bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modellversuch zur Beschreibung von Konkurrenzvorgängen zwischen Sommerweizen und einer aus Capsella bursa‐pastoris L., Stellaria media L. und Alopecurus myosuroides Huds. bestehenden Mischverunkrautung
Authors: Petry W. , Wirth H. , Kühbauch W. 
Published: April 2008

Abstract Investigation to Describe the Competition between Spring Wheat and a Weed Population Consisting of Capsella bursa‐pastoris L., Stellaria media L. and Alopecurus myosuroides Huds. When controlling weeds in cereals using economic threshold as criteria, weed populations must be evaluated for their potential to cause damage at a very early stage. As well as information of actual weed density or weed ground cover, further knowledge about the species specific growth and competition between weed populations is important.For this purpose the growth and competition between the weeds Capsella bursa‐pastoris L., Stellaria media L., Alopecurus myosuroides Huds. and spring wheat (Triticum aestivum L.) as a model of a typical weed mixture in cereals were studied in a container experiment. The growth with time of individual species was documented using true colour image processing. In that these measurements are non‐invasive, the system lends itself specially to time‐dependent analyses. The increasing amount of ground covered by leaves between two observation times served as a parameter to evaluate the increase in biomass over this time period and could be used as a evaluation of the competitiveness of the weed species studied.The results can be summarized as follows: 1) Stellaria media L. proved to be the most competitive of the studied species. 2) The competition to spring wheat from each weed species was similar. 3) A multi species weed population had a tendenci to a lower competitiveness to spring wheat, than a weed population of only‐one species.The importance of this and other similar studies for the improvement for the prediction of economic weed thresholds to estimate weed populations in early stages will be indicated.
The Effect of Nitrogen and Phosphorus Fertilization on the Nitrogen Absorption by Sunflowers
Authors: Loubser H. L. , Human J.J. 
Published: April 2008

I. AbstractLittle is known about the effect of fertilization on the N uptake of sunflowers. A 42 factorial trial with 0, 60, 120 and 180 kg N ha−1 and 0, 15, 30 and 45 kg P ha−1 was conducted over three years. The N content and concentration of leaves, stems and capitula were determined at three growth stages. High N levels increased the N content and concentration of all plant parts at all growth stages sharply. High P levels increased the N content of all plant components through better growth. P has an inconsistent effect on N concentration but tended to decrease it. After flowering the crop assimilated 20 to 25 % of the total N. This implies that N applied can still be applied and utilized by the crop at a late stage. This should be substantiated by further research.
Soil Temperature Model for CERES and Similar Crop Models
Authors: Hoffmann F. , Beinhauer R. , Dadoun F. 
Published: April 2008

AbstractFrequently the soil heat transfer is considered as a one‐dimensional (vertical) process which may be described by the differential equation (DE) of soil heat flow. Regarding the upper boundary, equations for bare and cropped fields are developed by means of data of Kiel and Michigan. For the lower boundary a theoretical and an empirical equation are given. The soil heat conductivity was estimated by the formulas of McInnes (1981). Equations are proposed for estimating the clay and quartz contents which are needed in these formulas. The convective term in the differential equation (DE) may be omitted without significant loss of precision. For the SALUS model in which the two upper layers are 2 resp. 5 cm thick a simple approximative solution for these two layers is given. The temperatures of the deeper layers are calculated by the DE for which in this case only two time steps per day are necessary. This yields short computing times.
Agronomic Potential of Three Vetches (Vicia spp.) Under Rainfed Conditions
Authors: Abd El Moneim A. M. 
Published: April 2008

AbstractThe major limiting factor to livestock production in West Asia and North Africa is the inadequate feed supply. The introduction of leguminous forage species into fallow lands represents a means of increasing feed supplies for the rapidly growing livestock population.Twenty five lines each of common vetch (Vicia sativa L.) wooly‐pod vetch (Vicia villosa ssp. dasycarpa Ten.), and bitter vetch (Vicia ervilia L.) were tested over three seasons with contrasting rainfalls and winter temperatures. For each species, seedling vigour, winter growth, cold effect, spring growth, leafiness, herbage yield at 100 % flowering, grain yield, harvest index and aspects of herbage quality were recorded. There were considerable variation among entries with the same species, entries of V. ervilia were the earlier in flowering and maturity, and V. villosa ssp. dasycarpa almost the latest by 45 days. V. sativa, was the most affected by frost whilst both V. villosa ssp. dasycarpa and V. ervilia proved to be cold tolerant.Although V. villosa ssp. dasycarpa produced high herbage yield in springs its grain yield is low resulting in a low harvest index. Both V. ervilia and V. sativa produced high grain yield with high harvest index. Seed yield was negatively correlated (P < 0.01) with days to flowering and maturity indicating the need of earlier types.Quality of the herbage in term of digestibility was far lower (46 % IVDMD) in V. villosa ssp. dasycarpa than the other two species (69 % and 72 %).The possible niches and utilization of each species as animal feed in the prevailing farming systems are discussed.
Der Einfluß der Wachstumsrate auf die Effizienz des produktiven Wasserverbrauches durch die Kulturpflanze unter Berücksichtigung von C3‐ und C4‐Arten
Authors: Neuhauser W. , Storchschnabel G. 
Published: April 2008

Abstract The influence of the growth rate on the water use efficiency by different cultivated plants in consideration of C3‐ and C4‐species The influence of the growth rate (dry matter production per unit of time) on the water use efficiency by different cultivated plants (maize, sunflower, durum wheat, sorghum, amaranthus) was examined using hydroponic culture. The water use efficiency was expressed by the relative water requirement (1 transpirated water per kg produced dry matter), at which the evaporation was absolutely eliminated. The results showed a definite conformity with the hypothesis, which was taken as the basis for these studies:– The relative water requirement was not constant on the basis of the changing growth rate during the course of growth and development of the plants. With increasing growth rate decreased the relative water requirement. The effect of the increasing growth rate on the decrease of the relative water requirement was greater all the more, the more the growth rate increased.– Plants of one and the same species and variety but with different growth rates had different relative water requirements. Those ones with a higher growth rate showed a lower relative water requirement.An influence of the growth rate on the different relative water requirement of C3‐ and C4‐species also was observed. Under better growth conditions for C3‐plants than for C4‐plants, the growth rate of C4‐plants was slowed down, so the relative water requirement was higher than by C3‐species.Concluding from this research, there is the possibility to employ the growth rate of plants for a measure to use water more efficient in plant cultivation.
Effect of Intercropping Cereal, Pulse and Oilseed Crops in Redgram on Yield, Competition and Advantage
Authors: Sarkar R. K. , Shit D. 
Published: April 2008

AbstractResults of a field experiment conducted in rainy season (June to December) of 1988 and 1989 at Deochanda Experiment Station, Bihar, India, indicated that intercropping cereals, pulses and oilseeds with normal planted base crop of redgram (Cajanus cajan [L.] Mill sp.) increased land use efficiency and gave higher total yields compared to pure cropping of redgram under rainfed conditions on upland oxisols of Bihar plateau. Cereals like maize, rice and fingermillet were more aggressive in intercropping system and they tended to have depressing effect on redgram. Intercropping of short duration pulses like blackgram and greengram and legume‐oilseed crops like peanut and soybean with redgram showed balanced competitive abilities and proved more efficient in the system. Intercropping system of redgram‐peanut proved to be the most efficient and productive.
Simulation Analysis of Variation among Seasons in Winter Wheat Yields in Northern Italy
Authors: SINCLAIR T. R. , Mosca G. , Bona S. 
Published: April 2008

AbstractWinter wheat growth and yield was observed in two sets of field experiments performed at the Experimental Farm of Padova University in Legnaro, over seven years beginning in 1981. A spring wheat model in which leaf area development was calculated as a function of temperature and biomass accumulation was utilized. The final number of leaves in each season was calculated based on a previous winter wheat model and the biomass accumulation was decreased when average daily temperature was below 10 °C. In addition to the two modifications described above, the soil/crop nitrogen submodels were modified so that denitrification was a function of temperature and plant nitrogen uptake rate was sensitive to variations in daily temperature. Nitrogen leached below 60 cm was assumed to be no longer available to the winter wheat crop. The winter wheat model with the soil/crop nitrogen budged resulted in good agreement between the simulated and observed yields (less than 14 % difference existed in 12 of 14 environments). A strong negative correlation (r = ‐0.74) existed between the simulated yields and the simulated amount of nitrogen leached out of the root zone. Under the conditions of nothern Italy, retention of root zone nitrogen appears to be particularly important in achieving high winter wheat yields.
Soil Moisture Conservation for Wheat Production in the Central Highlands of Jordan
Authors: Al‐Turshan M. A. , Battikhi A. M. 
Published: April 2008

AbstractA study was carried out at Mushaqqar Agricultural Experiment Station located in the Central Highlands of East Jordan. The objectives were to study and compare three crop rotations: Duck foot fallow–wheat; chemical fallow–wheat; and wheat–wheat, on soil moisture conservation and storage and on wheat yield.Results indicated that, the storage efficiency for the duck foot fallow treatment was higher than that of chemical fallow (13.4 and 8.7% respectively). Also it was found that two duck foot or chemical fallow applications, for weed control, were needed before June.Wheat yield was the highest after the duck foot fallow, followed by chemical fallow. Wheat yield had decreased from 3.34 Mg/ha to 1.08 Mg/ha, for continuous wheat.
Microbiological and Physicochemical Properties of Carbamate Insecticides Treated Soil
Authors: El‐Sayed M. A. , El‐Shanshoury A. R. , Swelim M. A. , Abd El‐Salam S. S. 
Published: April 2008

AbstractTreatment of clay loam soil with carbaryl (sevin), thiodicarb (larvin) and methomyl (lannate) at field and 10 folds the recommended doses showed a variable effect on population of total bacteria, azotobacters and nitrifying bacteria, in addition to the soil content of total soluble salts; the effect differed according to the herbicide and the dose level. The bacterial population was significantly increased in the first five days of treatment, then a decrease was recorded. The increase in the microbial population and total soluble salts were proportion to the levels of the insecticides. Moreover, supplementation of glucose to the soil caused substantial increase over that in the insecticide and/or glucose free soils.
The Effectiveness of Vernalization of Immature Embryos of Winter Wheat var. Grana as Related to Age and Exogenous Phytohormones
Authors: Dubert F. , Marcińska I. , Biesaga‐Kościelniak J. , Szmider I. 
Published: April 2008

AbstractStarting from the 10th day after pollination, immature embryos of winter wheat var. Grana were isolated and then vernalized for 4 to 8 weeks on Murashige and Skoog nutrients containing BAP (0.5 or 2 mg/dm3), NAA (0.5 or 2 mg/dm3), or GA3 (5 or 20 mg/dm3). Vernalized seedlings were cultivated in a greenhouse and the number of days to the heading of individual plants as well as the percentage of plants capable of generative development were estimated.The lower limit of size for 50 % survival of embryos strongly depended on the phytohormone used: from 0.9 mm in control, 1.1 mm in nutrient containing BAP, 1.2 mm for NAA, up to 1.7 mm in nutrient with GA3.Exogenous GA3 was lethal for embryos younger than 18 days but induced elongation of older embryos.Embryos isolated 2.5 to 4 weeks after pollination showed minimal requirements for the length of vernalization.BAP increased the percentage of heading plants originated from the youngest embryos.GA3 improved partial vernalization, strongly increasing the percentage of heading plants, but did not change the time from the end of vernalization to heading. It has been postulated that GA3 increases number of plants capable of overcoming the threshold of induction of generative development but does not accelerate the flowering process.Hormonized plants showed no deformation of generative development. As the effectiveness of vernalization increased, the heading of plants was faster but they were shorter, forming spikes with a smaller number of spikelets and producing fever lateral shoots.The very young embryos probably have in reserve sufficient amounts of auxins and gibberellins and therefore exogenous GA3 decreases their viability or even exerts a deleterious effect. However, as the embryos' ageing, gibberellin starvation develops. This being especially pronounced during vernalization.The de novo synthesis or activation of gibberellins takes place during the second stage of vernalization. This is why exogenous hormone improves the effectiveness of partial vernalization, though it is not possible to substitute by gibberellins the vernalization requirements of immature embryos.
Effect of Water Shortage on Main Shoot Development and Tillering of Common and Spelt Wheat
Authors: Cabeza C. , Kin A. , Ledent J. F. 
Published: April 2008

AbstractWater stress was imposed by cessation of watering (CW) on bread wheats and, in some experiments two spelt wheats, during 9–17 days, starting at the 4–5 leaves stage. Main shoot foliar stages (MSS) were delayed by CW and the effect remained thereafter.The presence of side tillers (intact or partly destroyed by heat or potassium iodide (KI) was not beneficial to main shoot foliar development after the end of CW. Emergence of tillers after the onset of CW was also delayed, but the effect was small if timing was expressed in MSS. Secondary tillers were the most sensitive to water shortage, their number, size and foliar stage were drastically reduced.The two cultivars of spelt wheats were not less sensitive to CW than the bread wheat tested.
Fruiting Efficiency in three Bread Wheat (Tritkum aestivum) Cultivars Released at Different Eras. Number of Grains per Spike and Grain Weight
Authors: Slafer G. A. , Miralles D. J. 
Published: April 2008

AbstractIncreasing sink size (i.e. number of grains m−2) has been the way of the genetic improvement for obtaining higher grain yield of wheat. We have studied under field conditions the number of fertile florets and grains per spike and individual grain weight of three bread wheat cultivars (Klein Favorito, Eureka FCS and Buck Pucara) which were previously selected to represent cultivars released at different eras (1920, 1940 and 1980, respectively) in Argentina (Slafer and Andrade 1989).The three cultivars Buck Pucara, Eureke FCS, and Klein Favorito averaged 56.9, 48, and 34.5 grains spike−1. Differences were observed in both main shoot and tiller spikes. The number of fertile florets at anthesis was greater in the modern cultivar than in the other two cultivars; however, the intermediate and old cultivars did not significantly differ in this trait. Differences in number of florets and number of grains spike were independent of the number of spikelets spike−1; spikelet numbers did not vary among the three cultivars. Therefore, both the number of fertile florets produced per spikelet and the ability of the cultivar to set grains in those florets were responsible for the different number of grains spike−1 among cultivars. The modern, high yielding cultivar had a lower individual grain weight than the old, low yielding cultivar when the average of all grains were considered; but basal grains of its central spikelets were as heavy as those of the other cultivars.We suggest (i) that the modern cultivars of Argentina have increased their ability both to produce fertile florets and to set grains, and (ii) that the lower individual grain weight of the modern cultivars does not imply an increased competition for resources as a consequence of their higher number of grains.
Effect of Agronomic Factors on Annual Leguminous Forage Crop in Mediterranean Environments
Authors: Martiniello P. , Ciola A. 
Published: April 2008

AbstractDry matter and seed production of five annual leguminous species hairy vetch (Vicia villosa Roth cv. Orsara), crimson clover (Trifolium incarnatum L. ecotype Campano), squarrosum clover (T. squarrosum L. ecotype Calabro), persian clover (T. resupinatum cv. Accadia) and fenugreek (Trigonella foenum‐graecum L. ecotype Maltese) was estimated in 1989–90 under two density and irrigation rates and with two cutting treatments. The experiments were done at the Forage Crops Institute of Foggia, which has a typical Mediterranean environment. The forage cut severely affected the regrowth of the plants in all species. The year and irrigation factors affect dry matter, seed production and seed yield components more than the plant density rates. The averages over the years, for dry matter and seed yield were 21.0 % and 20.5 % higher in the irrigated than the not irrigated ones. The lower plant density rate, for seed yield trait, gave better result in hairy vetch in irrigated and non‐irrigated treatment. Whereas in the other species, the lower rate of planting gave greater yield under non‐irrigated and the higher rate under irrigated growing condition. The seed yield components most influenced by irrigation were: thousand seed weight and seeds/pod in hairy vetch and heads/tiller and seeds/head in clovers species. Fenugreek was the earliest forage crop (cut at the beginning of March), followed by crimson and persian clovers (cut at the middle of April) and squarrosum clover and hairy vetch (cut in the middle‐late of May). All the cultivars and ecotypes considered not regrowth after cut and could represent an important fresh forage resource for the period March–May for the Mediterranean regions.
Effect of the Russian Wheat Aphid on the Composition and Synthesis of Water Soluble Proteins in Resistant and Susceptible Wheat
Authors: van der Westhuizen A. J. , Botha F. C. 
Published: April 2008

AbstractThe effect of Russian wheat aphid (Diuraphis noxia) infestation on polypeptide composition and protein synthesis in the presence or absence of chloramphenicol and cycloheximide were studied in genetically comparable wheat (Triticum aestvum) resistant (cv. PI 137739/5* Tugela) and susceptible (cv. Tugela) to the aphid. The aim is to gain information of molecular nature on the resistance phenomenon which may promote future breeding programmes. In the absence of feeding aphids polypeptide profiles of the two wheat lines were similar indicating the absence or presence at low levels of a constitutive resistance factor. Aphid infestation induced enhanced expression of certain genes in the resistant wheat only. A 100 kD nuclear encoded polypeptide is strongly induced in the resistant wheat. It is also evident that the synthesis of a 56 kD organel encoded polypeptide is suppressed by the feeding aphids in the susceptible wheat.
High Protein Soybean Performance Under Field Conditions
Authors: Ma B. L. , Leibovitch S. , Voldeng H. D. , Smith D. L. 
Published: April 2008

AbstractAn early maturing soybean [Glycine max (L.) Merr.] cultivar has been developed with substantially higher seed protein concentration than previously available cultivars. The objectives of this study were to evaluate the performance of the high protein line under field conditions in Eastern Canada, and to investigate the interrelationships between protein and oil concentrations, seed weight and yield. A field experiment, including the high protein line OT89‐16 and its recurrent backcross parent Maple Arrow grown side by side, was conducted at McGill University, during 1990 and 1991. The protein concentration of OT89‐16 was 17 % greater than that of Maple Arrow for both years. However, the protein yield of OT89‐16 was not significantly increased, the oil content was 19 to 23 % lower, and oil yield per ha was over 30 % lower than those of Maple Arrow. The lower yield of OT89‐16 was closely associated with its lighter seeds. Further efforts to improve the high protein line should attempt to maintain the same high protein levels but achieve yield equal to that of the parent line through selection for heavier seeds.
Model for Slurry and Manure in CERES and Similar Models
Authors: Hoffmann F. , Ritchie J. T. 
Published: April 2008

AbstractProceeding from the structures and hypotheses of the CERES and SALUS models a model for considering manures has been developed. The model includes the following processes: infiltration during application, ammonia volatilization, leaching of ammonium and organic bound nitrogen and mineralization before incorporation, incorporation, ammonia volatilization, mineralization and leaching of organic bound nitrogen after incorporation. With the CERES Maize model combined with the manure model simulations were calculated concerning the following problems:– influence of application time of slurry on nitrate leaching under German site conditions and– influence of long‐term slurry fertilization and of stopping slurry fertilization on organic N content, mineralization, uptake by maize and leaching under Southern Michigan site conditions.Results and conclusions are presented.