bluuebunny/crossref_metadata_2025 huggingface dataset:
Enzymes of Ammonia Assimilation and Transamination in Relation to Hybrid Vigour in Pearl Millet (Pennisetum americanum L. Leeke)
Authors: Chanda S. V. , Joshi A. K. , Vaishnav P. P. , Singh Y. D.
Published: April 2008

Changes in the activities of enzymes of ammonia assimilation viz., glutamate dehydrogenase (GDH), glutamine synthetase (GS) and glutamate synthase (GOGAT), together with the activities of glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) were analysed in the topmost fully expanded leaf of pearl millet (Pennisetum americanum L. Leeke) hybrid BJ‐104, and its parents, J‐104 and 5141‐A, during the entire period of growth in field. Ammonia assimilation enzymes showed strong ontogenic trends and the hybrid attained activities either equal to the better (male) parent or showed better parental heterosis. In contrast to this both GOT and GPT activities were slightly higher than the poor (female) parent. The role of these enzymes in relation to chlorophyll synthesis and transport of metabolites from cellular compartments of C4 plants, are discussed. Surveying the literature on attempts to propose biochemical criteria for hybrid vigour, it is proposed that there cannot be a universal criterion, rather rate limiting steps in different cultivars should be searched.
N and P Fertilizer Use in Soybean/Maize Mixture
Authors: Pal U. R. , Kalu B. A. , Norman J. C. , Adedzwa D. K.
Published: April 2008

Field experiments were conducted to investigate into the N and P fertilizer use in soybean/maize mixture during the wet seasons of 1985 and 1986 at Yandev Agricultural Experiment Station. Soybean/maize mixtures with 2/3 of the respective plant population of both crops in pure stands were raised at factorial combinations of four rates of N, 0, 40, 80, and 120 kg N/ha and four rates of P, 0, 13.2, 26.4 and 39.6 kg P/ha in a randomized complete block design with three replications.

The grain yield of maize cv. TZB (a pure line variety) in mixture and land equivalent ratio (LER) increased linearly up to 120 kg N/ha in 1985 as against significant increase in the grain yield of maize cv. 8322–3 (a hybrid variety) and LER up to 40 kg N/ha only in 1986 primarily due to greater fertilizer N recovery by the latter. Significant enhancement in LER was also recorded up to 26.4 kg P/ha in both years. The yield of soybean in mixture remained unaffected by N or P rates.

Total N uptake by shoots of soybean/maize mixture was significantly and linearly increased up to the application of 120 kg N/ha in 1985 as against significant increase in total N uptake by soybean/maize mixture only up to 40 kg N/ha in 1986 owing to the greater fertilizer N recovery by maize (69%) in the latter than the one (29.75—31.75%) in the former. Total N uptake by shoots of soybean/maize was also increased significantly due to the application of 26.4 kg P/ha.

Application of N and P also significantly enhanced P uptake by shoots of soybean/maize mixture and fertilizer P recovered by mixture was less (3.99—12.95%) in 1985 than the one (19.95—32.12%) in 1986.
Grain Yield of Intercropped Sorghum and Pearl Millet as Influenced by Sorghum Genotype and Cropping Pattern
Authors: Stützel H. , Vanderlip R. L.
Published: April 2008

Intercropping of sorghum and pearl millet with different growth cycles is used widely in third‐world countries to ensure and increase yields. However, it is questionable whether yield increases because of intercropping can be maintained under more developed systems, since temporal differences are necessary to allow mechanized planting and harvesting.

Three sorghum hybrids with expected growth cycles from 90 to 110 days were planted in sole stands and in alternate rows and mixed within the rows with a pearl millet hybrid having a growth cycle similar to that of the early sorghum. Sole stands of millet also were included. The plots were planted at three locations in Kansas, two dryland and one including dryland and irrigated. Results show that yields were consistently highest in sole stands of sorghum, owing to the higher yield level of sorghum. No yield increase could be found on a land equivalent ratio basis, indicating no intercropping advantages. However, under good moisture conditions, a tendency toward yield increase was observed with the later maturing sorghums, which had 1–2 weeks of grain filling after the millet was mature. When moisture supply was insufficient, millet showed higher competitiveness for water than sorghum, and sorghum was adversely affected more than pearl millet was favored. It was concluded that moisture conditions have to be good and that temporal differences between sorghum and millet have to be greater than those used in this experiment to achieve intercropping yield advantages.
The Influence of Crop Rotation with an Increasing Content of Cereals on Photosynthetic Potential of Winter Wheat
Authors: Grzebisz W.
Published: April 2008

In years 1982–1985 flag leaf area, concentration of chlorophyll and macronutrients (N, P, K, Ca, Mg, Na) and also their correlations to grain yield in static field experiment were studied. The main experimental plots comprised crop rotations containing 50, 75, 100% cereals. Treatments with or without irrigation were subplots and nitrogen levels (0, 60, 120, 180 kg N/ha) were sub‐sub‐plots.

The cultivation of winter wheat in rotations containing more than 50% cereals affected the drop of winter wheat grain yield, which was especially high on the plots without nitrogen fertilization or with low N level. The dose of 120 kg N/ha gave the highest grain yield in each rotation and, at the same time, decreased to minimum the differences between them, although wheat grown in the full cereal rotation yielded much less. The response of wheat grain yield to previous crop was affected by photosynthetic potential of a plant, which was constituated by flag leaf area and concentration of chlorophyll. The deteriorating nutrient economy in wheat plants grown in rotations containing more than 50% cereals decreased the photosynthetic potential of wheat. In addition, in these rotations the importance of macronutrients concentration in the flag leaf at anthesis as a source of nutrients for the developing grain is visible.
Comparative Analysis of Photosynthetic Parameters and its Evaluation in Pearl Millet Hybrid and its Parents
Authors: Chanda S. V. , Joshi A. K. , Vaishnav P. P. , Singh Y. D.
Published: April 2008

Fully expanded leaf occupying topmost position in a field grown pearl millet hybrid (BJ‐104) and its parents (J‐104 and 5141‐A) were analysed at weekly intervals for chlorophylls, Hill activity and phosphoenolpyruvate carboxylase activity. Large ontogenic drifts in these parameters, made the actual comparison between hybrid and parents, difficult. However, up to 52 d the hybrid leaf possessed considerably higher chlorophyll pigments than its parents. Amongst the inbreds, the male parent was initially better than the female parent while at later stages, the trend was reversed. Hill activity and PEPcase were more in the male than in the female parent and the hybrid followed the better parent. Rate limiting steps for productivity, measured as NAR (g dry weight)−1, were worked out in the female parent, using multiple regression and correlation analysis, and the significance of such an analysis is discussed in relation to plant productivity.
Pflanzenwachstum durch CO2/HCO3‐Eintrag über die Wurzel
Authors: Schäfer W.
Published: April 2008

Plant Growth after Application of CO2/HCO3 to the Roots

After applying H14CO3 to the root system of summer wheat in hermetically sealed pots, absorption and incorporation of HCO3 in the sugar‐, starch‐, and fibre‐fraction (approximately 50 % of the absorped 14C) could be shown. This fraction reached 0.44–1.21 % of total C‐assimilation of the shoot during growing stage F9/F10 on the Feeke‐scala. 1/3 of the HCO3‐fraction resting in the soil was bound organically indicating that microorganisms may be able to utilize exogenous anorganic CO2/HCO3 for their photosynthesis.
Growth and Yield of Peanut as Influenced by Degree and Duration of Shading
Authors: Rao L. J. , Mittra B. N.
Published: April 2008

Peanuts (Arachis hypogaea L.) which are commonly grown in intercropping systems often suffer from shading caused by the associated crop. Through this study an attempt has been made to estimate the effect of different levels of shade at different growth stages on crop yield. Field experiments were laid out during monsoon and winter seasons of 1985 and 1986 by creating artificial shading up to 25 and 50 per cent of the day/natural light at flowering‐pegging, pod filling and maturity stages of a Spanish bunch type peanut. Dry matter production has shown linear response to light intensity and due to 50 per cent shading it was reduced by 55 per cent. Vegetative growth rate during pod filling stage was very poor as a result of increase in shading at this stage. In shaded plants the nodulation was less and some reduction in chlorophyll content was also observed. However, oil content in kernel was not affected by shading. Shading caused significant reduction in pod number and kernel weight and thus there was decrease in pod yield. Flowering to pegging and pod filling stages seemed to be sensitive to shading while increase in shading at maturity stage did not cause any reduction in yield. It could be possible to obtain about 90 per cent pod yield by avoiding shading during flowering to pegging stage (45 DAS).
The Influence of Glyphosate on Germination Behaviour of Wheat (Triticum aestivum L.)
Authors: Hassan Esmat A.
Published: April 2008

The germination behaviour of glyphosate‐treated seeds of two wheat cultivars was investigated. Ten concentrations of the herbicide (480 g/L.) ranged from zero to 260 g. a.i./Fed. were applied to the dry seeds by soaking for two hours. Germination was then conducted in petri dishes on filter paper at average daily maximum and minimum temperatures of 19.65 and 6.15 °C in the laboratory. Seedling growth behaviour was recorded periodically at the 4th, 7th and 10th day of germination.

The results indicated that glyphosate treatment at different concentrations did not affect the germination percentage in both wheat cultivars. On the other hand, in comparison to the control, the herbicide treatment caused significant reduction in maximum seedling root and shoot lengths. The reduction increased proportionally by increasing the herbicide concentration. Treatments with high concentrations of the glyphosate caused significant reduction in total root number per seedling in cv. Sakha 8. At concentrations of 260, 130 and 65 g a.i./Fed. all seeds exhibited root aberration in both wheat cultivars.

Clear variation in cultivar susceptability to glyphosate treatment was observed, particularly at concentrations lower than 65 g a.i./Fed.

However, cv. Giza 155 seemed to possess better survival to glyphosate treatment than cv. Sakha 8 concerning root inhibition percentage and seedling part measurements. The results indicated the practical importance of the reactions of different genetic codes to the herbicide in the field including the crop and the weeds.
A Study on Identification of Agronomical Methods for Raising Seed Production in Buffel Grass (Cenchrus ciliaris)
Authors: Singh R. P. , Dwivedi G. K. , Sinha N. C.
Published: April 2008

Field trials were conducted at Indian Grassland and Fodder Research Institute, Jhansi to find out appropriate agronomical technique, as method of planting, sowing date, time and dose of nitrogen application and synergistic effect of companion crops. Results demonstrated that (i) six weeks old seedlings of Cenchrus ciliaris have good vigour potential for vegetative propagation, (ii) its planting is most appropriate in last week of June, (iii) it requires 80 kg N in split doses (40 kg N at sowing and 40 kg N 30 days after sowing) and (iv) seed yielding potential of Cenchrus ciliaris further increased with companion crop of Sesame (Sesamum indicum). Thus it is pointed out that these agronomical requirement is necessary for reaping potential seed yield of Cenchrus ciliaris.
Genotypic Variation for Nitrogen Fixation in Soybean
Authors: Garner E. Ramona , Sapra V. T. , Floyd M.
Published: April 2008

Twenty soybean cultivars from maturity groups IV, V, VI, VII and VIII were screened in the growth chamber study to determine their response to two Rhizobium strains through N‐fixation rates. Cultivars Lee 74, Essex and Bay showed high nitrogenase activities of 201.00, 93.75 and 74.86 nM C2H2/pl/hr, respectively. Braxton, Hutton and Bragg showed low nitrogenase activity rates of 4.73, 4.20 and 3.0 nM C2H2/pl/hr, respectively. A range of variation was found among the cultivars in shoot fresh and dry weights, nodule number and nodule weight.
Physiological Analysis of Growth and Yield of Watermelon (Citrullus ianatus Thunb Musf) in Relation to Irrigation and Nitrogen Fertilization
Authors: Hegde D. M.
Published: April 2008

Analysis of growth and yield of watermelon in relation to irrigation and N fertilization carried out at the Indian Institute of Horticultural Research, Bangalore, during 1983–84 and 1984–85 indicated that frequent irrigations when the soil matric potential at 15 cm depth reached ‐25 kPa resulted in maximum dry matter accumulation and distribution, leaf area index (LAI), leaf area duration (LAD), net assimilation rate (NAR) and crop growth rate (CGR) leading to higher fruit yield as compared to irrigations at ‐50 and ‐75 kPa. Imposing a stress of ‐75 kPa either during pre‐flowering or flowering or fruit development phase adversely affected various growth parameters resulting in reduced yield as compared to that irrigated uniformly at ‐25 kPa. Increasing levels of N fertilization increased the dry matter accumulation and distribution through higher LAI, LAD and CGR and contributed larger proportion of the dry matter to fruits resulting in higher fruit yield.
Effect of Nematicide and Herbicide Interactions on Field Population of Cyst Nematode and Agronomic Characters of Soybean
Authors: Oji Okoro , Sapra V. T. , Pacumbaba R. P.
Published: April 2008

Treatment of herbicides (Treflan and Lorox) and nematicides (Nemacur and Temik) and various combinations of these pesticides on Essex and Ransom in the field to control weeds and soybean cyst nematode (SCN) have produced significantly more abnormal seedling establishment, more number of pods and nodules per plant, and lesser field population of SCN. The differences in performance of Essex and Ransom with respect to SCN control with corresponding yield increases or decreases from pesticide treatments may have been due to the cultivar's different degree of susceptibility to SCN infestations and to their specific genetic make‐up. The recommended nematicides for the control of SCN with corresponding yield increases in Essex were Temik and Nemacur and the recommended nematicide‐herbicide combinations were Temik‐Treflan and Temik‐Lorox. The recommended nematicide for the control of SCN in cultivar Ransom was Temik. Bean yields were not affected by the application of pesticides.
Effect of NaCl Salinity and Putrescine on Shoot Growth, Tissue Ion Concentration and Yield of Rice (Oryza sativa L. var. GR‐3)
Authors: Prakash L. , Prathapasenan G.
Published: April 2008

Interactive effect of NaCl salinity and putrescine on shoot growth, ion (Na+, K+ and CI−) concentration in leaf, stem and inflorescence and yield of rice (Oryza sativa L. var. GR‐3) were studied. When rice plants were subjected to salt stress (12 dS/m) the extension growth and dry weight of shoot system as well as total leaf area and chlorophyll content were found markedly reduced. Analysis of leaf, stem and inflorescence of salt‐stressed plants showed higher concentration of Na+ and Cl ions and lower concentration of K+ ion compared to the control. Salinization also caused a considerable fall in grain yield.

Foliar application of putrescine (10−5M) significantly increased the growth and yield of salt‐stressed plants. Putrescine treatment decreased the influx of Na+ and Cl− ions and increased the K+ level in all the tissues of salinized plants examined. Putrescine also increased the chlorophyll content in salt‐stressed plants. These results suggest that exogenous application of putrescine can be used successfully to ameliorate the stress injuries caused by NaCl salinity in rice plants to a considerable extent.
The Translocation of 14C‐Sucrose and 14C‐Benzyl Adenine in Winter Wheat (Tritkum aestivum L.) in the Period of Kernel Formation
Authors: Ibrahim M. El.‐D. , Prochézka S. , Borkovec V.
Published: April 2008

The transport and distribution of 14C‐sucrose and 14C‐BA were studied in internode segments with ear of two winter wheat cultivars with a different mass of kernels in the period of kernel formation. While MC‐sucrose was transported and accumulated intensively in the developing ear, 14C‐BA was transported much less and only a small part of it was found in the ear. With the ear development the accumulation of both 14C‐sucrose and 14C‐BA in the ear increased but the 14C‐BA distribution pattern (ratio of the internode/kernel and the rest of the ear) did not change significantly. In the period of one to two weeks after anthesis the accumulation of 14C‐sucrose and 14C‐BA was higher in the kernels of the Slavia cv., i.e. in the cultivar with a higher mass of kernels.
Nitrogen and Carbofuran Effects on the Growth and Yield Performance of Mungbean (Vigna radiata [L.] Wilczek)
Authors: Hamid A.
Published: April 2008

Studies were carried out both in the semi‐controlled environment and in the field to evaluate the influence of nitrogen and carbofuran in the growth, dry matter partitioning and yield of mungbean. Both nitrogen and carbofuran increased leaf area, leaf N content, NAR, dry matter, most of the yield attributes, and grain yield. Dry matter accumulation during the reproductive phase was significantly influenced by nitrogen and carbofuran, and method of N application. Plants treated with nitrogen fertilizer and carbofuran produced higher amount of dry matter after flowering; but gave low harvest index values compared to control. The results suggest that mungbean yield can be substantially increased through efficient dry matter partitioning employing agronomic manipulations.
Effect of Planting Sequence and Time, and Nitrogen on Maize Legume Intercrop Yield
Authors: Bryan W. B. , Peprah S. A.
Published: April 2008

Productivity of maize (Zea mays L.) legume intercrops is determined by soil, management, and environment. Planting sequence and time and N fertilization are easily controlled management factors but their effects on intercrop yields are not well understood. Maize grown in monoculture or intercropped with polebean (Phaseolus vulgaris L.) or cowpea (Vigna unguiculata [L.] Warp.) was studied for two growing seasons at Morgantown, WV. Crops were seeded in the following sequences: maize before legume, both at the same time, and legume before maize. Planting times were early May or mid June. Nitrogen was applied at 0 or 160 kg ha−1. Maize grain and forage, legume grain and forage, and total forage production were determined on a dry matter basis. Intercropping (average of all treatments) reduced maize grain and forage yields compared to maize in monoculture but had no effect on total forage production. However, total forage production was greatest when the seeding sequence was maize intercropped at the same time or before cowpea. Cowpea never produced grain, but forage production was almost double that of polebean. Maize produced most forage when seeded before the legumes, and the legumes produced most forage when seeded before maize. Early planting increased maize production and decreased legume production. Nitrogen increased maize grain, maize forage, and total forage yields but had not effect on legume forage production. It is concluded that maize/legume intercrops show promise for increasing forage production in temperate areas and more research on planting times and densities, weed control, harvesting and management is needed.
Influence of Benzyladenine on Leaf Senescence and Photosynthesis in Sunflower (Helianthus annuus L.)
Authors: Srivastava G. C. , Goswami B. K.
Published: April 2008

The effect of foliar application of benzyladenine on sunflower leaf senescence, photosynthesis, RuBP carboxylase activity and diffusion resistance was investigated. A considerable drop in photosynthetic rate and rise in diffusion resistance were noted dunng the seed filling period. Benzyladenine application maintained the chlorophyll content and chlorophyll a : b ratio at higher level, enhanced RuBP carboxylase activity and net photosynthesis in both upper and lower leaves. A lower level of diffusion resistance was also observed by benzyladenine application during seed filling period. The results suggested that application of benzyladenine at 30, 60 and 90 days after sowing could help to maintain photosynthesis and assimilate supply to the developing seeds of sunflower.
Osmotic Adjustment and Stomatal Characteristics of the Secale cereale X Secale montanum Cross Permontra
Authors: Gordon‐Werner E. , Dörffling K.
Published: April 2008

Osmotic behavior, photosynthesis and leaf conductance under drought stress as well as stomatal morphology and stomatal recovery after stress were investigated in the drought tolerant Secale cereale x Secale montanum cross Permontra, five S. cereale cultivars and the wild rye S. montanum.

Water relations parameters were measured on potted plants during and after a 7 day stress period.

Osmotic adjustment occurred in all varieties but was greatest in Permontra. Size and frequency of stomata was not related to drought tolerance but stomatal recovery after stress was quickest in Permontra.
The Persistence of Tetraploid Perennial Ryegrass in a Mixture with Diploid Perennial Ryegrass
Authors: Roegiers P. , Reheul D. , van Bogaert G.
Published: April 2008

An investigation was carried out into the survival of two tetraploid varieties of perennial ryegrass (Lolium perenne L.), sown in a mixture with a diploid and very intensively grazed for over five years.

Mixture M1 consisted of the late heading varieties Meltra and Vigor, and mixture M2 of the early heading varieties Merlinda and Melino.

The ploidy was determined by microscopic analysis.

The share of the tetraploid component decreased in both mixtures. The decrease was more pronounced in the early heading mixture. Information was also sought on the technique of sampling such swards.
Soil Water Flux Below the Root Zone of a Peanut Crop
Authors: Khan A. R.
Published: April 2008

This paper reports the result of field experiments conducted in Agricultural Engineering Department Farm, Indian Institute of Technology, Kharagpur, India to estimate changes in water flux below the root zone of a peanut crop with varying irrigation levels in a lateritic sandy loam soil. The magnitude and direction of moisture flux around the root zone were considerably influenced by levels of irrigation and time.
Untersuchungen zur Bildung und Verteilung der Biomasse bei alten und neuen deutschen Sommerweizensorten
Authors: Feil B. , Geisler G.
Published: April 2008

Accumulation and distribution of dry matter in old and new german summer wheat‐cultivars

Five old german summer wheat varieties bred in the first third of this century were compared with five new varieties in an outdoor pot trial. The new genotypes outyielded the old varieties by only approximately 10%. It may be supposed that this small genetic gain in grain yield resulted from breeding for superior bread‐making quality. The new genotypes produced more kernels per plant. The tkw of both groups of varieties was nearly equal. However, new and old varieties did not show a particular yield structure. The grain/straw‐ratio of the new varieties was higher. The old varieties reached anthesis later and had produced more above‐ground biomass at anthesis as well as at maturity. Whereas the old genotypes had higher stem and sheath weights at flowering, the weights and areas of leaf laminae were simular for old and new varieties. The new genotypes tended to greater upper leaves and had greener lower leaves, but did not gain more dry matter after anthesis. The postfloral loss of dry matter from the vegetative tissue depended on the organ and the age of the varieties.
Effect of an Azolla Cover on the Conditions in Floodwater
Authors: Kröck T. , Alkämper J. , Watanabe I.
Published: April 2008

Azolla, a free floating waterfern which is used as green manure for rice, forms mats that cover the water surface. Light intensity, oxygen concentration and pH in the water under the Azolla cover were determined in the laboratory and in the field. The relative light intensity under a full cover of Azolla was about 10 percent. Azolla reduced the maximum oxygene concentration in water by 3–8 ppm. The pH was lowered by 1.4 points. The relationship between these characters and possible effects on the utrient conditions in floodwater and soil are discussed.
Effect of Air Humidity on Photosynthesis and Transpiration of Soybean Leaves
Authors: Zou D. S. , Kahnt G.
Published: April 2008

The responses of photosynthesis, transpiration, respiration, leaf conductance and cuticular transpiration to water vapour pressure deficit (VPD) have been simultaneously measured in single attached leaves of soybean in order to test the mechanism in the effects of air humidity on photosynthesis and transpiration. The results of present experiments have shown that the affecting mechanism of VPD or air humidity on the photosynthesis and transpiration is by means of controlling not only the stomatal behavior, but also the cultivars behavior, and the stomatal closure at high VPD or low air humidity is a function of the cuticular transpiration, rather than the stomatal transpiration.
Penetration Resistance, Root Growth, and Water Content in a Subsoiled Claypan1
Authors: Grecu S. J. , Kirkham M. B. , Kanemasu E. T. , Sweeney D. W. , Stone L. R. , Milliken G. A.
Published: April 2008

Penetration resistance, root length density, and water content of soil with maize (Zea mays L.), soybean (Glycine max [L.] Merr.), or a mixture of alfalfa (Medicago sativa L.) and fescue (Festuca arundinacea Schreb.) were measured during two summers, one of which was dry. Plants grew on a silt loam (Mollic Albaqualfs; fine, mixed, thermic), 0.25 m deep overlying a claypan, 1.75 m thick. Half of the plots were subsoiled before planting in the first year of the study and the other half were not subsoiled. During both years, subsoiling had no measurable effect in lowering the penetration resistance in the claypan. Root length density was greater in the claypan than in the topsoil. Subsoiling did not increase root length density in either year. Water content in plots that had been subsoiled was usually similar to that in plots that had not been subsoiled. In the dry year, roots of maize proliferated more in the claypan than did roots of soybean or alfalfa + fescue.
A New Hybrid Model for Panicle Growth in Rice (Oryza sativa L.)
Authors: Mohandass S. , Natarajaratnam N. , Kailasam C.
Published: April 2008

A significant positive correlation was found between grain yield of rice and rate of filling. We developed an hybrid model (combining both Richard's function and quadratic polynomial in one model) for calculating the filling rate. This model is found to be the best fit for panicle development in rice.
Effects of Shading Densities on Root Chemical Composition of Sugarbeet
Authors: Ghandorah M O. , Al‐Saad F. A. , El‐Rouby M. M. , Al‐Derfasi A. A.
Published: April 2008

The effect of different shading densities on some chemical composition of the roots of two sugarbeet cultivars was studied out during 1984/1985 season. Plants were grown under 0, 37, 50 and 70 % shading treatments.

Results showed that the capacity of root tissue in production or storage of sucrose was not directly dependent on light intensity as all the shading treatments did not change the sugar percentage. Therefore, it was suggested that the sucrose percentage in the root was a genetically‐dependent character more than an environmental one.

Also, shading had no significant effects on the chemical composition (protein, fiber, fat, ash and dry matter) of fresh roots at maturity, except the fiber percentage which was significantly increased only under the 70 % shading treatment.
Untersuchungen zum Wurzelwachstum von Jungpflanzen alter und neuer Winterweizensorten sowie eines Spelzweizens bei variierter N‐Versorgung
Authors: Feil B. , Geisler G.
Published: April 2008

Root growth of seedlings of old and new winter wheat cultivars and a spelt wheat at varying levels of nitrogen

Root growth of five old (time period 1882–1920) and five new (time period 1975–1982) winter wheal cultivars and a spelt winter wheat cultivar was investigated in two greenhouse trials. Nitrogen (NH4NO3) was supplied at six (Exp. I) and two (Exp. II) levels (sub‐ to supraoptimal for shoot growth). The seedlings were grown in sand‐filled polyethylene tubes of 4.5 cm diameter and 50 cm length at 20 oC. The plants were harvested 11 (Exp. I) and 12 (Exp. II) days after emergence. At this early stage of development root growth o: old and new cultivars differed only slightly. The old T. aestivum cultivars had more seminal roots. The longest roots of the modern cultivars penetrated into deeper layers of the substrate. For some traits, cultivar: seemed to respond specifically to the varying N‐supply. However, there were no significant difference: between old and new cultivars. Neither were old cultivars better adapted to low N‐fertilization nor were modern cultivars superior in tolerating toxic concentrations of NH4NO3. Increasing N supply changes root growth as follows: decline in root dry matter, increase in shoot/root ratio of dry weight, decrease in number of seminal roots, shortening of axes and more laterals, increase in diameter of the laterals and less significantly of the main roots, increase in density of laterals, decline in root surface area. The number of apices was affected only to a very small degree.
Grain Yield and Drought Resistance Indices of Oat Cultivars in Field Rain Shelter and Laboratory Experiments
Authors: Larsson S. , Górny A. G.
Published: April 2008

Oat cultivars (n = 22) varying in origin were examined in laboratory and field tests at Svalöv and Ultuna, Sweden, in 1985 and 1986. Comparisons were made between drought resistance characteristics of juvenile plants and drought responses in yield of crops grown in field. By using automatic, movable rain shelters in combination with drip irrigation systems, both high and low irrigation regimes could be effected in the field experiments.

Black oat cultivars were more stable under water deficiency conditions, particularly on sandy soil. They possessed the highest drought resistance indices both in the laboratory and field. Modern white oat cultivars were found to be most drought sensitive.

Drought resistance index (DRI) and seminal root length (RL), as assessed in seedling stage, were strongly correlated with field drought susceptibility index (S). It is suggested that DRI and RL could be used as selection criteria to increase drought resistance of oats.
Nitrate and Ammonium Uptake Kinetics of Three Annual Range Species
Authors: Dempsey P. M. , Shock C. C. , Williams W. A. , Carlson R. M.
Published: April 2008

The uptake kinetics of nitrate and ammonium ions was compared for the annual range species: subclover (Trifolium subterraneum L.), soft chess (Bromus mollis L.), and broadleaved filaree (Erodium botrys [Cav.] Bertol.) to study competitive interactions in nitrogen deficient soils. Fifteen‐day‐old seedlings were allowed to deplete solutions of nitrate or ammonium in the range of 5 to 500 μM concentrations for a 10‐hour period during which net uptake (depletion) was monitored by a sensitive conductance technique. Subclover uptake rates were markedly less than those for soft chess and filaree for both nitrate and ammonium at both low and high concentrations. The evidence supports the hypothesis that subclover is a poor competitor for soil N in part because of this physiological difference.
Root Distribution Characteristics of Paddy (IR 60) under Mechanical Impedance in Wetlands
Authors: Mathan K. K. , Natesan R.
Published: April 2008

Two field trials with paddy crop were raised to study the root distribution characteristics under mechanical impedance. Plots varying in bulk density were created by passing 400 kg stone roller (1 meter width) 8 times and 16 times. After harvest of the first crop 32P was injected to the paddy stubbles and the percentage of total radioactivity at different layers upto 30 cm was calculated to study the root distribution characteristics. The results revealed that 47.2 per cent of the roots are distributed in the first 10 cm of the soil, 29.5 and 23.3. per cent were found in the second and third 10 cm layers, respectively. As the mechanical resistance increased 62.9 to 67.0 per cent of the roots were found in the top 10 cm layer. The root distribution pattern in the second crop was studied by the procedure of Newman (1966). The trend of results were as for the first crop.
Temperature Regime of Azolla under Rice
Authors: Kröck T. , Alkämper J. , Watanabe I.
Published: April 2008

The effects of different rice canopies on the temperature regime of the Azolla plants and their immediate environment were studied in a paddy field in the Philippines.

Diurnal temperature cycles were measured in the field with thermocouples. Without rice plants Azolla temperature reached of up to 41°C, which was 6°C above air temperature. The rice canopy reduced the temperature of Azolla by up to 5°C. The relationship between the temperature of Azolla and of its environment (air and floodwater) is discussed. Differences between the two planting patterns of rice were obvious. With 20 × 20 cm spacing temperatures were reduced to a greater extend and at an earlier rice crop stage than with double‐narrow‐row spacing. Under extremely high temperatures the nee canopy may improve the conditions for the growth of Azolla.
Influence of Soil Water Regimes on VA Mycorrhiza
Authors: Sieverding E. , Toro T. S.
Published: April 2008

A greenhouse trial was conducted with cassava inoculated with seven different VAM fungal species, i.e. Acaulospora longula, A. myriocarpa, Entrophospora colombiana, Glomus fasciculatum, G. manihotis, G. occultum and Scutellospora heterogama. A wet and a dry soil water regime was established to study the effect of water stress on performance of these fungi with a drought tolerant cassava clone. At harvest, N, P and K concentration was analysed in leaves, petioles, stems and roots.

In unstressed plants, five endophytes were effective whereas in stressed plants only three fungi improved growth beyond the non‐mycorrhizal control. These were E. colombiana, G. manihotis and G. occultum which were most effective for P uptake under stress. Differential effects of VAM fungal species on root length and K. uptake were found. A. myriocarpa caused the greatest increase in length of feeder roots and G. occultum was one of the most effective for K uptake under both water regimes even though these fungi were not the most effective for dry matter production. Under each water regime, the concentration of N, P and K in leaves, petioles, stems and roots was influenced by the fungal species. Mycorrhizal endophytes differed in tolerance to dry soil conditions as found by root infection ratings. From the results it can be concluded that in addition to the improved P nutrition the enhanced root length and K uptake by VAM fungi may be important for drought tolerance of cassava.
Einfluß des Standortes, der N‐Düngung, der Sorte und des Erntezeitpunktes auf den Ertrag an fermentierbaren Zuckern bei Topinamburkraut und ‐knollen
Authors: Leible L. , Kahnt G.
Published: April 2008

Effect of location, N‐fertilization, variety and harvest date on the yield of fermentable sugars of Jerusalem artichoke tops and tubers

In the past, the production of fermentable sugar with Jerusalem artichoke (Helianthus tuberosus L.) resulted nearly exclusively from tubers.

It should be investigated to what extent the tops can be used beside tubers as a source of fermentable sugars, connected with studies about diverse components of yield and morphological characteristics.

In field trials at three locations in the south‐west of Germany in 1983 and 1984 yields of “Total Fermentable Sugars” (TFZ) with Jerusalem artichoke tops up to 6.7 t/ha were achieved according to variety, N‐fertilization and harvest date. While harvesting Jerusalem artichoke tubers yields of TFZ up to 8.3 t/ha had been feasible.

The presented correlations between components of yield and morphological plant characteristics refer to interesting mechanisms of reaction and dependence on the formation of yield with this crop. The high yield level of Jerusalem artichoke and its adaptability to different locations also present this crop as an interesting renewable biomass crop for the south‐west of Germany.
Alternate Selection Indices for Leaf Photosynthetic Rate in Greengram (Vigna radiata [L.] Wilczek) Cultivars
Authors: Chandra Babu R. , Moosa Sheriff M. , Muralidharan V. , Seetharani M.
Published: April 2008

Significant differences were observed for leaf net photosynthetic rate, chlorophyll content, soluble protein content, nitrate reductase activity, stomatal frequency and specific leaf mass among ten greengram cultivars. Leaf net photosynthetic rate had significant positive correlation with soluble protein, nitrate reductase activity, stomatal frequency and specific leaf mass. Leaf net photosynthetic rate had no relationship with leaf chlorophyll content in greengram.
Methodologische Entwicklungslinien in der Pflanzenbauforschung*
Authors: Krug H.
Published: April 2008

Methodological lines of development in plant production research

Concerning plant production research 2 lines of methodological development are presented: Physiological approaches orientated primarily to botany at low abstraction level and approaches primarily orientated to plant production based on the black box model at high abstraction level. The limits and chances of these approaches and the problems related to application are discussed. Their use for greenhouse production is presented concerning the development of planning‐, long term control‐ and on‐line control models at high abstraction level.

Für die Pflanzenbauforschung werden 2 me‐thodologische Entwicklungslinien aufgezeigt: Die vorwiegend an der Botanik orientierten, physiologischen Ansätze auf niedriger Ab‐straktionsebene und die vorwiegend pflanzen‐baulich orientierten, von der, black box“‐Me‐thode ausgehenden Ansätze auf hoher Ab‐straktionsebene. Die Grenzen und Möglich‐keiten dieser Ansätze und die mit ihrer An‐wendung verbundenen Probleme werden dis‐kutiert. Ihre Nutzung für die Gewächshaus‐produktion wird anhand der Entwicklung von Planungs‐, Steuerungs‐ und Regelungsmodel‐len auf hoher Abstraktionsebene beschrieben.
Variability in Salt Tolerance of Nine Spring Wheat Cultivars
Authors: Ashraf M. , McNeilly T.
Published: April 2008

The biotic approach to overcome salinity problems has recently received a considerable attention from many workers throughout the world. However the identification of existing crop varieties which have enhanced salt tolerance is clearly of considerable value for exploitation of saline soils for agriculture.

Salt tolerance of the nine spring wheat cultivars Bounty, Jerico, LU 26S, Minaret, Sonora 64, Timmo, Toban 66, Tonic, and Wembley was assessed at germination, and at maturity using solution and sand culture techniques. No consistent correlation was found between tolerance assessed at these two growth stages in any of the cultivars except Wembley.

The salt tolerant cultivar LU 26S had significantly higher germination percentage and germination rate than the other cultivars, but was intermediate in yield. By contrast cv. Tobari 66 had low germination percentage, intermediate germination rate, but had a higher yield than the other cultivars particularly at the highest salt level. The cv. Wembley had low values in all the characters studied and thus appeared to be very salt sensitive compared with the other cultivars. There was not any consistent relationship between yield characters and ionic content in these cultivars.

A general selection criterion based upon whole plant performance for assessment of salt tolerance in wheat is proposed.

Variabilität der Salztoleranz von neun Som‐merweizensorten

Die Salztoleranz von neun Sommerweizensor‐ten: Bounty, Jerico, LU 26S, Minaret, Sono‐ra 64, Timmo, Tobari 66, Tonic and Wembley wurden bezüglich des Keimens und der Aus‐reife untersucht. Bei den geprüften Sorten wa‐ren mit Ausnahme von Wembley keine Bezie‐hungen bezüglich der Salztoleranz für diese beiden Entwicklungsphasen festzustellen. Die Sorte LU 26S wies höhere Keimprozente und Keimraten auf als andere Sorten, ergab aber nur einen mittleren Ertrag. Die Sorte Tobari 66 hatte niedrige Keimprozente, eine mittle‐re Keimrate und höhere Erträge als andere Sorten; dies gait insbesondere für eine hohe Salzgehaltstufe. Die Sorte Wembley erschien dagegen sehr sensitiv in bezug auf die Salzver‐träglichkeit in alien untersuchten Eigenschaf‐ten. Es konnte kein konsistentes Verhältnis zwischen den Ertragseigenschaften und dem Ionengehalt nachgewiesen werden.
Möglichkeiten zur Beeinflussung der Ertragsleistung von Mais (Zea mays L.) durch Wachstumsregulatoren*
Authors: Kötting K. , Hofmann K. , Höfner W.
Published: April 2008

Possibilities to influence the productivity of maize (Zea mays L.) by growth regulators

The application of plant growth regulators to maize shalt improve the resistance to lodging by a reduction of ear — and plant height as well as by an increase of stalk diameter. At the same time, the sink‐capacity of the ear shalt increase because this is lucrative to all specializations of corn production.

The applicated plant growth regulators CCC and RSW 0411 antagonize the content of native gibberellic acids, so that these active substances may influence the stage of the stem elongation and the development of the inflorescences. However, it is very difficult to conceive the numerous interrelations between the several groups of hormones. During a period of 3 years, the plant growth regulator CCC, applied at fixed stages of the development, effected a significant increase of the number of kernels per ear and of the grain yield per pot. Only the plant growth regulator RSW 0411 caused vegetative modifications according to the fixing of an aim at an early treatment, whereby the grain yield was effected strongly negative by a considerable reduction of ear — and plant height.

In dreijährigen Gefäßversuchen unter Frei‐landbedingungen mit verschiedenen Maissor‐ten wurden die Auswirkungen der Wachs‐tumsregulatoren CCC und RSW auf die generative und vegetative Entwicklung beobachtet. Dabei erzielten wir folgende Ergebnisse: 1. Der Kornertrag wurde durch den Wachs‐tumsregler CCC, appliziert in ES 31/32, um 10,0 % und, appliziert in ES 34/35, um 8,9 % signifikant gesteigert. Der Wachstumsregula‐tor RSW wirkte sich bei einer frühen Behand‐lung in ES 21/23 stark negativ (‐ 14,4 %) auf den Kornertrag aus, zeigte jedoch bei späterer Applikation positive Tendenzen (+ 5,4 %),

2. Die Kornzahl je Kolben wurde durch CCC um 10,4 % (ES 31/32) bzw. um 7, 3 % (ES 34/35) signifikant angehoben. Der Wachs‐tumsregler RSW senkte bei frühem Einsatz in ES 21/23 die Kornzahl hoch signifikant um 19,2%.

3. Das TKG blieb bei alien Behandlungen unverändert.

4. Eine tendenzielle Einkürzung der Ge‐samtpflanzenlänge bewirkte der Wachstums‐regler RSW bei frühem Einsatz in ES 21/23.

5. Die Kolbenansatzhöhe wurde durch den Wachstumsregler RSW, appliziert in ES 21/23, um 30,7 % und, appliziert in ES 34/35, um 5,2 % signifikant reduziert. Der Wachstumsregler CCC zeigte bei der späten Behandlung eine statistisch abgesicherte Förderung dieses Parameters.

6. Die frühe RSW‐Behandlung (ES 21/23) bewirkte eine hoch signifikante Zunahme der oberen Stengellänge.

7. Das Strohgewicht blieb bei alien Behandlungen unverändert.

8. Die Gesamttrockensubstanzerträge je Ge‐fäß wurden entsprechend den Veränderungen der Kornerträge signifikant variiert.
Nitrogen Balance of Legume‐Wheat Cropping Sequences
Authors: Jung J. , Dressel J. , Kuchenbuch R.
Published: April 2008

In a lysimeter trial the legumes faba bean (Vicia faba), red clover (Trifolium repens), and alfalfa (Medicago sativa) were grown for two years, followed by winter wheat on all plots in the third year. Plots fertilized with mineral nitrogen and a rye/maize – wheat cropping sequence were included for comparisons. These four cropping sequences were replicated twice in 1982–1984 and 1985–1987, respectively. Two soils, a loamy sand and a sandy loam were used.

On average of both soils:

– N fixation during two years was 461 kg N/ha, 803 kg N/ha, and 790 kg N/ha for faba bean, red clover, and alfalfa, respectively.

– Leaching of nitrogen occurred mainly during the periods of winter fallow or, in case of the perennial legumes, after incorporation of residues into the soil and planting of wheat. Average leaching for all 6 years was 49, 28, and 29 kg ha−1 year−1 for faba bean, red clover, and alfalfa, respectively.

– In the period of wheat growth and before planting the new crop (1.5 years) in 1984/85 51–64 kg N/ha and 1986/87 68–94 kg N/ha were leached after growing legumes. Leaching was less for rye/maize fertilized with mineral N, 41 kg N/ha in 1984/85, and 51 kg N/ha in 1986/87, respectively.

– Winter wheat grown after legumes took up 18 kg N/ha < 47 kg N/ha < 65 kg N/ha on average of both soils and 2 years (1984, 1987) after faba bean, red clover, and alfalfa, respectively. This indicates a nitrogen recovery of 24–44% of the legume N potentially available, and consequently a loss by leaching from 56 to 76 %.

On the sandy loam amount of drainage water and N leaching were lower, and faba bean and wheat yields higher than on the loamy sandy soil.
Effects of Seed Vigor on Crop Characters in Uniform and Reduced Populations of Corn (Zea mays L.)
Authors: Adegbuyi E. , Burris J. S.
Published: April 2008

The relationship between seed corn vigor and some crop characters in uniform and reduced plant populations is poorly defined. This study, was designed to define the crop characters through which seed vigor is expressed in reduced and uniform populations of corn and to clarify which experimental technique should be used in seed vigor studies. Seeds of two corn hybrids, A632 x (H99 x H95) and B73 x (H99 x H95), were dried at two temperatures, 35 °C and 50 oC, and planted near Ames, Iowa, in 1983. The two drying temperatures created differential vigor levels between the seed lots. There were 21 crop characters measured in two populations, reduced populations due to lack of seed vigor and uniform population (thinning to stand). Early vegetative growth was influenced by seed vigor, but as the plant aged, the influence of seed vigor decreased. Increased early plant height, up to 6 weeks old, small stem diameter, low shoot dry‐matter content, delay in days from sowing to 50 % tasseling and to 50 % silking, narrow penultimate and ear leaf, and reduction in the number of ears and tiller production were observed in the uniform population. The differences in population density due to seed vigor did not have a significant effect on final grain yield inasmuch as plants in the reduced populations were able to compensate completely for missing stands.