bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Post Harvest Residue Management and Fertilization on Crop Yield1
Authors: Conrad B. E. , Holt C. E.
Published: July 2010

Yields of forage sorghum (Sorghum bicolor (L.) Moench.) were significantly different when grown under two management systems over a 5‐year period. Allowing regrowth to occur until October 15 resulted in first harvest forage sorghum yields in the succeeding season of approximately 79% of standard tillage. Fertilization response was also influenced by regrowth management. Similarly, in a 2‐year grain sorghumguar rotation, guar (Cyamopsis tetragonoloba (L.) Taub.) yields were reduced following a grain sorghum (Sorghum bicolor (L.) Moench.) stubble regrowth system.
Early Growth of Crownvetch under Reduced Light1
Authors: Langille Alan R. , McKee Guy W.
Published: July 2010

In 1963 and 1964, three varieties of crownvetch were subjected to six levels of shading (31% to 100% full daylight) to evaluate responses of this species to reduced light under field conditions. In neither year did shading significantly alter percentage total available carbohydrates in the roots but root weight was greatly reduced. Absolute carbohydrate levels varied significantly between years and varietal differences were significant. Under shaded conditions root growth was affected to a greater extent than top growth. Percentage crude protein in the forage increased as shading increased.
Serological Distribution of Soybean Root Nodule Bacteria in Soils of Southeastern USA1
Authors: Caldwell B. E. , Hartwig E. E.
Published: July 2010

Four soybean genotypes were sampled in eight different plantings during the years 1967 and 1968, to determine the variability in Rhizobium japonicum population. Considerable variability occurred among locations in the serological distribution of nodules in the cultivar ‘Lee.’ The serogronp patterns for nodules formed on soybean genotypes D49‐772 and D55‐4102 were different from those formed upon Lee at several of the locations. Results indicate that an effective relationship can be established between a soybean genotype and a wide range in serogroups of R. japonicum.
Root Response of Merion Kentucky Bluegrass Sods to Various Nitrogen Applications near the Time of Transplanting1
Authors: Dunn J. H. , Engel R. E.
Published: July 2010

Regrowth of the root system of transplanted sod has become a major concern in turf production. Since nitrogen is used on most turf sod installations, the amount of nitrogen applied and the time of its application may have important effects on the regeneration of roots from sods.

Re‐rooting of Merion Kentucky bluegrass sods given surface applications of N before transplanting, at the time of transplanting, and after transplanting to root observation containers in spring and summer was compared with that of sods given no N. Measurements included dry weights of roots grown from sods, rate of new root appearance, and color ratings.

Applications of 98 and 293 kg/ha of N to the surface of Merion Kentucky bluegrass sod before transplanting and at the time of transplanting increased re‐rooting compared with sods given no N.

Proper timing is important for the best use of N in root regrowth from sods. Applications of N dose to the time of transplanting were more beneficial to rerooting than applications at longer intervals before or after transplanting.

N decreased the carbohydrate content of topgrowth of sods by 20 to 25% at 23 days after transplanting in the summer test compared with sods given no N. Increased root regrowth was associated with decreased carbohydrates of topgrowth of sods given N at 4 days before transplanting and at the time of transplanting, but this did not occur when N was applied 9 days after transplanting.
Field Evaluation of Alfalfa Cultivars for Resistance to the Alfalfa Weevil in Mississippi — a Preliminary Study1
Authors: Pitre Henry N. , Watson Vance H. , Ward Coleman Y.
Published: July 2010

Significant correlation coefficients (P=.05) of −0.42 and −0.59 were obtained for first harvest dry matter yields of alfalfa and alfalfa weevil populations. ‘Vernal,’ ‘Rhizoma,’ and ‘MSHP7’ varieties were consistently lower in alfalfa weevil infestations than the other varieties evaluated. Population levels decreased rapidly in May and were not a serious problem after the first harvest.
Plant Varieties as Indicator of Aluminum Toxicity in the A2 Horizon of a Norfolk Soil1
Authors: Long F. Leslie , Foy Charles D.
Published: July 2010

Two varieties of barley (Hordeum vulgare, L., emend, Lam.) and two varieties of snapbeans (Phaseolus vulgaris, L.), known to differ widely in their tolerance to aluminum, were used as biological indicators of aluminum toxicity in the A2 horizon of an acid Norfolk soil (pH 5.2). Both top and root growth of the indicator varieties supported the conclusion that aluminum toxicity is an important growth‐limiting factor in the Norfolk soil studied. Leaf rolling observed in aluminum‐sensitive ‘Kearney’ barley (but not in aluminum‐tolerant ‘Dayton’) grown on the unlimed soil, was attributed to aluminum induced calcium deficiency.
A Versatile, Precision Plot Planter1
Authors: Brigham Raymond D.
Published: July 2010

A tool‐bar‐mounted four‐row plot planter, capable of precision‐planting many field crop and vegetable seeds, was designed and assembled. Four unit planters equipped with chisel‐pointed openers, covering knives, and soil press wheels were fitted with inclined plate boxes, modified with hand cranks and spring clutches for rapid emptying of remnant seed. Two gauge wheels, seats, footrests, racks for seed boxes, and a 3‐point tool carrier were also attached to the tool bar. The plot planter, operated by two men plus a tractor driver, can be quickly attached to any tractor of adequate size that is equipped with a 3‐point hitch, and can be used to plant on top of a bed, in a furrow, or on a flat seedbed.
Runoff Farming in the Desert IV. Survival and Yields of Perennial Range Plants1
Authors: Tadmor N. H. , Evenari M. , Shanan L.
Published: July 2010

Survival, performance and yields of 80 ecotypes of 30 perennial range plant species grown with water spreading in a 100‐mm winter‐rainfall desert, were recorded over a 9‐year period. Phalaris tuberosa, Oryzopsis miliacea, and Medicago sativa were outstanding in all respects, surviving a 34‐month drought period and recovering to yield 25 to 35 ton/ha fresh matter (6 to 11 ton/ha dry). Festuca arundinacea, Hyparrhenia hirta, Cynodon dactylon, Dactylis glomerata, Hordeum bulbosum, and Panicum antidotale also produced substantial yields.
Effect of Sulphur in Preventing the Occurrence of Chlorosis in Peas1
Authors: Singh H. G.
Published: July 2010

Results of a field experiment, comprising a control, two micronutrient preparations, two phosphate fertilizers, singly and in combination, with and without sulphur, showed that only the application of sulphur was effective in preventing the occurrence of chlorosis. The application of 250 kg/ha sulphur increased the grain yield of peas 100%. The chlorotic leaves contained 40% more Fe, 10% more Al, and 31% more Si but 10, 17, 10, 11, and 25% less N, K, S, Mg, and B, respectively, than green leaves. Differences in grain yield and leaf composition (except for sulphur) were statistically significant. Micronutrient treatments did not affect the yield of the crop but had significant effect on leaf contents of N, Na, Fe, Mn, Mo, and Al. Phosphate fertilizers slightly increased the grain yield but had no effect on leaf composition.
Summer Fallow Soil Water Losses on Intermountain Dryland and Its Effect on Cropping Winter Wheat1
Authors: Massee T. W. , Siddoway F. H.
Published: July 2010

Intermountain drylands lose water from the root zone during the summer of fallow even though they receive a monthly average of 3.1 cm of precipitation. Soil water content in the 7.5‐ to 15‐cm seed zone at the end of summer fallow was related to soil water content at the time tillage was initiated in the spring. Fall soil water content was not appreciably affected by variations in summer rainfall. Adequate soil water for winter wheat Triticum aestivum L. em Thell) emergence was best assured by initiating summer fallow tillage when the water content in the 7.5‐ to 15‐cm layer was relatively high, rather than depending on summer rain to rewet this layer.
Design and Use of an Anhydrous NH3 Applicator for Field Research1
Authors: Smiley R. W. , Papendick R. I.
Published: July 2010

A compact, tractor‐mounted anhydrous NH3 applicator for field plot studies was designed, constructed, and tested. The metering pump is driven by one of two depth control wheels. The applicator chassis was custom fabricated; commercially available components, including the main tank were used for construction of the NH3 application system. Important features include readily interchangeable tool bars holding the applicator shanks, and a second tank for applying formulations of anhydrous NH3 with other chemicals.
Nitrate Accumulation in Vegetables. II. Table Beets Grown in Upland Soils1
Authors: Peck N. H. , Barker A. V. , MacDonald G. E. , Shallenberger R. S.
Published: July 2010

abstract

Nitrate concentrations in table beet (Beta vulgaris L.) plant parts were determined for different sources and times of application of N fertilizers to a Honeoye fine sandy loam and a Lima silt loam to determine effects of N fertilization on the concentration of nitrates in the plant parts used for consumption for food.

Nitrate concentrations were determined potentiometrically, using a nitrate‐selective ion electrode, on plant samples taken at time intervals after N fertilization and at harvest stage for processing.

Nitrate concentrations in table beet roots, leaf blades, and petioles were increased significantly by applications of N fertilizers. Rate of N application was the most significant factor affecting NO3 accumulation in the plants. Carrier of N was a significant factor only when the N fertilizers were sidedressed shortly before harvest. Sidedressing before harvest with KNO3 and broadcasting before planting with NH4NO3 and urea gave similar concentrations of NO3 in the plants. Beet leaves were significantly higher in NO3 than roots.
Characterization of Corn (Zea mays L.) Canopies from Measurements of Individual Plants1
Authors: Daynard T. B.
Published: July 2010

abstract

Because of their distichous growth habit, the foliage structure of individual corn (Zea mays L.) plants can be diagrammed by placing them against a flat surface and outlining leaf positions on the surface by means of a marking pencil. A method is described whereby measurements made in such a manner are used by a computer program to predict the canopy characteristics of identical corn plants in various planting arrangements. The program output includes quantitative two‐dimensional descriptions of plants placed in different row‐width planting patterns, plus a measure of the leaf area and leaf angle characteristics of the various vertical layers of such canopies. Typical results with two common hybrids are presented.
Effect of Lime and Manganese upon Growth and Mineral Composition of Pea cv. ‘Dark Skin Perfection’1
Authors: Eaton G. W. , John Matt K.
Published: July 2010

Two greenhouse experiments on pea (Pisum sativum L.) nutrition were carried out in 1969. In the first, peas were grown in soil suspected to be deficient in Mn. and lime was added to determine whether it would prevent or aggravate any Mn deficiency symptoms. In the second experiment, peas were grown in nutrient solutions with Mn levels varying form 0 to 1.00 ppm. In both experiments, plant parts were harvested separately, dried, weighed, and analysed for mineral content. Statistical analyses were done on the results.

In the first study, lime was found to increase the height, number of nodes, and dry weights of pea leaves and stems. It reduced leaf P and Mg and stem Zn, but increased Mn in the pods. In the solution culture study, 1.00 ppm Mn in solution increased the dry weight of stems, leaves, pods, total tops, and whole plants and increased the top/root and pod/stem‐and‐leaf ratios over the control. Increasing levels of Mn generally decreased pod and stem P, pod K, pod and stem Mg, root Cu, and leaf Na and significantly increased root Mg, pod Fe, pod Al, and Mn in all tissues.
Effect of Population Levels on Growth Factors in Kenaf Varieties1
Authors: White G. A. , Adamson W. C. , Higgins J. J.
Published: July 2010

The response of seven varieties of kenaf (Hibiscus cannabinus L.), a potential new paper‐pulp crop, to population levels of 99,000, 198,000, and 296,000 plants/ha was studied at Glenn Dale, Md., and Savannah, Ga. Populations affected plant height, stem diameter, and yield more than varieties. As the population level increased, plant height and basal stem diameter significantly decreased and percent dry matter at harvest increased. The cultivar ‘Cubano’ usually was significantly higher in percent dry matter at harvest than other varieties. The initial population of 99,000 plants/ha remained essentially unchanged at harvest, but reductions of about 9 and 20% occurred for initial populations of 198,000 and 296,000 plants/ha, respectively. The varieties ‘SH/15R’, Cubano, and ‘C‐2032’ sustained the most severe stand reduction. Stem yields generally increased as population increased. Yield means for populations at Savannah did not differ. At Glenn Dale, data showed a significant yield advantage in 1968 of 296,000 plants over lower population levels. In 1969, the mean yield of 12.5 mt/ha for populations of 198,000 and 296,000 plants significantly exceeded the 11.1 mt/ha yield for 99,000 plants. In general, varietal differences and variety‐population interactions for height, stem diameter, and yield showed minor significance. ‘Ev71’ and SH/15R were usually the highest yielding varieties. The highest disease incidence occurred on Cubano, ‘BG52‐75’ and SH/15R.
Changes in the Ratio Between Sugar Beet Evapotranspiration and Pan Evaporation During the Growing Season
Authors: Gornat B. , Goldberg D. , Sadan D.
Published: July 2010

Evapotranspiration by sugar beets and evaporation from a Class A pan were measured at 4‐ and 6‐day intervals during the period November‐May. Plant development and the progressive coverage of the ground by foliage were also followed. The ratio between evapotranspiration and evaporation, which might be used as an indicator of how much irrigation water to apply, changed during the course of the growing season. This change was found to be independent of plant development or ground cover, but was related to evaporative conditions, and even more so to the moisture content of the upper soil layer. The effect of these two factors on the change in the ratio was linear.
Factors Affecting the Development of Flue‐Cured Tobacco Grown in Artificial Environments. I. Effects of Light Duration and Temperature on Physical Properties of Fresh Leaves1
Authors: Raper C. D. , Johnson W. H. , Downs R. J.
Published: July 2010

Tobacco (Nicotiana tabacum L. ‘Coker 319‘) plants were grown to maturity in the facilities of the North Carolina State University Phytotron (Southeastern Plant Environment Laboratory) to determine effects of temperature and light duration on the physical characteristics of fresh leaves. Leaf area, shape, and specific leaf weight (dry weight per unit leaf surface area) were determined at six stalk positions. The lower temperatures resulted in small, relatively wide leaves at the base of the plant and elongated leaves at the top. Higher temperatures tended to reverse the normal shape and size ordering sequence of leaves; at the highest temperature condition the largest, as well as the broadest, leaves were developed at the uppermost stalk positions. The specific leaf weight was increased by an increase in the duration of the high intensity light period and by decreases in temperature. The increased light duration also enhanced the relative width of leaves.
Stoloniferous behavior in Birdsfoot Trefoil (Lotus corniculatus L.)1
Authors: Wassom C. E. , Barnett F. L.
Published: July 2010

Stoloniferous behavior in birdsfoot trefoil, Lotus corniculatus L., under field conditions is reported. New growth was obtained only on old prostrate woody stems. There was no evidence of genetic control of the trait.
Computerized Information Retrieval for Soil and Crop Scientists1
Authors: Thiel T. J. , Dowdy R. H. , Larson W. E.
Published: July 2010

Improved methods of information retrieval and handling are urgently needed, especially by researchers and others who use published literature. Computerized information systems offer scientists great help in maintaining personal reference files. A number of computerized retrieval systems are available. However, this report is limited to experiences with one system, which has been successfully employed to: (1) create, maintain and use a bibliographic file for soil scientists; (2) prepare an author‐keyword index of about 600 soil and water references prepared by ARS staff; (3) answer general requests for information by writing search questions; and (4) list manuscripts by scientists, locations and journals. Computerized information retrieval systems are not difficult to establish or use; obtaining a data base is the most costly phase of the system. Any information retrieval system should be viewed as an adjunct to scientific literature study, not as the sole source of information.
Response of Corn to Small Amounts of Fertilizer Placed with the Seed: V. Seed Coating Compared with Banding1
Authors: Smid A. E. , Bates T. E.
Published: July 2010

Response of corn (Zea mays L.) to a complete NPK fertilizer banded with the seed was compared with response to the same fertilizer coated on the seed before seeding in the greenhouse. Fertilizer was more efficient in its effect on P uptake and growth of seedlings when coated on the seed than when banded with the seed. It was more toxic, however, than banded fertilizer. Thus a greater growth response was obtained with banded fertilizer at rates which did not seriously delay or reduce emergence than could be obtained with the lower rates required for similar emergence when fertilizer was coated.

In attempts to reduce the toxicity, a number of compounds were coated on the seed before the fertilizer was added. Sucrose and polyvinyl acetate reduced the toxicity of coated fertilizer appreciably, but probably not enough to make seed coating a practical method of fertilizing corn.
Effects of Ensiling on the Hydrocyanic Acid Potential of Sorghum Plants1
Authors: McCarty Glenn , Gray Elmer , Shipe Emerson R. , Brown Leonard D.
Published: July 2010

Levels of HCN‐p in plants of all sorghum (Sorghum bicolor (L.) Moench) cultivars and stages decreased during ensiling. Small amounts of HCN gas were detected in the gases released during aerobic respiration, and in the gases flushed from the silo after the aerobic respiration period. The levels of HCN‐p of all the forage sorghum silages approached 0 ppm; whereas, the HCN‐p of the grain sorghum silage was 62 ppm.
Relationships between Forms of Soil Phosphorus, Some Indexes of Phosphorus Availability and Growth of Sudangrass in Greenhouse Trials1
Authors: Zubriski J. C.
Published: July 2010

Sudangrass (Sorghum sudanense) grown in two greenhouse trials was used to measure P status and response to added P of 29 soil horizons. Forage was harvested six times over a period of 295 days. Chemical methods of assessing soil P status were total P, Bray No. 1 soluble P, and Olsen sodium bicarbonate soluble P. Other methods for assessing P status were Fried and Dean “A” and Dean “a” values. The chemical forms of P determined were aluminum, iron, calcium, and organic phosphates. Yield of dry matter, dry matter response to added P, percentage yield, P content of forage, yield of P, response of yield of P to added P, and recovery of added P were used as plant growth parameters for linear correlation and regression with chemical methods of assessing soil P status, forms of soil P, and with “A” and “a” values. Olsen sodium bicarbonate soluble P, Bray No. 1 soluble P, “A’, and “a” values correlated significantly with aluminum, iron, organic and total phosphates. Aluminum phosphate explained 87, 86, 78, 76, and 81% of the variations in Olsen sodium bicarbonate soluble P, Bray No. 1 soluble P, “A” value, “a” value first harvest, and “a” value six harvests, respectively. Yield of dry matter, percentage yield, and yield of P correlated significantly with aluminum, iron, organic and total phosphates, Olsen sodium bicarbonate soluble P, Bray No. 1 soluble P, “A” value, and “a” values. Dry matter response to added P and P content of forage correlated significantly with the same methods of assessing soil P status, except these did not correlate with total P content. Response in yield of P to added P and percent recovery of added P did not correlate significantly with any of the methods of assessing soil P status nor with forms of soil P. The level of calcium phosphate was high in all soils but did not correlate with plant growth parameters and was indicative of little soil weathering.
Relation of Tillers to Yield of Dent Corn, (Zea mays L.)
Authors: Earley E. B. , Seif R. D. , Bensley F. A.
Published: July 2010

Three single cross (Zea mays L.) corn hybrids, ‘Hy2×Oh7,’ ‘R4xl06,’ and ‘K4xl06’ were used to study the influence of tiller removal and the presence of grain‐bearing and nongrain‐bearing tillers on yield of grain, grain protein, and wt/100 kernels of main plants with one, two, or three ears each.

Plants3 of the three hybrids from which tillers were removed produced essentially the same yield of grain, grain protein and wt/100 kernels as compared to plants with no original tillers. Therefore, the tiller‐producing potential of plants of these hybrids was not associated with superior performance as compared to plants with no original tillers, except for yield of grain of K4 × 106.

Plants of the three hybrids with grain‐bearing tillers produced essentially the same yield of grain, grain protein and wt/100 kernels as did plants with no original tillers. Consequently, grain‐bearing tillers did not translocate significant amounts of nutrients to ears on the main plants, with one exception, even under stress of two or three ears per plant.

The stress of developing two or three ears/plant resulted in translocation of larger amounts of nutrients to cars on main plants from nongrain‐bearing tillers than from grain‐bearing tillers for the three hybrids, but the increases were significant only for Hy2 × Oh7 and R4 × 106.
Influence of Sulfur Sources and Magnesium on Forage Yields of Coastal Bermudagrass (Cynodon dactylon (L.) Pers.)1
Authors: Matocha J. E.
Published: July 2010

Yield response to sources and rates of S at three levels of Mg was studied on a Troup loamy fine sand.

Powdered gypsum, prilled elemental S and K‐Mag were each applied at 0, 50, and 200 kg S/ha. Forage yields were taken for two years following application of S and Mg. Yields in the first season were highest when 50 kg S/ha as gypsum was applied. The high rate of gypsum decreased yields in the first season but increased production in the second year. Prilled elemental S had no effect on yield the first year but gave significant response in the second year.

Magnesium decreased yields in both years. Addition of gypsum reduced the adverse effects of Mg and resulted in a significant S × Mg interaction on yields in the second year. Elemental S partially corrected the imbalance in plots receiving Mg alone. Magnesium failed to accentuate the response to elemental S and total yields were substantially less than for Mg plus gypsum or K‐Mag.
Influence of Date of Harvest on the Yield of Kenaf (Hibiscus cannabinus L.)1
Authors: Whiteley Eli L.
Published: July 2010

Kenaf is a promising new source of raw material for paper‐pulp. Studies were conducted to determine the earliest date at which economical yields would be obtained. Average dry matter yields in the range considered competitive with corn and soybeans were not obtained until late September and early October. Highest yields were obtained from late October harvests in all three years.

Cuba and Guatemala varieties tended to produce higher yields in the early harvests. ‘Everglades 71’ produced the highest yield in 2 of the 3 years of the test. Differences in varietal response indicated that earlier varieties might be obtained through a breeding program.
Identification of Compounds Which Account for Variation in P Concentration in Corn Hybrids1
Authors: Phillips J. W. , Baker D. E. , Clagett C. O.
Published: July 2010

Phosphorus accumulation by corn (Zea mays L.) has been shown to be genetically controlled. Since the difference in accumulation of total P could have been due to metabolic differences resulting in the production of different amounts of one or several phosphorylated metabolites, a study of the chemical bases for the genetic differences between varieties of corn was performed. Extraction and analysis of dried, ground ear leaf samples indicated the presence of mostly inorganic P. Inorganic P was also found to be the major P component of extracts of fresh plants and leaves. Young plants and excised leaves of high accumulators were found to accumulate higher levels of P than low accumulators, but the difference was not as great as that reported for mature field‐grown plants. Differences were found between varieties in the content of several P‐containing components separated by ion exchange chromatography. The major component was orthophosphate. Orthophosphate was the only component which could account for the observed differences in P levels between varieties. This variation in the content of inorganic phosphate may be due to genetic differencs in th mechanism of absorption.
Growth os Subterranean Clover Established with a Cereal Companion Crop1
Authors: McGowan A. A. , Williams W. A.
Published: July 2010

The establishment of subterranean clover (Trifolium subterraneum L.) pasture sown with a cereal companion crop (barley, Hordeum vulgare) was studied on nine sites in the Sacramento Valley and adjacent foothills in California. Where grain yields were 2,000 kg/ha or less and soil moisture was adequate in April (last month of the rainy season), undersown clover produced 300 to 500 kg/ha of seed, over 100 seeds per plant, and yields of grain were not reduced by the undersowing. Thus, in areas better suited to grazing than to cereal farming, a cereal companion crop can increase the forage produced in the first year of sowing while still allowing good growth and seed production of subterranean clover.
Soil Heating Studies with Cool Season Turfgrasses. II. Effects of N Fertilization and Protective Covers on Performance and Chlorophyll Content1
Authors: Ledeboer F. B. , Skogley C. R. , McKiel C. G.
Published: July 2010

A study was made during the winter of 1968–69 to determine the influence of protective covers and supplemental N on several grasses growing on electrically heated soil.

Turfgrass responses measured were visual turf quality, clipping dry weights, chlorophyll content, and verdure characteristics. In early winter, increased soil temperature, cover density and N treatments enhanced turf quality and growth. In February, effects of main factors became reversed and caused turf deterioration. Dense cover (73% shade) was most beneficial early, most deleterious late in the season. During March, turf quality, density and growth decreases were a function of treatment intensities.

Soil heating alone had little effect on turf quality and growth during most of the winter. In conjunction with protective covers and N fertilization, turf quality and growth were aided significantly during the early winter. With increased ambient air temperatures near spring, shading, produced by the covers, imposed severe limitation on the growing grasses, causing rapid foliar elongation and turf thinning. Nitrogen treatments enhanced these effects. Under practical management operations in the field, covers should be removed before sod deterioration occurs. Soil heating alone may be continued as long as desired without apparent damage to the turf.
Varietal Differences among Barley Seedlings Grown with Various Nutrient Solutions1
Authors: Jensen H. A. , Nittler L. W.
Published: July 2010

Seedlings of 24 spring barley (Hordeum vulgare L.) varieties were grown in sand with continuous light and supplied with a complete nutrient solution or with a solution lacking nitrogen or phosphorus. Significant differences were found among varieties in necrosis of first leaf blades induced by a lack of phosphorus. Average necrotic area of first leaf blades of ‘Svaloef Pallas,’ ‘Svaloef Bonus,’ and ‘Svaloef Hellas’ was 70% or more. On the other hand, no more than 1% of the leaf blade areas of ‘Dickson,’ ‘Erie,’ and ‘Vaughn’ was necrotic.

With all three nutrient solutions very obvious differences developed in color of lower leaf sheaths. These ranged from green to intense red. A few varieties contained a mixture of red and green plants but most were uniform for this characteristic.

‘Carlsberg II’ seedlings grown without phosphorus developed purple color on about one‐third of the area of second leaf blades. Other varieties had little or no purple color.

Varieties differed significantly in length of lower leaf sheaths when grown without nitrogen. Those of Calsberg II averaged three times as long as those of ‘Trebi.’
Evaluation of Water and Nitrogen Stress on Bromegrass Growth1
Authors: Powers J. F.
Published: July 2010

Percent stress [reduction in growth rate of bromegrass (Bromus inermis L.) due to deficiency] was calculated by the method of Greenwood et al. to evaluate the effects of deficiencies of N, water, and N plus water combined. Dry matter yields of bromegrass receiving either (a) 270 kg/ha of N, (b) complete irrigation, (c) N plus irrigation, or (d) no treatment 3 weeks earlier were determined at periodic intervals in the field at low, medium, and relatively high levels of N availability. Percent stress due to N deficiency was greatest where N availability was lowest, generally increased as the grass approached maturity, but was insignificant as long as a relatively large pool of inorganic N remained in the soil. Percent stress due to water deficiency was affected by precipitation, and was generally greatest for plots low in available N, even though soil water content (to 120 cm depth) was greater in those plots. Generally, percent stress due to deficiencies of water and N combined was approximately equal to the sum of stresses for the two measured separately. The concept of percent stress appears to be useful for quantifying the effects of both N and water deficiencies, alone and in combination, on growth rates of grass. In connection with other measures of physiological condition or activity, this concept may have considerable utility in agronomic research.
Soil Water Potential and Water Content Profiles with Wheat under Low Spring and Summer Rainfall1
Authors: Papendick R. I. , Cochran V. L.
Published: July 2010

Soil water potentials and water contents in the wheat (Triticum aestivum L.) root zone of several soils were measured late in the growing season under Pacific Northwest, U. S. A. conditions of low spring and summer rainfall. All profiles exhibited low potentials in the surface 1 to 1.5 m of soil, followed by a region of steep potential gradient over a depth increment of 30 cm or more. below this region the energy values were relatively constant with depth. In the dry zone the soil water potential in some cases reached −40 bars at the 60‐ or 90‐cm depth, and in one case, −40 bars at the 150‐cm depth. With coarser‐textured soils the potential gradient across the moist to dry zone was steeper as compared with a finertextured soil. Depth of root penetration appeared to coincide with the base of the steep water‐potential gradient. Plant wilting was absent or not pronounced when potentials below the steep gradient zone were −2 bars or higher; permanent or severe wilting occurred when the potential was −10 to −8 bars. Soil water potencials in the surface 1.5 m of soil were 8 to 10 bars lower with 110 and 220 kg N/ha applications on wheat than with no N. In most cases the water content profiles of the root zone bore little resemblance to the corresponding potential profiles.

These results indicate that in the field the lower limit of water extraction by wheat may reach −40 bars or lower. However, the mobility of water in the root zone or adjacent layers underlying the root zone of the field soil is probably more important to the concept of “water availability” for plants than the actual energy status per se.
Effect of Lithium on Growth, Salt Absorption, and Chemical Composition of Sugar Beet Plants1
Authors: Sims J. L. , Atkinson W. O.
Published: July 2010

Nicotiana tabacum L. cv. ‘Burley 21’ was grown in the field at Lexington, Ky., to determine the influence of N nutrition and suckering practices on concentration and distribution of principal mineral elements in different plant parts. Generally, total plant contents of K, Ca, Mg, and Mn all increased as the N fertilizer rate was increased from 112 to 224 kg N/ha, but increasing the rate to 448 kg N/ha provided no further increases in uptake with exception of Mn. The Mn content was nearly doubled by increasing the rate of N from 224 to 448 kg/ha. As an average of all treatments, total uptake of P, K, Ca, Mg, and Mn was 12, 211, 152, 26, and 0.8 kg/ha, respectively.

Practices to control suckers (axillary buds) and tops (seed heads), as well as the harvest date, influenced both total uptake and distribution of mineral elements among plant parts. Total uptake decreased with increasing degree of sucker control and was least for plants treated with maleic hydrazide. Data for harvest date indicated that considerable redistribution of elements occurred among plant parts between harvest dates. Elements generally considered to have the greatest mobility in plants, e.g., P, K, and to a lesser extent Mg, were present in relatively high amounts in tops and suckers and in relatively low amounts in leaves. The reverse was true for Ca and Mn.
Growing Barley (Hordeum vulgare L.) on Beds in Saline Soil
Authors: Day A. D. , Turner Fred , Kirkpatrick R. M.
Published: July 2010

Studies were conducted over a 2‐year period at Safford, Ariz, to compare two methods (conventional drilling and two rows per bed) and two rates (28 and 56 kg/ha) of planting spring barley (Hordeum vulgare L.) on elevated beds in saline soil. Beds were oriented in two directions: north to south and east to west.

Conventional drilling on beds resulted in both higher grain yields and grain volume‐weights than did the two‐row method of planting. Planting 56 kg/ha resulted in higher grain yields and volume‐weights than did planting 28 kg/ha. rain yields were higher from barley grown on east‐west beds than from barley grown on north‐south beds. The two‐row method of planting on beds resulted in more weeds than did the drilled method of planting. The research indicated that when barley was grown in saline soil, highest yields of quality grain were obtained when the crop was drilled at 56 kg/ha on east‐west beds.
Effects of Row Cultivation on Growth and Yield of Soybeans1
Authors: Russell W. J. , Fehr W. R. , Mitchell R. L.
Published: July 2010

Systematic comparisons of the effects of cultivation treatments on the growth and yield of soybeans have not been reported. We evaluated the effects of six cultivation treatments on yield, maturity, lodging, and height of four soybean [Glycine max. (L.) Merrill] varieties, (‘Hark,’ ‘Amsoy,’ ‘Hawkeye,’ and ‘Wayne’) in three environments. Treatments were combinations of 64‐ and 114‐mm depths of a standard cultivator half‐sweep spaced 152, 229, or 305 mm on each side of the row. We applied the treatments once at developmental stages 2, 4, or 6 and a double cultivation at stages 2 and 6.

Treatment response for yield varied with developmental stage and environment, but no significant treatment ✕ variety interaction was obtained. Low production or stress environments seemed to accentuate the yield loss associated with cultivation. For the average of environments none of the treatments was significantly different in yield than was the check at stages 2 and 4. At stage 6, cultivation 114 mm deep, 305 mm from the row was the only treatment that did not reduce yield. Cultivation 114 mm deep, 152 mm from the row, caused the greatest yield loss. For the 64‐mm depth, similar yield reductions were obtained at all distances from the row.

Varietal differences were observed for response to cultivation. Wayne was more resistant to cultivation injury than the other varieties evaluated.

No cultivation effects of practical importance were obtained for maturity, lodging, or plant height.
Effects of CCC on the Growth od Wheat Plants and their Untreated Progeny1
Authors: Bokhari U. G. , Youngner V. B.
Published: July 2010

The effects of a series of CCC concentrations and three methods of application on the growth and yield of Ramona 50' spring wheat (Triticum aestivum L.) were studied under greenhouse conditions. Results show that treatment of CCC as a soil drench was highly effective in reducing stem height, increasing the number of tillers per plant, and increasing yield. Foliar spray and seed soaking methods were less effective than soil drenching. Yield increase was attributed to more head‐producing tillers and to greater weight per grain. Untreated progeny of treated plants had more tillers and were shorter in height than the progeny of untreated plants, perhaps the result of CCC accumulation in the caryopses of treated plants.
Effects of Environment on an Infrared Field Thermometer1
Authors: McGinnies William J. , Aronson R. C. W.
Published: July 2010

Accuracy and reliability of an infrared field thermometer were evaluated in field and laboratory tests. Thermal and solar radiation on the instrument itself, ambient temperature, and the temperature of the surface being measured, affected the indicated temperature of the surface temperature being measured. An infrared field thermometer of the type tested was considered unsuitable for field use.
Effects of Controlled Plant Spacing on Growth and Mortality of Three Range Grasses1
Authors: McGinnies William J.
Published: July 2010

A new technique was devised to study effects of plant spacing on growth and morality of range grasses under semiarid conditions. Growing area per plant was controlled by establishing plants in sheetmetal pipes set vertically in the soil; the pipes restricted the plant roots to a predetermined surface area of soil. Pipes with diameters of 10.2, 15.2, 22.9, 30.5, and 45.7 cm simulated plant densities of approximately 123, 55, 24, 14, and 6 plants/m2. Crested wheatgrass (Agropyron desertorum (Fisch. ex Link) Schult.), Russian wildrye (Elymus junceus Fisch.) and blue grama (Bouteloua gracilis (H.B.K.) Lag. ex Steud.) were grown in pipes for 6 years in northern Colorado. As growing space became more restricted: (a) seedstalk height decreased; (b) number of seedstalks/ plant decreased; (c) number of seedstalks/m2 increased; and, (d) herbage yield/plant decreased. After 6 years, two sets of pipes of each species were dug out and the soil was washed off of the roots. As pipe diameter decreased, the root/shoot ratio increased for all species; and for crested wheatgrass and Russian wildrye, root yield/ha increased and the percentage of total root yield found in the surface 20 cm of soil increased. It was concluded that the use of sheetmetal pipes to restrict the area occupied by individual plants is a satisfactory technique for evaluating some effects of plant spacing under semiarid conditions.
Growth and Development of Hardy and Nonhardy Wheat Varieties (Triticum aestivum L.) at Near‐freezing Temperatures1
Authors: Kimball Steven L. , Salisbury Frank B.
Published: July 2010

Brevor and Lemhi wheat varieties (Triticum aestivum L.) were examined for growth and/or development during the winter months of 1968‐69. This activity was compared to the temperature environments of the air, plants, and soil, and to existing snow cover. Particular interest was given to processes occurring at near‐freezing temperatures. Both varieties showed slow though significant growth and development at near‐freezing temperatures when evaluated for root, leaf, and tiller number and for leaf area. The stage of development when subjected to low temperatures apparently determined the extent to which the varieties progressed. Underestablishment seemed most detrimental. Field mice showed a strong preference for the winter‐hardy Brevor.
Diurnal Changes in Cotton Leaf and Petiole Moisture Content as Related to Environmental Moisture Stress1
Authors: Longenecker D. E. , Lyerly P. J.
Published: July 2010

Continuation of gravimetric moisture content studies of topmost mature upland (Gossypium hirsutum L.) and American Pima (Gossypium barbadense L.) cotton leaves and petioles is reported. Diurnal moisture percentages of four varieties at 3 hours (7 to 8 AM, 1 to 2 PM, and 6 to 7 PM) during the day, and at 4, 11, 18, 25, and 32 days after irrigation are given. Results indicate that diurnal fluctuations in petiole moisture are less than those of leaves. Petiole moisture appears strongly related to the internal moisture stress conditions of the plant, both diurnally and with increasing environmental moisture stress. Ranges of moisture variation for leaves and petioles are shown to be similar. Previous findings that fresh weight petiole moisture percentages were continuously higher than those of attached leaves are substantiated.
Influence of a Root Crop on Physical Properties of a Clay Soil1
Authors: Gerard C. J. , Mehta H. C.
Published: July 2010

Studies to evaluate the influences of stages of growth of a root crop and two plant densities on certain physical properties of a swelling clay were conducted. selected physical properties of the swelling clay soil changed with time and depth. Bulk density of clay soil decreased during growing season. Density of soil was higher at 15 to 30 cm than in the top 15 cm of soil. Permeability of the 15‐ to 30‐cm depth was considerably less than top 15 cm of soil. Root development and drying due to evapotranspiration appeared to increase the permeability of the top 15 cm of soil but had little influence on permeability of soil at the 15‐ to 30‐cm depth. Field soil strength data indicated radishes compacted the soil from a 10‐ to a 30‐cm depth.
Walking Row Method of Tillage for Seed Production of Western Wheatgrass (Agropyron smithii Rydb.)1
Authors: Stroh James R.
Published: July 2010

The effects of five tillage treatments on the seed production of western wheatgrass (Agropyron smithii Rydb.) under irrigation were evaluated for a 4‐year period at Bridger, Mont. The purpose of this investigation was to evaluate a “walking row” method of tillage that would reduce sodbinding and maintain the plants in a vigorous growing condition.

The results showed the no‐tillage treatment to be more practical than the walking row tillage. Allowing stands to grow solid (no cultivation) from 91‐cm row spacings delayed sodbinding and produced the highest average yields over the 4‐year period. Weed invasion and production costs were lowest under this treatment.

Rhizomes were allowed to grow between 91‐cm spaced rows in the walking row treatment. After seed harvest the rows were mechanically removed and the rhizomes became the new rows for the next year's crop. This method maintained young plants for sustained high seed yields, but weed invasion and power requirements to walk the rows were high.

Maintaining original rows with fall, spring and fall, or spring cultivations hastened yield declines through forced sodbinding. Average 4‐year yields were lowest for these three cultivation treatments.
Variability in Grass Forage Clipping Experiments Comparing Fertilizer Rates and Sources1
Authors: Terman G. L.
Published: July 2010

Variability in yields of dry forage and in uptake of nutrients was studied in 10 greenhouse pot and three field plot experiments comparing various rates and sources of N, P, K, or Zn for grasses clipped three to eight times. Standard deviation (SD) increased in general with increase in mean yields of individual clippings. SD for cumulative yields, however, decreased or remained about the same with increase in cumulative mean yield, or increased proportionately less than did yield. Coefficients of variability (CV) decreased in all experiments with increase in cumulative mean yields. These results indicate that statistical analyses of cumulative yields are usually more meaningful and result in less percentage variability than do analyses of individual clipping yields. Experimental error decreased in the order sorghum‐sudangrass hybrid [Sorghum bicolor (L.) Moench ✕ Sorghum vulgare sudanense] > bermudagrass (Cynodon dactylon L.) > ryegrass (Lolium multiflorum Lam.) in greenhouse experiments and sorghum‐sudangrass hybrid > bermudagrass > fescue (Festuca sp.) in field experiments.
Effect of Nitrogen Fertilization of Festuca arundinacea Schreb. on Nitrate Nitrogen and Protein Content and the Performance of Grazing Steers1
Authors: George J. R. , Rhykerd C. L. , Mott G. O. , Barnes R. F. , Noller C. H.
Published: July 2010

Rapid acceptance of N fertilizer and a concern for nitrate toxicity suggest a need to relate forage nitrate N content to the performance of cattle grazing fertilized grass pastures. The nitrate N and protein contents of Festuca arundinacea Schreb. pastures fertilized with 0, 84, and 168 kg/ha of N were studied. The average daily gain of grazing steers was measured during the sampling period. The nitrate N and protein contents increased, reached a peak shortly after the N was applied, and declined over the remainder of the sampling period. The maximum nitrate N content observed in tall fescue was approximately 0.18%. Average daily gain was not influenced statistically by increasing increments of N fertilizer up to 168 kg/ha. No other effects were observed.
Soil Temperature, Water, and Phosphorus Effects upon Barley Growth1
Authors: Follett R. F. , Reichman G. A.
Published: July 2010

Barley (Hordeum vulgare L.) growth in the northern Great Plains is often limited by soil water, soil temperature, or soil fertility. Therefore, we investigated the sponse of ‘Sacramento’ spring barley to three levels each of soil temperature (T), water (W), and P fertility in a growth chamber. The yield of oven‐dry tops, crowns, and roots showed the beneficial effects of increased W and P on barley growth for all soil temperatures studied. Response of top and crown weight to added P declined as T increased or W decreased. Crown weight was highly correlated with numbers of tiller plus root buds initiated at the crown. The addition of P increased the numbers of tiller and root buds. Low available water and high soil temperature decreased the number of root buds per tiller bud. When low W limited barley growth, root weights were maintained in preference to top weight, and top weight in preference to crown weight. Where the fertilizer needs of barley have been met, methods devised to conserve water and control soil temperature at or slightly below optimum near developing root systems should favor yield responses.