the uptake of 90Sr90Y) by oat (Avena sativa L.) shoots by as much as 56%. However, the percent reduction was not high enough to justify their use as agents for decontaminating surface soil containing radioactive strontium.
Effect of Temperature and Methyl Parathion on Vegetative Development and Fruiting of the Cotton Plant1
Authors: Gipson Jack R. 
Published: July 2010

AbstractIn the northern areas of the Cotton Belt, suboptimum temperatures are rather common during the very early stages of growth and during the latter stages of boll development of cotton (Gossypium hirsutum). The effects of low temperature on boll development have been well defined, but little is known of the early season effects on plant fruiting and development. Thus, the purpose of this research was to determine how temperature influences early fruiting and vegetative development in cotton and to what extent the action of a chemical known to effect fruiting may be modified by temperature. Two diverse cotton cultivars, ‘Gregg 35’ and ‘Deltapine 16,’ were grown in field growth chambers under night temperature regimes of 10, 15, 20, and 25 C from the day of seedling emergence until frost. Methyl parathion was sprayed on half the plants of each cultivar at 10, 12, and 13 days after planting to assess the temperature chemical interaction. The observed effects, in the order of their magnitude were temperature > cultivar > chemical. Temperature‐cuitivar and temperature‐chemical effects were apparent in some cases. Earliness of fruiting as measured by days from emergence to first square, and bloom was most timely at 20 and 25 C. As temperature decreased below 20 C, however, there was a marked increase in both days to first square and days to first bloom. Nodal positions of first squares and blooms were essentially the same at 15 and 20 C, but either a reduction to 10 C or an increase to 25 C resulted in a significantly higher nodal position of these forms. The total number of limbs per plant was relatively constant across cultivars and treatments, but the ratio changed between vegetative and fruiting limbs. At 10 and 25 C the number of vegetative limbs increased at the expense of fruiting limbs. Number of bolls per plant and seed cotton yield were drastically retarded at 10 C for both cultivars. Maximum boll production was achieved at 15 C for Gregg and 20 C for Deltapine. Maximum yields were attained for both cuitivars at 20 and 25 C.
Ammonia Volatilization from Soils1
Authors: Mills Harry A. , Barker Allen V. , Maynard Donald N. 
Published: July 2010

AbstractIf NH4+‐N fertilizers are used, most agronomic crops grow best if the soil reaction is near neutrality. Previous studies have shown that if the soil pH becomes alkaline, NH3 volatilization losses of N occurs. The objective of this study was to determine whether or not a rapidly growing crop could reduce the volatilization losses of N, especially from soils above pH 7 to which large applications of NH4+‐N fertilizers were made. This study was conducted in a greenhouse using a closed system in which all NH3 evolved from the soil was swept away by a stream of air and collected. The amount of NH3‐N evolved from the soils was measured as a function of time, soil pH, amount of N application, and presence or absence of corn (Zea mays indentata Bailey) seedlings. Ammonia losses with or without plants in the system increased as the soil reaction and amount of NH4+‐N application increased. A sharp upward inflection in NH3‐N loss occurred at pH 7.2. Plants reduced NH3‐N losses by atleast 60% in the alkaline soils and by lesser amounts in the acidic and neutral soils. Rapid absorption of NH4+‐N by plant roots appeared to account for the conservation of N.
Effects of Germination on Cotyledon Nitrogen, Starch, Reducing Sugar, and Growth of Lima Seedlings
Authors: Hegwood D. A. , Gaines T. P. 
Published: July 2010

AbstractPoor seedling establishment which frequently reduces stands and causes uneven seedling growth in lima bean (Phaseolus lunatus L.) plantings points up the need for research to identify those changes occuring during the seedling establishment phase. This research is needed to show how these changes are associated with early seedling growth. Accordingly, cotyledons from seedlings of two lima bean cultivars, ‘Nemagreen and Jackson Wonder,’ were compared during pre‐ and postemergence for changes in total N, protein N, nonprotein N, starch, reducing sugars, and seedling growth.Cotyledons of Jackson Wonder were significantly higher in total N than Nemagreen because of the protein N fraction. The nonprotein N fraction did not differ between cultivars.The protein:nonprotein N in Nemagreen approached 1 on the sixth, seventh, eighth, and ninth day after planting. Maximum decrease of protein N and a corresponding maximum increase of nonprotein N occurred on the fourth, fifth, sixth, and seventh day for each cultivar. A net decrease in total N in cotyledons occurred during postemergence.Reducing sugars were present in cotyledons of resting seed and developing seedlings but did not differ in amount between cultivars.The period of most rapid starch depletion and cotyledon weight loss occurred during postemergence and was accompanied by rapid increases in top dry weight.
Seed Yield Coronilla Varia L.1
Authors: Al‐Tikrity Wail , McKee G. W. , Clarke W. W. , Peiffer R. A. , Risius M. L. 
Published: July 2010

AbstractAlthough average seed yields of crownvetch (Coronilla varia L.) are low, there are to our knowledge no published data on potential yields and on losses incurred during harvest. To secure such information, samples of crownvetch forage and the contained seed were hand harvested in 1970 and 1971 from a 24‐ha commercial seed field of the variety ‘Penngift.’ The seed was hand‐hulled and cleaned to certified standards. The mean yield of handharvested seed in 1970, a year of above‐normal precipitation and very heavy forage growth, was 257 kg/ha. In 1971, with precipitation slightly below normal, the mean yield was 530 kg/ha. Field losses during commercial harvest were about 61% in 1970 and 58% in 1971. Seed harvest in crownvetch is complicated by uneven maturity caused by an indeterminate flowering habit and by a tendency for the seedpod or loment to shatter readily when disturbed. In addition, a dense growth of foliage must be combined to recover the seeds.