Einfluß der Stickstoffernährung auf qualitative und quantitative Sameneigenschaften von Raps (Brassica napus L.)

Influence of the nitrogen-nutrition on qualitative and quantitative characteristics of seeds of rape (Brassica napus L.) An experiment was carried out under greenhouse conditions to analyse the influence of nitrogen nutrition on qualitative and quantitative characteristics of seeds of rape, variety “Erglu”. Increasing the level of nitrogen fertilization raised the crude protein content during the whole period of seed growth but decreased the lipid content during the main seed growth stages. Nitrogen nutrition only changed the fatty acid composition significantly during the early stages of seed growth. Increasing nitrogen fertilization resulted at maturity in a trend towards higher contents of palmitic and linoleic acids but in a lower content of oleic acid. At maturity the lipid content was not influenced by the level of nitrogen nutrition. The differences in seed-yield per pod between the main branch and axillary branch 5 became smaller when nitrogen nutrition was increased.     

Einfluß der Stickstoffernährung auf den Gehalt an Chlorophyll und Galaktolipiden alter und junger Rapsblätter (Brassica napus L.)

Effects of nitrogen nutrition on the contents of chlorophyll and galactolipids in young and older leaves of oil-seed rape (Brassica napus L.) The effect of nitrogen nutrition upon chemical characteristics of chloroplasts from young and older leaves of oil-seed rape (Brassica napus L.) were investigated. Nitrogen influenced the chlorophyll content especially of older leaves. As compared to the optimum supply, the values of young leaves were only reduced at the extreme deficiency and the excessive supply. In contrast to the content of chlorophyll the amounts of monogalactosyl diglyceride of both young and older leaves depended strongly on N-supply. Generally, the amounts of digalactosyl diglyceride were not related to leaf-age and N-supply. With the exception of extreme deficiency the contents of linolenic acid in galactolipids were influenced by nitrogen mainly in older leaves. (Brassica napus L., N-supply, Leaf-age, Chlorophyll, Galactolipids)     

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.     

Einfluß der Wachstumsregulatoren CCC und Ancymidol auf die Fertilität von genetisch einhalmiger Sommergerste (Hordeum vulgare L.)

Influence of the growth-regulators CCC and Ancymidol on the fertility of genetically monoculm ring barley (Hordeum vulgare L.). 2 years pot experiments with monoculm barley resulted in a 25 % increase of grain yield by the application of a mixture of CCC and Ancymidol. The main reason for this higher yield of grains was an improved fertility of the ears, resulting in a higher number of grains in the upper part of the ear and also of the total ear. The harvest index was shifted towards a higher fraction of grains by the growth regulators, whereby She dry matter yield of plant material remained unchanged. In the straw of all growth regulator trials, the percentage of leaves was higher than in the controls, though the absolute leaf weight was highest in the controls.     

Identifizierung und Bestimmung einiger Gibberelline und der Einfluß von Chlorcholinchlorid (CCC) auf das Gibberellinspektrum der einzelnen Getreidearten

Identification and determination of some gibberellins in the gibberellin spectrum of some cereals, als affected by CCC treatment The gibberellin contents of wheat, barley and oat plants, treated with CCC, were studied during the vegetative period. It was possible to identify a characteristic gibberellin spectrum for every cereal plant examined, although the variation was in a limited number of gibberellin forms. A great variation in the content of individual gibberellic acid forms was noticed, as well, among the different cereals studied. The highest content of gibberellins was found with GA₃. The content of GA₅ was lower than that of GA₉ while was not generally higher than that of GA₈. CCC-treated cereal plants showed lower values of gibberellins when compared with those of control. On the other hand, CCC treatment did not affect the content of gibberellins in the spikes which showed a considerably high content of GA₃, GA₅ and GA₉. A higher content of GA₇ was observed in both barley and oats, but not in the case of wheat, during tillering stage. However it was difficult, from the results of the present work, to indicate whether GA₇ is reponsible for the week effect of CCC obtained with both barley and oats or not.     

Der Einfluß der Kalium-Ernährung auf den Gehalt und das Spektrum löslicher Aminoverbindungen in Rotklee (Trifolium pratense L.)

Effect of potassium nutrition on the content and the spectrum of soluble amino compounds in Red Clover 1. A better K nutrition of Red Clover (Trifolium pratense) resulted in higher contents of soluble amino acids of the upper plant parts. The plants of the treatment with the highest K application showed nearly double as high contents of glutamic acid, aspartic acid, alanine and γ-aminobutyric acid than the plants of the K₀ treatment. The content of asparagine was not as much affected by the K nutrition and the content of glutamine was even lowered. 2. Red Clover responded on the K treatment with its content of soluble amino compounds quite different than non leguminous plant species which show decreasing contents of soluble amino acids with an increasing K nutrition. Therefore it is concluded, that the K nutrition of legumes affects the N₂-fixation of Rhizobium leguminosarum. 3. The higher contents of soluble amino compounds did not influence the protein content of the upper plant parts. But with the better K supply the yields were increased considerably and therefore also higher yields of proteins were harvested. Very low K supply resulted in a high protein content, due to an inhibition of plant growth.     

Einfluß der Cl-Ernährung auf Ertrag und Nitratgehalt von Spinat und Kopfsalat

Effect of Cl-supply on yield and nitrate content of spinach and lettuce The N-supply for maximum yield could be reduced for spring spinach from 250 to 200 kg N/ha, for autumn spinach from 200 to 150 kg N/ha without yield depressions by optimized Cl-supply. The optimal Cl-supply consisting of Cl-content in 0–60 cm soil depth and Cl-fertilization was about 350 kg Cl/ha. However, Cl-supply in top soil should not exceed 300 kg Cl/ha in order to avoid emergence decreases. Different amounts of Cl-fertilizer were necessary because soils of experimental sites contained chloride in the range of 66 to 435 kg Cl/ha. The nitrate content was reduced up to 50% by Cl-fertilization. This was caused by reducing the N-supply by 50 kg N/ha and to an increased nitrate reduction. The heighest head weight of lettuce could be achieved with N-supply of 90 kg N/ha and additional Cl-fertilization. Reducing the N-supply from 120 to 90 kg N/ha and improvement of Cl-nutrition decreased nitrate content considerably. Cl-supply should not exceed 150 kg Cl/ha in 0–30 cm, because lettuce reacts sensitive to saline conditions.     

Der Einfluß gesteigerter Stickstoffgaben auf die Entwicklung der Wurzelknöllchen,auf die symbiontische Stickstoffassimilation sowie auf das Wachstum und den Ertrag von Ackerbohnen (Vicia faba L.)

The effect of increasing nitrogen fertilizer rates on the development of root nodules, on the symbiotic N₂ assimilation, and on growth and yield of broad beans (Vicia faba L.) In pot experiments with broad beans (Vicia faba minor) the effect of increasing N fertilizer rates (0–800 mg N/pot) on nodulation, symbiotic N assimilation, plant growth, and yield has been studied. The plants were harvested at the beginning and at the end of flowering and at maturity. The following results were obtained: 1. No significant yield differences between treatments were found at the 1st and 2nd harvest, with exception of the 800 mg N/pot treatment which gave higher root yields at the first harvest. 2. At the 1st harvest (beginning of flowering) root nodule yield of the N-zero treatment was higher than the root nodule yield of the N treated plants. At later stages, however, no major differences in root nodule yield between the treatments N₁₀₀ and N₂₀₀ and the N-zero treatment were obtained. 3. Highest grain yields were obtained in the treatment with the lowest N-rate (100 mg N/pot) and in the treatment with the highest N rate (800 mg N/pot). The absolute highest amount of symbiotically fixed N was produced in the low N treatment (100 mg N/pot). Provided that the soil is low in available N a low fertilizer rate is required in order to exploit the full N₂ assimilation potential. 4. The total soil N remained fairly constant throughout the growing period.     

Der Einfluß von P-Ernährung und pH auf die Phosphataseaktivität von Zuckerrübenwurzeln

The influence of phosphorus nutrition and pH on phosphatase activity of sugar beet roots For the determination of acid phosphatase activity (P_ase) of sugar beet roots (cultivar: Reka), plants were cultivated in nutrient solution with 1 or 100 μM P in a growth chamber for 12, 18, 24, 30, 36 and 42 days. The phosphatase activity of intact roots was measured in buffer solutions with pH 4 to 7.2 and 14 mM p-Nitrophenylphosphate (NPP) after 10 min of incubation at 20°C. The influence of P nutrition on P_ase activity was significant at all intervals. At P deficiency the activity was increased by a factor of 4 to 20. During the experimental period the pH optimum was 6. At pH 5 and 7.2 the P_ase activity reached only 63 and 64% respectively of the optimum value. At P deficiency (1 μmol P L^—1) the absolute rate of NPP-hydrolysis at pH 6 was 144 nmol min¹ m¹ root length (day 12 to 36). The plants which received optimum P supply showed only 10% of this value. Sugar beet roots with P deficiency have a high potential of P_ase activity from the acid to the neutral pH-range. Therefore, under this condition they may effectively use dissolved organic phosphorus compounds.     

Einfluß von Bikarbonat auf die subzelluläre Verteilung von blatt- und wurzelappliziertem Eisen bei Sonnenblumen (Helianthus annuus L.)

Influence of bicarbonate on the subcellular distribution of iron applied to roots or leaves of sunflower (Helianthus annuus L.) 18 days old sunflower seedlings were transferred and cultivated for 9 days ( untill chlorosis appeared) in nutrient solutions. After that Fe concentration of roots and shoots and the subcellular distribution of Fe in the cytoplasm of the young leaves was determined. Bicarbonate in the nutrient solution with Fe reduced the concentration of Fe and chlorophyll in the young leaves of the plants, also the concentration of Fe and protein in the chloroplast fraction of the cytoplasm, but the subcellular distribution for Fe remained unchanged compared with the control. Leaf spray with Fe-EDTA to plants in nutrient solution without Fe + bicarbonate resulted in higher Fe but unchanged chlorophyll concentrations in the young leaves, while the cytoplasm fractions of these leaves had higher concentrations of iron and protein compared with the control. An inactivation of leaf iron by bicarbonate in the nutrient medium could not be demonstrated. There was no significant lowering of the concentration of disolved Fe in the nutrient solution by bicarbonate, indicating a disturbance of Fe-up-take rather than an insufficient Fe-supply as a factor for iron chlorosis. The physiological activity of leaf applied Fe was not diminished by bicarbonate in the nutrient solution. This observation too points to a primary effect of bicarbonate in the root area. The pH of the cytoplasm from young leaves remained unchanged after leaf spraying with Fe-EDTA. In spite of this there might be a local effect of sprayed solution (with pH 5,1) on the pH of solutes in the apoplast, influencing the mobility of leaf applied Fe.     

Der Einfluß von Gibberellinsäurespritzungen auf das Blühverhalten von Karotten

The influence of Gibberellic Acid Treatments on Flowering of Carrots . The influence of GA₃-treatments on flower formation of carrot plants at different light conditions was investigated. No flower formation occurent during natural long day conditions at all GA₃-concentrations (6, 30, 60 ppm). (Fig. 1). Nevertheless under artificial long day conditions flower formation was observed after application of 30 and 60 ppm GA₃. Apparently a positive interaction between GA₃-application and illumination on shooting exists. Conditions leading to the formation of vegetatives apices from generative are described. (Formation of ‘Hochrosetten’, Fig. 2).     

Einfluß von konstantem und abnehmendem Nährstoffangebot auf Aufnahme und Verteilung von K,Ca und Mg bei Sonnenblumen

Influence on the uptake of K, Ca and Mg in sunflowers with a constant and a diminishing supply of nutrients. . In a model-test with sunflowers it was investigated how the K-, Ca- and Mg-content in the plants is reacting when (a) a nutrient solution maintained constantly at the same level is given as in a ?good soil”? with a constant supply of nutrients, compared to (b) a solution with diminishing as in a highly fertilized soil but which hardly supplies nutrients itself. It was shown that, if the offer of the nutrient was constant, the cation content in the leaves could be maintained at the same level (the relation of cations is also maintained at the same time). Contrary to this with a diminishing nutrient solution due to removal of nutrients out of the solution without replenishing nutrients and the differentiated nutrient translocation the result was a lesser and lesser content of the nutrients inside the plant and more evident changes in the relation of cations, even before the insufficient supply was noted in a decreasing crop. Only in the leaves the relation of cations was nearly constant (K:Ca:Mg = 6:3:1). From these results it can be concluded that, through a high single supply of nutrients the effect of a constant flow of nutrients from the soil to the plant concerning the mineral contents of the plant cannot be compensated.     

Einfluß von Ethrel auf Form und Zuckergehalt der Zuckerrübe

Influence of Ethrel upon morphology and sugar content of sugar beet Repeated spraying of growing sugar beet plants with 100 and 200 ppm solutions of Ethrel changed the shape of the storage roots and reduced their sugar content. When CCC was added to the Ethrel solutions, the negative influence of Ethrel upon the sugar content was nearly abolished.     

Phytotoxizität von Thallium (TI) in Hydrokultur Teil2: Einfluß von TI(III) auf das Wachstum und die Schwermetallgehalte von Erbsen- und Ackerbohnenpflanzen

Phytotoxicity of Thallium (Tl) in Culture Solution Part 2: Effects of Tl(III) on the Growth and Heavy Metal Contents of Pea and Field Bean Plants The effects of Tl(NO₃)₃ and Tl(III)EDTA on growth and heavy metal contents of pea plants (Pisum sativum L. cv. Aromata) and field bean plants (Vicia faba L. cv. Hangdown) were compared in hydroponic culture experiments. In the presence of Tl(NO₃)₃, the essential heavy metals were available to the plants in their ionic forms. When Tl(III)EDTA was present the essential heavy metals were available as chelated complexes. Dry matter production of the pea plants was inhibited to a greater extent by TI(II1)EDTA than by Tl(NO₃)₃. The distribution of TI within the plant was unaffected by the accompanying anion, however an increase of the TI content of the stems and the leaves was observed in the presence of TI(II1)EDTA. The micronutrients exhibited different interactions with TI(II1). In the presence of increasing concentrations of Tl(NO₃)₃ the Mn content of each organ and the Zn content of the roots were lowered, but the Zn content of the stems was increased. Increasing concentrations of TI(II1)EDTA resulted only in a decrease of the Mn content of the roots, but in an increase of the contents of Fe and Mn within the stems, and Fe, Mn, Zn, and Cu within the leaves. The increases may be due to concentration by growth inhibition. In contrast to pea plants, growth of field bean plants was inhibited only by TI(N03)). The field bean plants retained most of the TI within the roots independent of the TI compound in the solution. Chelation of TI(II1) resulted in higher TI contents of both the roots and the stems, but equal or reduced TI contents of the leaves. Whereas increasing concentrations of Tl(NO₃)₃ reduced the Mn content of each organ as well as the Zn content of the roots and the leaves, TI(II1)EDTA only reduced the Mn content of the roots.     

Einfluß der VA-Mykorrhiza auf die Schwermetallaufnahme von Hafer (Avena sativa L.) in Abhängigkeit vom Kontaminationsgrad der Böden

Influence of VA-mycorrhiza on heavy metal uptake of oat (Avena sativa L.) from soils differing in heavy metal contamination The heavy metal uptake of mycorrhizal oat-plants (Avena sativa L.) was evaluated in pot experiments with two soils differing in heavy metal accumulation. The effect of the fungal isolates on the uptake of the immobile metals Zn and Cu differed between the two soils: In the soil “Kleinlinden” mycorrhizal colonization increased heavy metal uptake by up to 37%. In the highly contaminated soil “München”, mycorrhizal infection lead to a higher uptake (max. 59 %) in roots but to a reduced translocation to the aerial plant fractions. The higher uptake of Zn and Cu into the roots was related to the higher heavy metal concentrations in this soil. The Cd uptake showed no difference between the two soils, but was increased in the roots by VAM together with a lower translocation into the shoots. VAM-formation changed the root architecture by increasing the specific root length (m g^?1 root dry matter) and the total root length (km per pot). This increased absorbing surface of the roots was a major, but not the only cause for the differences in heavy metal uptake.