bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting Sugarbeet Dried Petiole NO3‐N by Using Fresh Petiole Juice1
Authors: Halvorson A. D. , Hartman G. P. , Reule C. A.
Published: July 2010

The amount of time required for petiole NO3‐N analysis by established procedures limits the practical application of petiole testing as a tool for sugarbeet (Beta vulgaris L.) management in Montana and other short growing season areas. This study was conducted to determine if fresh petiole juice NO3‐N could be used to predict dried petiole NO3‐N, thereby reducing analysis time.

Petiole juice NO3‐N was significantly correlated (r = 0.985) with dried petiole NO3‐N when the NO3‐N concentration was determined by steam distillation. Expressing the juice petiole NO3‐N concentration on a dry weight basis slightly improved the correlation (r = 0.994).

To accurately determine petiole NO3‐N concentrations using petiole juice, water content should be considered; but for routine testing and practical purposes, water content differences caused by seasonal and/or soil N fertility levels could possibly be estimated or disregarded without serious error in data interpretation.

The petiole juice method of determining petiole NO3‐N concentration requires less time, equipment, expense, and space than other established procedures.
Responses of Bermudagrass to Salinity
Authors: Ackerson R. C. , Youngner V. B.
Published: July 2010

Bermudagrass (Cynodon spp.) are salt‐tolerant grasses valuable for forage and turf. Experiments were conducted to determine specific responses to increasing salinity to provide a basis for breeding of more salt tolerant, agronomically desirable strains. The cultivar ‘Santa Ana’ (Cynodon hybrid) was grown in solution cultures containing increasing levels of NaCl and CaCl2 or K2SO4. Dry weight of tops decreased while dry weight of roots and total nonstructural carbohydrate concentrations of crowns, but not roots, increased with increased salinity of the culture solution. Net photosynthesis rates were not affected by high levels of NaCl and CaCl2 or K2SO4, although leaf water and osmotic potentials were decreased. Increased concentrations of Na+ and Ca2+ were observed in tops and roots corresponding with decreased concentrations of K+ and Mg2+ when NaCl and CaCl2 were used in the culture solution. When K2SO4 was used to adjust the solution osmotic potential, K2 concentrations were increased in tops and roots while Ca2+ and Mg2+ were decreased. Salinity tolerance of bermudagrass may be facilitated by shunting of photosynthate from top growth to root growth and carbohydrate storage, osmotic adjustment through ionic substitution and redistribution, or increased concentration of organic acids in the cell sap.
Performance of Bigflower Vetch Seeded into Bermudagrass and Tall Fescue Swards1
Authors: Templeton W. C. , Taylor T. H.
Published: July 2010

Bigflower vetch, Vicia grandiflora var. kitaibeliana W. Koch, is a self‐regenerating winter‐annual legume which has several excellent agronomic characteristics. It has never been used extensively in pasture programs, however, and little information on it is available in the literature. Two field experiments were conducted on a Typic Paleudults, clayey, mixed, mesic soil (Maury silt loam) to study vetch establishment, productivity, and ecological behavior when seeded into established swards of bermudagrass, Cynodon dactylon (L.) Pers., and tall fescue, Festuca arundinacea Schreb.

Vetch was broadcast by hand into a bermudagrass sod in fall and covered with a rototiller‐type sod scarifier (contravator). Red clover and various N treatments were included for comparison. Four different sod treatment‐seeding method combinations were used for planting into fescue and two N levels on the grass were also tested. The bermudagrass trial was repeated for 3 years and the fescue one twice. Seeding vetch into bermudagrass increased weed‐free dry‐matter production from 2,770 to 6,490 kg/ha (3‐year avg.). In terms of dry‐matter productivity, vetch‐grass mixtures were more productive than either bermudagrass or tall fescue receiving 100 kg N/ha. Planting vetch into a short sward of tall fescue was superior to planting in accumulated growth when the seed were not covered, but with tillage to cover the seed height of grass was unimportant. Seed coverage was less beneficial when the seedings were made into a short sward than when planted in tall herbage.

Vetch grew rapidly in spring and in bermudagrass exerted severe competition against winter annual weeds. With tall fescue the better seeding methods resulted in first‐growth harvests equal or superior in yield to those of tall fescue receiving 100 kg N/ha and herbages containing 48 to 70% vetch.

Owing to its ease of establishment and competitive abilities with established grasses it is concluded that bigflower vetch would be useful as a pioneer legume for grassland improvement and for use in permanent pastures where conventional seeding methods are impractical.
Yield and Quality Losses Due to Alfalfa Weevil1
Authors: Liu Beverly W. Y. , Fick Gary W.
Published: July 2010

Evaluation of management practices to control the alfalfa weevil (Hypera postica Gyllenhal) requires quantitative knowledge of the effects of insect defoliation on yield and quality of alfalfa (Medicago sativa L.). Measurements were made in 1971 when the uncontrolled population peaked at 2.7 larvae stem−1 and in 1972 when the peak was 1.1 larvae stem−1. With weevils chemically controlled, a three‐cut system gave seasonal dry matter yields of 10.1 and 10.5 metric tons ha−1 in 1971 and 1972, respectively, whereas weevil infested plots yielded 8.4 and 10.0 metric tons ha−1, respectively. Corresponding yields for two‐cut systems were lower at 6.4 and 9.1 metric tons ha−1 for non‐infested plots and 7.7 and 8.6 metric tons ha−1 for infested plots. In vitro true digestibility (IVTD) and crude protein (CP) percentages of leaves were reduced during peak larval feeding with the higher population of 1971. Weevil defoliation did not have a significant influence on leaf percentage or on the quality of the total herbage, apparently because stem growth was also retarded. However, yield of quality components was reduced. The greatest effect for a single harvest was in the second cut of the three‐cut system where feeding occurred in the early stages of regrowth. Total seasonal yield reductions in 1971 were highly significant for IVTD and CP, and significant for leaves. Losses for these components were 1.4, 0.3, and 0.8 metric tons ha−1, respectively,in the three‐cut system. Yields and quality tended to be higher in the two‐cut system when weevils were not controlled because of reduced lodging in late cut alfalfa and renewed growth when larval activity subsided. With the lower weevil population of 1972, there was no significant effect of weevil feeding on any of the measured yield and quality parameters.
Spotted Response of Overseeded Ryegrass to Sulfur‐Coated Urea1
Authors: Volk Gaylord M.
Published: July 2010

Sulfur‐coated urea (SCU) shows excellent potential as a controlled‐release N source for turfgrasses, but highly spotted appearance has always resulted during 3 years of tests in which SCU was used as an early application on winter ryegrass (Lolium perenne L.) overseeded on verticut bermudagrass (Cynodan sp.). Darker green spots 5 to 15 cm in diam constituted 20 to 50% of the surface area, with lighter green grass between the spots. The spots became smaller and the contrast greater as the season progressed. Chlorphyll content determined by methanol extraction of fresh grass was 8.5 mg/g on dry grass basis in representative darker green spots vs. 6.6 mg/g for lighter green interspot areas. Apparently, in the absence of retentive thatch, the large round SCU pellets were readily moved by sprinkler irrigation and rainfall, and concentrated into zones of stability. Poor initial distribution and mower pickup were not determining factors. Where effective thatch is lacking some means of incorporation sufficient to anchor the pellets should be devised.
Fertilization, Nutrient Composition, and Yield Relationships in Irrigated Spring Wheat1
Authors: Gardner B. R. , Jackson E. B.
Published: July 2010

Wheat acreage in Arizona has increased tenfold since the introduction of high yielding semidwarf spring wheats (Triticum aestivum L.). Because of the higher yield potential of these wheat cultivars, many growers have applied more fertilizer without evidence that these semidwarf spring wheats require more nutrients. This study was initiated to evaluate the effect of N and P fertilization on the growth and yield of semidwarf spring wheat and to develop a workable tissue test to determine the nutritional status of the wheat plan.

Tissue samples for chemical analysis were taken from uheat plants in three different field experiments. These experiments consisted of 1) six rates of N and three rates of P, 2) six rates of N and six wheat cultivars, and 3) six rates of N and three wheat cultivars.

The NO3‐N concentration in the lower 5 to 8 cm of the stem indicated the N status of the wheat plant. Minimum levels of NO3‐N for different stages of growth were established for Southwestern Arizona conditions. In two experiments excessive N decreased yields slightly when compared to sufficient levels of N. The main effects of N on grain yield components were to increase the number of heads/unit area, increase the number of seeds/ head, and decrease the weight of individual seeds. The total N content in the grain increased with increased N applications. Determination of P in the lower portion of wheat stems was not found to be suitable for indicating the P status of the crop.
Copper Industrial Byproducts for Improving Iron Deficient Calcareous Soils1
Authors: Ryan J. , Stroehlein J. L.
Published: July 2010

Laboratory and greenhouse experiments were conducted to evaluate an iron‐rich surplus by‐product (“jarosite”) from a copper refining process as Fe fertilizer. Combinations of H2SO4, which is a by‐product from copper smelting, with “jarosite” were studied in order to see if the iron solubility would be increased. Acidification of the “jaroste” greatly enhanced Fe solubility. As the “jarosite”/H2SO4 ratio increased from 1:1 to 7:1, the amount of the material solubilized as Fe decreased from approximately 12 to 2%. At ratios wider than 7:1, negligible amounts of Fe dissolved. At “jarosite”/H2SO4 ratios < 1, Fe solubility increased but the end product could not be handled as a conventional pelleted or powdered fertilizer.

In greenhouse experiments using sorghum (Sorghum bicolor ‘Double Dwarf Yellow Sooner’) in an Fe‐deficient calcareous soil, the 2:1 mixture of “jarosite”/H2SO4 was significantly more effective than either “jarosite” or H2SO4 alone in terms of increasing plant growth and chlorophyll content. The mixture compared favorably with conventional inorganic and chelated sources of Fe. Varying the ratio of “jarosite”/H2SO4 from 1:1 to 5:1 resulted in no differences in yield. Particle size of the mixture influenced plant growth. The < 1 mm fraction was most effective, the 1 to 2 mm and 2 to 6 mm fractions gave similar yields and the 6 to 12 mm fraction was least effective. Post‐harvest analysis of the cropped soil showed that the “jarosite”/H2SO4 mixture significantly increased the levels of DTPA‐extractable Fe.
Transmittance of the Multifoliolate Leaf Characteristic into Non‐Dormant Alfalfa1
Authors: Brick M. A. , Dobrenz A. K. , Schonhorst M. H.
Published: July 2010

Variation in leaf morphology and canopy architecture in alfalfa (Medicago sativa L.) has received comparatively little attention despite the importance of the leaf in photosynthesis and nutritive value of the forage. The multifoliolate leaf characteristics presents a potential mechanism whereby quality and leafiness can be changed. This investigation was designed to study the penetrance of the multifoliolate trait into ‘Mesa‐Sirsa,’ a non‐dormant trifoliolate cultivar.

Hand and bee‐pollinated reciprocal crosses were made between a trifoliolate (tf) Mesa‐Sirsa clone and four multifoliolate (mf) alfalfa clones to determine if genes for the mf trait could be transmitted and expressed in the F1 generation. Specific leaf weight and internode length were studied in the F1 generation of controlled handpollinated crosses.

The multifoliolate characteristic was effectively transmitted in both hand and bee‐pollinated experiments with an average expression of 33%. Expression of the mf trait among progeny of the four multifoliolate clones ranged from 8 to 47%. Average specific leaf weight was consistently higher in the mf progeny compared to the tf progeny, however, these differences were not significant expect in progeny of Mesa‐Sirsa × mf 2. Average internode length varied significantly among crosses and between the tf and mf progeny of crosses MS × mf 1 and MS × mf 2. The multifoliolate clones used in this study had the normal tetraploid complement of 32 chromosomes.

The multifoliolate characteristic is an easily transmittable trait and through careful selection could be used to improve the leafiness and canopy architecture of nondormant alfalfa.
Histological and in vitro Digestion Study of 1‐ and 4‐Week Stems and Leaves From High and Low Quality Bermudagrass Genotypes1
Authors: Hanna Wayne W. , Monson Warren G. , Burton Glenn W.
Published: July 2010

Anatomical information is limited on changes occurring with age of the forage and differences due to genotype affecting in vitro dry matter digestibility (IVDMD). Since this type of information would be ot value to those concerned with the production and use of forage, two bermudagrass, Cynodon dactylon (L.) Pers., clones with high IVDMD values (Coastcross‐1 and P.I. 293603) and two clones with low IVDMD values (P.I. 291715 and P.I. 291719) were studied histologically. No histological differences were observed in either the stems or leaves between the high‐ and low‐quality bermudagrass of the same age. The formation of a band of thick‐walled cells in the stem at 4 weeks of age more than doubled the percentage of anatomical components resistant to 72 hours of rumen fluid digestion and reduced IVDMD values by up to 44%, as compared to 1‐week‐old stems. The percentage of anatomical components resistant to digestion in the leaves and IVDMD values of leaves remained relatively the same in 1 and 4‐week‐old samples of a specific clone. This indicates that reduction in quality with age of bermudagrass forage is due mainly to changes occurring in the stem. The vascular bundles (except phloem), parts of the epidermal cells, and the thick‐walled cells in 4‐week‐old stems were resistant to digestion. The higher IVDMD values of the high‐quality bermudagrasses appear to be due to a larger soluble fraction and more digestible cell wall. No anatomical differences were observed between the high and low quality genotypes to account for the differences in IVDMD values.
Seed Production and Stand Regeneration of Bigflower Vetch, Vicia grandiflora var. kitaibeliana W. Koch, Grown with Cool‐Season Forage Grasses1
Authors: Templeton W. C. , Taylor T. H. , Wyles J. W. , Woolfolk P. G.
Published: July 2010

Research has shown that bigflower vetch, Vicia grandiflora var. kitaibeliana W. Koch, possesses a number of desirable characteristics as a forage plant. A deterrent to its use, however, is seed shattering, as the pods ripen. Also, no information concerning seed production potential of the species is available. Experiments were conducted, therefore, to gain information on seed production and the effect of spring cutting on seed yields and to explore the potential for regenerating stands from natural reseeding.

Two essentially identical field experiments were conducted in which bigflower vetch‐grass mixtures were uncut or cut one to three times in spring prior to harvesting vetch seed. Residual productivity and botanical composition of the swards were determined in a single spring cutting the year after seed harvest.

Early‐spring cutting of vetch‐grass mixtures markedly increased vetch seed production, with the most beneficial treatments resulting in clean‐seed yields of ca 600 kg/ha. The most intensive cutting treatments and cutting late in spring either almost or completely prevented seed production.

A third experiment, under pasture conditions, involved bigflower vetch and several other legumes seeded into mixed grasses and managed to favor natural reseeding or to deter it, and three levels of N fertilizer. Sheep were used to graze the plots during a 5‐year period.

Deferment of grazing in spring or early sumnmer to allow seed production and encourage natural reseeding of legumes increased the legume component of the pastures and sheep‐grazing days obtained from bigflower vetchgrass mixtures but not from other legume‐grass associations. Bigflower vetch‐grass, with the vetch allowed to reseed naturally, was as productive as grass receiving 112 kg N/ha/year.

The data indicate that once an adequate reservior of bigflower vetch seed is in the soil, satisfactory stands can be regenerated for at least 2 years without intervening seed production.
Growth and Mineral Composition of Rice at Various Soil Moisture Tensions and Oxygen Levels
Authors: Patrick W. H. , Fontenot W. J.
Published: July 2010

The better growth of rice in a flooded soil as compared to an upland soil has been attributed to the reducing conditions caused by submergence. No study has been carried out, however, in which the effects of the soil moisture status has been separated from the effect of the oxidation‐reduction conditions of the soil.

In the study reported here, the effect of soil oxidation‐reduction conditions on early growth and mineral composition of lowland rice (Oryza sativa L. ‘Saturn’) was determined by growing plants in artificially packed soil columns maintained under different soil moisture tension and oxygen conditions. Since soil aeration is largely governed by the moisture status of the soil, this study was designed to separate these effects by subjecting the rice plant to different aeration conditions while at the same time attempting not to limit moisture supply. In one experiment different redox conditions were established by maintaining soil columns at soil moisture tensions ranging from 0 to 80 cm during growth of the plants. In a second experiment plants were grown at soil oxygen levels of 0, 3, 8, and 12% while soil moisture was maintained at 10 cm moisture tension. Vegetative growth of rice was greater under reduced conditions than under oxidized conditions in both experiments. The P concentration of the plant was much higher under reduced conditions than under oxidized conditions. Reduced conditions increased the solubility of P, Fe, and Mn in the soil although no consistent effect of reducing conditions on plant uptake of Fe and Mn was observed.
Nitrogen Nutrition and Yield of Sugarcane as Affected by N‐Serve1
Authors: Prasad M.
Published: July 2010

Very few experiments have been conducted to evaluate N‐Serve [2‐chloro‐6‐(trichloromethyl) pyridine] formulated with N fertilizer for sugarcane (Saccharum officirarum L.). N‐Serve when fomulated with N‐fertilizer increased sugarcane yields in the Philippines and in Louisiana but failed to do so in Puerto Rico and in Mauritius. In view of the relatively few experiments conducted with N‐Serve for sugarcane and the conflicting nature of the results, a pot experiment in drums and a field experiment were conducted to study the effect of N‐Serve formulated with solid ammonium sulfate (AS) on sugarcane (‘HJ 5741’) yield, leaf N content, tillering, and on soil N. In the pot experiment two soils, a clayey loam (Typic Tropaqualfs) and a loamy sand (Aquoxic Tropudults) were used combined with a high and low irrigation treatment. There were two rates of AS with and without N‐Serve. A control treatment was also included. N‐Serve was applied at 2.5% of the weight of AS. In the field experiment on a sandy clay (Typic Tropaqualfs) there were three rates of AS with and without N‐Serve. A control treatment was also included. N‐Serve was applied at a flat rate of 24 liters/ha.

In the pot experiment N‐Serve increased the yield of sugarcane and leaf N‐content at the low rate of N application. However, N‐Serve reduced yields in the loamy sand soil at both rates of N under low irrigation. N‐Serve was effective in inhibiting nitrification at least up to 6 weeks in all four combinations but it was less effective in the loamy sand soil under high irrigation. High percentage of N in the leaf of the N‐Serve treatments reflected the higher efficiency of N fertilizer with N‐Serve. In the field experiment N at 103 kg/ha with N‐Serve gave yields almost equal to 206 kg/ha without N‐Serve. Nitrification was inhibited up to 12 weeks at N‐Serve application with low rate of N in the field. As in the drum experiment, the efficiency of the N‐fertilizer (as reflected by higher percentage N in the leaf) was improved with N‐Serve applications, especially with lower rates of N.
Effects of Gibberellic Acid on the Cool Season Regworth of Two Tropical Forage Grasses1
Authors: Whitney A. S.
Published: July 2010

Although the tropical grasses are very productive in Hawaii and elsewhere, their production at subtropical latitudes or elevations is often limited by seasonally low‐temperatures. The feasibility of overcoming low‐temperature effects by applying gibberellic acid (GA3) was therefore evaluated over a 4‐year period on swards of kikuyugrass (Pennisetum clandestinum Hochst. ex. Chiov.) at two sites and pangola digitgrass (Digitaria decumbens Stent) at one site.

Significant responses to 62 g GA/ha were obtained in all experiments over the range of N‐fertilization tested (68–180 kg N/ha). Over a 4‐year period, the average response of kikuyugrass to GA under a clipping regime was 1260 kg dry matter (DM)/ha. The average response to ammonium sulfate (at N rates ≥ 68 kg/ha) was 15 kg DM/kg N. Average pangola responses were 1450 kg DM/ha from GA treatment and 10.5 kg DM/kg N. In some cases, the GA responses could not be duplicated by higher levels of N fertilization.

GA applied on the date of clipping was as effective as GA applied 2 weeks later, but under some conditions, GA was less effective in increasing (DM) production once regrowth entered the boom portion of the regrowth curve. Growth retardation subsequent to the GA response occurred in clipped plots but not in plots which were left unclipped or were defoliated by 2 weeks of grazing.

GA treatment appears to be feasible for increasing production of kikuyugrass and pangola during the cool season. The responses were enhanced by a moderate level of N‐fertilization, and the full‐season responses from single applications of GA were better under grazing than under clipping. The GA‐treated forage was stemmier and thus less completely consumed by grazing animals, however.
Morphology and Growth of Bahiagrass at Three Rates of Nitrogen
Authors: Sampaio E. V. S. B. , Beaty E. R.
Published: July 2010

‘Pensacola’ bahiagrass, Paspalum notatum Flugge, is an important grass in the tropics and subtropics, including large areas in the southern part of the United States. Bahiagrass grows by adding new phytomers each with a bud, internode, node, leaf sheath, and blade and usually a root on each tiller growing at the terminal end of horizontal stolons. Rate of phytomer generation and growth/tiller determines forage production and an understanding of phytomer production and component longivity is essential for its effective management. N fertilization influences tiller numbers and possibly rate of phytomer generation and growth. This greenhouse investigation was concerned with rate of tillering and phytomer production and component growth/tiller over 90‐day growth periods when fertilized with 0, 100, and 300 kg/ha of N.

Tiller initiation in bahiagrass was relatively slow, and over the 90‐day period each original tiller produced one new tiller when no N was applied and three new tillers when 300 kg/ha N was applied. New leaf (phytomer) production ranged from 9.5 to 9.8/tiller for the 90 day period; total phytomer production was not influenced by N fertilization level. Leaves lived for 54 to 60 days and on N fertilized treatments leaf blades were slightly wider but no longer than were leaf blades on unfertilized treatments. N fertilization tended to accelerate phytomer development for 40 days following application and to delay it for the following 50 days as compared to that of the no N check.
Response of Three Hard Red Winter Wheat Cultivars to Four Planting Arrangements1
Authors: Ketata H. , Edwards L. H. , Morrison R. D.
Published: July 2010

As new and morphologically different wheat cultivars are developed, altered cultural practices may be required to obtain optimum performance from a particular cultivar. This study compared the relative responses of three contrasting hard red winter wheat cultivars (Triticum aestivum L. em Thell.) under four planting arrangements. Cultivars studied were ‘Triumph 64,’ ‘Sturdy,’ and ‘Parker.’ A split plot experimental design was employed with cultivars as main plots and planting arrangements (two row spacings and two drilling patterns) as subplots. Characters investigated were grain yield, tillers/unit area, kernels/spike, kernel weight, test weight, plant height, maturity, and protein content of the grain. The cultivars differed significantly for all characters except grain yield. Tiller count was significantly affected by row spacings and drilling patterns while kernels per spike was significantly influenced by row spacings. Planting arrangements did not induce significant responses in any of the remaining characters. A significant cultivar by spacing interaction was noted for test weight and a significant cultivar by drilling interaction was noted for plant height. The results of this experiment indicate that planting arrangements may influence yield components and other characters in the wheat cultivars studied. However, the optimum planting arrangement for increased yield could not be determined.
Leaching of Phosphate and Selected Cations from Sandy Soils as Affected by Lime1
Authors: Chaiwanakupt Pornphimol , Robertson W. K.
Published: July 2010

It is important to determine if and to what extent P moves through some acid sandy soils and, in view of the high cost of fertilizer P and the problems associated with pollution of ground water, what can be done to prevent or reduce the movement when it occurs.

Segmented columns, 25 cm in length and 5 cm in diam., were used to study P leaching in five mineral and one organic soil. A total of 25 or 50 cm H2O was passed through the columns, containing soil from various depths, after treatment in the top 2 cm with 0 to 600 ppm P tagged with 32P. Phosphorus and other ions were measured in the leachates and at the end of the leaching period in 5 cm segments of the soil columns. For those soils where leaching of P occurred, lime effects on its reduction were investigated by repeating the experiment with the addition of Ca(OH)2 at rates to supply 0 to 800 ppm Ca in the soil.

Movement of P from the column was nil in Red Bay fine sandy loam but occurred for the other soils as follows: Leon fine sand > Oldsmar fine sand > Eustis loamy fine sand > Lakeland fine sand > Tomoka muck. Leaching was positively related to rates of applied P and negatively related to rates of applied P and to the level of organic matter, Fe and Al contents, pH, and rate of liming. The degree to which these factors affected leaching varied with the soil as well as the location in the profile from which the sample was collected.

Leaching of K, Ca, and Mg occurred in all soils. The amount was generally related to the CEC or the levels present in the extractable form before the leaching began. Leaching of Fe and Al was determined only on soils where P leaching was appreciable. These ions generally leached with P but there was a direct relationship between leached and 0.1 N HC1 extractable ions. These data are of value in evaluating and determining P and lime requirements.
Relationship Between Physiological and Morphological Characteristics and Yield of Nondormant Alfalfa Clones1
Authors: Foutz A. L. , Wilhelm W. W. , Dobrenz A. K.
Published: July 2010

Alfalfa (Medicago sativa L.) breeders are constantly striving to improve the productivity of alfalfa. Yields have been increased primarily through the selection of plant materials resistant to insects and diseases. The objective of this study was to evaluate physiological characteristics which might be used as selection criteria in alfalfa improvement. Alfalfa clones were grown under field conditions on a Mojave clay loam soil. Carbon dioxide flux was evaluated in a closed system using an infrared gas analyzer. The physiological variables measured in these studies did not account for the variation in yield among the clones. Apparent photosynthetic rates, dark respiration rates, and postillumination CO2 burst rates expressed as mg CO2 dm−2 hour−1 were not correlated with dry matter production. However, when these physiological factors were multiplied by leaf area and expressed as total CO2 exchange per plant per hour, there was a significant relationship between yield and these calculated variables, in both studies. Regression analyses of more than 30 factors indicated that leaf area, leaf to stem‐petiole ratio, and leaf weight per plant accounted for more than 95% of the variation in yield among alfalfa clones. The data from these studies suggest that morphological factors were more reliable indicators of alfalfa productivity than physiological factors.
Oat Response to Manganese and Zinc1
Authors: Murray G. A. , Benson J. A.
Published: July 2010

Leaf symptoms that resembled Mn deficiency were observed on certain oat (Avena sativa L.) cultivars grown on a De Voignes series, fine‐silty, mixed, nonacid, frigid, Histic Humaquepts soil where Mn deficiency had not been previously reported. Results of preliminary field studies confirmed that Mn was deficient for optimum oat growth and suggested that Zn was marginally deficient. In addition, a Mn‐efficient oat cultivar (‘Park’) and a Mn‐efficient oat cultivar (‘Cayuse’) were identified. The objective of this field study was to measure the yield, protein, and test weight responses of Park and Cayuse to applications of Mn and Zn made over a 3‐year period.

Foliar applications of 1.8 and 3.6 kg/ha Mn to Park and Cayuse, respectively, increased grain yield an average of 588 and 1,097 kg/ha, respectively. One application of Mn at tillering increased yield as much as Mn applications made at both tillering and boot stages of oat development. Grain protein of Park and Cayuse was increased 2.65 and 0.6% by applications of 9.0 and 3.6 kg/ha Mn respectively in 1971. Neither cultivar showed increased protein from Mn application in subsequent experiments. Test weight was not influenced by Mn application. Zinc did not significantly alter yield, protein, or test weight. However, Zn tended to increase test weight in dry years and tended to increase yield in wet years.

Combinations of foliar applied MCPA (sodium salt of 2‐methyl‐4‐chlorophenoxyacetic acid) and Mn, or foliar applied Diuron (3‐(3,4 dichlorophenyl)‐1,1‐dimethylurea) and Mn gave yield increases comparable to Mn alone. Combinations of Mn and Zn were not better than Mn alone.
Growing Season and Location Effects on Water Uptake and Drying Rates of Peanut Seeds from Genotypes Resistant and Susceptible to Invasion by Aspergillus flavus Lk. ex. Fr.1,2
Authors: Ketring D. L. , Benedict C. R. , Yeager M.
Published: July 2010

As a means to detect differences in testae properties between peanut (Arachis hypogaea L.) seeds from genotypes resistant to invasion by A. flavus Lk. ex Fr. and seeds from genotypes susceptible to the fungus, the water uptake and drying characteristics of the seeds were compared. Testae properties that could aid in control of A. flavus invasion of peanut seeds and the effect of growing conditions on these properties were sought.

Seeds of both genotypes were grown in Puerto Rico in 1972 and Puerto Rico and Texas in 1973. Growing season and location significantly affected rate and total water uptake of cured seeds. With or without testae, the rate and total water uptake were greater for seeds grown in Puerto Rico than those grown in Texas. When growing conditions produced seeds with comparatively high water uptake capabilities (Puerto Rico), intact seeds of ‘Florunner’ and the genotypes resistant to invasion by A. flavus had slower water uptake rates than genotypes more susceptible to mold invasion. The data suggest that there are functional differences, indicative of structural differences, between testae of resistant and susceptible genotypes. When growing conditions produced seeds with comparatively low water uptake capabilities (Texas), there was less distinction between resistant and susceptible genotypes (based on water uptake patterns). However, one susceptible genotype retained a higher rate and total water uptake than all other genotypes. These data indicate that growing conditions affected testae structure that regulates the rate of water uptake by the seeds.

Seed drying tests showed that Florunner and genotypes resistant to A. flavus invasion dried to moisture levels (10% or less) unfavorable for A. flavus growth at rates significantly faster than the susceptible genotypes. Drying patterns were unaffected by growing location.

Lipid and protein contents of the seeds were not correlated with water uptake characteristics, although they varied with growing season and location.

Slow rates of water uptake and the rapid drying rates of seeds of the resistant genotypes are attributes favorable to control of A. flavus invasion. If these attributes, along with resistance to A. flavus invasion, could be genetically transferred to other peanut genotypes, it is likely that contamination of peanuts by A. flavus could be reduced.
Modified Milling Procedure for Separating Endosperm and Nonendosperm Portions of the Wheat Kernel for Protein and Lysine Analysis1
Authors: Vogel K. P. , Mattern P. J. , Lenser G. W.
Published: July 2010

Conventional milling does not uniformly separate endosperm and nonendosperm components of wheats (Triticum aestivum L.). Uniform separation of bran and endosperm is required for protein and lysine analyses because of a protein gradient in wheat endosperm. A modified milling procedure for separating endosperm and nonendosperm components of the wheat kernel was evaluated for its utility in processing small breeder lots of seed for protein and lysine analyses. After conventional milling and sifting, the endosperm adhering to the bran was removed by washing with a 80:20 (vol/vol) ethanol:acetone solution, filtered from the washing solution, dried, and added to the mill flour to reconstitute the endosperm. Reconstituted endosperm weight was used to calculate percent endosperm. Reasonably complete and uniform separations of the endosperm and nonendosperm components were obtained without any appreciable loss of components. Endosperm percentages of the wheats tested ranged from 72.8 to 85.5%. Endosperm protein percentages ranged from 10.8 to 21.0%. Bran protein percentages ranged from 13.1 to 25.1%. Endosperm lysine (percent of protein) percentages ranged from 2.1 to 3.1%. Bran lysine (percent protein) percentages ranged from 3.2 5.0%.
Growth Regulation of Kentucky Bluegrass With Several Growth Retardants1
Authors: Watschke T. L.
Published: July 2010

Growth retarding chemicals may be useful in maintaining attractive turf with less mowing. Six growth regulators were applied to an 8‐year‐old stand of ‘Pennstar’ and ‘Fylking’ Kentucky bluegrass (Poa pratensis L.) to evaluate turf growth suppression, phytotoxicity, total, nonstructural carbohydrates (TNC), and recovery from retardation stress. The materials were three experimentals with undisclosed formulas (EL‐509, Proxazolon, and MBR‐12325), chlorflurenol, Sustar (3‐trifluoromethyl‐sulfonamido‐p‐acetotoluidide), and maleic hydrazide. Proxazolon and MBR‐12325 retarded growth more than the other materials, but Proxazolon was slower acting than MBR‐12325. EL‐509 was the only material that did not significantly retard growth. Approximately 4 weeks after initial application, turf that had been significantly reduced in growth, grew faster than untreated. All materials caused an unacceptable discoloration lasting for 2 to 3 weeks. Lower rates tended to cause less discoloration, but growth suppression did not last as long as higher rates. Turf treated with MBR‐12325 had a significant accumulation of TNC, but this occurred only after discoloration subsided. Of the materials used in this experiment, only MBR‐12325 appeared to have potential for retardation of fine turf; however, discoloration was unacceptable at the rates used. The other materials could be of use on hazardous‐to‐mow, non‐use, or other areas where discoloration would not be objectionable.
Effect of Activated Charcoal on Herbicide Injury During Establishment of Centipedegrass1
Authors: Johnson B. J.
Published: July 2010

Controlling weeds with herbicides during the establishment of centipedegrass [Eremochloa ophiuroides (Munro) Hack.] often results in severe turfgrass injury. Experiments were conducted on Cecil sandy clay (Typic Hapludult) and Cecil sandy loam soils to determine if turfgrass sprigs dipped in activated charcoal before planting would protect the grass from herbicide injury when applied after planting for weed control.

Dipping centipedegrass sprigs in activated charcoal improved early growth and appearance of the turfgrass when treated immediately after sprigging with herbicides for weed control. The rate of turfgrass growth (ground cover) during the first growing season was also improved in most instances by activated charcoal dip when treated with all herbicides except DCPA (dimethyl tetrachloroterephthalate). Activated charcoal treatment did not generally affect weed control during the establishment period. Therefore, when herbicides are used for weed control during establishment of centipedegrass, the rate of establishment was improved by activated charcoal treatments.
Evaluation of Slow‐release Nitrogen Fertilizers on Pennpar Creeping Bentgrass1
Authors: Waddington D. V. , Duich J. M.
Published: July 2010

As new fertilizer materials become available for turfgrass fertilization, their relative merits should be evaluated under various field conditions so that sound recommendations can be made concerning their use. In this study on ‘Pennpar’ creeping bentgrass (Agrostis palustris Huds.), single applications of four slow‐release N fertilizers and multiple applications of urea applied to fine, mixed, mesic Typic Hapludalf soil were compared for four consecutive growing seasons. Split applications of slow‐release materials were also included in the fourth season. Clipping yields and turf color were used to evaluate response to fertilization. Growth patterns varied from year to year, but certain relationships between treatments generally remained the same: 1) greatest initial response occurred with IBDU (isobutylidene diurea); 2) yields from slow‐release treatments equalled or exceeded those from the urea treatment for 13 to 14 weeks, thereafter urea gave higher yields; 3) response from sulfur‐coated urea (21% 7‐day dissolution rate) and resin‐coated fertilizer (Agriform CRF 19‐3‐11) was intermediate between IBDU and ureaform (Uramite). Split applications of slow‐release sources reduced the flush of spring growth and increased turf color in the fall to an acceptable level. Color was unacceptable in the fall when single spring applications were used. The delay in response noted after IBDU applications on Kentucky bluegrass (Poa pratensis L.) in other experiments was not as apparent under the conditions of this study, possibly due to the incorporation of fertilizer by aerating and topdressing at the time of application and more liberal watering on the bentgrass area.
Fixation and Volatilization by Soils of Selenium from Trimethylselenonium1
Authors: Olson O. E. , Cary E. E. , Allaway W. H.
Published: July 2010

Selenium, an essential element for animals, is now being added to some livestock diets. The trimethylselenonium ion (TMSe+) is an important urinary metabolite of dietary Se. Selenium spillage onto soils is related to its natural cycling and seems important in creating Se excesses or correcting Se deficiencies in soils. Volatilization and fixation of Se from TMSe+ was studied using four soils: a Typic Quartzipsamment, an Aeric Fragiaquept, a Typic Hapludult, and a Glossoboric Hapludalf. For volatilization studies, soils treated with TMSe+ or TM75Se+ were placed in a closed system maintained at room temperature and equipped for aeration and collection of volatile Se or 75Se, which was determined at intervals over a period of several weeks. Volatilization occurred with all soils, but the rates varied widely. Treating the acid Aeric Fragiaquept with CaCO3 increased Se volatilization. Treatment with toluene or autoclaving of the Aeric Fragiaquept or the Glossoboric Hapludalf almost completely prevented the volatilization. A nitrogen atmosphere retarded the volatilization in all but the Aeric Fragiaquept soil. In one experiment, the volatilization and fixation of Se added to soils as Na275SeO4, Na275SeO3, or TM75Se+ were studied. Volatilization was measured by 75Se loss and was observed only when the TM75Se+ was added, being appreciable only with the Typic Hapludult and Glossoboric Hapludalf soils. Fixation was determined by measuring the 75Se not extracted with 0.1 M CaCl2 or with water, and was greatest for the 75Se from the Na2SeO3. Fixation of from TM75Se+ occurred in all soils during a 21‐day period to an extent of about 30 to 50% of that added. The data suggest that Se from urinary TMSe+ spilled onto soils would generally be soon lost to the atmosphere or fixed and thus become unavailable to plants.
Development of Cotton Fruit I. Accumulation and Distribution of Dry Matter1
Authors: Leffler H. R.
Published: July 2010

Investigations of cotton (Gossypium hirsutum L.) boll growth have usually been limited to studies of fiber formation. To relate cottonseed development to previous research on fiber, a general study of cotton boll development was made. Cotton was planted in a field of Bosket fine sandy loam, a fine‐loamy, mixed, thermic Mollic Hapludalf. Dry matter accumulation by cotton fruit was measured to identify ontogenetic relationships among the bur (carpel walls), the seed, and the fiber.

Measurements of boll growth were made between 10 days after flowering and maturity (boll cracking stage). Dry weight of the bur increased rapidly and reached final weight by the end of the 3rd week of development. At this time, dry weights of seed and fiber were only about 40% of their final values. Both the seed and the fiber accumulated dry matter for about 6 weeks, but the fiber accumulated dry matter at a slightly faster rate than did the seed. At maturity, the bur accounted for about 21%, the seed for about 38%, and the fiber for about 41% of the boll dry matter.

Although bolls had reached final dry weight by the end of the 6th week of development, they did not open until about 2 weeks later. Both the number of fruit competing for photosynthate and the environmental conditions prevailing during development were found to affect the accumulation of dry matter by the boll components.
Sulfur and Nitrogen Requirements of Sugarcane1
Authors: Fox R. L.
Published: July 2010

The internal S requirement of sugarcane (Saccharum officinarum L.) is not well defined and there are no published data on the external SO4‐S requirements. The objectives of this study was to provide this kind of information, and to provide data on sulfur distribution and N:S ratios in sugarcane.

Sugarcane was grown in solution cultures and in potted soil material which provided several concentrations and ratios of NO3 and SO4 in solution. External S and N requirements were estimated from plots of yield vs. SO4 or NO3 concentrations in solution cultures and in artificial soil solutions. The external S requirement at age 35 days was about 9 ppm. After 70 days the requirement was about 5 ppm when N was adequately supplied. The external NO3 requirement was about 50 ppm N. The internal S requirement for early growth was 0.36% S in the whole plant and 0.24% for leaf blades 3 through 6. When plants were 70 days old, 0.10% S in leaf blades or 0.08% S in leaf sheaths was sufficient. Sulfur‐deficient, field‐grown sugarcane 18 months old contained 0.075% S in leaves 3 through 6 and 0.072% S in the corresponding leaf sheaths. Sulfur fertilized sugar cane contained 0.138% and 0.232% for the same tissues. Ratios N:S differed for various tissues of the same plant. Distribution of S in the plant may be a valuable tool for assessing the S status of sugarcane. When S is deficient, old leaf blades contain more S than corresponding leaf sheaths, and blades and sheaths of leaves 3 to 6 contain about equal concentrations of S. Good S nutrition was associated with an elevated concentration of S in leaf sheaths as compared with leaf blades.
Grass Hay Production as Influenced by N‐P Topdressing and by Residual P1
Authors: Ludwick A. E. , Rumburg C. B.
Published: July 2010

Information is limited on the response of grass to top dressing N‐P combinations on soils deficient in both nutrients, especially concerning time of application. The purpose of this study was to compare fall and spring topdressing of N‐P combinations for grass hay production and to evaluate residual P during succeeding seasons.

A 4‐year experiment was conducted on a Fola cobbly sandy clay loam soil (Borollic Camorthid) near Gunnison, Colorado. Vegetation consisted of a mixed stand of bromegrass (Bromus inermis Leyss.), timothy (Phleum pratensis L.), orchardgrass (Dactylis glomerata L.), bluegrass (Poa pratense L.), and occasional plants of red clover (Trifolium pratense L.). Treatments were 4 rates of both N and P applied either in the fall or spring, prior to the first growing season. Residual P was evaluated the following three seasons.

Hay yields the 1st year (1972) were significantly increased from 2.51 metric tons/ha with no fertilizer to 10.77 for the highest fertilizer combination of 358 and 59 kg/ha of N and P fall applied. Yields increased with increasing rates of both nutrients. Yields from fall applied N‐P combinations averaged 1.0 to 2.5 metric tons/ha greater than yields from similar treatments spring applied. Apparently the additional time and opportunity for dissolution of the P granules and movement through the thatch and into the surface soil resulted in the fall treatments being superior to similar treatments spring applied. Uptake of both N and P followed trends similar to yields. Yields in 1973 and 1974 were increased over the control (O‐P) by the initial P treatments, although yields and P uptake declined each year. Time of initial fertilizer application (fall vs. spring) did not significantly affect yields nor P uptake beyond the first season.

Although residual P continued to increase yields and P uptake in 1975 (significant over the control at the highest P rate), reapplying P significantly increased both over all residual P levels.

Bicarbonate extractable soil P levels were markedly increased in the upper 2.5 cm of soil by P topdressing. There was no evidence of P movement below 5.0 cm.