bluuebunny/crossref_metadata_2025 huggingface dataset:
Establishment, Development and Yield of Forage Legumes and Grasses as Cover Crops in Grain Corn in Eastern Canada
Authors: Abdin O. A. , Coulman B. E. , Cloutier D. C. , Faris M. A. , Smith D. L.
Published: April 2008

Interseeded cover crops can minimize soil erosion, increase organic matter and nutrient levels and the yield of subsequent crops. However, their performance is very sensitive to local conditions. Field experiments were conducted at two Quebec locations in 1993 and 1994 in order to evaluate the potential use of forage legumes and grasses as interseeds in corn in eastern Canada. Twelve forage species were evaluated. Fall rye (Secale cereal L.), hairy vetch (Vicia villosa Roth), a mixture of red clover (Trifolium pratense L.) and ryegrass (Lolium multiflorum Lam), a mixture of white clover (Trifolium repens L.) and ryegrass, subterranean clover (Trifolium subterraneum L.), yellow sweet clover (Melilotus officinalis Lam.), black medic (Medicago lupulina L.), Persian clover (Trifolium resupinatum L.), strawberry clover (Trifolium fragiferum L.), crimson clover (Trifolium incarnatum L.), annual alfalfa (Medicago saliva L.) and berseem clover (Trifolium alexandrinum L.) were seeded at two planting dates (10 and 20 days after corn emergence). The control treatments were: hand weeding, chemical weeding and non‐weeded. Early seeded forages established better and had higher biomass accumulation than the late seeded ones. In the presence of larger weed populations, the interseeded forages did not develop well due to competition with the weeds. At Macdonald crimson clover provided good soil cover while Persian clover, fall rye and alfalfa provided relatively little cover. Strawberry clover and hairy vetch did not provide early ground cover due to their late development. Forage mixtures of red or white clover and rye grass established well and achieved high populations at the end of the growing season. Fall rye provided good early ground cover but senesced by the middle of the season. The better establishment and early germination of crimson clover caused a 19% reduction in corn grain yield in 1993. In 1994 none of the cover crops caused a reduction in corn yield.
Effect of Gibberellic Acid Spray and Basal Nitrogen and Phosphorus on Productivity and Fatty Acid Composition of Rapeseed‐Mustard
Authors: Khan N. A. , Ansari H. R. , Samiullah
Published: April 2008

Two field experiments were conducted during] 994‐95 to study the effect of spray of 10−5 M GA3 at 40 days after sowing on mustard (Brassica juncea (L.) Czern & Coss.) cv. Varuna grown with basally applied 0, 40, 80 and 120 kg N ha−1 (Expt. 1) and 0,15, 30 and 45 kg P ha−1 (Expt. 2) on pod number per plant, seeds per pod, 1000 seed weight, seed yield, biological yield, harvest index and fatty acid composition of oil. No significant difference between water and GA3 spray was found when basally applied nitrogen was 0 or 40 kg N ha−1. N80 proved to be the best for yield characteristics. In another experiment on phosphorus, GA3 and 30 kg P ha−1 individually enhanced the yield, but interaction of GA3 and P remained non‐significant. The fatty acid composition of oil in both experiments was significantly affected only by nitrogen and phosphorus treatments for oleic acid and erucic acid. It was found that return in the form of yield was more for every kg applied fertilizer under GA, spray treatment. The response was more for N fertilizer in comparison to P. GA3 at a low level of fertilization significantly increased the return from fertilization.
Crop Management Effects on Pre‐and Post‐Anthesis Changes in Leaf Area Index and Leaf Area Duration and their Contribution to Grain Yield and Yield Components in Spring Cereals
Authors: Peltonen‐Sainio P. , Forsman K. , Poutala T.
Published: April 2008

Seasonal changes in leaf area index (LAI) and leaf area duration (LAD, i.e. LAI integrated over cumulated degree days) have a marked effect on crop productivity. Three case experiments were conducted at Suitia (60°11′N) and Viikki (60°13′N) Experimental Farms, University of Helsinki, Finland, to evaluate the possibilities of accelerating pre‐an thesis expansion of leaf area and modifying pre‐ and post‐anthesis LAD in spring cereals through crop management. Effects of time of incorporation of a green manure crop residue into the soil [conventional tillage (autumn ploughing and seed bed preparation in the spring), conservation tillage (sole spring tillage) with and without a green manure crop, common vetch (Vicia saliva I.)]and N fertilizer rate (0, 50, 100kg N ha−1) on LAI and pre‐ and post‐anthesis LAD in wheat (Triticum aestivum L.) were studied in exp I; green manuring (common vetch) and N fertilizer rate (0,40, 70,110,150kg N ha−1) in barley (Hordeum vulgare L.), oat (Avena sativa L.), and wheat in exp II; and foliar application of chlormequat chloride (CCC) and ethephon in oat lines (dwarf, naked, modern, landrace) differing in canopy structure in exp III. Time of incorporation of the green manure crop residues into the soil (exp I), green manuring (exp II), N fertilizer rate (exps I and II), and selection for crop growth type (exp III), but not CCC and ethephon, modified LAI and LAD in spring cereals by affecting the rate of pre‐anthesis expansion and post‐anthesis reduction in leaf area rather than by markedly prolonging the growth period. High rates of N fertilizer accelerated expansion of leaf area, especially prior to stem elongation, and resulted in high pre‐anthesis LAD due to enhanced tiller growth (exps I and II) and more tillers per main shoot (exp I). Green manuring increased leaf expansion from the tillering stage most when combined with high N rate, and especially in barley (exp II), but no such effects were found in exp I. Use of a high N fertilizer rate (exps I and II) and green manuring (exp II) also resulted in high post‐anthesis LAD. Such modifications enabled higher rates of grain‐ and head‐filling, and in exp I contributed to increased head weight and grain yield. Selection for inherent differences in growth type provided an additional possibility for manipulation of canopy structure and yield formation.
Effect of Alternative Cropping Systems on Yield and Advantage in Direct Seeded Upland Rice Areas in Indian Sub‐tropics
Authors: Sarkar R. K. , Chakraborty A. , Bala B.
Published: April 2008

An experiment was conducted during rainy season (April‐August) of 1994 and 1995 to assess the performance of rice, maize, sesame, greengram and blackgram grown in sole and intercropping system on Gangetic alluvial upland (Entisol) in West Bengal. India. All intercropping systems except sesame + rice had higher total productivity in terms of rice equivalent yield and net returns than all the sole crops. However, maximum advantage was obtained from paired row planted maize blackgram system followed by maize + sesame, maize + blackgram and paired row planted rice + blackgram. Paired row planted maize + blackgram increased land use efficiency (42%), rice equivalent yield (2955 kg ha−1), monetary return (Rs. 7294 ha−1), income equivalent ratio (1.22), monetary advantage (Rs. 3701 ha−1) compared with other cropping systems, which proved to be the most efficient system. The same treatment also indicated a modest competitive ratio (4.65:0.21) and gave a good value for the product of crowding coefficient (8.28).
Effect of Varied N‐fertilization on Yield Formation of Winter Wheat under Particular Consideration of Mainstems and Tillers
Authors: Maidl F.‐X. , Sticksel E. , Retzer F. , Fischbeck G.
Published: April 2008

Two‐year field trials with winter wheat in nine N‐fertilizer treatments were conducted in southern Bavaria to investigate the basis of yield stability and yield superiority of N‐fertilization strategies with emphasis on N‐application during stem elongation. In measurements of individual plants the contribution of mainstems and tillers to yield formation was examined. While grain yield showed only slight differences, significant differences between harvest indices were observed among the fertilizer treatments. High harvest indices were regularly recorded in low stand densities. Individual plant analysis proved that early N‐application led to high stand densities which intensified reduction processes during ear development. N‐fertilization with emphasis on stem elongation lessened reduction processes. Low yield of tillers was mainly attributed to a low grain number per ear. Differences in grain yield between mainstems and tillers could not be modified by means of N‐fertilizer treatment. Highest yields on mainstems as well as on tillers were recorded in N‐fertilizer treatment with emphasis on stem elongation. This study demonstrates that an excessive initiation of yield components causes an unproductive consumption of resources which is detrimental to yield formation. It is concluded that optimum N‐fertilizer treatment should aim at plant stands with strong individual plants which can be achieved by emphasis of N‐fertilization during stem elongation. The stimulation of the initiation of yield organs is of minor importance as compared to a decrease of reduction process.
Yield and Persistence from Mixtures of a Winter Hardy and a Verticillium Wilt Resistant Lucerne Cultivar
Authors: Stout D. G. , Acharya S. N. , Hall J. W. , Broersma K.
Published: April 2008

In British Columbia, Lucerne stand persistence is reduced by inadequate disease resistance, winter hardiness, or both. We evaluated the possibility that persistence could be improved by sowing mixtures of winter hardy and verticillium wilt (VW) resistant cultivars. Our hypothesis was that dry matter yield of mixtures of two Lucerne cultivars could be calculated simply from the proportion of each cultivar in the mixture and their yield in pure stand. A winter hardy cultivar, Beaver, was grown in mixtures with each of three VW (caused by Verticillium albo‐atrum Reinke & Berthier) resistant cultivars (WL316, Sparta, or Barrier) in proportions of 0, 0.25, 0.5, 0.75, and 1.0. The yield of a mixture of two cultivars could be calculated from the proportion of each cultivar in the seed mixture and their yields in monoculture. In the absence of a winter where severe injury to Lucerne stands occurred, the VW‐resistant cultivar Barrier yielded about 2 t ha−1 year−1 more than the more winter hardy Beaver.
Potassium Release from Soil Clays by Diammonium Phosphate, Ammonium Bicarbonate and Ammonium Chloride
Authors: Zia M. S. , Rahmatullah M. S. , Ali A.
Published: April 2008

We have studied the release of potassium (K) by diammonium phosphate, ammonium bicarbonate and ammonium chloride from Ca‐saturated clay fractions of four Aridisols (Bhalwal, Gujiana, Miranpur and Pacca series), one Inceptisols (Miani series) and one Alfisol (Pindorian series). The six soil clay fractions contained mica, kaolinite smectites as their major mineral components and vermiculite and chlorite as minor constituents. Total K in the soil clays ranged from 2.65 to 3.55%. Of total K, 2–3% in the soil clays was extracted by the three extractants: diammonium phosphate, ammonium bicarbonate and ammonium chloride. However, there was significant (P < 0.01) main and interactive effect of soil x extractant on the amount of K extracted from soil clays. Potassium extracted from the soil clays was described by the Elovich equation. Amount of K extracted by the three extractants from six soil clays, except in Pindorian series, followed the order: ammonium bicarbonate > ammonium chloride > diammonium phosphate.

The profound influence of bicarbonate, chloride and phosphate anions on differential K replacement behaviour of NH4can be an important factor for K nutrition of plants in arid region soils.
Effect of Nitrogen and Sulphur Application on Yield and Fatty acid Composition of Mustard (Brassica juncea L.) Oil
Authors: Joshi N. L. , Mali P. C. , Saxena Anurag
Published: April 2008

The effects of nitrogen and sulphur on the yield and fatty acid composition of mustard (Brassica juncea L.) oil were studied in a field experiment. Significantly higher grain and oil yields were obtained with N and S application. Applications of nitrogen up to 60 kg ha−1 and sulphur up to 40 kg ha−1 favourably influenced the grain yield. Increasing levels of N decreased the oil content while application of sulphur improved the oil content. The contents of linoleic and linolenic acid were maximum (16.82 and 8.73%, respectively) with 60 kg N along with 40 kg S ha−1. No use of fertilizers led to higher contents of undesirable fatty acids such as palmitic (hypercholesterimic) and erucic (do not have food value) acids.
Genistein and Daidzein Concentrations and Contents in Seedling Roots of Three Soybean Cultivars Grown under Three Root Zone Temperatures
Authors: Pan B. , Smith D. L.
Published: April 2008

Daidzein and genistein are plant‐to‐bacterium signal compounds involved in soybean nodule formation. They can induce nod gens expression in Bradyrhizobium japonicum. The objective of this study was to determine whether the production of signal molecules was affected by low root zone temperatures (RZTs) in a manner that varied among soybean cultivars. Daidzein and genistein concentrations of soybean seedling roots were measured at three RZTs by high performance liquid chromatography (HPLC). The results indicated that daidzein content and concentration per plant were higher at 15 and 17.5°C than those at 25°C. AC Bravor had higher daidzein contents and concentrations than did Maple Glen and KG20. At 17.5°C. KG20 had higher genistein content and concentration levels than Maple Glen, and no difference existed for the two cultivars at 15 and 25 C. Daidzein contents and concentrations of Maple Glen and AC Bravor increased with harvest time. However, for cultivar KG20, the content and concentration decreased at 19 days after inoculation. Genistein contents and concentrations of the three cultivars increased under each RZT up to the last harvest. There was an interaction between soybean cultivar and RZT for root genistein and daidzein contents and concentrations. The content and concentration of daidzein in soybean seedling roots were much higher (more than five times) than those of genistein.
Potential and Actual Yields of Potato at Different Elevations and in Different Seasons in Subtropical Southwest China
Authors: He W. , Struik P. C. , Wang J. , Zhang X.
Published: April 2008

Potential potato yields of nine spring and five autumn seasons at elevations ranging from 150 to 2650 m asl in subtropical China were assessed by a simple growth model and compared with attainable and experimental (actual) yields. Generally, both potential and actual yields were higher at higher elevation because of cooler temperatures and longer growing periods. The spring crops showed higher potential and actual yields but had lower light use efficiencies than the autumn crops, especially at higher altitudes. Specific relationships were given for relevant potential and attainable yields over altitudes and seasons. Light use efficiency declined with ascending elevation during the autumn season. The ratio actual: potential yields (range0.25–0.56) and the ratio actual: potential light use efficiency (range 0.34–0.70) were low because of drought stress, hot temperatures in the low elevations, presence of diseases and pests, low quality seed, and lack of adequate fertilization.
Growth and Yields of Cowpea (Vigna unguiculata (L.) Walp) as Influenced by Seed Characters, Soil Moisture and Season of Planting
Authors: Sangakkara U. R.
Published: April 2008

Cowpea (Vigna unguiculata L. Walp) is an important food legume grown under rainfed conditions in the tropics. However, the yield of this crop varies widely in most tropical ecosystems due to crop and environmental factors. Experiments were carried out to evaluate the effects of seed characteristics, soil moisture at planting and the season of crop establishment on growth and yield parameters of cowpea as these influence the productivity of the crop. Growth and yield of cowpea plants grown from small seeds with a high conductivity of their lea‐chates were significantly lower than those grown from large seeds. Root growth of seedlings was most prominent under moderate soil moisture levels. Low soil moisture retarded root growth by reducing dry weights and suppressing the development of laterals. Shoot growth was more sensitive to increasing soil moisture stress than root growth. Planting cowpea in the wet season produced the highest yields. Within a season, growth and yield were higher when the crop was planted early. Establishment of the crop later in the season produced better quality seeds measured in terms of germination after controlled deterioration.
Effect of Seed Soaking on Seedling Vigour, Growth and Yield of Rice
Authors: Jeyabal A. , Kuppuswamy G.
Published: April 2008

Studies were conducted over two years to evaluate the effect of seed soaking with biodigested slurry, zinc sulphate, Azospirillum, phosphobacteria and phytohormone in rice. The result of pot culture study showed that seed soaking in a combination of biodigested slurry. Azospirillum, phosphobacteria, zinc sulphate and phytohormone improved seedling characteristics such as plumule length, radicle length, biomass and seedling vigour. The N uptake increased by 11.8% at seedling stage (30th day). Soaking of seeds in a combination of nutrients enhanced the growth and yield attributes. Seed soaking in this combination of nutrients increased the grain yield by 8.8 % over unsoaked seeds. Uptake of N, P and K also enhanced by various soaking treatments. Uptake of zinc was not influenced by soaking treatments. The study indicated that seed soaking in a combination of organic, inorganic nutrient and biofertilizers is a good pre‐sowing technique for rice.
The Effect of Bradyrhizobium Strains on Monocropped and Intercropped Soybean (Glycine max L. Merr.) Biomass and Protein
Authors: Martin R. C. , Astatkie T. , Cooper J. M.
Published: April 2008

Intercropping soybeans with corn can produce yields of silage comparable to monocrops of corn but with a higher protein concentration. To maximize N2‐fixation by soybeans, it is important to use a strain of bradyrhizobium that is well adapted to local soil and climate conditions. In 1991 and 1992 an experiment was conducted in Truro, Nova Scotia, Canada, to compare a locally isolated bradyrhizobium strain. NS1 with a commercial strain (COM). Corn‐soybean intercrops and soybean monocrops were grown and various response variables were measured to assess the efficacy of each strain. NS1 proved to be superior to the commercial strain of bradyrhizobium in both intercrops and monocrops when soybean plant protein concentration, soybean seed protein concentration and soybean seed biomass yield were measured. For intercrop protein yield and intercrop protein concentration NS1 outperformed COM only in monocrops. Protein yields per hectare of soybeans grown in either system were higher when NS1 was used as an inoculant. No differences were observed between inoculants in biomass yields of soybeans grown in either system. Since soybeans only contributed 28.5% to the total biomass of intercrops, the biomass of the corn probably masked the differences between the two inoculants for intercrop protein yield and concentration. However, even under the stressful conditions for soybean plants associated with intercropping, soybean protein concentrations and yields when grown in intercrops were higher for the NS1 strain of bradyrhizobium. It appears that selection of a locally adapted strain of inoculant for soybeans can prove useful in both monocropping and intercropping systems.
Physiological Factors Limiting Grain Growth in Wheat Ears Cultured in Sucrose Solution
Authors: Arora A , Singh V. P.
Published: April 2008

Detached wheat ears (15 days post‐anthesis) were cultured in liquid nutrient medium containing different sucrose concentrations (2. 6 and 10%). The volume of solution taken up was highest from 2% sucrose solution and decreased with increasing sucrose concentration. Grain development in terms of grain weight, glumes and rachis weight, nitrogen and protein content showed a linear increase in these variables over 11 days. Dry weight per grain increased with the sucrose level in the medium and the reduced uptake of solution did not decrease the moisture percentage of the grain. The culture of ears decreased the solution pH more with 2% than with 10% sucrose. Addition of 0.5% chloramphenicol to the culture solution had no adverse effect on grain weight, rather it prevented contamination and maintained a higher pH of the solution.
Effect of Gibberellic Acid Spray during Ontogeny of Mustard on Growth, Nutrient Uptake and Yield Characteristics
Authors: Khan N. A. , Ansari H. R. , Samiullah
Published: April 2008

In a field trial conducted during 1993–1994, mustard (Brassica juncea L. Czern & Coss.) cv. Varuna was sprayed with either deionised water or 10−5 M GA3 at 40 (vegetative stage), 60 (flowering stage) or 80 (pod fill stage) days after sowing (DAS) to select the suitable growth stage for spray for augmenting productivity of the crop. Shoot length per plant, leaf number per plant, leaf area per plant, dry weight per plant and leaf area index and accumulation of N, P and K were recorded at 100 DAS. Pods per plant, seeds per pod, 1000 seed weight, seed yield, biological yield, harvest index and seed yield merit were computed at harvest. Growth, NPK accumulation and yield were maximal when spraying was done at 40 DAS. However, spraying at 40 and 60 DAS gave at par values for most of the growth and yield parameters. It was also noted that there was a significant difference in spray treatment at different growth stages only when G A, was sprayed and not when water was sprayed.
Wheat Seed Presoaking for Improved Germination
Authors: Ahmad Shahbaz , Anwar Muhammad , Ullah Hameed
Published: April 2008

Seed presoaking improves wheat germination under marginal moisture conditions. The duration of seed presoaking was studied at The University of Arid Agriculture, Rawalpindi, using 10 wheat varieties. Seed presoaking beyond 12 h does not improve germination further, and beyond 21 h, germination rate is drastically reduced.
Effect of Sowing Season and Seeding Rate on the Morphological Traits and Yields in Pea Cultivars of Differing Leaf Types
Authors: Uzun A. , Açikgöz E.
Published: April 2008

The effects of three seeding rates (25, 50, and 100 seeds m−2) on several morphological traits, and dry matter, seed and protein yields were evaluated in two leafed, two semi‐leafless and two tare‐leaved pea (Pisum sativum L.) cultivars, with fall and spring sowing for 3 years. The experiments were conducted under rain‐fed conditions in the Bursa Region of Turkey.

Sowing season, seeding rate and cultivar type had a significant effect on most of the measured traits and the yield determinants. The actual number of seedlings per unit area varied greatly among varieties, sowing seasons and climatic conditions during emergence. Fall sowings had taller plants, and more pods and seeds per plant. The number of tillers per plant usually increased with declining seeding rate. Semi‐leafless varieties had improved standing ability particularly at higher seeding rates and fall sowing conditions. The harvest index was higher for short strawed, tare‐leaved varieties than both leafed and semi‐leafless varieties. Harvest index was hardly affected by sowing season and seeding rate.

In general, fall sowings and the highest seeding rate produced the highest dry matter, seed and protein yields in all pea cultivars. The yields of spring sowings varied greatly, primarily depending on the amount and distribution of the spring rainfall. In the wet spring of 1993, dry matter, seed and protein yields from spring sowing was higher than those of fall sowings for all varieties. The semi‐leafless pea varieties, Countess and Niva, presented a clear advantage in the yield determinants under Bursa rain‐fed conditions.
Seed Size and Water Potential Effects on Water Uptake, Germination and Growth of Lentil
Authors: Al‐Karaki Ghazi N.
Published: April 2008

Seed size is an important parameter for plant growth and yield. The effects of seed size and water potential on seed water uptake, germination and early growth of lentil (Lens culinaris Medik. cvs. Jor‐1 and Jor‐2) were investigated. Rate of water uptake by seed size (small, medium and large) from solutions containing different water potentials (0, –0.5 and –1.0 MPa, as polyethylene gly‐col‐8000) was higher in large than in medium or small seeds of both cultivars, regardless of water potential. Rate of water taken into seeds was higher in Jor‐2 than in Jor‐1. Decreasing water potential (more stress) had adverse effects on rate of water uptake by seeds in both cultivars. In another experiment, with lentils grown in a greenhouse at different soil metric potentials (–0.03, –0.15 and –0.30 MPa), seed size or cultivar had no effects on germination percentage (GP), but GP was reduced as soil water potential decreased (more stress), in greenhouse soil, shoot dry matter (SDM), root dry matter (RDM), plant height, total root length (TRL) and number of primary branches per plant of 35‐day‐old plants from large seeds were larger than those of plants from medium and small seeds of both cultivars. Increasing soil water deficit progressively decreased each of these traits. Plants from large seeds had higher SDM, RDM and TRL than those from small seeds at intermediate soil water potential (–0.15 MPa) in comparison with the control (–0.03 MPa) or severe (–0.30 MPa) soil water potentials. Larger seeds produced larger plants than smaller seeds, and this appeared to be more pronounced under intermediate than well‐watered or more severe water‐stressed conditions. Faster early growth of plants from larger seeds may be advantageous in establishing plants under semiarid conditions.
Ein allgemeiner Ansatz zur Quantifizierung des Einflusses der Güte der Sätechnik auf den Flächenertrag
Authors: Hühn M.
Published: April 2008

A general approach to determine the effect of accuracy of sowing technique on yield per area

Caused by nonperfect seed placement accuracy of sowing machines as well as by many other abiotic and biotic factors the resulting plant stands exhibit nonregular plant distributions. Based on several simplifying assumptions a stochastic approach provides a quantitative determination of the effects of accuracy of sowing technique on yield per area. In this approach, two random variables are assigned to each individual plant: single plant yield E and single plant area A, which is calculated in this paper by the construction and quadrature of the so‐called Thiessen‐polygons. The yield per area F is calculated as the expectation of the ratio E/A. By assuming a deterministic mathematical relationship between E and A, the calculation of F reduces to the calculation of the expectation of a function of only one random variable A. A simple approximation with sufficient accuracy for many applications only depends on the mean and on the variance of the areas of the individual plants. For demonstration purposes, the theoretical approaches and results have been finally applied to three data sets for drilled seeds of winter oilseed rape (plant density: 60 plants/m2 and distance between rows: 10 cm). These data sets exhibit different accuracies of the longitudinal distributions within rows which have been quantitatively measured by the coefficient of variation for the distances between plants within rows: Yield depression increases with an increasing variability of plant distances within rows.
Effect of Nitrogen and Phosphorus Levels on Barley Cultivars Grown in Semi‐arid Conditions
Authors: Turk M. A.
Published: April 2008

Most farmers in the rainfed parts of Jordan who use fertilizers use less than optimum rates of N and P because of the uncertainties associated with rainfall. Research results obtained by the national program indicated that the use of improved barley cultivars and fertilizers would result in substantial yield increases. The objective of the present investigation was to determine the optimum combination level of N and P for newly promising cultivars. The effect of 0–0, 5–10, 10–20 and 15–30 kg.ha−1 of nitrogen (N) and phosphorus (P) levels on barley cultivas Rum, Giza, Fun, Harmel and Arta under rainfed conditions in the Mediterranean climate was studied during two cropping seasons, 1994‐95 and 1995–96. Increased grain and straw yields, total N and P uptake and RUE were recorded with increasing N and P levels for almost all cultivars. Rum was significantly (P = 0.05) the highest grain and straw producer and highest RUE at the 10 N‐ and 20 P kg.ha−1 level. The cultivar × fertility level (N–P) interactions were not significant for both grain and straw yields and for total N and P uptake.
Rapid and Synchronous Germination of Cicer Milkvetch (Astragalus cicer L.) Seed following Diurnal Temperature Priming
Authors: Stout Darryl G.
Published: April 2008

Experiments were conducted to determine if diurnal temperature variation could be used to prime cicer milkvetch (Astragalus cicer L.) seed and thereby shorten the time for seed germination. For untreated cicer miikvetch seed at constant 20°C, 50% of the seeds germinated in 8.2 days and 90% of the seeds germinated in 10.5 days. In contrast, seed that was first primed for 7 days with a diurnal temperature variation (35 (8h)/5 (16h) °C) had values of 1.9 days and 3.3 days, respectively. A second experiment evaluated priming of seed in bulk to test if a procedure might be developed that could be scaled up to prime commercial quantities of seed. A bulk sample of seed was soaked in water for 5h at room temperature and then kept in a high humidity atmosphere during 7 days of priming at 35/5°C. Hydrated seed from the bulk sample had 50% germination in 2.7 days and 90% germination in 5.3 days. When the bulk sample was dried for 8 days at room temperature, the benefit of priming on shortening germination time was retained. It is likely that diurnal temperature priming could be adapted to large volumes of seed.
Methods for Comparing the Yield Stability of Cropping Systems
Authors: Piepho H.‐P.
Published: April 2008

The stability of yield is an important characteristic to be considered when judging the value of a cropping system relative to others. In the context of agricultural research, the analysis of yield stability has been largely confined to multienvironment trials of crop cultivars. This review emphasizes that methods for comparing the stability of cultivars can also be used for comparing different agronomic treatments in general, of which cultivars are but a special case. Throughout the paper, different agronomic treatments are referred to as cropping systems. Some of the methods useful for stability analysis of cropping systems are discussed and a brief review of applications of these methods is given. The paper puts different stability measures into a unifying mixed model perspective.
Calculation of Optimal Fertilizer Rates: A Comparison of Three Response Models†
Authors: Olness A. , Evans S. D. , Alderfer R.
Published: April 2008

Determination of optimal N‐fertilization rates, NOR, for crop production that minimize risk of environmental degradation require accurate application of a response model. Several models are available to describe crop yield response to N fertilization. The objective of this work was to compare the relative accuracy of a quadratic, f(NQ), a modified Mitscherlich, and tanh(N) models on 48 data sets. Data were collected from a Tara silt loam (fine‐silty, mixed, frigid Pachic Udic Haploboroll) over a 6‐year period using two maize (Zea mays L.) hybrids and four tillage treatments, mouldboard plough, chisel plough, ridge tillage and no‐tillage. In about one‐third of the cases, all models performed about equally well. Generally, the tanh(N) and modified Mitscherlich models gave better fit between N rate and grain yield data. The NOR, ranged from about 140 to 170 kg ha−1 for the modified Mitscherlich model, 136 to 184 kg ha−1 for the tanh(N) function, and 124 to 173 kg ha−1 using the f(NQ) model. Estimated grain yields at these rates ranged between 6.58 ± 1.30 to 7.59 ± 1.69 Mg ha−1 for the 90‐day Minnesota maturity rated (MR) hybrid and between 7.52 ± 2.40 to 8.72 ± 1.70 Mg ha−1 for the 95‐day MR hybrid.
Accumulation of Zinc and Molar Ratio of Phytic Acid and Zinc during Maize Grain Maturation
Authors: Horvatić M. , Gačć M. , Filajdić M.
Published: April 2008

Dynamics of the accumulation of total ash and zinc, and their relationships with total dry matter, crude proteins and phytic acid during maize grain maturation were investigated. The investigation was carried out on normal maize hybrids grown under the same topographical and agrotechnical conditions over two consecutive vegetation years.

The amount of total ash, expressed on fresh and dry matter bases, changed significantly (P = 0.05 and P = 0.01) during grain maturation depending on maturity stage and variety. The dynamics of the accumulation of ash in fresh grain matter during maturation as well as the ash amount in dry matter of mature grains were significantly affected by environmental conditions.

The accumulation of zinc in fresh matter of developing grain was significantly affected (P = 0.05 and P = 0.01) by the degree of grain maturity and by variety, and correlates significantly (P = 0.001) and positively with the deposition of total dry matter, crude proteins as well as with phytic acid in both vegetation years.

The molar ratio of phytic acid and zinc increased significantly during grain maturation indicating a possible decrease of zinc availability.
Osmotic Adjustment in Maize (Zea mays L.): Changes with Ontogeny and its Relationship with Phenotypic Stability
Authors: Lemcoff J. H. , Chimenti C. A. , Davezac T. A. E.
Published: April 2008

Genetic variation for osmotic adjustment was examined in a group of maize hybrids during vegetative and silking stages. Estimates of osmotic adjustment were derived from measurements of leaf relative water content (RWC) and osmotic potential (Ψo) before day‐break. The degree of adjustment was estimated from the In RWC/In Ψo relationship. All cultivars examined showed some degree of osmotic adjustment and significant differences (P < 0.05) were found among them. The utility of measurements in early vegetative stages as a mean of selection for osmotic adjustment in silking stage was established. A positive tendency was observed between osmotic adjustment and phenotypic stability.
Interactive Effects of Salinity and Biological Nitrogen Fixation on Chickpea (Cicer arietinum L.) Growth
Authors: Zurayk R. , Adlan M. , Baalbaki R. , Saxena M. C.
Published: April 2008

The effect of salinity on the nodulation, N‐fixation and plant growth of selected chickpea‐Rhizobium symbionts was studied‐ Eighteen chickpea rhizobial strains were evaluated for their growth in a broth culture at salinity levels of 0 to 20 dS m−1 of NaCl + Na2SO4. Variability in response was high. Salinity generally reduced the lag phase and/or slowed the log phase of multiplication of Rhizobium. Nine chickpea genotypes were also evaluated for salt tolerance during germination and early seedling growth in Petri dishes at five salinity levels (0–32 dS m−1). Chickpea genotypes ILC‐205 and ILC‐1919 were the most salt‐tolerant genotypes. The selected rhizobial strains and chickpea cultivars were combined in a pot experiment aimed at investigating the interactive effect of salinity (3, 6 and 9 dS m−1) and N source (symbiosis vs. inorganic N) on plant growth. Symbiotic plants were more sensitive to salinity than plants fed mineral N. Significant reductions in nodule dry weight (59.8 %) and N fixation (63.5 %) were evident even at the lowest salinity level of 3 dS m‐1. Although nodules were observed in inoculated plants grown at 6 dS m‐1, N‐fixation was completely inhibited. The findings indicate that symbiosis is more salt‐sensitive than both Rhizobium and the host plant, probably due to a breakdown in one of the processes involved in symbiotic‐N fixation. Improvement of salinity tolerance in field grown chickpea may be achieved by application of sufficient amounts of mineral nitrogen.
Short‐ and long‐term patterns of sponge diversity on a rocky tropical coast: evidence of large‐scale structuring factors
Authors: Carballo Jose Luis , Vega Cristina , Cruz‐Barraza José Antonio , Yáñez Benjamin , Nava Héctor , Ávila Enrique , Wilson Miroslava
Published: April 2008

The importance of a long‐term ecological perspective is well documented, yet long‐term data are not widely available. This paper represents the first quantitative description of sublittoral sponge assemblages over long temporal scales (6 years) along the coast of the East Pacific Ocean (Mazatlan Bay), with the goal of describing their levels of intra‐ and inter‐annual variability, and their relationship to changing environmental conditions. It was possible to detect an apparent short‐term pattern (intra‐annual), with a highly diverse and stable structure, usually in the drought season, which was consistent most of the years. However, only a few species showed regular (predictable) seasonal cycles. The species per square meter (from 0.1 to 0.5), total species per sampling (14–21), and H’ diversity using loge (1.4–2) also fluctuated greatly between years, suggesting that although a consistent short‐term pattern was found most of the years, the inter‐annual variability was also high. The univariate and multivariate results and regression models indicated that local winds played a key role in this short‐term pattern (intra‐annual). During the rainy season, or during the transition between the drought and rainy season, the winds coming from the southwest (WSW) produced an increase in the net sediment movement, which was an important factor for diversity. The long‐term fluctuations (annual pattern of diversity) also correlated positively with wind speed (88% of the variance observed) and with sediment deposition (69% of the variance observed). In addition, the results indicated the existence of large‐scale structuring factors, as the annual pattern of diversity also was correlated positively with the Southern Oscillation (SOI) and Multivariate ENSO (MEI) indices (82% and 88% of the observed variance, for MEI and SOI, respectively). In conclusion, this study suggests that sponge assemblages in Mazatlán Bay are extremely dynamic, and changes in this community are associated with processes that occur over the short‐ and long‐time scales (several months to several years). The significant positive relationship between wind speed and sediment deposition showed that the main factors controlling the diversity in these shallow rocky ecosystems are the winds and the swell. A high proportion of coarse sand also indicated a very high energy in the environment, which, combined with the effect of silting, abraded and removed sponges and other organisms. These features contribute to the instability of the community by producing dramatic fluctuations in species abundance and preventing competitive processes from producing a more stable community.
TOPICAL OXYGEN THERAPY INDUCES VASCULAR ENDOTHELIAL GROWTH FACTOR EXPRESSION AND IMPROVES CLOSURE OF CLINICALLY PRESENTED CHRONIC WOUNDS
Authors: Gordillo Gayle M , Roy Sashwati , Khanna Savita , Schlanger Richard , Khandelwal Sorabh , Phillips Gary , Sen Chandan K
Published: April 2008

Chronic wounds, especially in diabetics, represent a serious threat to human health.

Correcting a compromised state of tissue oxygenation by the administration of supplemental O2 is known to benefit wound healing. Beyond its role as a nutrient and antibiotic, O2 supports wound healing by driving redox signaling.

Hyperbaric oxygen (HBO) therapy is widely used and approved by Center for Medicare and Medicaid Services to treat specific ulcerations. The current literature supports the notion that approaches to topically oxygenate wounds may be productive.

Here, we present the results of two simultaneous studies testing the effects of HBO and portable topical oxygen (TO) therapies. These two therapeutic approaches have several contrasting features.

In total, 1854 patients were screened in outpatient wound clinics for non‐randomized enrolments into the HBO (n = 32; 31% diabetic) and TO (n = 25; 52% diabetic) studies.

Under the conditions of the present study, HBO treatment seemed to benefit some wounds while not benefiting others. Overall, HBO did not result in statistically significant improvements in wound size in the given population over the time monitored in the present study.

However, TO significantly improved wound size. Among the three O2‐sensitive genes (VEGF, TGFb1 and COL1A1) studied in wound edge tissue biopsies, TO treatment was associated with higher VEGF165 expression in healing wounds. Expression of the other genes mentioned was not affected by TO. There was no significant change in the expression levels of any of genes studied in patients in the HBO study. This establishes a link between VEGF gene expression and healing outcome for TO therapy.

Taken together, the present study provides evidence demonstrating that TO treatment benefits wound healing in patients suffering from chronic wounds. Treatment with TO is associated with an induction of VEGF expression in wound edge tissue and an improvement in wound size.
ELEVATED CATALASE AND HEME OXYGENASE‐1 MAY CONTRIBUTE TO IMPROVED POSTISCHAEMIC CARDIAC FUNCTION IN LONG‐TERM TYPE 1 DIABETES
Authors: Shen Wei‐Li , Zhong Mei‐Fang , Ding Wen‐Long , Wang Jian , Zheng Lin , Zhu Ping , Wang Bing‐Shun , Higashino Hideaki , Chen Hong
Published: April 2008

Although increased oxidative stress has been shown repeatedly to be implicated in diabetes, the cardiovascular anti‐oxidant state and heart response to ischaemia in long‐term Type 1 diabetes remain largely unknown. The present study was designed to observe heart tolerance to ischaemia–reperfusion and endogenous anti‐oxidants in the cardiovascular system in long‐term hyperglycaemic rats.

Hearts from Sprague‐Dawley rats surviving up to 6 months with streptozocin‐induced severe hyperglycaemia (blood glucose > 20 mmol/L) were isolated and subjected to global ischaemia and reperfusion. Cardiac function, electrocardiogram and anti‐oxidants in the myocardium and aorta were examined. In addition, the morphology of the myocardial mitochondria and the in vitro function of aortic vessels were assessed.

Hearts from diabetic rats demonstrated lower baseline heart function but had higher postischaemic coronary flow and left ventricular developed pressure compared with their respective controls (P < 0.05). In addition, hearts from diabetic animals had fewer arrhythmias (P < 0.01) and lower left ventricular end‐diastolic pressure during reperfusion (P < 0.05). Higher catalase and heme oxygenase‐1 content was found in the aorta and myocardium from diabetic rats (P < 0.01). In aortas from diabetic animals, acetylcholine‐induced vasodilatation was enhanced and was approximately 15% after inhibition of nitric oxide synthase, comapred with 0% in controls. The 15% relaxation was abrogated by heme oxygenase blockade. Mitochondria from the myocardium of diabetic rats showed significant increases in both size and number (P < 0.05).

Hearts of long‐term Type 1 diabetic rats demonstrated improved recovery of postischaemic cardiac function and reduced reperfusion arrhythmia. Hyperglycaemia may enhance cardiovascular anti‐oxidant capacity and mitochondrial neogenesis, which renders the heart resistant to ischaemia and oxidative injury.
N‐ACETYLCYSTEINE PREVENTS BUT DOES NOT REVERSE DEXAMETHASONE‐INDUCED HYPERTENSION
Authors: Krug Susanne , Zhang Yi , Mori Trevor A , Croft Kevin D , Vickers Janine J , Langton Leanne K , Whitworth Judith A
Published: April 2008

We have shown previously that N‐acetylcysteine (NAC) prevents the increase in blood pressure induced by adrenocorticotropin treatment. The present study investigated the effect of NAC on dexamethasone (Dex)‐induced hypertension.

Male Sprague‐Dawley rats were randomly divided into six groups (n = 10 in each). In a prevention study, NAC (10 g/L in the drinking water) was given for 4 days prior to and 11 days during concurrent treatment with saline (0.1 mL/rat per day) or with Dex (10 mg/rat per day). In a reversal study, daily injections of Dex or saline began 8 days before NAC and cotreatment continued for 5 days. Systolic blood pressure (SBP) was measured on alternate days using a tail‐cuff system.

Dexamethasone significantly increased SBP from 113 ± 4 to 139 ± 6 mmHg (n = 10; P < 0.01). N‐Acetylcysteine alone had no effect on SBP. In NAC + Dex‐treated rats, SBP was significantly lower than that of Dex‐treated rats (P¢ < 0.01). In fully established Dex‐hypertension NAC was ineffective and SBP remained high.

Both Dex and NAC treatments decreased bodyweight gain. N‐Acetylcysteine reduced food and water consumption. Dexamethasone reduced thymus weight (P¢ < 0.01) but NAC treatment did not alter this marker of glucocorticoid activity.

Dexamethasone tended to decrease plasma NOx, whereas NAC restored plasma NOx concentrations to control levels. N‐Acetylcysteine had no effect on Dex‐induced increased plasma F2‐isoprostane concentrations.

In conclusion, NAC partially prevented, but did not reverse, Dex‐induced hypertension.
Relationship between testicular size by ultrasonography and testicular function: Measurement of testicular length, width, and depth in patients with infertility
Authors: Sakamoto Hideo , Yajima Takatoshi , Nagata Masakazu , Okumura Taisuke , Suzuki Kohta , Ogawa Yoshio
Published: April 2008

Objectives:  The relationships between simple testicular sizes, including the testicular length, width, and depth and testicular function were evaluated to determine the usefulness of measuring these simple parameters.

Methods:  The mean of right and left testicular length, width and depth were measured in 408 men with infertility (mean age, 35.9 ± 5.3 years) using ultrasonography. The ultrasonographic testicular volumes were calculated as the length x width x depth x 0.71. To evaluate the relationship between the testicular size and function, the patients were divided into seven to ten groups according to each testicular size parameter.

Results:  The mean testicular volume, length, depth, and width were 13.4 ml, 3.86 cm, 1.80 cm, and 2.59 cm, respectively. These three testicular dimensions significantly correlated with sperm density, total sperm count, total motile sperm count, serum follicle‐stimulating hormone and luteinizing hormone equal to ultrasonographic testicular volume. The mean sperm density was in the oligozoospermic range in patients with a mean testicular volume below 10 ml, a mean length below 3.5 cm, a mean depth below 1.75 cm, and a mean width below 2.5 cm. The mean total sperm count was subnormal in patients with a mean testicular volume below 10 ml, a mean length below 3.5 cm, a mean depth below 1.5 cm, and a mean width below 2.25 cm.

Conclusions:  The testicular length, width, and depth measured by ultrasonography significantly correlated with the testicular function as well as the ultrasonographic testicular volume. A simple measurement of the testicular length, width, and depth is useful for evaluating the testicular function.
Catheterization: Possible complications and their prevention and treatment
Authors: Igawa Yasuhiko , Wyndaele Jean‐Jacques , Nishizawa Osamu
Published: April 2008

Abstract:  Intermittent catheterization (IC) is a more preferable method for bladder drainage than indwelling urethral or suprapubic catheterization. Several complications with IC have been described, however, including urinary tract infection, genital infection, urethral bleeding, urethritis, urethral stricture, and bladder stones. To prevent these complications, patients should be well instructed on the technique and the risks of IC. Indwelling catheterization should be used only exceptionally, under close control and the catheter should be changed with adequate frequency.