Kohlehydratfraktionen im reifenden Weizenkorn unter dem Einfluß von Stickstoff und Chlorcholinchlorid

Components of carbohydrates in wheat kernels during the ripening process influenced by nitrogen fertilization and chlorcholinchloride The variability of carbohydrates was analysed in ripening kernels of wheat treated with nitrogen and chlorcholinchloride. 1. Proceeding ripening in wheat kernels (green, yellow, matured kernels) shows an important decrease of monosaccharides and total sugar. A distinct Influence of CCC — just as a possible postponement of ripening — marked with usually higher contents of monosaccharides and total sugar could be ascertained in green kernels only. 2. The synthesis of starch is not influenced by high nitrogen fertilization and essentially finished till the grain is yellow. By CCC-treatment, compared with untreated plants, a much lower content of starch is caused in green and yellow grains, in matured such differences are detectable scarcely. The decrease of starch content with high nitrogen fertilization is more important than that caused by CCC.     

Entwicklung und Ertrag von Sommerweizen in Hydrokultur unter dem Einfluß verschiedener Ernährungsbedingungen

Development and yield of spring wheat in water culture as influenced by nutrient concentration. The development of spring wheat cv. Solo grown until maturity in nutrient solutions of normal concentration changed weekly, differs from similar plants growing in soil. In experiments in which nutrient supply was reduced at different growth stages, an attempt was made to minimize the differences. These consist mainly of permanent tillering, retarded senescing of leaves and in dry matter accumulation in the grain. 1) Reducing the total nutrient supply during the grain filling period decreases the chlorophyll-con-tent of the flag-leaf at an earlier stage and hence also its ability to assimilate CO₂. This reduction in nutrient supply has thus a beneficial effect on the development of the grain by allowing a better coordination with leaf senescence and an increase in nitrogen and dry matter transfer from the flag leaf to the grain. 2) The retarded response to a reduction of the nutrient concentration points to a “luxury consumption” in the vegetative phase. This might be the reason why it was not really possible to achieve optimal timing of vegetative and generative development. 3) After examination of the effect of lowering the nutrient supply in the vegetative phase, a nutritional design for growingspring wheat in water culture was proposed. This consists of lowering the concentration to meet the needs of plants and comprises a rise and fall of the concentration (0.25,0.5, 0.75,0.5 and 0.25 of the normal conc., see fig. 4). 4) Comparing 0.4 and 0 mMol/l N during the grain filling(other nutrients supplied according to the concept outlined above), the relevance of nitrogen for the CO₂,-assimilation capacity and more obviously for the senescence of the flag leaf was shown. Nitrogen deficiency decreases the assimilation ability within a short time and depresses grain development. These findings confirm the validity of the nutritional concept proposed.     

Anorganisch-katalytische Umsetzungen von Cyanamid und dessen Metaboliten in Quarzsand II. Cyanamidabbau unter dem Einfluß von Metalloxiden und Temperatur

Inorganic catalytical breakdown of cyanamide and its metabolites in quartz sand II. Cyanamide breakdown as influenced by metal oxides and temperature The inorganically catalysed breakdown of cyanamide with addition of water in presence of metal oxides was studied in quartz sand. Cyanamide breakdown and the formation of metabolites was investigated in relation to the kind and quantity of metal oxides as well as temperature.

• 1 The oxides or hydroxides of Mn, Cu, Zu, Ni, Co influenced the rate of cyanamide breakdown very differently.
• 2 Decreasing the quantity of oxides (amorphous Fe(III) – hydroxide, ochre, rust) from 0.5 to 0.1 g or 0.05g/100g of quartz sand retarded cyanamide breakdown in an oxide specific formation of urea and dicyanamide.
• 3 The influence of temperature (5 and 18°C) on the breakdown was not so great as that of moisture (5% and 150% of the water capacity).
• 4 A low temperature (5°C) and high moisture regime (150% of the water capacity) retarded cyanamide breakdown considerably almost completely stopping it. The type and concentration of the metal oxide (iron oxide) as well as the moisture and temperature of the reaction medium are very important in the inorganically catalysed cyanamide and water reaction leading to the formation of urea or dicyanamide.

     

Anorganisch-katalytische Umsetzungen von Cyanamid und dessen Metaboliten in Quarzsand I. Mechanismus des Cyanamidabbaues unter dem Einfluß von Eisenoxiden und Feuchtigkeit

Inorganic catalytical transformation of cyanamide and its metabolites in quartz sand I. Mechanism of cyanamide breakdown as influenced by iron oxides and moisture A study was made of the inorganically catalysed breakdown of cyanamide by iron oxides in quartz sand, and the formation of metabolites in relation to the type of iron oxide and the moisture level in the system. The possibility that cyanamide breakdown was biological and enzymic was largely eliminated.

• 1 In the absence of iron oxides the added cyanamide was practically unchanged over the 100 days of the experiment.
• 2 With the addition of iron oxides such as amorphous Fe(III)-hydroxide, ochre or rust, the cyanamide rapidly took up water after a few hours and urea was formed. Water uptake was dependent on the type of iron oxide added. When the moisture level in the reaction medium was low (5% of the total water capacity) the process was accelerated.
• 3 Different amounts of dicyanamide and guanylurea were produced depending on the iron oxides applied. When the water content was high, reactions leading to the production of these compounds were slowed down.
• 4 The inorganically catalysed breakdown of cyanamide depends on reaction conditions. It can result either in the uptake of water to produce urea directly or in the production of dicyanamide which gives rise to guanylurea by the further addition of water.

     

Variabilität der Ertragsstruktur von Sommerweizenähren unter dem Einfluß von Stickstoff – Düngung,Thermoperiode und Wachstumsregulatoren

Variability of the yield structure of spring wheat ears caused by nitrogen – supply, thermoperiod and growth regulators In two years pot experiments with spring wheat, the effect of different exogenous growth factors (N - supply, growth regulators, thermoperiod) on ear development in monoculm plants was studied. All three growth factors brought about a comparible change in the internal dominance structure of the ear. Medial-dominance within the ear was diminished by both increased N supply and growth regulators whereas it was augmented by raised temperature during organogenesis of the ear. The application of growth regulators reduced the number of spikelets per ear, but did not necessarily lead to reduced fertility of the total ear. The influence of the growth regulators with anti-gibberellic effect on dominance structures in the plant is explained by an increase in respiration which improves attraction of assimilates into the ear.     

Reinprotein,Chlorophyll, Carotin und Kohlenhydrate bei Daucus carota im Verlauf der Vegetationsperiode des ersten Jahres unter dem Einfluß von Wachstumsregulatoren

Pure protein, chlorophyll, carotene, and carbohydrates of Daucus carota throughout the vegetative period of first year as influenced by growth regulators (CCC, GA and BA) . 1) Carrot plants were treated for 9 weeks with gibberellic acid (GA₃), benzyladenine (BA) and chlorcholinechloride (CCC). 2) Yield of carrot roots (g/plant) was reduced by GA, and changed insignificantly by CCC and BA. Leaf yield was increased with GA and BA, and decreased with CCC. 3) The quantity of pure protein in carrot roots (mg/plant) increased with CCC and decreased with GA and BA. Opposite results were obtained for leaves. 4) The quantity of hydrolysable carbohydrates (g/plant) in roots decreased with GA, BA and CCC. In leaves GA and BA increased the yield of carbohydrates whereas CCC decreased it. 5) The quantity of carotene (mg/plant) in roots decreased strongly with GA and negligibly with BA. CCC increased the yield of carotene. 6) The quantity of chlorophyll (mg/plant) increased with GA and decreased with CCC. BA increased chlorophyll during the first half phase of the vegetative period and decreased in the other half phase. 7) Following relations were calculated for the duration of the vegetative period: a) hydrolysable carbohydrates to pure protein of leaves and roots. b) carotene (in the roots) to pure protein (in the leaves) c) Carotene (in the roots) to carbohydrates (in the roots) d) carbohydrates to chlorophyll in the leaves, furthermore was calculated e) the storing power of the living system of leaves for carbohydrates in the roots. 8) The time curves for daily synthesis capacity of system of leaves or their storing capacity for products in the roots show that protein, chlorophyll and carotene of leaves behave as components of the system while carbohydrates (as expected) belog to the product. Contrary to that the daily storing capacity of the system of leaves shows that protein, carotene and carbohydrates in the roots belong to the product. Thus the root proves to be a genuine storage organ in which the major quantities of protein and carotene are not involved in the metabolic processes but can be regarded as stored or end products. .     

Zuckerbildung in Möhren unter dem Einfluß einer Behandlung mit Harnstoffderivaten,Carbamaten und Amiden

Effect of applications of phenyl-ureas, -carbamates and -amides on synthesis of sugar in carrots . In field and pot trials with mineral and peaty soil respectively lower moor the synthesis of sugar was studied with carrots treated with herbicides of the type of phenyl-ureas, -carbamates and amides. In field trials the success of the chemical weed control determines the yield and sugar content. In pot trials the application of herbicides diminishes the yield and formation of sugar. From the 3 predominant sugars of carrots (glucose, fructose and sucrose) the disaccharid is reduced the most in spite of frequently unchanged respectively slowly increased reducing sugars. It is supposed, that the synthesis of disaccharides from monosaccharides is inhibited by an increased activity of phosphatase.     

Chlorophyllumwandlungen im lebenden Blatt unter dem Einfluß von KCN

Zusammenfassung Bei Chlorophyll b-freien Mutanten der Sorte Donaria vonHordeum vulgare war unter dem Einfluß von KCN im lebenden Blatt ein Farbstoff aufgetreten, der bei 650 nm absorbiert. Es konnte gezeigt werden, daß es nicht Chlorophyll b ist, sondern ein Umwandlungsprodukt von Chlorophyll a. Seine Bildung wurde durch Licht stimuliert und trat in vitro nicht ein.

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Chlorophylldecompositions, induced by KCN in the living leaf

Summary In mutants of the sort Donaria fromHordeum vulgare, that lacked chlorophyll b, a pigment appeared under the influence of KCN in the living leaf, that had an absorption band at 650 nm. It was possible to show that this pigment was not chlorophyll b, but a decomposition product from chlorophyll a. Its formation was stimulated by light and did not occur in vitro.

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V (Hordeum vulgare) , b, KCN , 650 . , b, a. in vitro.

     

Standorteigenschaften und Wasserhaushalt von versiegelten Flächen

Site characteristics and hydrology of sealed aereas Soil physical and chemical properties of typical sealed urban sites in Berlin were measured. Water components were determined using lysimeters with differently sealed surfaces. Water storage and infiltration is small and depends on sealing materials. Evapotranspiration and drainage are reduced whereas runoff is increased. During summer time high surface temperatures might occur on sealed surfaces. Because of high dust input, infiltration of old sealed sites is reduced by an order of magnitude compared to sites which have been sealed recently. Long-term input of dust resulted in an increase of clay, silt, organic material and heavy metals. Finally specific recommendations for land planners are given.     

Einfluß der Berechnungsbasis auf die Interpretation von Daten zum Corg-und Nt-Umsatz bei Rotteprozessen unter besonderer Berücksichtigung des Einsatzes von Zuschlagstoffen

Influence of the calculation basis on the interpretation of C_org and N_t data in decomposing processes of organic materials with particular regard to the use of additives The suitability of the parameters fresh matter (FM), dry matter (DM) and ash as a basis of calculation in the interpretation of changes in C_org and N_t contents are discussed from model experiments with cattle slurry and forest litter. Total ash which remains constant is well suited to give information about the absolute changes in C_org and N_t. The addition of bentonite to both slurry and litter revealed that the use of additives which affect the FM:DM:ash ratio in the decomposing material may lead to misinterpretations. Appropriate formulas are suggested for mathematical correction of these parameters accounting for the effect of additives.     

Einfluß von Bewässerung und Plazierung von markierten Stickstoff-Düngern auf Ertrag und Stickstoffentzug bei Weizen unter semiariden Klimabedingungen im Iran

Effect of Irrigation and Fertilizer Placement on the N-Uptake by Wheat under Semiarid Conditions of Karadj/Iran Field and greenhouse experiments were conducted under semiarid conditions of Karadj/Iran on a sandy to silty loam of alluvial soils (pH% 8,2) to study the effects of soil moisture regimes and N-fertilizer placement on yield, N-uptake and recovery of fertilizer N from ¹⁵NH₄ ¹⁵NO₃, (¹⁵NH₂)₂CO and (¹⁵NH₄)₂SO₄. There were two moisture regimes as main plots (W₁ = Irrigation at 50% and W₂ = Irrigation at 25% available water in 0–30 cm depth of soil), and two methods of fertilizer placement (broadcast and band application). Irrigation at (W₁) increased the grain and straw yield 11 and 19% but not total N-uptake in the field experiment. (W₁)-irrigation combined with band application resulted in the highest yield and total N-uptake. Utilization of applied N, however, was higher with (W₂)-irrigation in both fertilizer placements. This result was confirmed by the data of the greenhouse experiment. Band application was superior to broadcast application for fertilizer N-uptake with both water managements. Ammonium sulfate showed the highest and urea the lowest difference between the two fertilizer placements.     

Einfluß der VA-Mykorrhiza auf P-Aufnahme und Regenerationsfähigkeit von Mais (Zea Mais L.) unter Wasserstreß

Influence of the VA-Mycorrhiza on P uptake and recovery potential of corn (Zea mays L.) under water stress conditions In a seven week pot experiment the influence of the VA-Mycorrhiza on P uptake and water stress tolerance of corn was investigated. During the eight day water stress period the VAM-plants took up less phosphorus than the control plants. However, during the successive five day recovery period under a normal water regime the VAM-plants showed an increased root growth and an enhanced phosphorus uptake compared with the control plants. The free prolin concentration was lower in leaves of VAM-plants than in those of nonmycorrhizal plants at the end of the water stress period, pointing to a different water stress tolerance.     

Nährstoffgehalte von lössboden-toposequenzen in südniedersachsen und franken unter dem einfluss der bodenerosion

This paper deals with the effects of soil erosion on the horizontal and vertical distribution of nutrients in loess soil topo-sequences in southern Lower Saxony and Frankonia (W. Germany). Each topo-sequence consists of three parts: an upper plateau (or edge of a piedmont plain) with little soil erosion up to now, a slope which as a whole has been eroded very much, and a slope foot which is covered with colluvial sediments. Compared to the pure loess the soils contain more K, Na, and P, and less Ca. The distribution of the nutrients within the investigated topo-sequences is caracterized by high contents of potassium on the slopes, provided that the A₁-horizon is eroded, so that the B¹-horizon has come to the surface. Finally it is considered whether the erosion-made differentiation of nutrients has negative or positive consequences on the productiveness of the arable soils.     

Der Wasserhaushalt von Fichte in Abhängigkeit von Boden und Atmosphäre

The water regime of spruce in relation to soil and atmosphere Simple observations of the water regime of potted spruce trees and measurements in the field are reported, followed by a discussion of spruce water potential in relation to soil and atmosphere water potentials. When the soil is sufficiently moist water regime of spruce is determined by the atmosphere. As higher the atmospheric demand and as lower the hydraulic conductivity of the soil as more difficult it is for a spruce plant to supply transpired water and more and more the potential transpiration rate is reduced. For short term aspects water storage in leaf tissues is of high importance. Observations show the possibility of water uptake by needles if wetted by rain or dew. The maximum amount of this way of water absorption is also given by the internal storage capacity.     

Einfluß von N-Lignin auf Wachstum und N-Stoffwechsel von Weizen-Zellsuspensionskulturen

The effects of N-Lignin on growth and N-metabolism in wheat cells in suspension cultures N-Lignin is an organic N-fertilizer which is synthesized from waste liquors of the pulp industry by oxydative ammonisation. Nearly 40% of its N-content is available as ammonium, the rest is linked in organic compounds. Water-soluble fractions of N-Lignin were added to the nutrient solutions of wheat cells in suspension cultures in order to study the effects on growth and N-metabolism. The experiments show that N-Lignin is a suitable nitrogen source for growing wheat cells. The best growth was achieved when 50% of the total nitrogen content of the medium were added as N-Lignin nitrogen. This mixture of N-Lignin and nitrate was even superior to the standard B-5-medium with respect to the final dry weight. However, higher concentrations of N-Lignin inhibited cell growth. The effect of N-Lignin on cell growth is not only influenced by ammonia. If wheat cells were grown on media with ammonium-N as the sole nitrogen source acids of the citrate cycle had to be added to support growth. This was not necessary with N-Lignin. N-Lignin therefore seems to effect the energy metabolism. High amounts of ammonium-N or the reduced N-fractions of N-Lignin respectively resulted in an increase of certain amino acids and especially of the two amides glutamine and asparagine. Furthermore root formation was observed with cells grown in media containing N-Lignin or ammonium-N. The root formation seemed to be correlated with added amounts of reduced nitrogen. Root formation was not observed with cell cultures incubated with N-Lignin solutions which were made free of ammonium-ions with a cation exchanger (Amberlite IR-120) loadad with potassium. This indicates that the differentiation of roots in the normally embryonic cells is due to the ammonium-N content of N-Lignin. A possible correlation between the content of glutamine and asparagine and the formation of roots is discussed.     

Einfluß von Monoethanolamin auf Ertrag und Wasserausnutzung von Sommergerste

Effect of monoethanolamine on yield and water use efficiency of barley The effect of monoethanolamine (EA) on yield and water use efficiency (WUE) of spring barley plants was tested in pot experiments. The application of EA (8 to 12 mg/pot) increased the grain yield and WUE by about 4 to 15 per cent under stress conditions. In addition, EA improved the utilization of fertilizer nitrogen. The yield-increasing effect of EA was associated with an increase of the number of ear-bearing tillers and an improved root growth. The effects of EA were only significant at α = 0.05.     

Wasserhaushalt und Dickenwachstum von Kiefern in Abhängigkeit des Grundwasserflurabstandes

Water budget and annual ring growth of pines for different groundwater depth conditions Relation between annual ring width and water supply was examined for different groundwater depth in an old pine stand on a sandy soil. The quotient Ereal/Epot is a suitable parameter to quantify water stress. Multiple regression analyses were used to describe the dependence between annual ring width and water stress. Mean growth of basal area can be expressed by Ereal/Epot of the actual and previous year. This site specific function was used to quantify growth reduction affected by ground-water lowering for various soil conditions.