bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physiological Basis of Yield Variation in Short‐duration Pigeonpea Grown in Different Environments of the Semi‐Arid Tropics1
Authors: Chauhan Y. S. , Johansen C. , Saxena K. B. 
Published: April 2008

AbstractFive short‐duration pigeonpea (Cajanus cajan (L.) Millsp.) genotypes were grown at three plant populations in three locations during the 1986 and 1988 rainy seasons, to determine the physiological basis of observed variations in yield. Significant differences were found in seed yield (Y), crop growth rate (C), and the durations of vegetative (Dv) and reproductive (Dr) growth, and partitioning (P). These were attributable to genotypes and their interactions with environments (except for C). Variation in C, Dr, and P together explained 78 % of the observed variation in Y due to different genotypes and environments. Crop growth rate alone contributed about 71 % of the variation in Y, and reached an optimum value of around 6.5 kg ha−1°Cd−1. Crop growth rates increased with the duration of the vegetative period and with plant population. However, a negative relationship between C and P resulted in plant population having little effect on seed yield. The maximum‐yielding genotype, ICPH 8 had the highest C and an intermediate P.
Effect of Seeding Rate on Seed and Hay Yield in Common Vetch (Vicia sativa L.)
Authors: Aydoǧdu L. , Açikgöz E. 
Published: April 2008

AbstractThe effects of six seeding rates (50‐300 seeds m−2:) on some morphological traits with hay and seed yield were evaluated in common vetch (Vicia sativa L.) under fall and spring sowing conditions. The mutual correlations among yield and yield components were also determined.The sowing seasons and seeding rates significantly affected hay and seed yield, and most of the yield components. Fall sowings resulted in significantly higher hay and seed yield than spring sowings at all seeding rates, and the highest seed and hay yield was achieved in densities of 250 and 300 seeds m−2. In spring sowings there was a positive response in hay yield up to 250 seeds m−2 while no further increase in seed yield at the seeding rates higher than 150 seeds m−2. Average protein content of hay and seed was found to be higher in spring sown crops than fall. The highest protein yields of hay and seed were obtained at 250 seeds m−2 in fall sowings, and 150 seeds m−2 in spring sowings.Most of the correlations between both hay and seed yields with the yield components were not consistent and differed with the sowing time. Only the correlations between number of the plants per unit area with hay yield, and number of the pods and seeds per unit area with seed yield were statistically significant in both sowing seasons. Close positive associations were obtained between hay and seed yield.
Growth dynamics of winter wheat in the field with daily fertilization and irrigation
Authors: Flink M. , Pettersson R. , Andrén O. 
Published: April 2008

AbstractIn a field experiment with fertilized and irrigated winter wheat the above‐ground crop was sampled once a week. Phenological development, plant density and canopy height were recorded and the green surface areas of leaves, stems and ears were measured. Soil mineral nitrogen was sampled and the field climate monitored. There were four treatments. The daily irrigated/fertilized (IF) and daily irrigated (I) treatments were both irrigated by a drip‐tube system. Liquid fertilizer was applied to IF following a logistic function according to calculated plant uptake. A total of 200 kg N ha−1 was applied. Treatment I, control (C) and drought (D) were all fertilized once in spring with 200 kg N ha−1. In treatment D transparent screens were used to divert rainwater. Dry matter production ranged between 1400 in D and 2352 g m−2 in IF. The corresponding amount of nitrogen uptake ranged between 15.8 and 24.6 g m−2. After harvest, soil mineral nitrogen was lowest in IF.An increase in the availability of nitrogen and water enhanced total biomass production as well as grain yield and leaf area. The daily supply of nitrogen according to crop demand delayed nitrogen uptake and increased total uptake. The results suggest that when the nitrogen is supplied in accordance with crop demand, the efficiency with which the applied fertilizer is utilized increases and the risk for nitrogen leaching decreases.
Light Interception, Leaf Area Index and Dry Matter Yield in Fodder Sorghum at Different Plant Populations
Authors: Bhatt R. K. 
Published: April 2008

AbstractFodder sorghum (M. P. Chari) was grown at varying populations to examine its influence on light interception, leaf area index and biomass production. DMY, CGR and IPAR depending on LAI reached maximum at LAI 5 of 150 000 plants ha−1 stand and thus yielded higher biomass. Therefore, physiological potential of fodder sorghum crop was found to be maximum at a population density of 150 000 plants ha−1. Further increases in population developed mutual shading and adversely affected the crop growth rate and dry matter accumulation. Significant linear relationships of dry matter yield with IPAR, plant population densities, LAI and CGR clearly indicate the interdependence of these characters.
Correlation and Path Coefficient Analysis for Ear Characters in Triticale Under Mediterranean Climatic Conditions
Authors: Yaǧbasanlar T. , ÖZkan H. 
Published: April 2008

AbstractIn this study, the correlation and path coefficients between ear characters and grain yield per plant were determined in triticale under Mediterranean climatic conditions.Weight of grains per ear and number of ears per plant were the most important direct components of yield. Characters like ear length and the number of spikelets per ear were not found to be the important component characters of grain yield. It could be concluded that among ear characters in triticale, the number of ears per plant and the weight of grains per ear are the most important yield contributing characters and these characters should get due consideration in future triticale breeding programmes.
Interference Effects in Grass Varieties Grown as Pure Stand, Complex Mixture and Binary Mixture with White Clover
Authors: Piano E. , Annicchiarico P. 
Published: April 2008

AbstractThe study aimed at: i) assessing the agronomic value of the pure stand (PS), of the complex mixture (CM) and of the binary mixture with each of six white clover genotypes (MWC) of eight grass varieties belonging to four species and contrasting for earliness of flowering; and ii) investigating the relationships of competitive abilities in CM and MWC with some morpho‐physiological traits of the grass varieties. CM showed a 24 % dry matter yield (DMY) advantage over mean value of PS but did not outyield the pure stand of the best yielding component. For grass‐white clover associations, the DMY advantage as Relative Yield Total over PS of the components averaged 43 %. DMY of the grass varieties averaged across MWC conditions was related positively to total DMY (r = 0.99) and negatively to associated clover DMY (r = ‐ 0.96). Competitive abilities as Relative Yield of the grass varieties in CM and in MWC correlated (r = 0.84) and were both positively associated to DMY, canopy height and inclination of leaves in PS. The results suggested that association of white clover with a grass of moderately high vigour, intermediate earliness and relatively erect leaves may provide the best option for rotational meadows in the experiment environment.
Using a Chlorophyll Meter to Optimize Nitrogen Fertilizer Application for Intensively‐Managed Small‐Grain Cereals
Authors: Peltonen J. , Virtanen A. , Haggrèn E. 
Published: April 2008

AbstractMost methods used to estimate N status require collection, processing and analysis of soil and/or plant tissue samples. In this study, leaf chlorophyll content of cereals, determined in the field with a portable chlorophyll meter (Minolta SPAD‐502), was used to predict N availability of wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), oats (Avena sativa L.) and rye (Secale cereale L.). The results indicated that accurate nitrogen (N) fertilizer recommendations based on chlorophyll content have both environmental and economic advantages. Determination of leaf chlorophyll content with a chlorophyll meter accurately indicated plant N status allowing N fertilizer requirement to be accurately determined and resulting in increased N uptake efficiency. Applying N fertilizer on this basis improved production economics and improved physical input‐output ratio during grain yield formation. Using a chlorophyll meter, responsive and non‐responsive categories can be determined at the stage of maximum number of florets per ear primordium (Zadoks' GS 37‐41) and at pollination (i.e. pollen grains on well‐developed stigmatic hairs, GS 52‐58).
Nitrogen Fertilizer Rate and Timing Effect on Bread Wheat Protein in Eastern Canada
Authors: Ayoub Micheline , Guertin S. , Smith D. L. 
Published: April 2008

AbstractNitrogen management for production of bread quality wheat (Triticum aestivum L.) in eastern Canada has received little research attention. An experiment was conducted for 2 years at each of two sites in Québec to study the effect of level and timing of nitrogen (N) fertilizer application on grain protein concentration, protein content per seed, non‐protein seed dry matter, grain protein yield and nitrogen harvest index (portion of plant N in the grain) of four hard red spring wheat cultivars known to have potential as bread wheats in eastern Canada. The soil types were Bearbroock clay (fine, mixed, non‐acid, frigid, Humaquept) and Ste‐Rosalie clay (typic, non‐acid, frigid, Humaquept). The experiment was a 4 × 4 × 2 factorial. Four cultivars were used: Columbus, Katepwa, Max and Hege 155–85. In both years 0, 60, 120 and 180 kg Nha−1 were applied either all at seeding or 60 % at seeding and 40 % at heading. Grain protein concentration and grain protein yield increased consistently with increasing N fertilizer and with split N application. Nitrogen harvest index was not increased by increasing applications of N fertilizer. Protein content per seed was more critical in determining grain protein concentration than non‐protein seed dry matter content. The western Canadian cultivars Columbus and Katepwa generally had greater grain protein concentration than the European cultivars Max and Hege 155–85, With reasonable N fertility the grain protein concentration of spring wheats grown in eastern Canada are sufficient for bread production.
Nitrogen Requirements at Different Growth Stages of Short‐duration Pigeonpea (Cajanus cajanL. Millsp)1
Authors: Kumar Rao J. V. D. K. , Johansen C. , Usha Kiran M. 
Published: April 2008

AbstractThe response to N fertilization of a short‐duration pigeonpea genotype, ICPL 87, was studied in the field to assess the scope for genetically improving symbiotic N2fixation by pigeonpea. The field study was undertaken during 1985, 1986 and 1987 growing seasons on Vertisol and Alfisol at ICRISAT Center (peninsular India), Inceptisol at Gwalior (central India) and Entisol at Hisar (northern India) in as non‐limiting environmental conditions as possible. Nitrogen fertilizer was applied to the soil at various growth stages to determine when N becomes most limiting. There was a significant response in grain yield to fertilizer N applied at flowering in Vertisol but not in Alfisol, Inceptisol or Entisol. This suggests that biological N2fixation by short‐duration pigeonpea was not adequate to meet N requirements of the crop grown in Vertisol but that it was probably adequate in the other three soil types. These results are discussed in relation to the nodulation and acetylene reductase activity of pigeonpea and also N mineralization potential of different soils. It can be concluded that there is a need for genetic improvement of N2fixing ability of short‐duration pigeonpea grown on heavy textured soils such as Vertisols.
The Effect of Different Shade Levels on Growth and Tuber Yield of Sweet Potato: II. Tuber Yield
Authors: Oswald A. , Alkämper J. , Midmore D. J. 
Published: April 2008

AbstractEight sweet potato cultivars (Ipomoea batatas Lam.) were grown under four different light regimes (0, 26, 42 and 60 % light reduction (LR)) at two experimental sites of the International Potato Center (CIP) in Peru during the 1990 and 1991 growing season. Increasing shade diminished the tuber yield of five cultivars, two showed a tolerance for slight (26 % LR) and moderate (42 % LR) shade and one had the same yield in full sunshine and slight shade. Shade mainly reduced the sink‐size (tubers m −2) of sweet potato and to a lesser extent the sink‐strength. The growth of the plant top was hardly affected by shade; slight shade even favoured shoot development of some cultivars. The plant top was the stronger sink under shade conditions and tuber yield was not only reduced by lesser assimilate production as a whole but also by an altered assimilate partitioning.
Pod, Seed and Germination Characteristics of Selected Cardamom (Elettaria cardamomum (Linn.) Maton) Varieties
Authors: Sangakkara U. R. 
Published: April 2008

AbstractCardamom is a popular and important tropical spice, traditionally propagated by rhizomes, although seeds which are considered recalcitrant are being increasingly used in planting programmes. Thus a study evaluated the effects of pod maturity on pod, seed and germination characteristics of three popular varieties, along with the influence of drying on seed germinability.Green and yellow mature pods and seeds of all varieties had a high moisture content. The variety Mysore, which is considered high yielding, had larger pods with a greater number of heavy seeds. Although the pods of Vazukka were heavier than the Malabar variety due to greater seed weights, seed numbers were similar in both varieties. Seed moisture contents declined with increasing pod maturity, while seed weights and germinability increased.The germinability of Mysore seeds were greater, while that of the other varieties were lower. The larger seeds of all varieties germinated 15–20 days earlier, giving rise to a greater percentage (20–25 %) of seedlings. Desiccation at 20 °C maintained germinability for a longer period (5–9 days) in all varieties, than when dried at 30 °C. The seeds of the variety Mysore was more tolerant to desiccation than other varieties. The study illustrated the importance of selecting large seeds from yellow mature pods of cardamom for propagation and the value of establishment immediately after harvest to obtain a greater number of seedlings.
Transferability of Chickpea Selection Indices from Normal to Drought‐prone Growing Conditions in a Mediterranean Environment*
Authors: Singh K. B. , Bejiga G. , Saxena M. C. , Singh M. 
Published: April 2008

AbstractChickpea (Cicer arietinum L.) is normally grown as a spring‐sown rainfed crop in the Mediterranean region in areas receiving more than 400 mm of rainfall annually. Because of large fluctuations in the total amount and distribution of the rainfall, the crop occasionally suffers from extreme terminal drought. Breeders face a dilemma in selecting materials for both normal moisture regimes and drought conditions because it is often difficult to conduct two parallel breeding programmes. This study examines the transferability of the selection indices (developed as a multiple regression of yield on most influential traits) from one environment to another with the objective of selecting an appropriate environment for the development of cultivars adapted to both environments. Experiments were conducted for 3 years (1989‐1991) during the spring at two locations with normal moisture regime (hereafter referred to as drought‐free) in Syria and Lebanon and one drought‐prone location in Syria. Each year, 192‐240 newly bred lines were evaluated in replicated trials for seed yield, days to flowering and maturity, plant height and 100‐seed weight. Correlation analyses showed that increased seed size, early maturity and reduced plant height at the drought‐prone location and early maturity at the drought‐free location were of prime importance in increasing seed yield. Regression equations developed to predict seed yield showed that days to flower and maturity accounted from 67‐80 % variation in seed yield at the dry location, whereas at the drought‐free locations the contribution of days to maturity was smaller except in 1991 in Lebanon. The percent success in the transferability of the selection indices from the drought‐free environments to the drought‐prone environment was higher than that from the drought‐prone environment to the drought‐free environment. These results indicate that chickpea breeding material developed under drought‐free environments could be useful under drought‐prone conditions. Early‐maturing lines selected under normal environments would also perform well under drier conditions.
Notes on the Variance of Relative Yield as a Measure of Stability
Authors: Hühn M. 
Published: April 2008

AbstractThe actual yields from multilocation variety trials are commonly analysed as a two‐way table (rows = varieties, columns = locations) of mean yields. In this paper, relationships between the recently proposed new stability parameter ‘variance of relative yield’ and the two stability parameters of the ‘classical’ joint regression approach in stability analysis, are investigated. The variance of relative yield as a measure of stability exhibits an undesirable dependence on the mean yield of the respective variety. Generalizations and improvements of some recent results and conclusions of Piepho (1994) are discussed.
Do Increasing Atmospheric CO2 Concentrations Contribute to Yield Increases of German Crops?
Authors: Manderscheid R. , Weigel H. J. 
Published: April 2008

AbstractThe global atmospheric CO2‐concentration is increasing and there has been an increase in Germany of about 30 ppm from 340 ppm to 370 ppm CO2 during the last two decades. The hectare yield of many crops has also increased during this time period. The objective of the present study was to estimate whether the past and future change in the atmospheric composition significantly contributes to the increase in hectare yield.Different crop species (beans, Phaseolus vulgaris, cv Pfälzer Juni; spring barley, Hordeum vulgare L., cvs. Alexis and Arena; spring wheat, Triticum aestivum L., cvs. Star and Turbo; maize, Zea mays L., cvs. Bonny and Boss) were grown at ambient (372 ppm) and at slightly elevated CO2‐concentrations (459 ppm and 539 ppm) in open‐top chambers and the effect of the different CCVconcentrations on the growth and yield of the plants was measured. The past and future CO2‐effect was estimated from the slope of a linear CO2‐yield curve (percentage increase in yield per ppm CO2′ 100% at 370 ppm) fitted to the data and those from previous studies on wheat and maize. The percentage increase in yield per ppm CO2 is insignificant for beans, of borderline significance for silage maize (0.06 % per ppm), and 0.35 % per ppm and 0.26 % per ppm for barley and wheat, respectively. The COj‐elevation primarily decreases the tiller dieback of the cereals. Considering the increase in CO2 of 30 ppm and in the hectare yield of 25 % (barley) and 28 % (wheat) from 1970 to 1990, the contribution of CO2 to the increase in the agricultural production is estimated to be one fourth up to one half of the increase in hectare yield of spring cereals. Given a recent yearly increase of 2 ppm the future CO:‐related increase in hectare yield is estimated to be about 0.5–0.7% per year.
Influence of chloride and sulphate ions on soil enzymes
Authors: Dinesh R. , Ramanathan G. , Singh Harjit 
Published: April 2008

AbstractAmmonium chloride (AC) and ammonium sulphate (AS) are commonly used nitrogen fertilizers. But the effect of chloride and sulphate ions from these fertilizers on soil enzyme activity has received scant attention. Hence, we conducted a pot culture study to assess the influence of chloride (as AC) and sulphate (as AS) on the activities of urease, amidase, phosphatase and dehydrogenase in soil using rice as the test crop. Chloride and sulphate levels were fixed at 132, 264 and 396 kg ha−1 respectively. Controls were also performed. The enzymes were assayed at three stages of the crop growth viz., active tillering, panicle initiation and harvest.The enzyme activities decreased with increasing chloride and sulphate levels; however, the degree of inhibition varied among the enzymes assayed and the nature and amounts of salts added. The inhibition may be due to the specific effects of chloride and sulphate ions on microbial growth and subsequent enzyme synthesis, osmotic desiccation leading to microbial cell lysis, and a salting‐out effect modifying the ionic conformation of the active site of the enzyme protein.
Post‐harvest Evaluation of Nitrogen Sufficiency for Small‐grain Cereals by Measuring Grain Protein Concentration
Authors: Virtanen A. , Peltonen J. 
Published: April 2008

AbstractNitrogen (N) fertilizer is an important and expensive input in small‐grain cereal production, and growers therefore should aim to optimize its use. Possibilities for using grain protein concentration for post‐harvesr evaluation of N sufficiency were determined in this study. Field experiments including spring wheat (Triticum aestivum L.), spong barley (Hordeum vulgare L) and spring oats (Avena sativa L.), and various rates of N fertilizer application were conducted in southern and western‐Finland over 2 years. Grain yield and grain protein were positively correlated and firred quadratic regression models. Both critical and optimum levels for grain protein concentration were determined by Cate‐Nelson analysis Critical values were 12.2 for wheat, 10.2 for barley and 10.9 for oats, and corresponding optimum values were 13.3, 11.1 and 12.7, respectively. The accuracy of the method was tested using results from on‐farm spring wheat trials. The results indicated that N fertilizer uptake and grain yield were best in held where gram protein concentration exceeded the critical values but not the optimum. Growers should use more intensive N fertilization management if grain protein concentration does not exceed critical values. Grain protein concentrations above optimum values indicate over‐fertilization for maximum grain yield. Analysing previous research data to identify the “critical level” of grain protein concentration is not difficult, and will provide powers, extension personnel, and fertilizer dealers with a cost effective means of evaluating the efficiency of N use by the crop and for developing N fertilization recommendations.
Chilling Tolerance of 10 Maize Genotypes as Related to Chilling‐induced Changes in ACC and MACC Contents
Authors: Janowiak F. , Dörffling K. 
Published: April 2008

AbstractWe studied chilling‐induced changes of 1‐aminocydopropane‐1‐carboxylic acid (ACC) and of 1‐(malonylamino) cyclopropane‐1‐carboxylic acid (MACC) contents in seedlings of ten maize genotypes with different chilling tolerance. Seedlings at the third leaf stage were chilled at 5°C and at 65% RH. Immediately before and after two and five days of chilling the contents of ACC and of MACC in the third leaf were measured. Water content and – after recovery – the degree of necrotic injuries and the percentage of seedling survival were also determined.After 2 days of chilling, the ACC content increased in all genotypes investigated. The increase was significantly higher in the sensitive genotypes than in the tolerant ones. There was a significant correlation between ACC content and necrotic injuries of seedlings. Chilling for 5 days increased the ACC content further and the difference between the two groups of genotypes still existed.The MACC content increased after 5 days of chilling in all genotypes investigated. The increase was greater in the tolerant genotypes than in the sensitive ones. However, the difference in MACC accumulation between the two groups of genotypes investigated was not significant, and thus no correlation between MACC accumulation and chilling susceptibility was found.The possible causes for the increase of ACC and MACC contents under chilling conditions and the possibility of using the ACC content as an indicator of chilling tolerance in maize breeding are discussed.