bluuebunny/crossref_metadata_2025 huggingface dataset:
A Sampling Design With Incomplete Dichotomy
Authors: Calvin Lyle D. , Miller John D.
Published: July 2010

Synopsis

Sampling schemes utilizing a nondichotomous breakdown over several categories are illustrated and discussed. The designs offer possibilities for considerable savings of time and money as compared to conventional sampling schemes by reducing the total number of samples taken for analysis or evaluation.
Root and Top Growth of Corn1
Authors: Foth H. D.
Published: July 2010

Synopsis

Root growth was found to occur in a series of stages which caused roots to appear in different locations of the soil at different times. Root growth stages were associated with stages of top growth.
Variation in Protein Content of the Grain in Four Varieties of Triticum aestivum L1
Authors: Haunold Alfred , Johnson V. A. , Schmidt J. W.
Published: July 2010

Synopsis

Atlas 66 had the highest and Wichita had the lowest grain protein content among the varieties studied. At low levels of soil nitrogen availability grain protein was negatively correlated with yield in all varieties.
Chemical, Physical, and Baking Properties of Preripe Wheat Dried at Varying Temperatures1
Authors: Finney K. F. , Shogren M. D. , Hoseney R. C. , Bolte L. C. , Heyne E. G.
Published: July 2010

Synopsis

Loaf volume, crumb grain, and mixing time of preripe hard red winter wheat were affected adversely when dried at temperatures over 160° F., depending on amount of moisture in the grain.
Mowing of Turfgrass. II. Responses of Three Species of Grass1
Authors: Madison John H.
Published: July 2010

Synopsis

Responses to mowing of Highland and Seaside bentgrasses and Alta tall fescuegrass evaluated by yield were similar. Greatest yield was produced by Aha, in the spring season (Mar), and at longer intervals between mowing. Chlorophyll content of clippings was greatest at mowing intervals of 4 and 10 days. Regrowth on the day following mowing approached the mean growth rate at mowing intervals of 10 or more days.
Preparation of Plant Samples for X‐Ray Emission Spectrography1
Authors: Chesnin Leon , Beavers A. H.
Published: July 2010

Synopsis

Briquets of ground corn leaves were made using a cementing agent called Permount and analyzed for zinc content by X‐ray spectrography. Briquets prepared in this way were uniform in composition and could be stored for long periods without physical or chemical changes.
Spatial Distribution of Net Radiation in a Corn Field1
Authors: Denmead O. T. , Fritschen L. J. , Shaw R. H.
Published: July 2010

Synopsis

On clear days, after maximum leaf area development, the net radiation at the ground constituted only 25% of the total net radiation measured above the crop, 75% being expended within the crop canopy. Some 73% of the energy expenditure within the crop occurred in its upper half. It is estimated that closer row spacing than 40 inches could increase the energy available to the crop for photosynthesis by 15 to 20%.
Effect of Varying Leaf Area by Partial Defoliation and Plant Density on Dry Matter Production in Corn1
Authors: Hoyt Paul , Bradfield Richard
Published: July 2010

Synopsis

The net assimilation rate of corn was linear to leaf area index when this was less than 2.7 but declined rapidly when it was above that value. In a stand with a leaf area index of 3.3, dry matter produced per square meter of leaf area from grain initiation to maturity by the top, middle, and bottom leaves was of the ratio 4:2.2:1.
Precision of Estimates of Evapotranspiration in Missouri Climate1
Authors: Decker Wayne L.
Published: July 2010

Synopsis

Penman and Thornthwaite derived estimates of evapotranspiration were compared with the measured evapotranspiration from corn. Both methods of estimation approximated the measured values, with the method of Penman giving a lower variability.
Effect of Nitrogen Rate and Clipping Frequency on Yield of Pensacola Bahiagrass1
Authors: Beaty E. R. , Powell John D. , Brown R. H. , Ethredge W. J.
Published: July 2010

Synopsis

Forage production of Pensacola bahiagrass was increased by nitrogen fertilization up to 200 pounds of N per acre. Six‐week intervals between harvests resulted in higher yields than 1‐, 2‐, 3‐, or 4‐week intervals. The leaf‐to‐seed stalk ratio was not affected by either the N fertilization or clipping interval.
A Modified Alveograph Method for Hard Winter Wheat Flour1
Authors: Shogren M. D. , Finney K. F. , Bolte L. C. , Hoseney R. C.
Published: July 2010

Synopsis

Differentiation, ranking, and replicability were improved by modifying the original alveograph method for testing hard winter wheat flour quality.
Influence of Time of Harvest on Yield of Dry Matter and Predicted Digestibility of Four Forage Grasses1
Authors: Austenson H. M.
Published: July 2010

Synopsis

First harvest yields of orchardgrass, perennial ryegrass, and tall fescue increased at nearly uniform rates up to full bloom and rose relatively little after that. Timothy had the same growth rate, but extended over a longer time. It outyielded other species at heading and flowering stages. Most uniform seasonal distribution of pasture yield was provided by ryegrass and timothy. Digestible dry matter of each species, predicted by the regressions of other investigators, was maximum at full bloom.
Water Absorption of Alfalfa as Affected by Low Root Temperature and Other Factors of a Controlled Environment1
Authors: Ehrler William L.
Published: July 2010

Synopsis

Water deficit and wilting can be caused by low root temperatures, even though the water supply is not limiting. To predict wilting it is necessary to know the transpirational demand, the root temperature, and the duration of subnormal temperature.
Responses of the Sugar Beet to Low Soil Moisture at Two Levels of Nitrogen Nutrition1
Authors: Loomis R. S. , Worker G. F.
Published: July 2010

Synopsis

Moisture stress reduced vegetative growth and increased sucrose concentration (fresh basis) in the roots of sugar beet plants grown at high and low levels of N nutrition. Beet purity and sucrose yield were increased by N deficiency but not by moisture stress. Effects of the two factors were independent and additive. Changes in sucrose concentration are interpreted on an osmotic basis.
Soil Salinity Effects on the Chemical Composition of the Oil and the Oil Content of Safflower Seed1
Authors: Yermanos D. M. , Francois L. E. , Bernstein L.
Published: July 2010

Synopsis

Soil salinity depressed oil content, seed weight, protein content, and the seed contribution to total yield of the tertiary heads. It increased percent hull content of the seed but did not affect the fatty acid composition of the oil.
Effect of Cutting Height on Alfalfa and Two Grasses as Related to Production, Persistence, and Available Soil Moisture1
Authors: Van Riper G. E. , Owen F. G.
Published: July 2010

Synopsis

Height of cut affects the botanical composition, plant height, and the total carbohydrate food reserves of grass swards. Grasses grown with alfalfa were 7.96 to 8.32 percentage units lower in total available carbohydrates than grasses grown in pure stands. Cutting height affected the soil moisture use under the forages.
Effects of Cutting Frequency of Orchardgrass and Nitrogen Rate on Yield, Plant Nutrient Composition, and Removal1
Authors: Mortensen W. P. , Baker A. S. , Dermanis P.
Published: July 2010

Synopsis

Nitrogen fertilization greatly increased dry matter and crude protein yields over a 4‐year period. Less frequent harvest improved the efficiency of N in terms of dry matter production but had negligible effect on crude protein. Plant nutrient removal by the forage was directly related to N rate. Separate of N, the K content and removal in forage were much more affected by N fertilization than were those of other nutrients.
Effect of Nitrate and Ammonium on Growth of Corn in Nutrient Solution Sand Culture
Authors: Bennett William F. , Pesek John , Hanway John J.
Published: July 2010

Synopsis

Nitrate was superior to ammonium as a source of N during the first 4 to 9 weeks of growth of corn in 2 greenhouse experiments. Part of the cause was the deleterious effect of ammonium on the growth and condition of the root system.
Response of Corn to Nitrogen in Oxamide and Ammonium Nitrate in Greenhouse Experiments1
Authors: Engelstad O. P. , Hunt C. M. , Terman G. L.
Published: July 2010

Synopsis

Recovery of N by a single crop of corn from oxamide mixed with the soil decreased with increase in granule size, but total recovery by 3 successive crops was similar for several sizes of oxamide. Similar high recoveries of N by a single corn crop resulted from mixed application of the fine oxamide, urea, NH4NO3, and (NH4)2SO4. Recovery from surface‐applied urea and fine oxamide was much lower.
Shattering, Moisture Content and Seed Temperature of Soybeans as Influenced by Row Direction1
Authors: Prine G. M. , West S. H. , Hinson K.
Published: July 2010

Synopsis

Ogden soybeans had 80% of seed shattering from the south side of east‐west rows and 58% from the west side of north‐south rows. There was no difference in seed yield or amount of shattering between the two row directions studied. Seed temperatures were higher on the sides of rows where greatest shattering occurred. Average moisture content of seed was lower on north‐south rows suggesting that seed in these rows would be ready to harvest earlier than in east‐west rows.
Barley Production Under Various Nitrogen and Moisture Levels1
Authors: Stanberry Chauncy O. , Lowrey Mark
Published: July 2010

Synopsis

A three‐year barley study with irrigation and nitrogen variables at Yuma, Arizona, demonstrated the importance of investigating components leading to yield such as: plants per unit area, heads per plant, seeds per head, and individual size or weight per seed. Nitrogen rate increased barley yields appreciably, predominantly by increasing heads per plant and seeds per head. Moisture utilization efficiency—pounds of grain per acre‐inch of water—was favored by higher N rates and the drier moisture regimes.
Effect of Soil Temperature on the Response of Winter Wheat to Phosphorus Fertilization1
Authors: Gingrich Joe R.
Published: July 2010

Synopsis

Yield of dry matter was affected very little by applications of phosphate fertilizers when soil temperatures were maintained at 50° F. regardless of available phosphorus in the soil. At 65° and 80° F. soil temperatures, applications of phosphate doubled the yield of dry matter on a low phosphorus soil and had a variable effect on the high phosphorus soil. Phosphorus percentage of the top growth was not affected by soil temperature but was increased considerably by the application of phosphate to the soil.
Coleoptile Length, Seed Size, and Emergence in Intermediate Wheatgrass (Agropyron intermedium (Host) Beauv.)1
Authors: Hunt O. J. , Miller D. G.
Published: July 2010

Synopsis

Seed size, coleoptile length, emergence, and seedling height varied widely in intermediate wheatgrass. High positive correlations were found among all characters. Variance for general combining ability was high. Analysis of a diallel cross indicated a strong maternal influence on coleoptile length. A discussion of the potential for improvement and methods for improving these characters is presented.
Dry Matter and Protein Yields and Nitrate Content of Piper Sudangrass (Sorghum sudanense (Piper) Stapf.) in Response to Nitrogen Fertilization1
Authors: Summer D. C. , Martin W. E. , Etchegaray H. S.
Published: July 2010

Synopsis

The experiments conducted suggest that 200 pounds of nitrogen is about the optimum as a split application when pasturing or greenchopping irrigated Piper sudangrass. Greater amounts do not appreciably increase yields but do account for relatively high rates of accumulated nitrate (NO3‐) in the harvested forage.
Effects of Repeated Drought Periods on Photosynthesis and Survival of Cereal Seedlings1
Authors: Todd Glenn W. , Webster Daniel L.
Published: July 2010

Synopsis

There were no significant differences in photosynthetic rate among wheat varieties differing in drought hardiness although slightly higher rates were obtained at lower turgor for nearly all cereal varieties after they had been subjected to a single drought period. Photosynthetic rates paralleled moisture stress during successive drought periods. A method of screening for relative drought hardiness among wheat varieties was devised and tested and this correlated well with known field hardiness.
Phosphorus Nutrition of Italian Ryegrass Relative to Growth, Moisture Content, and Mineral Constituents1
Authors: Hylton L. O. , Ulrich A. , Cornelius D. R. , Okhi K.
Published: July 2010

Synopsis

Plant growth and the absorption of P by Italian ryegrass from nutrient solution was affected by P supply, whereas the distribution and accumulation of P within the ryegrass was largely determined by the kind of, and age of, tissue sampled. Blade 1, the youngest blade that was fully open and had a ligule, and H2PO4‐P were selected, from 6 plant parts sampled and 2 forms of P determined, as the best combination to diagnose the P status of Italian ryegrass. About 750 ppm of H2PO4‐P in blade 1 tissue was tentatively set as the critical concentration for growth of the ryegrass.
Frequency and Rate of Irrigation as Factors in Forage Growth and Water Absorption1
Authors: Lucey Robert F. , Tesar Milo B.
Published: July 2010

Synopsis

Alfalfa irrigated with 3 inches of water whenever available soil moisture to an 18‐inch depth was 60, 40, 20, or 0% produced relative yields of 100, 81, 63, and 37%. Moisture absorption was greatest in upper 6 inches of soil and decreased when available soil moisture dropped to 25 to 30%. Below 15% available soil moisture, plants showed moisture stress and rate of stem elongation dropped almost to nil. Similar water efficiency in production of top growth, decreased production, and rate of stem elongation as soil approached the permanent wilting point indicates that water is not equally available between field capacity and permanent wilting point.
Effects of Seeding Rate and Chemical Weed Control on Establishment and Subsequent Growth of Alfalfa (Medicago sativa L.) and Birdsfoot Trefoil (Lotus corniculatus L.)1
Authors: Wakefield R. C. , Skaland Nils
Published: July 2010

Synopsis

Plant size and yields of both alfalfa and birdsfoot trefoil were influenced by weed control treatments and seeding rates during the season of establishment. Pre‐emergence control of weeds increased first year yields of both legumes, had no effect on plant numbers but increased size of root‐crowns. Plants were larger at low seeding rates, particularly where weeds were controlled, and initial yields were comparable to those at higher seeding rates. Second year yields were influenced more by plant numbers than size of root‐crowns.
Effects of Nitrogen Level and Osmotic Pressure of the Nutrient Solution on Incidence of Puccinia graminis and Helminthosporium sativum Infection in Merion Kentucky Bluegrass1
Authors: Cheesman Jerry H. , Roberts Eliot C. , Tiffany Lois H.
Published: July 2010

Synopsis

Merion bluegrass grown in solution culture produced lower yields of foliage under low levels of nitrogen and high levels of osmotic pressure than when treated with high nitrogen and low osmotic pressures. Turf was resistant to inoculation with Puccinia graminis Pers. at all treatment combinations. Numbers of Helminthosporium sativum Pammel, King, and Bakke lesions per leaf blade and average size of lesions increased with increasing levels of nitrogen and decreasing osmotic pressure.
Root Development of Wheat, Oats, and Barley Under Conditions of Soil Moisture Stress1
Authors: Salim Muhammad H. , Todd Glenn W. , Schlehuber A. M.
Published: July 2010

Synopsis

Extent of root growth of cereal plants was highly correlated with the soil moisture level. With oats, wheat, or barley, little penetration of soils at or below the permanent wilting point occurred, but penetration by side‐oats grama and sand lovegrass under the same conditions was fairly extensive. Leaf growth continued after root extension ceased on the most drought‐susceptible oat and wheat varieties.
Evaluation of Corn Silage Harvested at Two Stages of Maturity1
Authors: Bryant H. T. , Blaser R. E. , Hammes R. C. , Huber J. T.
Published: July 2010

The effect of harvesting an early maturing corn hybrid when the grain was at the milk, as compared to well dented, on chemical composition, ear to plant ratio, grain and silage yield, digestibilities, palatability, and milk production was studied for 2 years. The ears of corn at the latter harvest as compared to the earlier harvest made up a considerably larger portion of the total silage yield. Correspondingly, the leaves, stalks, and husks were a smaller portion of the mature than of the immature corn plants. There was a large incrcease in silage and grain yields by delaying harvest to a more mature stage of growth. Each year the crude protein and crude fiber were significantly lower and the nitrogen‐free extract significantly higher for the silage harvested at the mature as compared to the immature stage. The total digestible nutrients values were slightly higher for the corn cut at the dent stage. The mature silage was more palatable than the immature silage.

The persistency of milk production of the cows fed mature silage was slightly higher than for those fed immature silage.
Photosynthesis Under Field Conditions. VIII. Analysis of Windspeed Fluctuation Data to Evaluate Turbulent Exchange Within a Corn Crop1
Authors: Wright J. L. , Lemon E. R.
Published: July 2010

Turbulent transfer within a crop of corn was characterized by an aerodynamic approach. The distributions of windspeed within an immature and a mature crop were measured using both cup and heated thermocouple anemometers. A combination of the statistical and mixing‐ length theories was employed to analyze the wind data for transfer coefficients.

Eulerian time scales of turbulence were calculated from the windspeed fluctuations of selected 30‐second periods of semi‐steady wind. Momentum transfer coefficients were determined from the scale of turbulence by equating it to the mixing length and assuming isotropy. The resulting values were as large as 8,000 cm2 sec−1. The shearing stress profiles calculated with these values had unrealistically sharp maximums just below the top of the crop. This anomaly was considered an artifact of the method resulting from extreme anisotropy in the turbulent shear flow.

The K values obtained by the statistical mixing length method were approximately ten times larger than those determined by logarithmic profile analysis. The latter values were considered more nearly correct and were used as a basis for correcting the other values.

The results showed that the magnitude of turbulent transfer is several orders of magnitude greater than molecular diffusion even at levels deep within the crop. The transfer coefficient showed a marked attenuation with depth below the top of the corn but remained a function of windspeed at all heights.
Effect of Boron on White Clover (Trifolium repens, L.) Seed Production1
Authors: Johnson Wiley C. , Wear John I.
Published: July 2010

In a coarse‐textured soil with a water‐soluble boron content of 0.10 ppm, the addition of boron at the rate of 560.7 g/ha significantly increased white clover seed production. This response was due entirely to an increase in the number of seed per seed head. No increase in seed yield was obtained with higher rates of B or other trace elements. There was no effect of boron or other minor element additions on forage production.
Investigations into the Nature of Thatch and Methods for its Decomposition1
Authors: Ledeboer F. B. , Skogley C. R.
Published: July 2010

The rate of thatch decay in turf was investigated following treatment with certain mono‐ and disaccharides in combination with calcium and fertilizer. In a field study on 15‐year‐old velvet bentgrass putting turf, sucrose treatments decreased turf quality and modified the stimulating effects of fertilizer. Lime had no influence on turf quality. Sucrose tended to increase the incidence of dollar spot disease, while fertilizer decreased it.

In a greenhouse study on heavily thatched lawn sod, glucose, cellulase, and soil topdressings did not affect turf quality. No increase in thatch decomposition was obtained in these experiments. Chemical analysis of the thatch gave an average lignin content 10% higher than that reported for cereal straws and 12 to 13% greater than for live top growth.

An investigation into the physical thatch structure showed that sclerified vascular strands of stems and leaf sheaths were more resistant to decay than clippings or sloughed leaves. Nodes and crown tissues were most resistant. Intact fibrous roots were numerous in the upper thatch layer; only few extended through the thatch into the soil.
Residue of Bensulide in Turfgrass Soil Following Annual Treatments for Crabgrass Control1
Authors: Bingham S. W. , Schmidt R. E.
Published: July 2010

A series of experiments was used to evaluate bensulide treatments in terms of crabgrass control, soil residue, leaching and effect on seedling establishment. Annual treatments of 16.8 kg/ha (15 lb/acre) of bensulide gave continuous preemergence control of crabgrass (reseeded annually) in bentgrass turf. The turfgrass vigor was improved through crabgrass control as compared to untreated plots with competing crabgrass. Bensulide residue in the soil was determined by a bioassay developed by measuring the rate of root growth of milo from seed. With the granular formulation large amounts of bensulide were found in the soil at eleven months after the fourth annual application. Detectable quantities were obtained to depths of 12.75 cm. The emulsifiable concentrate treatments did not persist for eleven months following the fourth application in detectable quantities in the soil.

Soil properties affected the response of milo to bensulide. It was demonstrated that more bensulide was required to produce injury to milo roots in soil from the surface layer (0‐2.5 cm) than in soil from lower layers. Milo phytotoxicity was inversely related to organic matter and nutrient content of the soil.

Three dates of planting five turfgrass species following herbicide treatment were evaluated. Bensulide affected all species planted on the day of treatment but all species emerged well when planted 30 to 60 days after herbicide application to the soil surface.
Yield and Sugar Production by Sugar Beets as Affected by Leaf Area Variations Induced by Stand Density and Nitrogen Fertilization1
Authors: Campbell R. E. , Viets F. G.
Published: July 2010

Sugar beets (Beta vulgaris L.) were grown in combinations of three stand densities with four rates of N application during the season and the leaf area and production of dry weight and sugar measured at weekly intervals to determine the effects of superoptimal N fertilization on beet growth and quality at Huntley, Montana. The highest sugar percentage and yield of extractable sugar were produced without N fertilization with beets 46 cm apart in the row. The highest extractable sugar yields were associated with the lowest leaf area index both at harvest and throughout the season, with the lowest leaf area duration, and with the lowest top:root ratios on a dry‐weight basis. Net assimilation rates per unit of leaf area were negatively correlated with leaf area index and leaf area duration. Optimum leaf area index did not appear to be much above 1.9 at October harvest or above 3 at any time during the season. Although the best beets were produced without N fertilization on this fertile soil, lower rates of N than those used might have been beneficial. High N rates produced more leaf area and higher total use of sunlight, as measured by total dry weight production, but resulted in lower sugar yields and juice purity. The net photosynthesis was calculated to be only about one‐third of the theoretical total photosynthesis for the climatic conditions.
Aluminum Tolerance of Two Barley Varieties in Nutrient Solution, Peat, and Soil Culture1
Authors: MacLeod L. B. , Jackson L. P.
Published: July 2010

‘Charlottetown 80’ and ‘Herta’ barley were grown in nutrient solution (pH 4.3) with 0, 4, 6, 8, 10, and 12 ppm of added aluminum, in peat at pH values of 4.3, 5.5, and 6.2 each with 0, 3, 6, and 12 ppm of added Al, and in mineral soil at pH values of 4.7, 5.5, and 6.5. Actual concentrations of aluminum ion in solution were 0, 0.7, 1.5, 2.2, 2.6, and 3.0 ppm. Using the yield of Charlottetown 80 at 0 ppm as l00%, the yields of tops for the above Al concentrations were 100, 100, 96, 93, 49, and 42% for Charlottetown 80 and 41, 49, 32, 31, 20, and 23%, respectively, for Herta. Corresponding root yields were 100, 112, 113, 111, 76, and 66% (Charlottetown 80) and 42, 48, 39, 32, 24, and 31% (Herta). Saturation extracts from peat (pH 4.3) contained 2.0 ppm Al which reduced the top and root yields to 56 and 43% and 55 and 43% for Charlottetown 80 and Herta, respectively. Heavy fertilization reduced root yields in unlimed soil and increased root yields in limed soil. Percent K, Ca, and Mg in tops and roots decreased while percent Al increased with increasing Al concentration. Both uptake and translocation of P decreased with increasing Al concentration.
Curing Coastal Bermudagrass Hay: Effects of Weather, Yield, and Quality of Fresh Herbage on Drying Rate, Yield, and Quality of Cured Hay1
Authors: Hart Richard H. , Burton Glenn W.
Published: July 2010

Moisture losses and changes in yield and quality of 64 lots of Coastal bermudagrass hay were studied during curing. Water content of grass after a day of curing was significantly influenced by initial water content, vapor pressure deficit of the air, solar radiation, and yield; there was a significant interaction of initial water content with the other three factors. Water content of the grass might increase or decrease during the night, depending upon water content at the end of the previous day, vapor pressure deficit, and yield. Dry matter yield and crude protein and digestible dry matter content decreased slightly in good curing weather and sharply in rainy weather. Carotene losses were associated with total radiation received during curing. We concluded that rain during curing would produce greater losses in quality than delaying harvest until better weather was predicted.
Persistence of Birdsfoot Trefoil under Pasture Conditions1
Authors: Templeton W. C. , Buck C. F. , Wattenbarger D. W.
Published: July 2010

Behavior of birdsfoot trefoil in association with Kentucky bluegrass during a 12‐year period is described. From 1962 to 1966 spring managemenst schemes, each permitting natural reseeding in summer, were compared. Under conditions favorable for reseeding birdsfoot trefoil shows promise for pasture improvement in some areas where its use has not been considered feasible.
Effect of Phosphorus and other Deficiencies on Leaf Temperature in Tobacco1
Authors: Wallace A. , Frolich E. , Ashcroft R. T.
Published: July 2010

Decreased transpiration in tobacco leaves resulting from phosphorus deficiency results in a marked increase in leaf temperature. Other deficiencies result in increases which are not so pronounced as that of phosphorus. Wilting itself results in increases.
Effect of Viewing Angle on Canopy Temperature Measurements with Infrared Thermometers1
Authors: Fuchs M. , Kanemasu E. T. , Kerr J. P. , Tanner C. B.
Published: July 2010

Crop surface temperatures were measured with infrared thermometers at various viewing angles and for a range of solar zenith angles. The temperature readings of crops with continuous and uniform canopies were not related to the above angles. In the case of open row crops, the side of the row facing the sun was 1 to 3 C warmer than the shaded side.
Performance of Bluegrass Varieties at Two Cutting Heights and Two Nitrogen Levels1
Authors: Goss Roy L. , Law Alvin G.
Published: July 2010

Dwarf type Poa pratensis L. selections (‘Merion,’ ‘Newport,’ and Washington State University selections 602, 402, 104, and 205) and “tall” or erect types (‘Park’ and ‘Delta’) were planted in replicated plots 2.5 ✕ 3.1 m on a Caldwell silt loam soil. Levels of P, K, and Ca were considered adequate for normal turfgrass growth. The plots were allowed to establish for 1 year and were then split into four subplots of two cutting heights (1,27 and 2.54 cm) and two nitrogen levels (3.6 and 1.1 kg/92.9 m2 per season). The plots were mowed once weekly for 20 weeks and all clippings were saved for yield and nitrogen analysis. Cores of soil 10.2 cm in diameter and 20.3 cm deep were analyzed for roots at the end of the season each year.

There were significant differences (P = .05) in yield of shoots among varieties in the first but not the second treatment year. Significant differences were found in root yield among varieties both years. Cutting heights produced significant differences both years. Most shoots in 1957 were produced at the 2.54‐cm cutting height, but more shoots in 1958 were produced at the 1.27‐cm height.

Significantly more shoots were produced both years from the highest N rate. The same treatment produced significantly fewer roots both years. The high N treatment resulted in higher tissue nitrogen content, but the greatest percentage nitrogen was recovered by the grass with the low N treatment.

Shoot:root ratios were computed and are shown.
Winter Cover Crops for Sod‐Planted Corn: Their Selection and Management1
Authors: Moschler W. W. , Shear G. M. , Hallock D. L. , Sears R. D. , Jones G. D.
Published: July 2010

Winter cover crops for sod‐planted corn (Zea mays L.) were studied in 11 location‐year field experiments in Virginia during the 1962–1966 period. Conventionally tilled corn with cover crop turnplowed and sod‐planted corn were also compared. Rye (Secale cereale L.) was the most satisfactory because of superior winter hardiness, susceptibility to herbicidal killing, and the production of relatively large amounts of persistent mulch. Wheat (Triticum aestivum L.) and oats (Avena sativa L.) were comparable as mulches except at higher elevations where oats winterkilled. Barley (Hordeum vulgare L.) was the least satisfactory winter grain tested because of resistance to herbicides. Inclusion of crimson clover (Trifolium incarnatum L.) or hairy vetch (Vicia villosa Roth.) in winter grain seedings slightly increased mulch forage but not corn yields.

In general, highest corn yields occurred where largest amounts of cover crop mulch occurred, except for Italian ryegrass (Lolium multiflorum Lam.). The additional mulch produced by late versus early killing of particular cover crops tended to increase corn yields, though not always significantly. Planting corn in rye stubble after removal of forage for hay or silage reduced corn yields an average of 47% in three of seven comparisons with rye left as mulch, while yields in the remaining four were comparable.

Yields of sod‐planted corn in rye sod averaged 44% higher than conventionally tilled corn in 4 of 13 comparisons and were comparable in the remaining nine. More soil moisture was found under sod‐planted corn than under conventionally tilled corn, especially during the first half of the growing season.

Corn yields were increased or at least maintained, in comparison to conventional tillage, by sod‐planting in rye over a wide range of soil and moisture conditions, with the added advantages of improved soil and water conservation.
Weed Root Profiles1
Authors: Davis R. G. , Johnson W. C. , Wood F. O.
Published: July 2010

The spatial extent of the root systems of Xanthium Pennsylvanicum Wallr. (cocklebur), Tribulus terrestris L. (puncturevine), Kochia scoparia (L.) Schrad. (kochia), Digitarius sanquinalis (L.) Scop. (large crabgrass), Solanum rostratum Dunal. (buffalobur), Salsola kali L. var. tenuifolia Tauch (Russian thistle), Amaranthis retroflexus L. (redroot pigweed), and sorghum was determined at 10 weeks after transplanting and at maturity by digging and exposing the roots. The plants were grown without competition under favorable moisture conditions. At maturity, the root profile areas varied from 5.20 m2 for pigweed to 17.93 m2 for cocklebur. Plants within the extremes in increasing order of root profile area were sorghum, Russian thistle, buffalobur, crabgrass, kochia, and puncturevine.
Soil Degradation of Diazinon, a Phosphorothioate Insecticide1
Authors: Konrad J. G. , Armstrong D. E. , Chesters G.
Published: July 2010

Degradation of the insecticide diazinon was followed in acid soil‐free systems and in soil systems. The mechanism of diazinon degradation in soils is a partial chemical hydrolysis with formation of 2‐isopropyl‐4‐methyl‐6‐hydroxypyrimidine and diethyl thiophosphoric acid; hydrolysis in soils is adsorption rather than acid catalyzed. Degradation rates were 11, 7, and 6% per day for Poygan sicl, Kewaunee c, and Ella Is, respectively, and these rates were related to organic matter content and pH of the soil.
Effect of Mulches and Bed Configuration. I. Early‐Season Soil Temperature and Emergence of Grain Sorghum and Corn1
Authors: Adams John E.
Published: July 2010

Clear plastic film, petroleum mulch, and two bed configurations (ridge and 20° south slope) were used on Austin and Houston Black clay to evaluate their effects on soil temperature (7.6‐cm depth) as compared with flat surface (conventional planting).

All treatments caused some increase in soil temperature as compared with conventional planting. Mulches had a highly significant effect (1% level) on soil temperature during seedling emergence. Average daily soil temperature (7.6‐cm depth) was increased from 0.6 to 2.2 C by petroleum mulch and from 1.1 to 4.4 C by clear plastic. Bed configuration caused a small (0.3 to 0.6 C) but nonsignificant increase in the average daily temperature of bare soil during emergence.

Mulches had more effect on initial emergence than bed configuration. Grain sorghum (Sorghum vulgare) and corn (Zea mays L.) emergence was fastest on clear plastic‐mulched plots and slowest on bare plots. Treatments with earliest emergence also had the densest stand. Both mulches and bed configuration had a highly significant effect (1% level) on seedling emergence. Emergence time for grain sorghum decreased 1 day for each 0.9 C increase in average daily (7.6‐cm depth) soil temperature between 12.8 and 20.6 C (r = −0.94).

Results indicate that the soil is too cool at normal planting time for maximum emergence and stand of grain sorghum and corn in the Texas Blackland area.
Effects of Clipping on the Performance of Spring Barley (Hordeum vulgare L. emend Lam) Seeded in October1
Authors: Day A. D. , Thompson R. K. , McCaughey W. F.
Published: July 2010

A 4‐year experiment was conducted to study some of the effects of clipping on the yield and quality of simulated pasture forage and grain from ‘Harlan’ spring barley planted in October and grown under irrigation at Mesa, Ariz. Four treatments (0, 1, 2, and 3 clippings at the onset of jointing) were evaluated in a replicated randomized complete block design. Forage and grain harvests were made with small‐plot equipment. Clipping two times by late January reduced plant height, eliminated lodging, and produced maximum yields of quality grain. In addition, the pasture forage provided an economical source of protein and digestible laboratory nutrients (D.L.N.).
Effect of Soil Nutrients and pH on Nitrate Nitrogen and Growth of Pearl Millet [Pennisetum typhoides (Burm.) Staph and Hubbard] and Sudangrass [Sorghum sudanense (Piper) Staph]1
Authors: Smith D. T. , Clark N. A.
Published: July 2010

Pearl millet [Pennisetum typhoides (Burm.) Staph and Hubbard] and sudangrass [Sorghum sudanense (Piper) Staph] were compared in 1963 on a mineral‐deficient, low pH Monmouth sandy loam under four rates each of K and P, and three rates each of Ca and Mg with one element varied per plot. In 1964, pearl millet was grown on a Sassafras sandy loam under three pH levels and four potassium levels. A greenhouse experiment was conducted the following winter with pearl millet grown in soil from the low‐K plots of the first experiment. Treatments were three pH levels and four K levels. Plant samples from each experiment were chemically analyzed. Although K fertilization had no effect on nitrate N in sudangrass, nitrate N in pearl millet tended to incrtase with K applications. Concentrations of 3 to 6% K in plant tissue were common. P and Mg fertilization showed no effect on nitrate N concentrations in plant tissue. Nitrate in millet increased with soil pH increases. Millet was less sensitive to soil fertility than sudangrass was and extracted greater amounts of N, P, and K.
Effects of Plant Parts on the Grain Yield, Kernel Weight, and Plant Height of Wheat and Barley1
Authors: Saghir A. R. , Khan A. R. , Worzella W. W.
Published: July 2010

A field study was conducted on dry land to determine the contribution of different plant parts to the kernel development of wheat and barley. Shading of the spike proved to be the most effective treatment in reducing the grain yield and 1000‐kernel weight of wheat and barley. The least significant effect was obtained by the removal of the lower leaves. Treatments made 1 week before anthesis caused maximum reductions in grain yield and 1000‐kernel weight. Plant height was least affected by shading or removal of the different plant parts.

Clipping full awns at anthesis had the most significant effect on the grain yield and 1000‐kernel weight of wheat, reducing the yield 20.8% and the weight 13.4%. This reduction corresponded to the proportion of the awns clipped and the advancement of the stages of growth studied. The plant height was not affected by clipping the awns.
Carbowax 6000, Mannitol, and Sodium Chloride for Simulating Drought Conditions in Germination Studies of Corn (Zea mays L.) of Strong and Weak Vigor1
Authors: Parmar M. T. , Moore R. P.
Published: July 2010

The investigations concerned the influences of simulated drought conditions on germination and early nonphotosynthetic stages of seedling growth of two lots of dent corn differing in energy. Carbowax polyethylene glycol 6000, (C6M), mannitol, and NaCl were used osmotic substrates to prepare aqueous solutions having 0 to 10 atmospheres of osmotic pressure (O.P.), corresponding to different drought conditions. The tetrazolium test was used to evaluate seed energy.

Water absorbed by seeds decreased with increasing O.P. levels. Increased O.P. levels progressively delayed and reduced germination. Linear regression coefficients were ‐3.45, ‐1.09, and ‐0.49% germination per 1 atm O.P. for the above three substrates, respectively. The rapidity of gernfination and the seedling vigor in growth tests of the two lots tended to parallel the vigor ratings obtained from tetrazolium tests.

Trends were noted indicating more adverse effects of increasing O.P. levels on the low than on the high energy lot, and on the shoot than on primary root elongation. Correlation steadies indicated that shoot growth alone was an acceptable measure of evaluation for the simulated influence of drought conditions.
Efficiency of Rape, Oats, Soybeans, and Flax in Absorbing Soil and Fertilizer Phosphorus at Seven Stages of Growth1
Authors: Kalra Y. P. , Soper R. J.
Published: July 2010

A greenhouse experiment was conducted in an attempt to determine the phosphorus requirements of rape, oats, soybeans, and flax at various stages of growth. Radioactive phosphorus was used in order to differentiate between the amount of phosphorus derived from the fertilizer and from the calcareous soil used. Phosphate fertilizer was applied as a band about 1.3 cm below the seeds at the time of planting.

“A” values differed amongst these crops and at different stages of growth for the same crop. The “A” values decreased in the order soybeans, flax, oats, and rape. Soybeans were much more efficient than rape, oats, and flax in extracting soil phosphorus. For most of the growth cycle rape and flax were similar in absorbing phosphorus from the soil and in this respect oats were less efficient than these two crops except for the last two stages. It would appear that the differences amongst the “A” values of rape, oats, and flax are largely due to differences in their abilities to extract fertilizer phosphorus. The “A” values of soybeans were very high, which would seem to be largely due to their greater efficiency in absorbing soil phosphorus.
Kernel Color and Shape as Guides to Potential Flour Performance in Wheat Marketing1
Authors: Barmore Mark A. , Bequette Robert K.
Published: July 2010

A 16‐year summary of flour quality data for important Pacific Northwest wheat varieties is used to illustrate that primary responsibility for maintaining an orderly wheat marketing system rests with plant breeders and associated cereal technologists.

The exact rate at which flour strength increases as protein content increases is an inherent varietal property which influences the suitability of hard‐endosperm wheat flours for yeast‐leavened products, and of soft‐endosperm flours for chemically leavened baked goods. The U. S. Grain Standards group varieties having visibly similar identifying kernel characters into classes (or subclasses) which represent inherent differences in flour properties and use potential. Subclasses (except White Club and Western White) are based on kernel vitreousness as an estimate of protein content, which is in turn an estimate of flour strength.

The grading and marketing problems created by a hard‐endosperm bread wheat variety with a white bran coat suggest that until a quick quality test is developed, varietal quality should be defined as: “the suitability for the end‐use normally associated with the market class (or White Wheat subclass) in which a variety is automatically placed because of kernel color and shape”.
Effect of Soil Salinity on Water Potentials and Transpiration in Pepper (Capsicum frutescens)1
Authors: Ehlig C. F. , Gardner W. R. , Clark M
Published: July 2010

Total leaf water potential, osmotic potential, turgor potential, and transpiration rate were measured on pepper plants irrigated with saline water having an osmotic potential of −2 bars. Results were compared with similar measurements on nonsaline treatments. Plants were allowed to extract water from the soil until the total water potential reached about −16 bars.

The difference between the leaf water potential and the soil water potential was the same for both treatments. The relation between the leaf water content and component water potentials was that predicted from the nonsaline leaves, assuming an osmotic adjustment in the saline leaves of −2 bars. No further adjustment due to concentration of the soil solution was observed. The relative transpiration rate was reduced at a much higher soil water content for the saline than for the nonsaline case.
Use of Multiple Regression in Fertilizer Evaluation1
Authors: Engelstad O. P.
Published: July 2010

The application of standard Multiple regression programs to fertilizer evaluation via nutrient uptake is shown to be both feasible and convenient. A common intercept and regression coefficients are calculated for any number of fertilizers being compared, along with additional data needed for statistical comparisons. Statistical tests for determining significant differences among coefficients are provided. Linear segments of yield curves can also be used.
Photosynthesis Under Field Conditions. XI. Soil‐Plant‐Water Relations During Drought Stress in Corn1
Authors: Shinn J. H. , Lemon E. R.
Published: July 2010

The variation of leaf water potential at different heights in a corn crop canopy (Zea mays) and with time during a period of increasing drought stress were examined along with soil moisture tension and evapotranspiration. These measurements plus growth measurements permitted an evaluation of the soil‐plant‐water transport system and its effects on plant growth during drought.

On clear summer days the upper leaves of the corn crop had higher water potentials with a bimodal tendency in contrast to the lower leaves which had lower and almost constant water potentials.

On high stress days the magnitude of the maximum afternoon leaf water potential increased by an amount equal to the increase in soil moisture tension. On days of comparable evaporative demand, the gradient of water potential from the upper leaves to the soil increased regularly with an increase in soil moisture tension in the root zone.

Since total transpiration was not bimodal even though upper leaves exhibited bimodal variations of water potential, it is concluded that if midday stomatal closure of the upper leaves occurred, it apparently was ineffectual or compensating transpiration must have been carried on by lower leaves.

A 2‐week drought period was examined in detail. Computation of the “effective conductance” of liquid water in the plant was compared with the moisture conductivity of the soil. This permitted a calculation of the “effective root length” where the gradient of water potential from plant to soil was assumed to represent the gradient from the root surface to the ambient untapped soil moisture. This calculated length was small by comparison to those calculated by Slatyer (1957), but the computational error is large.

Transpiration was not detectably changed by the decrease in effective plant conductance and soil conductivity, so it is. concluded that the plant was still able to keep pace by maintaining sufficient potential gradient to transport the needed amount of water. The growth processes, however, were slowed down with increasing leaf water potential and decreasing turgor of the tissues. This slowdown was evident even at the relatively low soil moisture tension of less than one bar and a leaf water potential of less than 3.5 bars.
Defoliation by Sheep‐Grazing Versus Mower‐Clipping for Evaluation of Pasture1
Authors: Cuykendall C. H. , Marten G. C.
Published: July 2010

Yields within three grass species and two alfalfa varieties defoliated by sheep‐grazing or machine‐clipping were nearly identical in a year of limited moisture. With adequate moisture, grazing caused higher yields of all forages, until extremely high levels of N (for grasses) and K (for alfalfa and grasses) were applied to both treatments. Sheep excreta significantly increased K levels of soil and plant tissue. Comparable heights of defoliation by the two methods left twice as much residual leaf and stem tissue after grazing, but this did not increase subsequent forage yields. Significantly more weeds invaded clipped plots in late summer. Regrowth of sod cores in darkness at the end of each season indicated more total reserves per unit area under grazing due to more tillers and roots per unit area. However, no differences in grams of top growth per gram of stubble and root appeared under the two methods of defoliation.
Effects of Rainfall and Temperature Interactions During the Growing Season on Corn Yield1
Authors: Runge E. C. A.
Published: July 2010

Maximum daily temperatures and rainfall were found to have a large effect on corn yield from 25 days before to 15 days after anthesis. This corresponds to the average calendar interval of June 30 through August 8 at Urbana. The maximum effect of temperature and rainfall on corn yield occurs approximately one week before anthesis and remains at a high level one week to either side of the maximum. The models solved in this investigation indicate that high temperatures (maximum daily temperatures between 32.2 and 37.8 C or 90 and 100 F) can be beneficial to corn yield if moisture available to the corn plant is adequate.
Effect of Soil Salinity on External Morphology of Cotton Leaves1
Authors: Gausman Harold W. , Cardenas Ruben
Published: July 2010

Fourth leaves from the apex of cotton plants were sampled in a field containing areas of low and high levels of soil salinity. Microscopic examination revealed that high salinity caused fewer epidermal cells and stomata per unit area, increased surface size of epidermal cells, and increased leaf thickness.