bluuebunny/crossref_metadata_2025_split huggingface dataset:
Procedure for Adjusting the Yield of Plots of Burley Tobacco (Nicotiana tabacum L.) for Differential Stands1
Authors: Gupton C. L. , Archer L. E. 
Published: July 2010

AbstractDuring 1968 and 1969 we conducted a study to determine whether the precision of yield estimates could be improved by adjusting plot yields for differences in stand of burley tobacco (Nicotiana tabacum L.). Plants were removed from the plots at four different stages of growth and in five different patterns. Both the stage and pattern of plant removal had significant effects on the plot yield of cured tobacco.To derive an adjustment procedure for missing plants, we estimated the amount of compensation resulting from each stage and pattern of plant removal as the difference between the actual yield per plot and the expected yield, assuming no compensation. The proportion of the check plant average compensated for in a given pattern was computed as the ratio of the estimated amount of compensation to the average yield per check plant. A direct adjustment of plot yields to a full stand basis is possible after adding the equivalent number of plants resulting from compensation to the stand count.The efficacy of our procedure was determined by applying it to data from a yield and quality trial that had a poor stand in 1971. Relative efficiencies were 100, 129, 139, and 149 for no adjustment and adjustment by Crew‘s procedure, covariance analysis, and our procedure, respectively.To determine the nature of compensation by plants adjacent to missing plants, we computed standard partial regression coefficients, which were 0.2437 for plant height, 0.0180 for length of leaf, and 0.5972 for width of leaf. Plant height appears to exert a small influence on compensation, but the major influence is apparently the leaf width component of leaf size.
Opposite Alluminum and Manganese Tolerances of Two Wheat Varieties1
Authors: Foy C. D. , Fleming A. L. , Schwartz J. W. 
Published: July 2010

AbstractAcid soil and solution culture studies showed that ‘Atlas 66’ wheat (Triticum aestivum L.) from North Carolina was more tolerant to excess Al but less tolerant to excess Mn than ‘Monon’ wheat from Indiana.In greenhouse pots of Al‐toxic Bladen soil (pH 4.6 to 5.1) the top yields of Atlas 66 were significantly higher (5% level) than those of Monon; liming the soil to pH 5.8, however, equalized top yields of the two varieties. In Mn‐toxic Zanesville soil (pH 4.7 to 5.2) the varietal yield difference was just the reverse. At pH 5.2 the tops of Monon plants had fewer leaf symptoms (rolling and chlorotic spots) and yielded significantly more than those of Atlas 66; at pH 5.9 or 6.9, however, the two varieties were not significantly different in top yield.In nutrient solutions containing between 4 and 32 ppm Mn at pH 4.6 the tops of Monon showed fewer leaf symptoms of Mn toxicity and yielded significantly more than those of Atlas 66, but with O or 2 ppm Mn added, the top yields of the two varieties were not significantly different. With Mn levels of 2 to 32 ppm, Monon root yields were significantly higher than those of Atlas 66, but with no Mn added the two root yields were not significantly different. At all Mn levels of 2 to 32 ppm in solution both tops and roots of Monon contained higher Mn concentrations than those of Atlas 66, but Monon plants showed less injury. For example, in Monon tops 2,561 ppm Mn was associated with a yield reduction of 12%. In Atlas 66 tops 1,250 ppm Mn (the highest concentration reached in Atlas 66) was accompanied by a yield reduction of 21%. In Monon roots 8,534 ppm Mn was associated with a root yield reduction of 20%, but 7,172 ppm Mn in Atlas 66 roots coincided with a 45% reduction in root yield.Tolerance to one acid soil factor in a given plant genotype does not necessarily mean tolerance to another.
Effects of Spring Planting Date and Row Spacing on the Agronomic Characteristics and Chemical Composition of Crambe1
Authors: Massey John H. , Jellum M. D. 
Published: July 2010

AbstractCrambe (Crambe abyssinica Hochst. ex R. E. Fries) has potential as a new oilseed crop. Since crambe is not winter hardy, an experiment was conducted at Experiment, Ga. to study the effects of spring planting dates and row spacing on agronomic characteristics and chemical composition of the seed. P.I. 247310 was spring seeded in 1969 and 1970 at four 1‐week intervals in three row spacings, 36, 53, and 71 cm. Seed yields were similar for all planting dates and averaged 724 kg/ha. Planting dates did not affect oil content or fatty acid composition of oil in 1969, but the earliest planting produced higher oil and erucic acid contents in 1970. Each 18‐cm decrease in row width produced approximately 30% more seed. Row spacing did not affect oil content or fatty acid composition. Planting date and row spacing did not significantly affect test‐weight, pod percentage, or plant height.
A Major Cereals Project to Improve Maize, Sorghum and Millet Production in Africa1
Authors: Eberhart S. A. , Sprague G. F. 
Published: July 2010

AbstractThe objectives of this project, initiated in 1963, were 1) to increase cereal production in Africa through cooperation with and support of research organizations in Nigeria, Kenya, and Uganda, 2) to stimulate and sponsor cooperative research in all aspects of cereal production throughout the area, and 3) to provide in‐service training at the headquarters stations to individuals sponsored by their governments. This integrated program included plant breeders, entomologists, pathologists, and cereal technologists to develop new high‐yielding, disease and insect resistant varieties with increased food values, agronomists to develop a package of recommended cultural practices to exploit the potential of the new varieties, and research‐extension liaison officers to help extension personnel to reach the local farmers with the new varieties and recommended agronomic practices. Encouragement and assistance were given to cooperating agencies and companies for seed production, the development of marketing systems, and the utilization of the excess production. Kenya has been greatly increasing its maize production, and other African countries are moving forward.
Cotton Leaf Temperatures as Related to Soil Water Depletion and Meteorological Factors1
Authors: Ehrler William L. 
Published: July 2010

AbstractIn two field experiments with cotton (Gossypium), the relation between moderate soil water depletion and leafair temperature difference (ΔT) was investigated for feasibility of measurement and possible use as a guide to irrigation scheduling. Hourly temperatures of the upper leaves and of the air 1 m above the canopy were obtained for three cultivars of short‐staple cotton (G. hirsutum L.) and one of long‐staple (G. barbadense L.). In addition, hourly measurements were made of the vapor pressure 1 m above the crop. These data were taken during six irrigation cycles extending over two summers and encompassing a wide range of saturation deficit (SD).In contrast to previous experiments in which a severe drought had been developed deliberately to intensity plant response, the experimental plots were irrigated on a schedule to obtain a high lint yield.The temperature differences were measurable and predictable. When the SD remained steady from day to day, the mean daytime ΔT decreased 1 C on the day of irrigation and an additional degree the next day owing to leaf rehydration and consequent stomatal opening. Conversely, this 2 C decrease upon irrigation reflects the rise in ΔT that had occurred during the previous drying cycle. When the SD decreased appreciably, the stomatal opening caused by irrigation was masked. Because the SD seldom remains steady over long periods, a measurement of ΔT alone is not a sufficient indicator for irrigation. Thus, allowance was made for such changes in SD by calculating a regression of ΔT on the SD from data taken from a recently irrigated crop.Although the use of ΔT to schedule irrigations seems feasible, the method is restricted primarily to regions with sunny climates. Even here it requires accurate, wellreplicated leaf temperature measurements as well as measurements of air temperature and vapor pressure.
Protein Content of Winter Wheat Grain as Related to Soil and Climatic Factors in the Semiarid Central Great Plains1
Authors: Smika D. E. , Greb B. W. 
Published: July 2010

AbstractProtein content of wheat (Triticum aestivum L.) grain has decreased in recent years in the Central Great Plains. Conflicting reports concerning the causes for this decrease prompted this investigation. Protein content data from North Platte, Neb.; Akron, Colo.; and several southwestern Nebraska locations were shown to be negatively correlated by linear regression with total precipitation >1.25 cm for a 15‐day period 40 to 55 days before maturity (r = −0.70**) or with available soil water at seeding to a depth of 1.2 or 1.8 m (r = −0.79**). Grain protein levels were shown to be positively correlated by linear regression with total soil NO3‐N to depths of 1.2‐ or 1.8‐m (r = 0.82**) and by curvilinear regression with maximum air temperature for a 5‐day period 15 to 20 days before maturity (R = 0.74**). With all four factors combined, R2 = 0.96. With available soil water at seeding plus NO3‐N in the soil profile at seeding and protein content of wheat grain, R2 = 0.86. Maximum yield was obtained with 28 cm of soil water available at seeding, and at least 106 kg/ha of NO3‐N at seeding was needed to obtain grain with 12% protein.
Operational Value of Weather Information in Relation to Soil Management Characteristics1
Authors: Ewalt R. E. , Wiersma D. , Miller W. L. 
Published: July 2010

AbstractImproved understanding is needed of factors that may govern the degree of usefulness of weather information to farm operators. This study was undertaken to evaluate the usefulness of precipitation forecasts and field conditions forecasts to farm operators in planning and conducting field operations. Possible relationships between farm operator valuations of forecasts, soil management characteristics, and the accuracy of precipitation forecasts were studied.Two‐thirds of the 145 interviewed farm operators used both precipitation and field conditions forecasts in planning and conducting major field operations. These operators valued both types of forecasts at higher levels of usefulness than did the remaining one‐third, who used only precipitation forecasts. The usefulness of precipitation forecasts and field conditions forecasts increased with increasing water‐holding capacity and susceptibility of soils to physical problems such as cloddiness, tillage pans, and surface sealing.Farm operators who used both types of forecasts valued them at approximately the same levels of usefulness in relation to major field operations conducted during the crop season. Highest values were associated with field operations that are conducted during the spring months. Precipitation forecasts were more useful than field conditions forecasts in making general management decisions. No relationship was found between the error rates of precipitation forecasts and farm operator evaluation of their usefulness.
Effect of Seed Maturation and Plant Population on Soybean Seed Quality1
Authors: Burris J. S. 
Published: July 2010

AbstractSoybean (Glycine max (L.) Merr.) seed producers have shown a renewed interest in the premature defoliation of seed fields to facilitate earlier dry‐down and efficient harvest. This interest prompted this study on the effects of seed maturation (days after flowering) on seed quality. Four cultivars of soybeans were grown at 4 and 8 plants/ 30 cm rows in rows 75 cm apart. Individual flower nodes were identified at flowering. Pods were removed 30, 40, 50, and 60 days after flowering and allowed to air dry in the laboratory. The hand shelled seed was used to determine wt/100 seed, germination percentage, shoot and root dry matter, and cotyledonary weight remaining at the end of the seven‐day growth period. Seed size increased linearly with increased time after flowering. The low population produced significantly smaller seed than the high population. Germination percentages increased with increasing time after flowering, although the varieties Amsoy and Corsoy exhibited a reduction in germination between 30 and 40 days, primarily accounted for by an increase in the hard seed percentage. Shoot and root growth increased with increased time after flowering. Shoot growth was greatest and root growth was least in the high population.
Chemical Desiccation Experiments with Hard Red Spring Wheat, Triticum aestivum L.1
Authors: McNeal F. H. , Hodgson J. M. , McGuire C. F. , Berg M. A. 
Published: July 2010

AbstractChemical treatments were applied to ripening spring wheat (Triticum aestivum L.) cultivars over a two year period to determine if plant maturity and harvesting could be hastened. Bromoxynil, dalapon, NH4NO3, diquat, ametryne, and amitrole plus ametryne were applied as one or more spray treatment rates at weekly intervals, starting four weeks after heading. Agronomic and quality data from the chemical treatments were then compared to similar data from swathing and check treatments.None of the chemical treatments reduced head moisture percentages significantly faster than that which occurred in the check. Also, diquat, ametryne, and swathing treatments at four weeks after heading significantly reduced test weight and grain yield.Compared to the check plot, chemical treatments did not adversely affect milling and baking traits. Swathing, particularly that at four weeks after heading, reduced wheat protein, loat volume, and grain and texture by significant amounts. Increases occurred in grain protein percentages from ametryne treatments, but these increases were related to lower grain yields from these treatments.It was concluded that these chemical treatments were ineffective as dessicants for spring wheat.
Microanatomical Differences of Warm‐Season Grasses Revealed by Light and Electron Microscopy1
Authors: Akin Danny E. , Burdick Donald 
Published: July 2010

AbstractThe warm‐season grasses, ‘Coastal’ and ‘Coastcross‐1’ bermudagrass (Cynodon dactylon (L.) Pers.) and ‘Pensacola’ bahiagrass (Paspalum notatum var. saurae Parodi), and the cool‐season species ‘Kentucky 31’ tall fescue (Festuca arundinacea Schreb.) were investigated for differences in lignification sites and microanatomy. Leaf samples were examined by light, transmission electron, and scanning electron microscopy. In all the grasses studied, lignin was apparent in the tissue separating xylem and phloem in all first order vascular bundles. The bermudagrasses possessed a rigid, lignified inner bundle sheath surrounding the ground tissue of first order vascular bundles; bahia possessed only a lignified, partial inner sheath in this region. The second order bundles had a single, nonlignified sheath in all warm‐season grasses examined. Tall fescue appeared to have double‐sheathed vascular bundles with the outer sheath composed of thin‐walled cells. The inner sheath in the first‐order bundles of tall fescue contained slight amounts of lignin in cells adjacent to phloem tissue. Reported differences in microanatomy could be factors responsible for digestibility variances of grasses.
Overwinter Changes in the Percent Ca, Mg, K, P, and N in Vegetation and Mulch in an Eastern South Dakota Prairie1
Authors: White E. M. 
Published: July 2010

AbstractVegetation and mulch were collected from a moist and a dry site of a native prairie in eastern South Dakota on September 3 and November 5, 1969 and April 29, 1970 to study the overwinter changes in percent Ca, Mg, K, P, and N. The percent Ca in the vegetation was similar on the three dates for both sites; the percent Mg, K, P, and N in vegetation was greatest on the first sampling date for the moist site. The percent Ca, Mg, and K in mulch tended to be greatest on November 5. The percent P and N varied from date to date. The Ca, Mg, and K leached from the decaying vegetation before November 5 may temporarily have increased the amount in the mulch but it was lost by spring.
Sorghum Growth and Nutrient Uptake in Relation to Soil Fertility: I. Dry Matter Accumulation Patterns, Yield, and N Content of Grain1
Authors: Roy R. N. , Wright B. C. 
Published: July 2010

AbstractAn understanding of the seasonal dry matter accumulation pattern of the sorghum [Sorghum bicolor (L.) Moench] plant under varying fertility levels is important for planning an efficient fertilization program. Field experiments were conducted to determine the effects of varying rates of N (0, 60, and 120 kg/ha) on the dry matter accumulation pattern, yield, and grain N content of a sorghum hybrid. Plant samples were collected at weekly intervals and partitioned into component parts for dry matter estimation.The rate of dry matter accumulation in fertilized plants was rapid early in the season and continued almost linearly until maturity (91 days after sowing), but in unfertilized plants it began to drop after 70 days. In general, dry matter weight of leaves and stems reached a maximum by the 56th and 70th days, respectively, and then remained almost constant. The subsequent increase in total dry weight was due to increased head weight. Accumulation rate in the heads of fertilized plants at 70 and 77 days was very high in comparison to that of unfertilized plants. Contributions of stem, leaves, and head to the total dry matter yield with N0P0 and N120P26 treatments were 41, 23, and 36%, and 32, 18, and 50%, respectively.Dry matter yield of whole plant, grain yield, and grain N content were higher with 60 kg N/ha than with no nitrogen by 26, 47.6, and 14.5% respectively. They were also higher (9.2, 8.8, and 10.9% respectively) with 120 N/ha. Dry matter and grain yields were higher with 26 kg P/ha than with no P by 25.6 and 46.2% respectively. N content of grain was unaffected by addition of P.
Isolated Soil Columns for Plant Research: Procedure and Uniformity Trial1
Authors: Keller Wesley , Bleak Alvin T. , Hull A. C. 
Published: July 2010

AbstractIsolated soil tolumns offer one means of studying the influence on yield and other plant characteristics of different amounts of precipitation while other environmental factors are unaltered. These columns may be regarded as an inexpensive substitute for lysimeters. This study describes the establishment of 67 columns 1.22 m2 in a single row in 1967 and 79 and 88 columns in adjacent rows in 1969. The first year after establishment, a uniform crop of barley (Hordeum vulgare L.) was grown on the isolated columns as well as on two opposite sides. Coefficients of variation for total yield of barley ranged from 8.17 to 11.42%. A brief description is given of catchments to increase precipitation on the plots by 50% or to reduce it by 33%. These catchments are being used in studies with perennial forage species.
Soybean Emergence Under Field Conditions1
Authors: Fehr W. R. , Burris J. S. , Gilman D. F. 
Published: July 2010

AbstractSoybean (Glyclne max (L.) Merr.) cultivars differ hypocotyl elongation and percentage seedling emergence when grown in the laboratory at certain soil temperatures and planting depths. The study reported here was conducted to determine if differences among cultivars for percentage seedling emergence also are present under different soil temperature regimes and planting depths in the field.The study was conducted on a Nicollet silt loam at Ames, Iowa for 2 years. Percentage emergence was based on the number of seedlings that emerged per 100 viable seeds planted. Percentage emergence of cultivars with short hypocotyls at 25 C in the laboratory (‘Amsoy’ and ‘Beeson’) was compared to types with intermediate (‘Chippewa 64’ and ‘l.indarin’) and long hypocotyls (‘Hawkeye’ and ‘Wayne’). Three planting dates were used each year to obtain a range of soil temperatures. Planting depths of 5 and 10 cm and seeding rates of 5 and 10 viable seeds/30 cm of row were evaluated.Planting depth had a major influence on percentage emergence. Average emergence was 73% from 5 em and 44% from 10 em. Emergence as low as 13% was observed with the 10‐cm depth.Seeding rates of 5 and 10 viable seeds/30 cm of row resulted in the same percentage emergence for all planting dates and planting depths studied. Seeding rate altered the number of seedlings that emerged, but not the percentage of seedlings that emerged.Soil temperatures for date 1 were below 20 C and temperatures for dates 2 and 3 were generally between 20 and 30 C. There was no consistent difference in percentage emergence among planting dates for the 2 years. The data indicated that soil temperature did not consistently influence percentage emergence of the cultivars studied.Hawkeye had significantly better emergence from the 10‐cm depth than the other five cultivars. Percentage emergence of the five cultivars was not significantly different. Although differences in soil temperatures among planting dates did not appear to have a consistent influence on the emergence ability of the cultivars, the emergence of the short and intermediate hypocotyl cultivars was inferior to the long hypocotyl cultivar Hawkeye. The superior emergence of Hawkeye compared to Wayne suggests that differences for ability to emerge under high soil resistance may exist among long hypocotyl genotypes. A combination of laboratory evaluation at 25 C and field testing may be needed to identify genotypes with superior emergence potential in the field.
P Uptake by Wheat and Resin‐Extractable Phosphate after Incubation in Soil Derived from Volcaninc Ash1
Authors: Zunino H. , Peirano P. , Aguilera M. , Caiozzi M. 
Published: July 2010

AbstractThe heavy fertilization of volcanic ash derived soils required to obtain adequate yields demands good routine methods to test availability of phosphate in these soils. Therefore a resin‐extractable P method was tested against a biological one.Working with three selected soils, samples of each soil were fertilized with 0, 22, 66, and 132 ppm P as Ca(H2 PO4)2‐H2O and P determined after 0, 30, 60, 120 and 180 days of incubation.A close P added/P uptake correlation is maintained in nearly all soil‐samples after any incubation period studied. However, added P and resin‐extractable P were directly related up to 60 days of incubation only. This seems to be due to the formation of new P compounds as a result of the strong P fixing properties of these soils. These P compounds may have a different relative availability to plants than to chemical extractant as compared to the Ca(H2PO4)2‐H2O initially added.