bluuebunny/crossref_metadata_2025 huggingface dataset:
Salinity Effects on Nitrogen Use by Wheat Cultivar Sonora 641
Authors: Jadav K. L. , Wallihan E. F. , Sharpless R. G. , Printy Wilma L.
Published: July 2010

The importance of N nutrition to fulfilling the high production potential of some semidwarf wheat (Triticum aestivum L.) cultivars under irrigation culture raises problems of balance between N and salinity. Inasmuch as growth may be limited in salt affected soils, thereby reducing total N requirement, the usual rates of fertilizer application may be excessive and thus contribute to the salinity problem.

This study with ‘Sonora 64’ wheat was done to measure the effects of salinity and stand density on plant growth and grain yield, to estimate N uptake in relation to salinity and the stage of plant development, and to evaluate leaf‐N as a basis for diagnosing the N status of the plant.

Plants were grown in sand cultures (pots) in the greenhouse and out of doors. Treatments were factorial combinations of salinity and N supply. Stand densities of 5, 10, and 15 plants/pot were compared. Some comparisons were made with an old line cultivar ‘Ramona 50’ grown simultaneously with the Sonora 64.

Depression of grain yield by added chloride salts was caused primarily by reduced tillering, suggesting that significant compensation can be achieved by using higher seeding rates.

Data on N concentrations in various plant tissues indicate that total N is not a useful index of N status. At flowering, factors other than N supply controlled tissue N concentrations and, at maturity, total N concentration increased with salinity. At flowering NO3‐N in Y‐leaves correlated well with grain yield but did not reflect levels of N supply under saline conditions.

Variations of apparent salinity tolerance associated with differences in plant density 1) indicates that this relationship needs to be included in salinity studies, and 2) raises doubts about the value of pot cultures for the purpose.
Nutrient Uptake by Corn and Grain Sorghum Silage as Affected by Soil Type, Planting Date, and Moisture Regime1
Authors: Fribourg H. A. , Bryan W. E. , Lessman G. M. , Manning D. M.
Published: July 2010

Few data have been published on whole‐plant nutrient removal by silage crops as influenced by soil types and species. In order to quantify nutrient removals by corn (Zea mays L.) and grain sorghum (Sorghum bicolor (L.) Moench) silage crops, early (30 April‐15 May) and late (2‐12 June) plantings of ‘Funk G‐4831’ corn and ‘AKS 614’ sorghum were grown in 1969 in 34 environments on 12 soil types, two soils at each of six locations in Tennessee. Non‐irrigated plots of the two plantings were grown on all soils, and irrigated plots were added to five of the soils. The corn was harvested for silage when 80 to 90% of the kernels were dented, and grain sorghum when the oldest seeds were in the soft dough stage. Tissue samples were collected and analyzed for N, P, K, Ca, and Mg. Total seasonal uptake was calculated by multiplying percent composition of each element by dry matter yield/ha. Corn silage yields ranged from about 6 to 28 metric tons/ha, and sorghum silage yields ranged from about 7 to 18 metric tons/ha. Nutrient uptake generally increased linearly with yield. Mean total uptake of N, P, K, Ca, and Mg were, for corn silage, 192, 28, 144, 39, and 37 kg/ha; and, for grain sorghum silage, 169, 26, 143, 40, and 35 kg/ha, respectively.
Quantity and Quality of Triticale Forage Compared to other Small Grains1
Authors: Brown A. R. , Almodares A.
Published: July 2010

Several triticale cultivars are being used as supplemental wintergrazing in the southeastern United States. This experiment was conducted to provide comparative data on the yield and quality of forage of triticale Triticale hexaploide Lart.), rye (Secale cereale L.), wheat (Trticum aestivum L.) and oats (Avena sativa L.).

Triticale cultivars ‘Fasgro 385’ and ‘Fasgro 514’ produced as much forage as ‘Jefferson’ oats and ‘Holley’ wheat during the 1971‐72 season but were inferior to ‘Athens Abruzzi’ and ‘Pennington Wintergrazer 70’ ryes. In the 1973–74 season triticale cultivars ‘Fasgro 131’ and Fasgro 385 produced as much or more forage as the other small grain cultivars except Athens Abbruzzi rye. Triticale cultivars differed considerably in their ability to survive low temperatures (—11.1 C) during the 1971–72 season.

Crude protein content of the triticale forage at comparable stages of growth was similar to rye, wheat and oats. The only exceptions to this were Funk's Rosner and Graze Green 70 at the last clipping in 1972. Cell wall content of the triticale cultivars was lower than rye or rye‐wheat mixtures late in the season; however, their CWC was similar to Holley wheat throughout the growing season. Triticale CWC was similar to oats at all harvest dates except the last one in 1974.
Field Performance of Alfalfa Cultivars Resistant and Susceptible to Phytophthora Root Rot1
Authors: Lueschen W. E. , Barnes D. K. , Rabas D. L. , Frosheiser F. I. , Smith D. M.
Published: July 2010

Because phytophthora root rot (PRR) resistant cultivars of alfalfa (Medicago sativa L.) are new developments, there have not been opportunities to determine what effect PRR resistance may have on forage production in different alfalfa growing areas. This paper presents results from several experiments comparing the performance of PRR susceptible and resistant cultivars grown under a range of environments in Minnesota.

Broadcast plots were established in April and May in three different years. Some plots received only natural rainfall; others received an additional period of supplemental sprinkler irrigation during mid‐June each year to simulate a 10 to 14‐day wet period.

Natural levels of Phytophthora megasperma Drechs. inoculum were adequate in the soil to cause significant yield losses. PRR resistant cultivars usually out‐yielded susceptible cultivars in plots receiving supplemental irrigation or when natural rainfall was sufficient to induce PRR. The most severe losses occurred during the seedling year. PRR killed seedlings and damaged the normal tap root system of alfalfa. Injured plants usually produced adventitious lateral roots, resulting in a shallow root system. This appeared to make the plants more sensitive to stress, such as drought and frequent harvesting. Resistant cultivars appear to be a feasible method for reducing losses from PRR. A minimum of 60% resistant plants may be necessary in a cultivars to provide an adequate amount of protection under severe PRR conditions.
Comparison of Modified Montmorillonite to Salts and Chelates as Carrier for Micronutrients for Plants: I. Supply of Copper, Zinc, and Manganese1
Authors: Banin Amos , Navrot Jerzy
Published: July 2010

The purpose of the study was to compare the effectiveness of a novel micronutrient fertilizer, modified montmorillonite clay, to the of the conventionally used salts and chelates as carriers of micronutrients to plants. Three elements — Cu, Zn, and Mn — in combination in various rates, and in three forms, as sulphates, EDTA chelates, or attached to montmorillonite clay, were applied to two micronutrient deficient sandy soils. Tomato (Lycopersicum esculentum Mill.) and beans (Phaseolus vulgaris L.) were grown under controlled greenhouse conditions in the treated soils. The application of micronutrient elements, in all of the forms used, significantly increased plant yields. In addition, the supply of micronutrients significantly increased the elemental concentrations of the plants. However the highest concentration of elements found in the plants did not always correspond to the highest yields. Generally the lower levels of addition of combined micronutrients improved the growth conditions considerably and the higher ones were less effective. The clay carrier was similar to the expensive chelates and generally more efficient than the salts in element supply and this resulted in better yield responses. The optimal rate of application of the combined elements for dry yield production in tomato plants in the soils studied appeared to be: 0.5 mg Cu, 1.6 mg Zn, and 2.5 mg Mn per kg of soil for the clay and chelate forms and somewhat higher for the salts.
Moisture Conservation Potential with Conservation Tillage Treatments in the Thick Loess Area of Western Iowa1
Authors: Miller E. L. , Shrader W. D.
Published: July 2010

Moisture is usually in short supply for production of corn (Zea mays L.) on thick loess derived soils in western Iowa. Practices that conserve moisture should increase crop yields but quantitative data is very scarse. The objectives were to develop a yield response curve for moisture applicable in western Iowa and evaluate the potential effect of conservation tillage systems on corn yields. Computerized modeling techniques were used to develop the yield response curve and to evaluate conservation practices.

Moisture stress indices, which were highly correlated with measured corn yields, were used to evaluate the effectiveness of modeled tillage treatments in terms of corn yield. The model budgeted daily soil moisture use based on initial soil moisture measurements, actual weather data, and simulated hydrologic processes. The appropriate hydrologic processes were modified to approximate the tillage system under study. The hydrologic processes assumed most altered by conservation tillage management were surface runoff and surface evaporation in the spring fallow period.

The modeled tillage practices were evaluated at three assumed spring soil moisture levels in combination with actual long term weather records. When spring soil moisture levels were at 100% of the plant‐available water capacity (PAWC), tillage practices had little effect on estimated corn yields. At the medium and low spring soil moisture levels, modeled conservation tillage was effective in increasing yield estimates over those obtained with conventional tillage.
Effect of Shade and Fertility on NO3‐N Accumulation, Carbohydrate Content, and Dry Matter Production of Tall Fescue1
Authors: Stritzke J. F. , Croy L. I. , McMurphy W. E.
Published: July 2010

Nitrate‐N poisoning is a suspected cause of death among cattle grazing in tall fescue (Festuca arundinacea Schreb.) under cloudy or shade conditions. The practice of aerially seeding tall fescue into sprayed brush areas is of special concern since fescue plants grow in shade at times. The purpose of this research was to evaluate the effects of shade and N fertility levels on NO3‐N, carbohydrate content, and tall fescue production. An artificial shade study was designed in which tall fescue and a check forage (wheat, Triticum aestivum L.) were grown in containers at shade levels of 0, 30, 47, 63, 80, and 94%, using Saran shade cloth. Production was measured during three periods of the growing season.

Dry matter production of tall fescue increased with some shade. Seedlings did best with 47 and 63% shade. Older plants produced best with 30 and 47% shade! As shade levels increased, there was a reduction in forage production of wheat, and water soluble carbohydrate content of both tall fescue and wheat. More than 63% shade was required to significantly increase NO3‐N content of fescue forage grown with a low level of fertility, whereas only 30% was necessary in high fertility conditions. At 80% shade, fescue forage grown at high fertility showed concentrations of NO3‐N above 9,000 ppm. Levels of NO3‐N in wheat forage were much lower, and no NO3‐N levels above 5,000 ppm were detected.
Crown, Tiller, and Rhizome Characteristics of Kentucky Bluegrass Cultivars1
Authors: Nittler L. W. , Kenny T. J.
Published: July 2010

To protect superior Kentucky bluegrass, Poa pratensis L., cultivars from becoming contaminated, it is important to develop techniques for testing seed lots for cultivar purity. This study was conducted to detect seedling characteristics that can be used in addition to characteristics described previously for making cultivar purity determinations.

Seed of 26 cultivars and six experimentals lines were planted in inert sand and were grown in a growth chamber for 6 weeks with continuous light of 23,000 lux (22,000 lux from cool white fluorescent tubes and 1,000 lux from incandescent bulbs). A complete nutrient solution was used and temperature was kept at 24 C.

Tillers of some cultivars grew horizontally 1 cm or more before turning upward. This formed a spreading crown. Tillers of others grew upward with little or no lateral spread to form a compact crown. Other cultivars tended to be intermediate in crown type. No plants of ‘Belturf’, ‘Fjord’, ‘Park’, or ‘Troy’ were classed as having spreading crowns. In contrast, 93% of ‘Bonnieblue’ plants had spreading crowns and the remaining 7% had semi‐spreading crowns.

Troy had an average of 1.9 tillers/plant compared to 6.4 for ‘Sydsport.’ Cultivars also differed in number of rhizomes, with Fjord and ‘Kenblue’ each averaging 0.3/plant and ‘Sodco’ averaging 2.6/plant.

Percentage of total stems that were rhizomes was only 6 for ‘Prato’ compared to 41 for Sodco.

Cultivars with spreading crowns such as Bonnieblue and ‘Fylking’ could be distinguished from those with compact crowns such as Park or Troy. Likewise contrasting types in regard to tiller or rhizome number could be distinguished from each other.
Effect of Saponins on Palatability of Alfalfa to Meadow Voles1
Authors: Kendall W. A. , Leath K. T.
Published: July 2010

Forage constituents that effect the plant palatability are one of many factors that control animal intake. Saponins are biologically active compounds that occur in alfalfa (Medicago sativa L.) in various concentrations and may affect palatability. The purpose of this research was to evaluate the role of saponins in palatability. The meadow vole (Microtus pennsylvanicus) was used to test palatability because its small size and ready acceptance of forage permitted the assay of small amounts of forge and extracted saponins.

Meals from alfalfas selected for high‐ or low‐saponin content with the Trichoderma viride Pers. ex Fr. or hemolysis bioassays were compared for palatability using meadow voles. The voles were fed a commercial mouse food ad libitum and offered a choice of the commercial food or test diet for 30 min at 0800 and 1600 daily. Saponin activity of the meals was evaluated with the T. viride bioassay. Purified saponin mixtures from ‘DuPuits’ and ‘Lahontan’ alfalfa and quinine sulphate were evaluated at various concentrations for palatability to voles.

Meals of low‐saponin lines of alfalfa were generally more palatable than their corresponding high‐saponin lines except for selections of Lahontan which were both very palatable. The growth of T. viride was greatest on substrates with extracts of alfalfa meals that were most palatable to meadow voles. Purified saponins from Lahontan and DuPuits alfalfa reduced intake at a concentration of 4% of the diet. The palatability of 3% saponin from DuPuits in the diet was not increased by mixing with sucrose. Intake of quinine sulphate was inversely related to concentration, indicating that voles perceived the bitter substance.
Nitrogen‐Silicon Interaction in Plants Grown in Desert Soil with Nitrogen Deficiency1
Authors: Wallace A. , Romney E. M. , Mueller R. T.
Published: July 2010

The relationship of N to some other anions was investigated for plants grown in infertile soil low in soil organic matter from bare desert areas compared with plants grown in more fertile soil from around natural shrub clumps. The objective was to determine nutrient relationships in the infertility of desert soils even when supplied with N. Range grass [Hilaria rigida (Thurb.) Benth. ex Scribn.], barley (Hordeum vulgare L. ‘Atlas 57’), and bush beans (Phaseolus vulgaris L. ‘Improved Tendergreen’) were grown in such soils in a glasshouse. The latter two were with and without addition of N fertilizer. Plants grown in the infertile soil compared with the fertile soil had greatly decreased yields, were low in N, generally had increased concentrations of Si, and had slightly less total cation concentrations. Nitrogen fertilizer improved yields only slightly in the infertile soil but it increased N concentration and decreased that of Si in plants. The Si seemed to enter into the cation‐anion balance in the plants.
Nitrate‐N and Total N Concentration Relationships in Several Plant Species1
Authors: Terman G. L. , Noggle J. C. , Hunt C. M.
Published: July 2010

Accumulation of NO3‐N in plants is important in regard to plant N nutritional status, in the formation of NO2‐N toxic to animals and people consuming the plants, and as a producer of lethal gas in silos. This paper describes relationships between NO3‐N and total N concentrations in plants grown in several greenhouse pot experiments, as affected largely by response to applied N and by continuing growth. Corn (Zea mays L.) was grown in soil with 200 to 800 mg of N/pot and in nutrient solutions with 2 to 16 ppm of N. Both crops were harvested at 4‐day intervals. Spinach (Spinacea oleracea L.) and mustard (Brassica pervirdis L.) were grown in soil with several rates of N, P, and K, and tall fescue (Festuca arundinacea Shreb.) with 1.0 and 2.0 g of N/pot.

These experiments conducted on N‐deficient soils resulted in marked yield response and higher concentrations of total N and NO3‐N with increase in rates of applied N. Concentrations decreased with age, dry matter accumulation, and depletion of N. Total N was higher in leaves than in stems, but the reverse was true for NO3‐N. Concentrations of NO3‐N started to increase in various crops above minimum total N values of 1.5 to 4.5%, which were highest for leaves, intermediate for leaves + stems, and lowest for stems or petioles. Below these minimum total N values, NO3‐N remained near zero (< 0.1%). Discontinuous regression models appear most satisfactory to fit the entire range of the relationships between total and NO3‐N. It was concluded that NO3‐N concentrations in plants are negligible if the total N was < 1.5% to 4.5%, depending largely on plant part composition, plant species, and N source.
Soybean Root Development and Soil Water Depletion1
Authors: Stone L. R. , Teare I. D. , Nickell C. D. , Mayaki W. C.
Published: July 2010

We conducted a field study to investigate soybean (Glycine max L. Merr., ‘Williams’) root growth and water depletion patterns. Field water depletion and rooting data are needed to assist in developing and refining models that consider root‐soil‐water interactions.

Irrigated and nonirrigated soybeans were grown on a deep, barrier‐free, Muir silt loam soil (fine‐silty, mixed, mesic, Pachic Haplustoll). Soil water content, determined using neutron moderation (15‐ to 150‐cm profile), was used to calculate water depletion rates. Soil water content and desorption curves (obtained for each 15‐cm profile depth increment) were used to estimate soil water potential. Available soil water was estimated using —15 bars soil water potential as the lower limit of availability. We collected soil volumes (centered on the crop row) 76 cm wide, 7.6 cm thick, and 180 cm deep (sectioned to 15‐cm increments) and washed roots free using 35‐mesh screen.

During the first half of our study, maximum root and water depletion depths were nearly equal. Later, water depletion tended to be about 15 cm deeper than root growth (possibly as a result of upward water movement into the water‐depleted root zone). Our data indicate that, as soybean root weight increased, there was a drying effect so available soil water and soil water potential decreased. Depletion effectiveness (defined as cm3 of water/g of root/day) was greatest with lower root weights, higher soil water potentials, and greater available soil water. Depletion effectiveness increased with depth in the soil profile; probably as a result of the roots being younger, in wetter soil, and less crowded. Our data indicate that a small portion of the root system can be responsible for much water uptake.
Seedling Growth of Crownvetch, Ladino Clover, and Alfalfa under Shade1
Authors: Hart Richard H.
Published: July 2010

Crownvetch (Coronilla varia L.) is more difficult to establish than many other legumes. This difficulty has been attributed to slow seedling growth of crownvetch when shaded by competing vegetation. We wanted to determine 1) do seedlings of crownvetch grow more slowly under shade than seedlings of other legumes, and (2) do seedlings of weedy crownvetch, derived from plants which survived 2 years in a weedy nursery, grow faster under shade than seedlings of cultivated crownvetch, derived from plants grown in a cultivated nursery? We seeded ‘Penngift,’ ‘Emerald,’ “weedy,” and “cultivated” crownvetch, ‘Vernal’ alfalfa (Medicago sativa L.), and common ‘Ladino’ clover (Trifolium repens L.) in pots in the greenhouse during winter and again during spring. Seedlings were grown for 4, 6, 8, and 10 weeks under shade screens which transmitted 76%, 35%, or 14% of total solar radiation. Emerald, Weedy, and Cultivated crownvetch grew at the same rate, which indicated there had been no natural selection for seedling vigor or shade tolerance in the wedy nursery. Penngift grew more slowly than the other crownvetches. Crownvetch grew faster than Ladino clover in both winter and spring, and faster than alfalfa in winter. However, under higher radiation in the spring, crownvetch tops grew at the same rate as alfalfa tops, and crownvetch roots grew slower than alfalfa roots. We concluded that crownvetch grew about as well as other legumes under shade, and that low seedling vigor under shade is not a major cause of establishment difficulties of crownvetch.
Alfalfa Weevil Effects on Regrowth of Alfalfa1
Authors: Fick Gary W.
Published: July 2010

Earlier work indicated that large reductions in second cutting yields of alfalfa (Medicago sativa L.) could occur when larvae of the alfalfa weevil (Hypera postica Gyllenhal) fed on the stubble following the first harvest. To study the problem further, larval populations of known size were transferred to alfalfa plots after the first harvest was removed. The larvae fed on basal buds and, at the highest population (about 10,000/m2), completely destroyed active growing points in the stubble within 2 days. Measurements taken during the 40 days following the first harvest showed increasing regrowth delays for each increment of weevil population. Herbage yield, morphological stage, height, leaf percentage, in vitro digestibility, and crude protein content were all affected. Total nonstructural carbohydrate accumulation in taproots was also delayed by weevil damage to basal buds. The maximum delay in regrowth was 6 to 10 days and up to one‐third of the yield potential of the 40‐day regrowth period could be lost. The regression equation to predict the percentage of the maximum loss (Y) from the insect population in larvae/m2(X) was as follows: Y = 0.0531X. The regression equation, which was forced through the origin, had an r2 value of 0.868.
Methods of Computing Area1
Authors: Shih Sun‐Fu
Published: July 2010

The methods of computing area from maps are classified under two categories: 1) bounded area and 2) weighted sub‐areas. Pioneering methods of planimeter, coordinate squares, triangular rule, trapezoidal rule, Simpson's rule, double‐meridian‐distance, coordinates, and digitizer are compared with the newly introduced methods of weighing technique and finite segments, and also with a recently developed Monte Carlo process. The results indicate that the weighing technique and finite segments are relatively easy to use in laboratory and computerized procedure, respectively; and the Monte Carlo method is more applicable and powerful than other computerized methods.
Effects of Herbicides on Establishment of Centipedegrass1
Authors: Johnson B. J.
Published: July 2010

The control of weeds during the first growing season after centipedegrass [Eremochloa ophiuroides (Munro) Hack.] sprigging is a major problem for most homeowners. Field and greenhouse experiments were conducted on the effects of herbicides applied at different time intervals during the establishment of centipedegrass on weed control and rate of turfgrass cover. The soil type was either a Cecil sandy loam (member of the clayey, kaolinitic, thermic family of Typic Hapludult) or Cecil sandy clay loam.

The survival of centipedegrass sprigs was as good with single applications of DCPA (dimethyl tetrachloroterephthalate) at 11.2 kg/ha, atrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino‐s‐triazine], at 1.1 kg/ha, simazine [2‐chloro‐4,6‐bis(ethylamino)‐s‐triazine], at 1.1 and 2.2 kg/ha, and oxadiazon [2‐tert‐buty‐4‐(2,4‐dichloro‐5‐isopropoxyphenyl)‐Δ2‐1,3,4‐oxadiazolin‐5‐one], at 3.4 kg/ha, applied immediately after sprigging as in untreated plots. The turfgrass cover at the end of the growing season was as good or better in single treated plots as in multiple treated plots. Repeated applications of atrazine, simazine, and oxadiazon increased the control of large crabgrass [Digitaria sanguinalis (L.) Scop.] and goosegrass [Eleusine indica (L.) Gaertn.] when compared with the control in single treated plots. These results indicate that complete weed control is not necessary for optimum centipedegrass cover during the first season after sprigging.
Phosphorus Uptake Rate of Soybean Roots as Influenced by Plant Age, Root Trimming, and Solution P Concentration1
Authors: Edwards J. H. , Barber S. A.
Published: July 2010

An understanding of the phosphorus, P, uptake characteristics of plant roots is important for developing practices that improve P fertilizer efficiency. Since little is known about the nutrient uptake characteristics of soybean [Glycine max (L.) Merr.] roots, the objective of this research was to measure the P influx kinetics of intact soybean roots. Experiments were conducted with soybeans ranging in age from 18 to 74 days. Rate of P depletion from solution vs. P concentration in solution was used to determine maximum P influx, Imax; Michaelis constant, Km; efflux, E; and the lowest level to which the plants can reduce P concentration in solution, Cmin. The effect of increasing plant P requirement per meter of root length on P influx kinetics was studied by removing half of the roots 2 days before influx measurement.

Average Imax for P decreased with increasing plant age, however the rate of decrease was less than previously observed with corn (Zea mays L.). Trimming roots increased Imax of 18 to 35‐day‐old plants so that P uptake per plant on trimmed plants was similar to that for untrimmed plants. Both Km and Cmin values increased with plant age. Root trimming had little influence on Km, and E was not influenced by plant age or root trimming. Phosphorus influx kinetics of soybean roots as affected by plant age and root trimming were different from those observed for corn so that P fertilization practices that give the highest efficiency for use of applied phosphate may differ for the two crops.
Cutting Height and Nitrogen Effects on Improved Perennial Ryegrasses in Monostand and Polystand Communities1
Authors: Carrow R. N. , Troll J.
Published: July 2010

New turf‐type perennial ryegrasses are being widely used by turf managers, however, little information is available on their competitiveness in polystands. The growth and persistence of three perennial ryegrasses (Lolium perenne L.) were evaluated in the greenhouse and growth chamber in monostands and in polystands with ‘Merlon’ Kentucky bluegrass (Poa pratensis L.) and ‘Penncross’ creeping bentgrass (Agrostis palustris Huds.). Cutting height treatments were 1.26, 2.54, 3.80, and 5.08 cm. Ryegrass tillering was greatest at the 1.26 cm cut, while no differences in tiller numbers were detected between 2.54 to 5.08 cm treatments. All ryegrasses competed well in bluegrass sod at .2.54 to 5.08 cm cuts but did not grow well in the bentgrass, regardless of cut.

In two field studies several ryegrasses were seeded 25: 75 (seed number basis) with Merion Kentucky bluegrass and 50:50 with ‘Seaside’ creeping bentgrass. Mowing treatments and N treatments were imposed on the various mixtures in both studies. ‘Manhattan’ and ‘Pennfine’ ryegrasses were most competitive during establishment and the most persistent over 23 months in bluegrass mixtures. Shoot densities of the ryegrasses were not affected by cutting height or N treatments but bluegrass density was. When seeded with bentgrass, Manhattan and Pennfine were most competitive during establishment but no ryegrass cultivar composed more than 14% of the stand after 23 months. Low cutting height (1.26 cm) and high N (2.44 kg N/100m2) improved the competitiveness of the bentgrass but not that of the ryegrasses.

The data from these studies indicate that the competitiveness of new turf‐type ryegrasses is dependent upon the companion grass. When seeded in mixtures with Kentucky bluegrass the new ryegrasses were persistent at cutting heights above 1.90 cm. In mixtures with creeping bentgrass the ryegrasses responded as temporary grasses.
Dry Seed Fatty Acid Composition and Seedling Emergence of Pima Cotton at Low Soil Temperatures1
Authors: Bartkowski Edmund J. , Buxton D. R. , Buxton D. R. , Katterman R. H. , Kircher Henry W.
Published: July 2010

The development of a rapid test to predict cotton lines (Gossypium spp.) which exhibit increased resistance to chilling injury would be a valuable breeding tool. The objective of this study was to evaluate the relationship of Pima cottonseed (G. barbadense L.) lipid composition to seed germination and seedling emergence under field conditions with low soil temperatures. Seed fatty acid methyl esters of selected genotypes were analyzed by gas‐liquid chromatography. Total seed lipid was fractionated into polar and neutral components and their associated fatty acid methyl esters were similarly analyzed. Low correlations were obtained between unsaturated/ saturated (U/S) fatty acid ratios of total seed lipid and laboratory germination percentages. However, seedling emergence under field conditions with low soil temperatures correlated strongly with U/S fatty acid ratios of total seed and polar lipids (r = 0.97** and 0.95% respectively)3. No advantage was realized by using polar lipids over total seed lipid for the analysis. Results of this study suggest the feasibility of using the rapid analysis of total seed lipid associated U/S fatty acid ratios for identifying cotton lines with chilling resistance during seed germination and emergence.
Massive Accumulation of Calcium Carbonate and its Relation to Nitrogen Fixation of Sainfoin1
Authors: Ross William D. , Delaney Ronald H.
Published: July 2010

Sainfoin (Onobrychis viciifolia Scop.) has many desireable qualities as a legume forage, but it is not widely grown because of its lack of persistence and poor N‐fixation on many sites. The effect of competition by non‐N‐fixing soil microorganisms on N‐fixation was studied at 0, 50, 80, 95, and 100% levels of autoclaved soil sterization. Plants were grown aseptically for 30 days, dipped in Rhizobium inoculum, and transplanted to the sterilized soil. After 47 and 87 days in the growth chamber at 24/18 C, the plants were harvested. Nitrogen fixation was determined by the acetylene reduction capacity of the complete root system. Unexpectedly, root distortion accompanied by massive accumulation of CaCO3 was stimulated in sainfoin roots that were grown in autoclaved soil to reduce the soil microorganisms. The purpose of the data presented is to describe the accumulation of Ca and its affect on N‐fixation in sainfoin. Distorted roots of plants grown in 100% sterilized soil contained up to 33% Ca. High levels of Ca in the roots were accompanied by low levels of Ca in the plant forage. Number of nodules produced and the capacity of roots for reducing acetylene decreased as root distortion and CaCO3 accumulation increased. The properties of sterilized soil that stimulate CaCO3 accumulation were not determined, but several possibilities are discussed. Root distortion also occurs in field‐grown plants and may be related to the decline of sainfoin stands in the field.
Yield, Leaf Growth, and Tillering in Bahiagrass by N Rate and Season1
Authors: Beaty E. R. , Engel J. L. , Powell J. D.
Published: July 2010

If tiller numbers/area of Pensacola bahiagrass (Paspalum notatum, Flugge) could be correlated with yield and tillers/area is related to N fertility status, fertility and yield research would be simplified. To test the concept that a yield predictive model could be developed, an established Pensacola bahiagrass sod was fertilized with 0, 84, 168, and 336 kg/ha N in 1973 and 1974. Starting in early June and continuing until October plots were clipped monthly at heights of 2.5 and 7.5 cm. Before clipping, 1.0 tillers with mature leaves/plot were collected and numbers of clipped elongated and unclipped leaves were determined. Tillers on duplicate (15 cm)2 areas were counted after clipping.

Dry forage was increased over the 0 N check by adding 84 and 168 kg/ha N. The 336 kg/ha N did not increase forage yields over 168 kg/ha N. Clipping at 2.5 cm produced almost three times as much forage as clipping at 7.5 cm. Number of leaves/stolon/season averaged between 20.2 and 22.0 and was influenced by N rate. At each of the five harvest dates, an average of 1.3 leaves/tiller (growing point) was elongating. Nitrogen application increased tiller numbers by up to 300% and the largest number of new tillers occurred in June. Some data as collected were predictive of N and leaf generation rate, but variations in tiller numbers/area and probably leaf weight/N relationships prevented the development of an effective yield prediction model. Further refinement of the data is needed.

Statistical models based on tillers/area were not effective in predicting yields. The lack of an effective relationship between tillers/area and yield was believed due to many young tillers dying before contributing to yield and variations in leaf size reflecting N fertilization and tiller age.
Method of Soil Temperature Control for Turfgrass Research1
Authors: Aldous D. E. , Spaulding R. A. , Kaufmann J. E.
Published: July 2010

Since growth of cool season grasses is more related to soil temperatures than air temperatures, a method was developed for independent control of soil and air temperatures utilizing a modified chest‐type freezer placed inside a controlled environment growth chamber. The freezer door was replaced with a plywood top insulated with styrofoam. Pots containing two cultivars of Poa pratensis L. were suspended through holes in the top into the freezer chamber and root zone temperature was controlled utilizing a sensitive thermostat. Carboys containing nutrient solution were placed in the chamber and subirrigation was accomplished by pressurizing the carboys with an air pump. The temperature of the material in the pots reached equilibrium with the freezer environment in 4 hours. The system was effective in controlling root‐zone temperatures at optimum for shoot growth (22 C) during a 10‐week period where ambient temperatures were increased in 4 C increments every 2 weeks from 22 C to 38 C. The system could be used wherever growth or physiological responses to soil temperature must be separated from responses to air temperature.
Influence of Six Plant Growth Regulators on Spanish Peanuts1
Authors: Wu C. H. , Santelmann P. W.
Published: July 2010

Plant growth regulators show considerable promise for use in peanuts (Arachis hypogaea L. ‘Comet’). However, new materials need to be evaluated. The influence of soil moisture on peanut response to SADH (succinic acid, 2,2‐dimethyl hydrazide) was examined in a growth chamber. Effects of SADH, PP 528 (ethyl 5‐(4‐chlorophenyl)‐2H‐tetrazol‐2‐y‐lacetate), FMC 28979 (2‐chloro‐3‐(3‐chloro‐2‐methylphenyl)propionitrile), mefluidide (N‐[2,4‐dimethyl‐5‐[(trifluoromethyl) sulfonyl]‐amino]‐phenylacetamide). TIBA (2,3,5‐triiodobenzoic acid) and TD 6817 (chemistry not released) were also evaluated in the field. SADH reduced plant size of peanuts grown under the wet regimes but not under dry conditions. Average peanut leaf area was not affected by SADH. However, SADH did increase the root weight in both wet and dry conditions in the growth chamber. Peanut yields were not increased by SADH in any of the 3 years in the field. No plant growth regulators used at any rate at any growth stage significantly increased peanut yield. The reduction of plant size by SADH might be significant to irrigated peanuts or in high rainfall areas where rotting of peanut vines may take place.
Pre‐sowing Seed Treatments, Seed Coats, and Metabolic Activity of Lehmann Lovegrass Seeds1
Authors: Haferkamp Marshall R. , Jordan Gilbert L. , Matsuda Kaoru
Published: July 2010

Data from both field and laboratory studies have suggested germination of Lehmann lovegrass (Eragrostis lehmanniana Nees.) caryopses (seeds) can be improved by various pre‐sowing seed treatments. Effective treatments include moistening and drying, oven‐drying, scarification, and pre‐chilling on a moist substrate. The increased germination may be due to improved seed‐coat permeability or to a change in the metabolic state of the seed. A growth chamber study was undertaken to determine if pre‐treating air dry Lehmann lovegrass seeds with moistening, oven‐drying, or mechanical scarification increased: (1) metabolic activity upon remoistening; (2) seed‐coat permeability relative to moisture imbibition; and (3) percent germination in low concentrations of oxygen (O2).

Lehmann lovegrass seeds were pre‐treated and immediately following treatment samples were either: (1) imbibed in darkness at 24 C and analyzed after 9 hours for adenosine triphosphate (ATP) content and after 24 hours for percent germination; (2) imbibed in darkness at 24 C and analyzed after 0, 6, and 18 hours for moisture content; (3) imbibed for 37 hours at 24 C in atmospheres containing either 5, 10, or 21% O2 and analyzed for percent germination; or (4) viewed with a scanning electron microscope to evaluate damage to seed coats.

Treated seeds germinated better and contained more ATP than untreated seeds. Oven‐dried, scarified, and moistened plus oven‐dried seeds germinated the best, while scarified and moistened plus oven‐dried seeds contained the most ATP.

Rate of moisture imbibition was increased by pretreatments. After 6 hours of imbibition, scarified, ovendried, and moistened plus oven‐dried seeds contained significantly more moisture than air‐dried seeds. After 18 hours the differences were not as large.

Treated seeds germinated best in atmospheres of 5, 10, and 21% O2, but germination was poorest in the 5% O2.

Seed coats appeared affected by treatments. Scarified seeds appeared scratched and the gelatinous coating surrounding the seeds appeared loosened and torn from moistening and oven‐drying.
Yield and Leaf Nitrogen of Nodulating and Nonnodulating Soybeans as Affected by Nitrogen and Molybdenum1
Authors: Parker M. B. , Harris H. B.
Published: July 2010

Investigators have suggested that soybean [Glycine max (L.) Merr.] response to Mo was essentially a correction of N deficiency, and a series of experiments was conducted on acid soils (pH ranged from 4.5 to 5.6) to evaluate the suggestion.

In the first series of experiments, yield response to Mo and N rates was studied for 3 years on soybean cultivars grown on Dyke 1 (Typic Rhodudult) and State 1 (Typic Hapludult) soils. Molybdenum was as effective in increasing yields as 134 kg N/ha in one experiment, 67 kg N/ha in a second experiment, and less effective than 67 kg N/ha in a third experiment. However, the combined effect of Mo plus N was greater in two out of three experiments than each element applied singly.

In the second series of experiments, plant response to Mo and N rates was studied for 3 years on nodulating and nonnodulating isolines of soybeans grown on State 1, Etowah sl (Typic Palendult), and Cecil scl (Typic Hapludult) soils. Leaf N of nonnodulating soybeans was increased by N, but Mo was ineffective in all experiments on nonnodulating isolines. Molybdenum without N increased leaf N on nodulating types in all four experiments where leaf N was determined. Nitrogen without Mo increased leaf N of nodulating types in three of four experiments. Yields of nonnodulating isolines were not affected by Mo in any of the experiments, but Mo increased yields on nodulating isolines in four of five experiments. Average yields for five experiments with nodulating types indicated that Mo without N produced yields greater than did 67 kg N/ha but less than was produced by 134 and 201 kg N/ha. Results from four of eight exeriments with nodulating soybeans indicate that N efficiency may be improved by the addition of Mo.

Results of these experiments indicate that the primary function of Mo was to correct a N deficiency and that enough soil Mo was available for nitrate reduction but not for symbiosis.
Alterations of Yield, Test Weight, and Protein in Lodged Grain Sorghum1
Authors: Larson Jeffrey C. , Maranville Jerry W.
Published: July 2010

Lodging can be a detriment to yield and quality of grain sorghum (Sorghum bicolor (L.) Moench). However, the magnitude of the changes which occur in yield and quality has not been determined. An experiment was conducted to measure the alteration in yield, protein, and test weight of this crop by artificially simulating two types of lodging observed to occur naturally in the field. Plants were manually forced to a 45‐degree angle (root lodging) or the stalk broken in the vicinity of the peduncle node (stalk break) at heading, early dough, and hard dough growth stages.

Lodging treatments decreased yield and test weight for all years studied. Results for 1973 showed a general increase in protein concentration from lodged plants, but 1974–75 increases were not significant. Grain yields were lowest in the earliest and most severely lodged treatments. Yield reductions were due primarily to reduced test weights. Total protein production (concentration × yield) was determined by level of grain yield rather than protein concentration of the grain. It was concluded that yield losses occur in lodged plants due to a hindrance of physiological function and this loss is independent of that which may occur mechanically during harvest.
Sources, Rates, and Frequencies of N Application in Subirrigated Hay Meadow1
Authors: Daigger L. A. , Moline W. J.
Published: July 2010

Inadequate supplies of soil nutrients often limits hay production of western U. S. subirrigated meadows. Our purpose was to evaluate the effectiveness of three N‐sources at various rates in alternating sequences of N‐applied annually, biennially, and triennially for meadow hay production. The hay consisted of a complex mixture of Agropyron, Poa, Sorghastrum, and Carex species harvested from a subirrigated meadow of an Aquic Ustifluvent soil. Sulfur‐coated urea (SCU), urea, and ammonium nitrate (AN) were broadcast in the spring on subirrigated hay meadows at rates of 0, 34, 67, and 135 kg N/ha applied during 1971, 1972, and 1973.

All N sources and rates increased hay yields. There were no differences in hay yields among N sources at the low rates of 34 and 67 kg N/ha, however, at high N‐rates AN and SCU produced higher hay yields than urea. Under these meadow conditions, N‐recovery percentages from SCU were greater than with urea or AN. Total protein production increased with increasing rates of N. Where fertilizers were applied once in 2 years, higher total protein yields were produced with SCU than from urea or AN at the 67 kg N/ha. At higher N rates protein differences between SCU and AN were not observed in the 2‐and 3‐year intervals of N application. Thus, efficient use of N fertilizer can be attained when applied once in 2 years for hay production in subirrigated meadows, where transport of fertilizer materials to the field site is difficult.
Effect of IBDU and UF Rate, Date, and Frequency of Application on Merion Kentucky Bluegrass1
Authors: Wilkinson J. F.
Published: July 2010

IBDU (isobutylidene diurea) and UF (ureaformaldehyde) are two popular synthetic, slow‐release nitrogen sources for use on turf. IBDU‐N release is a dissolution process, whereas N release from UF is dependent upon microbial activity. As a result, different turf responses to the two sources are expected. The objective was to compare IBDU coarse and fine, UF, and AN (ammonium nitrate) applied to ‘Merion’ Kentucky bluegrass (Poa pratensis L.) grown on Brookston silt loam, a member of the fine‐loamy, mixed, mesic Typic Argiaquolls, with a pH of approximately 7.3. Each N source was applied at 1, 2, or 3 kg N/are. The 1 and 3 kg N rates were applied in April. The 2 kg N rate was applied either in April, September, split between April and September, or split between April, June, July, and September. Treatment response was measured monthly by turf quality ratings, clipping weights, and N uptake. Turf response to coarse and fine IBDU was very similar. Single spring applications of IBDU produced a poor initial turf response compared to UF. IBDU provided a much better turf response than UF at low temperatures, whereas there was relatively little difference in turf response to IBDU and UF during the summer months when applied at the same rate and date. Frequency of application affected turf quality response more with IBDU than UF. Two IBDU applications were required for most uniform turf quality response. Uniformity of response improved only slightly with multiple UF applications.
Growth and Chemical Composition of Alfalfa Fertilized in Greenhouse Trials with Deproteinized Alfalfa Juice1
Authors: Walgenbach Richard P. , Smith Dale , Ream H. W.
Published: July 2010

Alfalfa (Medicago sativa L.) needs adequate fertilization to maintain herbage yields. The deproteinized alfalfa juice (DAJ) remaining after the protein is extracted from green alfalfa has been used to fertilize alfalfa and other crops. However, plant damage occurred when the DAJ was applied at depths greater than 1.25 cm. The purpose of this greenhouse study with alfalfa was to observe more closely the possible causes of plant damage when DAJ is applied as fertilizer. DAJ was applied to alfalfa stubble after herbage harvest, and the alfalfa was cut three times at 24‐day intervals. Alfalfa plants were growing in Plano silt loam soil (Typic Argiudoll) in Exp. 1, and in Miami silt loam soil (Typic Hapludalf) in Exp. 2. In Exp. 1, DAJ rates were 0, 1.25, 2.5, 5.0, 7.5, and 10.0 cm, and in Exp. 2, rates were 0, 0.16, 0.31, 0.62, 1.25, and 2.50 cm. Treatments also included two rates of K as K2SO4 and the ashed equivalent (AE) of 5.0 cm DAJ in Exp. 1 and of 1.25 cm in Exp. 2. Alfalfa plants fertilized with DAJ at rates of 1.25 cm or higher showed chlorotic symptoms and growth retardation. Only a few plants survived at the 5.0, 7.5, and 10.0 cm rates. Plants fertilized with K2SO4 and with AE of DAJ grew normally. First‐harvest and overall herbage yields were similar to those of the control, except for significantly lower yields at 5.0, 7.5, and 10.0 cm rates in Exp. 1. Concentrations of N, K, Cl, and Mn in first‐harvest herbage generally were increased by DAJ treatments, while other elements were decreased or were similar to control herbage. Soil salt indexes (conductivity of soil solution) increased with each increase in DAJ, but initial plant damage at high DAJ levels did not appear to be due to salt accumulation nor to any elemental toxicity. It is concluded that unknown phytotoxins contained in the DAJ or produced as microfloral breakdown products are the probable causes of plant damage. Further work is needed to identify these phytotoxic substances.
Effect of Root Temperatures on Growth and Cation Composition of Festuca arundinaceae Schreb1
Authors: Leggett J. E. , Egli D. B. , Bush L.
Published: July 2010

The accumulation of cations by many cool season forages has been shown to be influenced by both air and soil temperature. This investigation investigated the influence of root temperature on the cation composition of a tall fescue (Festuca arundinaceae Schreb.) derived from an annual ryegrass (Lolium multiflorum L.) × tall fescue hybrid. Plants were collected from field‐grown, spaced plants, transplanted to a greenhouse hydroponics system, and grown on a modified Hoagland's nutrient solution. The temperature of the roots on some of the plants was maintained at approximately 12 C by cooling the nutrient solution reservoir, while roots on the control plants were maintained at the ambient temperature (approximately 25 C). Cooling the roots reduced the weekly accumulation of dry matter of the tops by nearly 50% but had no effect on the concentration of K, Ca, and Mg in the tissue or on the ratio of K/(Ca + Mg).