bluuebunny/crossref_metadata_2025 huggingface dataset:
Moisture Storage and Spring Wheat Yields on Level‐Bench Terraces as Influenced by Contributing Area Cover and Evaporation Control1
Authors: Haas H. J. , Willis W. O. , Boatwright G. O.
Published: July 2010

Level‐bench terraces on land with 5 to 9% slope increased water storage and wheat yields as shown in a study conducted from 1959 through 1962. Various types of contributing areas were used. Runoff from wheat or grass contributing areas had minor influence on moisture storage and yields on the bench. An impervious contributing area increased moisture storage on the bench by 1.3 inches and wheat yields by 4.7 bushels per acre. Deep percolation near the base of the impervious slope caused some nutrient leaching and moisture loss. Partial evaporation control (32‐inch wide plastic film strips covering 90% of minor ridges on the bench) from harvest to seeding increased moisture storage by 1.4 inches and wheat yields by 3 bushels per acre.

Results indicate possible methods of conserving precipitation normally lost, particularly during the dormant or winter period. Principal advantages of level‐bench terraces appear to be collecting snow, preventing runoff of snow‐melt and torrential‐type rains, reducing erosion, and increasing yields through moisture conservation.
Relationship of Creeping Bentgrass (Agrostis palustris Huds.) Root Growth to Environmental Factors in the Field1
Authors: Beard James B. , Daniel William H.
Published: July 2010

Temperature was found to be the most consistent environmental factor in accounting for variation in root number and color of irrigated creeping bentgrass. Soil temperature at the 6‐inch depth was most highly correlated with root growth. Light intensity ranked second in accounting for variation in root activity while soil moisture was quite low. There were only two times when new roots were produced. In both cases, this new root growth occurred right after a very sharp drop in temperature suggesting that lower temperatures either initiate root elongation or are required for the elongation of new roots from bentgrass crowns.
Effect of Nitrogen Forms on the Absorption of Bromide by Sorghum1
Authors: Chao T. T.
Published: July 2010

Pot experiments were conducted to determine the effect of nitrogen forms on the absorption of bromide added as NaBr by sorghum. Plants supplied with NH4‐N absorbed a greater amount of bromide than those with NO3‐N while plants with a combination of NH4‐N and NO3‐N (1:1 ratio) were intermediate. There was a linear relationship between the amount of bromide applied and that absorbed by sorghum. The recovery of bromide in plant tops amounted to two‐thirds of the bromide applied. Soil fumigation with D‐D coupled widi N‐Serve effectively inhibited nitrification of NH4‐N fertilizer applied to soil. Such technique may be useful in studies where the effect of NH4‐N versus NOs‐N on plant nutrition is to be compared.
Yield and Nutrient Uptake by Orchardgrass as Affected by 14 Annual Applications of N, P and K1
Authors: Singh R. N. , Martens D. C. , Obenshain S. S. , Jones G. D.
Published: July 2010

Orchardgrass (Dactylis glomerata) grown on Davidson clay loam showed a yield response to N in 1949 and 1950, to N and K from 1951 to 1953 and to N, P and K from 1954 to 1962. During the latter period, yield response to a given nutrient occurred only if adequate amounts of the other two were applied. Lower yields were obtained with 171 than with 114 kg of N/ha in 1958 without applied K and in 1960 to 1962 with applied K. This apparently resulted from higher uptake of K with 171 kg of applied N and a cumulative depletion of available K in the soil.
Evaluation of Mulching Methods for Erosion Control on Newly Prepared and Seeded Highway Backslopes1
Authors: Barnett A. P. , Diseker Ellis G. , Richardson E. C.
Published: July 2010

abstract

Evaluation of several mulching methods used by different highway departments showed that 2 tons of grain straw per acre provided adequate protection to newly prepared and seeded 2½:1 backslopes when subjected to l‐year frequency storms, 1.3 inches of rain in 30 minutes. However, when subjected to a 10‐year frequency storm, 2.7 inches in 60 minutes, two treatments stood out as superior. These were “whisker dams”, called the Florida method, which permitted 41% runoff and 10 tons per acre soil loss; and surface mulch, called the Cartersville method, which permitted 40% runoff and 11 tons per acre soil loss.

In all cases where asphalt spray was a part of the treatment, the effectiveness of mulch was decreased when tested by the 10‐year frequency storm. Runoff and soil loss from mulch and mulch plus asphalt were 1.1. inches and 11 tons per acre and 1.3 inches and 32 tons per acre, respectively. Mulch mixed and mulch mixed plus asphalt were the same‐l.3 inches and 27 tons per acre‐indicating that the asphalt had no beneficial effect.

The California method was a checkerboard arrangement of straw pressed into the surface. This treatment was inferior to the “whisker dams” because the staggered arrangement permitted more soil transport by over‐land flow. Runoff and soil loss for these two treatments were 1.2 inches and 44 tons per acre and 1.1 inches and 10 tons per acre, respectively.

Bare, unprotected backslopes eroded at the rate of 97 tons per acre and permitted 62% runoff. Six months or more after planting, satisfactory stands had been established with all mulch treatments.
Influence of Nitrogen and Potassium on Variations in Content of Malate, Citrate, and Malonate in Non‐Nodulating Soybeans (Glycine max)1
Authors: Pattee H. E. , Teel M. R.
Published: July 2010

The influence of nitrogen and potassium on metabolism in non‐nodulating soybeans was studied. Nonprotein nitrogen was increased by high nitrogen rates but markedly reduced with increasing potassium levels. Malate decreased with increased potassium at low nitrogen fertility but increased at high nitrogen fertility. Citrate was reduced by additional potassium, irrespective of nitrogen level. Malonate was increased in nitrogen‐deficient plants when potassium was supplied. The sum of the three acids accounted for approximately 72% of the total acidity, irrespective of fertility treatments.

It is suggested that, with plants growing under high nitrogen‐low potassium regimes, PEP is shunted into alternate pathways, thereby causing a shortage of acetyl CoA. The data suggest that OAA is preferentially produced from PEP in potassium‐deficient plants, since OAA derivatives accumulate.
Toxicity of Decomposing Crop Residues to Cotton Germination and Seedling Growth1
Authors: Megie Christian A. , Pearson R. W. , Hiltbold A. E.
Published: July 2010

Toxicity of un‐ionized ammonia was the primary reason for inhibited germination and reduced growth of cotton seedlings following incorporation of plant residues in a sandy loam soil. The accumulation of ammonia in toxic amounts resulted from increased soil pH and ammonium N content, whicn were proportional to the organic N content of the residues. Plant growth decreased sharply with increasing ammonia and levels above about 10 ppm were lethal.

Under sterile conditions, 1:50 plant‐water extracts did not reduce germination, but with the onset of microbial decomposition, extracts of all materials were highly toxic. At concentrations above 1 :50, alfalfa extracts reduced radicle elongation even under sterile conditions, indicating the presence of a toxic constituent, possibly saponin.
Potassium and Sodium Interrelations in Growth and Mineral Content of Italian Ryegrass1
Authors: Hylton L. O. , Ulrich A. , Cornelius D. R.
Published: July 2010

Growth and mineral content of Italian ryegrass were affected by K and Na treatments when studied by a nutrient solution technique. Potassium influenced plant growth more than did Na. Sodium substituted partly for K in top growth when K was low in the nutrient solution. Changes in the amount of K in solution affected leaf and tiller sizes more than numbers. Visual K deficiency symptoms were delayed and were less severe when Na was high in the solution.

Potassium and Na concentrations in all plant parts were directly related to K and Na treatments. Potassium concentration was higher in old blades than in young blades when plants were K deficient, regardless of Na treatment. Sodium concentration, unlike K, generally decreased with increased blade age. Potassium and Na concentrations in the stem were high, compared to other plant parts.

The youngest blade that was fully open and had a ligule, blade 1, was determined to be the best plant part to sample. It was necessary to determine Na in addition to K in blade 1 in order to diagnose the K status of the ryegrass adequately. The critical K concentration was 0.8% for blade 1 tissue that contained more than 2.4% Na, dry basis. The critical K concentration was 3.5%, however, for blade 1 tissue that contained less than 0.3% Na, dry basis.
An Evaluation of Birdsfoot Trefoil (Lotus corniculatus) in Pasture Improvement1
Authors: Wedin W. F. , Vetter R. L. , Scholl J. M. , Woods W. R.
Published: July 2010

In southern Iowa, pastures renovated with birdsfoot trefoil but containing white clover were compared over an 8‐year period (1956–1963) with unimproved pastures and also with Kentucky bluegrass—white clover pastures fertilized with nitrogen (N) and phosphorus (P) (fertilized grass). A 2.7‐fold increase in beef produced per hectare resulted for pastures renovated with birdsfoot trefoil over unimproved pastures. A 1.7‐fold increase was obtained for fertilized grass over the unimproved.

Average daily grain for yearling steers was significantly greater at 0.76 kg/day for pastures renovated with birdsfoot trefoil, as were grazing days and beef production (423 kg/ha) (P < 0.01) over fertilized grass. In addition, growth and grazing of birdsfoot trefoil pastures were more favorably distributed over the season.

Considering renovation of pastures vs. N purchased annually for grass pastures, renovation with birdsfoot trefoil is strongly favored. Unimproved pastures require little expenditure but do not produce cheap forage if cost of land, fencing, etc., are considered. The extensive use of permanent pastures should be rejected because each site amenable to improvement may eventually need to be used at the level where all controllable inputs are maximized.

Although pastures renovated with birdsfoot trefoil were superior to fertilized grass pastures, the decline in contribution by the legume in renovated pastures suggests need for research at higher levels of fertility and management than those used in these studies.
Self‐Propelled Plot Forage Harvester1
Authors: Swallow Clarence
Published: July 2010

A machine to harvest forage from experimental plots was developed at Kansas State University. This harvester is similar to theworking characteristics of commercially available machines. The harvested material is cut with a standard type sickle and guard arrangement, passed through a chopper, and delivered to a weighing container.
Residual Nitrate Nitrogen in Fertilized Deep Loess‐Derived Soils1
Authors: Herron G. M. , Terman G. L. , Dreier A. F. , Olson R. A.
Published: July 2010

Asbtract

Distributions of NO3‐N were studied in deep loess‐derived profiles of Sharpsburg silty clay loam and Hastings‐Crete silt loams cropped to irrigated corn (Zea mays L.) in eastern Nebraska. Only with soils very high in N and high applications of fertilizer N was there any indication of appreciable leaching of NO3‐N below 180 cm in the profiles. Most of of the water‐ or KCI‐extractable N was usually found in the surface 0‐90 cm of soil. High correlations were found (r > 0.9) for a given soil site between amounts of NO3‐N in the surface 30 cm and totals to 180 cm. However, the proportion found in the surface soil varied widely among years and sites. At a given site there was a high correlation between NO3‐N in the profiles in the fall after harvest and corn yields without applied N the following year. Simple correlations of profile NO3‐N with percentage yields for different years, soils and management levels, however, were usually too low to have predictive value.
An Improved Forage Harvester for Experimental Plots1
Authors: Allen R. J. , Casselman T. W. , Thomas F. H.
Published: July 2010

A flail type, self‐propelled, small plot forage harvester, patterned after a machine previously reported, has been built. A full width supporting roller, a deflecting shield, a simplified takedown, and a lever‐operated flail clutch equipped with a brake for a safety feature have been added as improvements. Forage from 20 to 92 cm tall may be cut at 2.5 to 20 cm above ground and deposited into a removable collection box.

Blueprints for this improved model or address of commercial builder can be obtained from the Everglades Experiment Station.
Effect of Fertilizers, Soil Drainage Class and Year upon Protein Yield and Content of Oats1
Authors: Portch S. , MacKenzie A. F. , Steppler H. A.
Published: July 2010

Percent crude protein and yield of protein information from oat fertilizer trials was collected from twelve sites, including eight soil types and two drainage classifications.

Nitrogen was responsible for increases in crude protein content of the grain grown on all soil types studied. Phosphorus and potassium generally reduced the crude protein content of grain, although there were some slight increases recorded. Imperfectly drained soils produced grain of higher crude protein content than well drained soils.

Nitrogen, and to a lesser extent phosphorus, was necessary for maximum yield of protein on the well drained soils. Nitrogen alone on the imperfectly drained soils gave maximum protein yields. Potassium had little effect on the yield of protein on either drainage system. Significant seasonal differences in yield of protein were recorded. Higher yields of protein were found on the well drained soils than on the imperfectly drained soils.

Yield of grain and yield of protein were highly correlated (r = + .93). Thus, yield information alone is capable of predicting 86% of the variability of yield of protein.
Sulfur Response by Alfalfa (Medicago sativa L.) on a Sulfur‐Deficient Soil1
Authors: Seim E. C. , Caldwell A. C. , Rehm G. W.
Published: July 2010

Field experiments were conducted in a S‐deficient area in Minnesota to determine the soil S status, atmospheric contributions of S, and the response of alfalfa to S fertilization. In general the sulfate — S, the available S, and the reserve and total S in the soil were higher than is normally expected in S responsive soils. The average annual addition of S to the soil from atmospheric sources was 5.4 kg/ha (4.8 lb/acre) at the rural experimental site and 27.4 kg/ha (24.4 lb/acre) at a metropolitan area site. Alfalfa responded to all S treatments regardless of the material source. Treated plots yielded three times as much alfalfa as the check plots. Increases were obtained from residual as well as annual applications. Elemental S was as effective as gypsum in increasing alfalfa yields. Sulfur treatments significantly decreased the mortality of young alfalfa. The critical S level in mature alfalfa tissue ranged from .12 to .15% and the highest yields were obtained above 0.3%.
Influence of Temperature on the Yield and Chemical Composition of ‘Vernal’ Alfalfa at First Flower1
Authors: Smith Dale
Published: July 2010

The first‐flower stage of growth of ‘Vernal’ alfalfa (Medicago sativa L.) was reached in 21 days in the warm (W) temperature regime (32 C day/24 C night), but not until 37 days in the cool (C) regime (18 C/10 C). Herbage yields were considerably higher in the C than in the W regime. The first‐flower herbage in the C regime was highest in concentration of in vitro digestible dry matter, nonstructural carbohydrates, Ca, Mg, Ba, and Sr, but was lowest in protein, amino acids, ether extract, total ash, P, K, Al, Fe, B, Cu, Zn, and Mn. Composition of the leaflet and stem fractions was also in this order, but for a few exceptions. Crude fiber percentage was highest in the leaflets of the W regime and in the stems of the C regime, but there was no difference for the total herbage. All chemical constituents analyzed were in higher concentration in the leaflets than in the stems, except for reducing and total sugars, crude fiber, and K. Even though the soil contained 560 kg/ha of exchangeable K, the herbage from the C regime contained less than 1.5% of K, while that in the W regime contained over 2%.
Summer Defoliation and Autumn‐Winter Production of Phalaris Species and Tall Fescue Varieties1
Authors: Berry R. F. , Hoveland C. S.
Published: July 2010

The effect of summer defoliation on autumn‐winter (October—February) growth of koleagrass, hardinggrass, ‘Ky 31’ and ‘Goar’ tall fescue was studied for two years. Clipping in June and July reduced the autumn‐winter forage yield of harding 55% and kolea 47% as compared with that of plots unclipped from May to September. Percent total available carbohydrates (TAC) in July was positively correlated with autumn‐winter production of both Phalaris species. Kolea was more summer dormant than harding.

Clipping in mid‐July reduced autumn‐winter growth of Ky 31 but had no effect on Goar tall fescue. Clipping in early June sharply reduced autumn‐winter production of Goar but did not affect Ky 31. Summer clipping reduced the percent TAC in early September for Goar and TAC was correlated with autumn‐winter growth. TAC and autumn‐winter growth of Ky 31 were not correlated.

Summer resting of these Phalaris species and tall fescue varieties appears necessary for maximum autumn‐winter production in the lower southeastern United States.
Measuring Rooting of Sodded Turfs1
Authors: King J. W. , Beard J. B.
Published: July 2010

A technique was developed for measuring the rooting of sodded turfs. ‘Merion’ Kentucky bluegrass sod pieces, transplanted from organic and mineral soil, were placed in a frame having a fiberglass screen bottom. The frames containing the sod pieces were placed on a sandy loam soil and allowed to root. After 5 weeks the sod was lifted vertically from the underlying soil with a block and tackle technique. Sod grown on organic soil rooted into the underlying soil better than that produced on mineral soil.
Influence of Nitrogen Fertilizers on Washington Creeping Bentgrass, Agrostis palustris Huds. II. Incidence of Dollar Spot, Sclerotinia homoeocarpa, Infection1
Authors: Markland F. E. , Roberts E. C. , Frederick L. R.
Published: July 2010

A field experiment was established to evaluate influence of nitrogenous fertilizers on susceptibility of ‘Washington’ creeping bentgrass, Agrostis palustris Huds., to dollar spot disease, Sclerotinia homoeocarpa F. T. Bennett. The field study also supplied soil and plant tissue used in a series of laboratory experiments to investigate effects of activated sewage sludge and processed tankage on growth of S. homoeocarpa in pure culture. Influences of nitrogenous fertilizer on soil fungistasis and on plant tissue fungistasis were also investigated.

High levels of available nitrogen reduced dollar spot injury in field tests. Activated sewage sludge, which was most effective in producting disease resistant turf, did not possess any measurable fungitoxic agents. Soil microbiological activity, fertility, fungistasis and pH were not altered significantly by fertilizer treatment.
Response of Corn to Zn‐EDTA and ZnSO4 in Field Investigations1
Authors: Schnappinger M. G. , Martens D. C. , Hawkins G. W.
Published: July 2010

Field experiments were conducted in 1968 to determine the effect of rates of Zn‐EDTA and ZnSO4 application on yield and Zn content of corn (Zea mays L.) grown on Litz silt loam and Norfolk loamy fine sand. Placement of Zn‐EDTA was also included as a variable in the experiment on the Norfolk soil. Corn plants on the Norfolk soil “grew out” of Zn deficiency; whereas plants on the Litz soil remained stunted throughout the growing season. Highest corn grain yield occurred on both soils where ZnSO4 was broadcast at a rate of 14 kg Zn/ha. Rates of 2.24 kg Zn/ha as broadcast Zn‐EDTA and of 1.12 kg Zn/ha as banded Zn‐EDTA increased corn yield on the Norfolk soil. A higher rate of 4.48 kg Zn/ha as broadcast Zn‐EDTA was required to increase corn yield on the Litz soil. The ear leaves of corn plants on check plots of the Litz and Norfolk soils contained 10.8 and 12.4 ppm Zn, respectively, during the silk stage.
Growth of Sugar Beets as Affected by Root Temperatures Part I: Greenhouse Studies1
Authors: Radke J. K. , Bauer R. E.
Published: July 2010

Sugar beets (Beta vulgaris var. saccharifera) were grown in the greenhouse at 10 different constant root temperatures. The temperature intervals were maintained at 2.8 C between 12.8 and 37.8 C. Optimum root temperature for sugar beet emergence occurred in the range of 25–35 C. The optimum root temperature for dry matter production in sugar beet tops progressively decreased from 26.3 C at 6 weeks following emergence to 23C at 13 weeks following emergence. Optimum temperatures for sugar beet roots remained between 24 and 25 C for the 7‐week period. Percent sucrose in the sugar beet roots increased with root temperatures above 19 C. High sucrose yields were obtained between 18 and 32 C, with rapid decreases outside of this range. Concentrations of N, P, K, and Na in the sugar beet tops and roots were not dependent on root temperatures; thus, the total uptake of these nutrients was directly proportional to dry matter accumulation in the plant.
Field Losses in Harvesting Wilted Forage
Authors: Gordon C. H. , Holdren R. D. , Derbyshire J. C.
Published: July 2010

A procedure is described for obtaining sufficient field loss data for statistical analysis. Some sources of loss are identified and methods of preparing wilted forage for ensiling compared. Use of a combination mow‐condition‐windrow machine resulted in less loss than the conventional mow‐condition‐wilt‐rake method. Losses caused by leaching and slow drying appeared minor compared to physical losses from raking.
Effects of Copper on the Composition and Anatomy of Tobacco1
Authors: Struckmeyer B. Esther , Peterson L. A. , Tai Florence Hsi‐Mei
Published: July 2010

Effects of different concentrations of copper in nutrient solutions (0.02, 0.04, 0.08, 0.16, 0.32, and 0.64 ppm) on the composition and anatomy of tobacco plants were studied. Plants grown with 0.32 and 0.64 ppm Cu showed external chlorotic symptoms and internal toxic effects about 8–10 days after the start of the treatments, while plants grown on Cu concentrations of up to 0.16 ppm displayed no toxic malformations. Increasing concentrations of Cu .in the nutrient solutions were associated with the accumulation of Cu in the roots but not in the aerial portion of the plant. Dry weights of tops and roots were highest at the 0.04‐ and 0.08‐ppm Cu and lowest at the 0.32‐ and 0.64‐ppm treatments. Toxic Cu concentrations were associated with abnormal cellular growth and development throughout the plant. Primary roots developed short, thick, closely‐spaced lateral roots. Hypertrophy of the internal and external phloem resulted in crushed cells with a subsequent necrosis in the phloem. Cells in the xylem tissue were occluded or collapsed with irregularly shaped walls. Palisade and spongy parenchyraa cells of the leaves were deranged with very few chloroplasts. Cellular disintegration also occurred in this region.
Phosphorus Uptake from Soils by Corn Hybrids selected for High and Low Phosphorus Accumulation1
Authors: Baker Dale E. , Jarrell Ann E. , Marshall Leon E. , Thomas Walter I.
Published: July 2010

Field, greenhouse, and laboratory experiments were conducted over a period of 4 years to relate P accumulations in ear leaves of different corn hybrids and other plant responses to addition of P to soils and root morphology, including the length of the radicle, diameter of the radicle, and the number of seminal roots produced after 4 days in an incubator of high relative humidity at 28 C. In addition, experiments were conducted to determine the relationship of P accumulation in ear leaves and grain yields to P concentrations in seedling plants, seedling growth rate and P uptake from a zone 25 cm (10 inches) below the soil surface.

It was concluded that the concentration of P in seedling plants can be used to predict the availability of P in the soil. The concentrations of P accumulated in ear leaves by the different hybrids could not be explained on the basis of the P‐absorption characteristics of their roots, but inherent differences among hybrids with respect to depth of rooting was suggested.
Gahi‐1 Pearl Millet and Two Sorghum ✕ Sudangrass Hybrids as Pasture for Yearling Beef Cattle1
Authors: Dunavin L. S.
Published: July 2010

‘Gahi‐1’ pearl millet [Pennisetum typhoides (Burin.) Stapf and C. E. Hubb.] was compared with ‘Lindsey 77F’ and ‘Sudax’ (SX‐11) sorghum (Sorghum vulgare Pers.) ✕ sudangrass [Sorghum sudanense (Piper) Stapf] hybrids as pasture for yearling beef cattle. The experiment covered 3 years and included an early and a late planting in each year. Pastures were planted with a grain drill and grazing was rotational. The cattle, which were of British breeding, received no supplemental feed except for salt and other minerals. Gahi‐1 millet produced superior gains per hectare per day (3.70 kg) to SX‐11 (2.64 kg) or Lindsey 77F (2.34 kg) on early planted pastures. Gahi‐1 also produced higher gains per hectare per day (2.60 kg) than Lindsey 77F (1.85 kg) or SX‐11 (1.73 kg) on late planted pastures. Carrying capacity was greater on pastures of millet for both dates of planting. Clipping trials were also conducted with these three annual grasses during the three years of the experiment. The clipping trials utilized row plantings at a spacing of 0.914 m. Dry matter production of the three grasses was similar in each year except in 1964 when Gahi‐1 produced a significantly (P<.01) greater amount (3.18 metric tons) than Sudax (2.32 metric tons) or Lindsey 77F (2.18 metric tons).
Rooting Systems of Soybeans. I. Differences in Root Morphology among Varieties1
Authors: Raper C. D. , Barber S. A.
Published: July 2010

Field experiments were conducted to delineate morphological differences among root systems of 26 soybean varieties (Glycine max (L) Merr.). ‘Aoda’ and ‘Harosoy 63,’ were selected from the 26 varieties and strains as representative of extremes in rooting patterns.

A core sampling technique was used to quantitatively analyze the rooting systems in single‐plant plots. Harosoy 63 had a more extensive root system, including a nearly twofold greater root surface area, than Aoda. The rooting morphology in single‐plant and row plots was studied qualitatively by a soil monolith method. Both varieties lacked a distinctive taproot development below a zone of profuse branching. The disposition of primary branches in the soil was apparently influenced by intraspecific competition.
Alteration of Carbohydrate Composition of Corn (Zea mays L.) Seedlings during Moisture Stress1
Authors: Maranville Jerry W. , Paulsen Gary M.
Published: July 2010

Carbohydrate composition and constituents associated with carbohydrates were determined in corn (Zea mays L.) seedlings subjected to three levels of moisture stress. Stress had no effect on fructose and glucose concentrations, increased sucrose concentration slightly, and decreased starch concentration markedly. Chlorophyll concentration decreased with increasing moisture stress, and chlorophyll a was affected more than chlorophyll b. Sucrose and starch synthesis, measured by 14C‐glucose incorporation, were not changed by stress. Enzymatic hydrolysis of sucrose decreased and hydrolysis of starch increased during stress. The latter changes were apparently survival adaptations to stress conditions. Maintaining or increasing concentrations of low molecular weight carbohydrates probably helped plants retain turgidity and protected protoplasmic constituents.
Foliar Absorption and Distribution of 2,3,5‐Triiodobenzoic Acid (TIBA) in Soybeans (Glycine max)1
Authors: Sant'Anna Renato , Ohlrogge A. J. , Christian J. E. , Breckinridge C. E.
Published: July 2010

The anticipated commercialization of TIBA as one of the first growth regulators for use on a major field crop in the USA, created a need for information on its absorption and movement in the soybean plant under field conditions. Such information would be of assistance in metabolite and residue studies.

TIBA tagged with I‐131 was applied at early bloom in two field experiments and in a third study it was applied at the beginning of the pod filling stage of growth. Whole plants were sampled periodically, divided into their morphological parts and their dry weights and I‐131 activities were determined.

Approximately 45 percent of the total activity measured at “zero time” was lost from the plants within 48 hours. Biological half lifes of 40.3 and 42.0 days were found for the I‐131 in the early spray experiments. The rapid absorption and movement into the vascular stream was indicated by the detection of I‐131 activity in the roots of the “zero time” samples. Sites of active TIBA I‐131 activity were regions of high meristematic activity. Such sites of accumulation loss I‐131 activity to other areas when their relative metabolic activity declined.

Ultraviolet light was shown to cause small but significant deiodozation of TIBA.

Sixty days after TIBA was applied the plant parts were found to contain the following percentages of the applied radioactivity: roots 4%, leaves that were sprayed with TIBA 15%, leaves that emmerged after TIBA application 1.5%, petioles that received application of TIBA 2.5%, stems 3.0%, pods including seeds 7%. When the TIBA was applied at the beginning of the pod filling period, the seeds at physiological maturity contained 0.56 ppp TIBA equivalent or 2.5% of the originally applied activity.
Forage Composition and Losses from Orchardgrass Silage As Affected by Maturity and Nitrogen Fertilization1
Authors: Sprague Milton A. , Taylor B. Brooks
Published: July 2010

Experiments were conducted during two seasons where‐by orchardgrass (Dactylis glomerata L.) previously treated with three rates of nitrogen fertilizer was harvested at two stages of maturity, chopped, and ensiled in large plastic bags. Chemical analyses of fresh forage and silage determined dry matter, nitrogen, hydrolyzable carbohydrate, pH, total titratable acidity, volatile acid, nonvolatile acid, and volatile base content of samples. The relationships between constituents in the fresh forage and losses of these items during preservation and storage were of special interest. Replicate 1‐ton silos permitted statistical analysis of data collected. Hydrolyzable carbohydrate content of fresh forage was higher and protein content lower during both seasons which low rates of nitrogen fertilizer were used. Losses of protein during storage were much lower following low nitrogen fertilization and particularly during the warmer drier season. These losses were related to high protein and hydrolyzable carbohydrate content of the forage and resulted in very high volatile base content of the silage. A ratio of 1:1.5 or greater of crude protein to hydrolyzable carbohydrate in the fresh forage is suggested to maintain low losses during storage.
Relationship of Chemical Composition and Morphological Characteristics to Palatability in Sudangrass and Sorghum ✕ Sudangrass Hybrids1
Authors: Rabas D. L. , Schmid A. R. , Marten G. C.
Published: July 2010

Palatability differences occurred among two sudangrass varieties (Sorghum sudanense (Piper) Staph.), and four sorghum ✕ sudangrass hybrids (Sorghum bicolor (L.) Moench.) ✕ (Sorghum sudanense (Piper) Stapf.). The grazing preference of both cattle and sheep for these varieties was negatively correlated with HCN concentration. Leaf width, stem diameter, percent leaf, and percent dry matter were not associated with palatability in seven of eight trials. Total sugar concentration was never directly associated with palatability. The lack of association between percent leaf or sugar concentration and palatability did not agree with previous reports. The results suggest that selection for low HCN concentration to avoid prussic acid poisoning may also result in increased palatability.
Influence of Tannin Content on Preharvest seed Germination in Sorghum>1
Authors: Harris H. B. , Burns R. E.
Published: July 2010

Preharvest seed germination occurs in grain sorghum, Sorghum bicolor (L.) Moench, during periods of prolonged rainy weather where temperatures are conducive to germination. Differential preharvest seed germination among 42 hybrids in a grain sorghum hybrid test conducted at Midville, Georgia, in 1969 occurred after 5 days of near continuous rainfall. Hybrids were rated for preharvest seed germination, and this index was correlated with astringent tannin content of seed and days from planting to 10% anthesis (maturity). The correlation coefficient between germination index and astringent tannin content was negative and highly significant (r = ‐0.83). High tannin hybrids were significantly lower in preharvest seed germination than low taninn hybrids. Although tannin content of seed apparently was the dominant influence inhibiting preharvest seed germination, maturity among the nonbrown‐seeded hybrids was also involved. Later maturing nonbrown‐seeded hybrids showed a lower preharvest germination index than earlier hybrids.
Influence of Soil Moisture and Ambient Temperature on Yield and Quality of Alfalfa Forage1
Authors: Vough L. R. , Marten G. C.
Published: July 2010

Alfalfa grown at high soil moisture stress in growth chamber and field studies yielded less dry matter than that grown at low soil moisture stress. A higher percentage of leaves, higher percentage of in vitro digestibility (IVDDM), and lower percentages of acid detergent fiber (ADF) and lignin (ADL) often occurred in forage grown at high soil moisture stress. Soil moisture did not affect the percentage of crude protein (CP) consistently.

Under controlled‐environment conditions, alfalfa grown at high temperatures (27 C day/21 C night) yielded less dry matter and had lower digestibility and higher ADF and ADL than that grown at lower temperatures (16 C day/10 C night). This occurred even though percentage of leaves and CP increased at high temperatures. The lowest ADF concentration (indicative of highest quality) occurred at low temperatures and high soil moisture stress; also, IVDDM was among its highest and ADL among its lowest levels under these conditions (also indicative of high quality).

Low temperatures and low soil moisture stress were generally associated with a higher yield of a relatively higher quality forage than were high temperatures and high soil moisture stress.

Crude protein failed to estimate alfalfa quality when forage was produced in diverse climates, confirming earlier reports.
Application of an Extraction‐Term Model to the Study of Moisture Flow to Plant Roots1
Authors: Molz F. J. , Remson Irwin
Published: July 2010

A one‐dimensional extraction‐term model is used to simulate the moisture flow and removal process in the vicinity of plant roots. The dependence of model results on root depth and soil type are investigated. Moisture contents, root moisture absorption rates and soil moisture fluxes are computed and discussed for several hypothetical root systems in a sandy soil and in a clay soil.

The model is solved numerically with a procedure based on the Douglas‐Jones predictor‐corrector method. Results indicate that moisture extraction by the roots from soil in their immediate vicinity is the dominant process, with Darcian flow in the root zone playing a smaller but often significant role.

Extraction‐term models are versatile and seem able to describe many of the phenomena associated with moisture removal by the roots of transpiring plants.
Influence of Nitrogen Fertilization, Gapping, and Burning on Seed Production of Newport Kentucky Bluegrass1
Authors: Evans David W. , Canode C. L.
Published: July 2010

A study was conducted to determine the influence of nitrogen fertilization, gapping and burning on the seed yields and age‐associated seed yield decline of ‘Newport’ Kentucky bluegrass (Poa pratensis L.). The bluegrass was grown in rows under furrow irrigation. Treatments were applied in a split‐split plot design. Increasing the rate of nitrogen fertilization increased seed yields, seed weight per panicle, panicle numbers, and weight of 100 seeds. Weight of 100 seeds was least affected. Gapping by removing alternate 30‐cm sections of the row in late summer of alternate years reduced panicle numbers but increased seed weight per panicle in the year following treatment. Panicle numbers were reduced more by gapping at high than at low rates of nitrogen fertilization. Seed yields were increased by gapping at the low nitrogen rates but not at the high rates. Burning yearly after harvest had variable effects. The drop in seed yield associated with increased stand age was not prevented by any treatment.
Growth and Response to Atrazine of Six Selection of Inbred Corn GT1121
Authors: Eastin E. F.
Published: July 2010

The relative growth (height and dry weight) and response to 2‐chloro‐4‐(ethylamino) ‐6‐(isopropylamino)‐striazine (atrazine) of six selections of ‘GTI12’ inbred corn (Zea mays L.) were studied. There were no significant differences in growth of the untreated selections. Five of the selections were resistant to atrazine at 5.60 kg/ha preemergence but GTII2‐S was killed or stunted by 5.60 or 1.12 kg/ha, respectively, after 4 weeks. Atrazine applied to the soil surface at 5.60 kg/ha when GTll2‐S was 8 weeks old killed this selection in 10 days. In nutrient solution atrazine at 0.25 ppm killed GTI12‐S after 2 weeks as compared with very susceptible soybean [Glycine max (L.) Merrill, var. Lee], which was killed by 0.l ppm atrazine.
Use of Helminthosporium maydis Race T Pathotoxin to Determine Disease Reaction of Germinating Corn Seed1
Authors: Lim S. M. , Hooker A. L. , Smith D. R.
Published: July 2010

Several methods of pathotoxin production and corn (Zea may L.) seedling bioassays are described as techniques to determine the disease susceptibility of corn to southern corn leaf blight. Toxin produced by race T of H. maydis is specific in inhibiting the elongation of primary roots of seedlings with T cms cytoplasm; primary roots of seedlings with normal cytoplasm are not so greatly inhihited. Filtrates obtained by several different methods from race T grown in culture all exhibited a similar pathotoxic specificity. Extracts obtained from corn leaves with T cms cytoplasm and infected with race T also produced the specific reaction in corn seedlings. The corn seedling bioassay with race T pathotoxin is a useful technique to determine the proportion of T cms and normal corn in any blended seed lot.
Corn Emergence in Relation to Soil Temperature and Seeding Depth1
Authors: Alessi J. , Power J. F.
Published: July 2010

Field and growth room experiments at Mandan, N. D., evaluated the effects of seed depth and soil temperature on corn (Zea mays L.) germination and emergence. In the growth room, from 4 to 24 days were required to achieve 80% emergence, depending upon soil temperature and seed depth. Increasing soil temperature from 13.3 to 26.7 C reduced the time for 80% emergence. Temperature had a much greater effect than seed depth on emergence. A highly significant linear relationship existed between percent emergence and cumulative degree‐days above 10 C.

In field treatments with adequate soil water for germination, 8 to 13 days were required for near 80% germination. About one additional day was required for each 2.5‐cm increase in depth of planting. For corn placed at 7.6 cm, about 10 days and 68 cumulative degree‐days were required for emergence. Similar degree‐day requirements occurred for the 12.7‐cm depth. Degree‐day requirements for field experiments agreed very well with those obtained in the growth room.
Effect of Tillage Practice on Corn (Zea mays L.) Root Distribution and Morphology1
Authors: Barber S. A.
Published: July 2010

Corn root distribution in a Raub silt loam was measured seven and eight years after starting eight different tillage‐residue management‐cropping practices with continuous corn. Root distribution was measured by taking 6.25‐cm diameter cores to a 60‐cm depth. Cores were taken 12.5 and 50 cm from the corn row. Roots were washed from the cores and measured for weight and length. Tillage treatments included plowing to 20 cm, chiseling to 20 cm, rototilling to 5 cm and no tillage. Plow and no tillage practices were also conducted without cropping for six years, then corn was grown. Residue treatments consisted of all residues removed, residues returned and double residues returned, using conventional plow‐disk tillage.

Tillage influenced root growth. When the soil was plowed annually corn roots developed more extensively to a greater depth than where soil was not tilled or tilled to a 5‐cm depth only. Removal of residues depressed root growth in the 0‐10 cm depth. Roots were finer and longer/g in tilled soil than in untilled soil. They were also finer at depths below 15 cm where no crop had been grown for 6 years than where corn had been grown. The amount of root growth averaged 12 mg/cm2 in 1968 and 42 mg/cm2 in 1969 although average corn grain yields were 9380 kg/ha in 1968 and 8980 kg/ha in 1969.
Forage Yield of Switchgrass (Panicum virgatum) in Pennsylvania1
Authors: Berg C. C.
Published: July 2010

The production of forage by a warm‐season grass species (switchgrass, Panicum virgatum L.) was compared with cool‐season grasses in the cool, humid northeastern United States. Dry‐matter yields were obtained from two varieties of tall rescue (Festuca arundinacea Schreb.) and orchardgrass (Dactylis glomerata L.) and three varieties of switchgrass in 1969. Two other varieties of switchgrass failed to become established and another two did not survive the first winter. Plots were harvested at approximately monthly intervals from May 15 to Sept. 15, 1969.

Orchardgrass and tall rescue began growing much earlier in the spring, continued to grow later in the fall, and produced 3,200 to 5,000 kg/ha more dry forage over the entire season than switchgrass. During midsummer the switchgrass varieties produced as much or more dry matter than the cool‐season grasses; however, a high value must be placed on the production of forage at this time of year to justify considering switchgrass as a forage species in the cool humid northeastern United States. Yield data were limited to one harvest year (1969) because the switchgrass did not survive the following winter.
Grass Seed Production as Influenced by Cultivation, Gapping, and Postharvest Residue Management1
Authors: Canode C. L.
Published: July 2010

A study was conducted to determine the influence of cultivation, gapping of the initial stand, and in situ burning of the postharvest residue on the seed yields of ‘Pennlate’ orchardgrass (Dactylis glomerata L.) and ‘Newport’ Kentucky bluegrass (Poa pratensis L.). The two grasses were grown in separate but adjacent blocks. The experimental design for each species was a split‐plot with cultivation treatments as the main plots.

One cultivation with a rotary hoe (minimum cultivation) in April of each year was the best method under conditions of these experiments. Additional cultivation with sweep‐shovels (conventional cultivation) reduced the seed yields of Kentucky bluegrass and did not influence the seed yields of orchardgrass. Kentucky bluegrass seed yields were reduced more by conventional cultivation in April than by similar cultivation in September. Conventional cultivation leaving a 30‐cm row width reduced seed yields more than leaving a 46‐cm row width.

Gapping of the rows in the seedling year reduced the seed yields of both orchardgrass and Kentucky bluegrass in the first crop but had little effect on subsequent crops. Mechanical removal of postharvest residue was as effective as burning in orchardgrass seed production. Burning compared with mechanical removal of the postharvest residue produced lower seed yields of Kentucky bluegrass in the second and third crops, but higher yields in the fourth and fifth crops.
Diurnal Variation in Nonstructural Carbohydrates of Festuca arundinacea (Schreb.) With and Without N Fertilizer1
Authors: Lechtenburg V. L. , Holt D. A. , Youngberg H. W.
Published: July 2010

The purpose of this research was to (i) define in detail, under field conditions, the normal diurnal accumulation and depletion pattern of the various nonstructural carbohydrates in tall fescue (Festuca arundinacea Schreb.) herbage and (ii) investigate the influence of N fertility on diurnal variation in these carbohydrates. The implications of these daily trends with regard to forage management and quality and to carbohydrate metabolism in this species were considered.

Tall fescue herbage was sampled several times daily during first and second growth periods. Reducing sugars and sucrose were extracted from freeze‐dried, ground herbage with alcohol. Next, fructosan was removed by water extraction, and the residue from these extractions was treated with 0.2 N sulfuric acid to hydrolyze other nonstructural polysaccharides. Ferricyanide, resorcinol, and phenol‐sulfuric acid procedures were used to quantitatively assay sugars in the extracts. The daily trends in various carbohydrates were analyzed statistically using orthogonal regression techniques.

During the first growth period the average sugar percentage of leaves and stems increased from 8.2% at 6 AM to 10.3% at 6 PM. Sucrose accounted for most of the increase with some diurnal variation in percent glucose. Percent fructose did not vary significantly. In the second growth forage only sucrose varied significantly, increasing from 2.7% at 6 AM to 5.1% at 6 PM. Thirty‐seven percent of the daily increase in sucrose was respired or translocated between 6 PM and 12 M, while 63% was utilized after midnight. Fructosan concentration did not vary diurnally during either growth period.

Nitrogen fertilization reduced the average fructosan concentration from 7.3 to 0.4% of the dry weight in the first growth and from 1.6 to 0.5% of the dry weight'in the second growth forage. Fructosan accumulated in the unfertilized forage as the first growth period progressed. Nitrogen fertilization did not influence the average amount of reducing sugars present during either growth period. Sucrose content was reduced by N during the first but not the second growth period. Diurnal trends were not affected by N fertilization.

Acid (0.2 N H2SO4)‐soluble carbohydrate percentage, which consisted primarily of pentosan, varied diurnally during the first growth period. Nitrogen fertilization reluced this fraction from 12.6 to 7.3% during the first growth period and from 10.3 to 6.5% during the second growth period.

To the extent that carbohydrates contribute to the acceptability of a forage or that a forage is lacking in energy, N fertilization may decrease forage quality. Yield and other quality factors enhanced by N fertilization may compensate for carbohydrate losses.