Symptome von Mangan-Überschuß bei Bohnen (Phaseolus vulgaris)

Symptoms of manganese toxicity in beans (Phaseolus vulgaris L) In water culture experiments with bush bean plants (Phaseolus vulgaris L. var. ?Red Kidney”?) the macro- and micro-symptoms of manganese toxicity had been studied. Typical symptoms of Mn toxicity are small distinct blackish-brown spots, first at the older leaves and at more severe toxicity also at the petals and stems. Using the autoradiographic technique on ⁵⁴Mn-distribution and comparing this with corresponding light microscopic studies it could be demonstrated that the blackish-brown spots in the leaves resemble Mn-precipitations. These precipitations are Mn-compounds of higher oxidated form and are primarily localized in the walls of cells in vicinity of the vessels. The extend to which these precipitations occur is not only a function of the Mn-content of the leaves but also of their age. At comparable Mn-content the extend of the precipitation increases with the leaf age. As secondary symptom of Mn-toxicity under certain conditions (presence of silicon e.g.) induced Fe deficiency (chlorosis of the youngest leaves) and Ca deficiency (?crinkle leaf”?) may occur. It is assumed that the process of Mn precipitation within the leaves is enzymatically regulated. The severe reduction in the growth of leaf blades at Mn toxicity is presumably related to an interference with the growth hormon balance.     

Der Einfluß von Bormangel und von mechanischer Zerstörung des Spitzenmeristems auf die Zellteilung bei Sonnenblumen

Influence of boron deficiency and destruction of the apical meristem on the cell division in sunflowers With a severe, nearly absolute boron deficiency metabolism and formation of tissues are so disturbed that the primary symptom of boron deficiency can not be recognized with certainty. Investigations here had to clarify if cutting the tops or destruction of the apical meristem with a red-hot needle will induce symptoms similar to those of boron deficiency or how symoms develop under mild boron deficiency. With the red-hot needle technique, it was possible to obtain cambial enlargement in plants with a normal boron nutrition. Cutting off the tops also, induced an enlargement of the hypocotyl. In this case the enlargement was however due to an enlargement of the cortex by formation of an aerenchymlike tissue. A boron supply near the deficiency level caused development of deficiency symptoms in growing plants (chlorosis, inhibited enlargement of the stem, small deaf' blades, small-celled xylem, malformed and discoloured cell walls and appositions on the young cell walls). As long as the shoot apex displayed growth, enlargement of the cabium did not appear as a rule. This symptom seems to be a secondary symptom of boron deficiency caused by damage to the shoot apex and, thus disturbed auxin metabolism.     

Aufnahme und Verlagerung von 15N-Stickstoff bei Sommergerste in Abhängigkeit von K-Ernährung und Mehltaubefall

¹⁵N uptake and distribution by spring barley in relation to K nutrition and mildew attack Barley cv. Aramir was grown in complete nutrient solution containing 0,5 (K₁), 1,5 (K₂) and 4,5 mM K (K₃) respectively till maturity. Part of the plants was infected by mildew (Erysiphe graminis), whereas control treatments were kept mildew-free by fungicide sprays. Symptoms of mildew attack were less at K₂ and K₃ and grain yields of infected plants were raised from 98 (K₁) to 160 (K₂) and 165 g/pot (K₃). In control treatments grain yields were 130 (K₁), 164 (K₂) and 163 (K₃) g/pot. During anthesis nitrogen in the nutrient solution was labelled with ¹⁵N for two days and ¹⁵N metablism was studied within 7 consecutive days. The aim of this pulse-chase experiment was to find out, how mildew attack and K nutrition influence N metabolism. The following results were obtained: a) ¹⁵N uptake increased from K₁ to K₂ in infected and healthy plants, though at slightly lower levels in the infected treatments. b) During 7 days after the ¹⁵N pulse up to 17,1% of the ¹⁵N absorbed were translocated into the grains. Better K status as well as spray treatments stimulated nitrogen translocation. c) Mildew attack of leaves does not seem to influence the conversion of grain-¹⁵N into grain proteins. Better K supply stimulates the rate of protein synthesis in the grain. d) In mildew infected leaves relatively more of the ¹⁵N absorbed is incorporated into leaf proteins. But this may be a consequence of slower grain growth, because already 7 days after anthesis infected plants in all K treatments had significantly lower grain yield. In spite of the short duration of the experiment the ¹⁵N data do not indicate that the visible depression of mildew attack by better K nutrition of the crop might inter alia be due to K stimulated defense reactions within N metabolism. This is in agreement with a previous experiment.     

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.     

Ertragsbildung,Bestandesaufbau und Stickstoffverwertung von Winterweizen bei kombinierter Gülle- und Mineraldüngung

Effect of combined slurry and mineral fertilization on yield formation, yield components and nitrogen efficiency of winter wheat From 1984/85 to 1987/88 field trials were conducted on the experimental farm Roggenstein in order to examine the efficiency of pig slurry applied at different developmental stages of winter wheat combined with different dosage and distributions of mineral N-fertilizer. On the average over 4 years, maximum grain yield by applying exclusively mineral N-fertilizer has been achieved with 120 kg N/ha, with the optimal amount of N-fertilizer at the 3 developmental stages being 40 kg N/ha, respectively. Decreased yields induced by a reduced mineral N-fertilization could be compensated by application of 20 m³/ha or 40 m³/ha slurry either at the beginning of the growing period, EC 30-31 or EC 33-35 developmental stages. However, mineral fertilizer equivalents calculated on the basis of the NH₄^? N-content of slurries for each year ranged from 25 to 79 in dependence of application date and prevailing weather conditions. Regarding the effect on yield components, no difference between slurry and mineral N-fertilizer were observed. The mediocre and very variable efficiency of slurry-N leads to the conclusion, that the use of slurry in cereal production may be of limited value for agronomic as well as for ecological reasons, as long as no efficient and cost-effective application techniques are available.     

Verteilung von Stickstoff auf Sproß und Wurzel bei jungen Bohnenpflanzen nach der Aufnahme von NO und NH

Translocation of nitrogen to the shoot of young bean plants after uptake of NO and NH by the root Phaseolus vulgaris plants (var. nana, cv. Saxa) at the primary leaf stage (without nodules) were fed during 6 hours with ¹⁵NO and ¹⁵NH, respectively. 24 hours after the absorption period more ₁₅N from the absorbed NO was translocated from the root to the shoot. The presence of NH in the nutrient solution enhanced the translocation of ¹⁵NON, probably by an inhibition of nitrate reductase. NH_4-⁺¹⁵N is mainly retained in the root by a high incorporation into the root protein. It can be concluded that nitrogen from newly absorbed NO is not retained and used for protein synthesis in the root according to the root's potential to synthesize protein. Nitrate reduction in the root is considered to be the limiting factor. This is supported by the fact that withdrawal of NO in the nutrient solution prior to the ¹⁵N-experiment increased NOtranslocation to the shoot as a consequence of a lowered level of nitrate reductase. In an experiment with ¹⁴NOsupply to the roots and ¹⁵NOapplication to the primary leaves (infiltration method) a considerable amount of ¹⁵N was translocated from the leaves to the roots. This indicates that an insufficient NOreduction in the root can be substituted by a retranslocation of reduced N-compounds from leaves to the roots. The proportion of NO reduced in the root influences also the pattern of primary distribution of nitrogen in the shoot of plants at the 4 leaf stage. At a concentration of 0,2 meq/l NO in the nutrient solution as compared to 20 meq/l NO during 10 hours a relative higher amount of ₁₅N was transported from the root to the younger, growing leaves i.e. via the phloem to metabolic sinks.     

Abbau und Auswaschung von Chlorcholinchlorid bei Weizen

Decomposition of Chlorocholine Chloride in Wheat Plants and its Leaching from leaves The decomposition of ¹⁴C-labeled chlorocholine chloride (CCC) in intact plants and its leaching by rainfall were investigated in pot trials with spring and winter wheat. The results can be summerized as follows:

• 1. CCC is relatively stable in intact plants and is rather not metabolized. Nearly all CCC applied to the leaves or the roots of the young plants was found as undecomposed CCC in later growth stages (Table 1 and 2).
• 2. Only a small amount of decomposition products containing ¹⁴C could be dedected in the wheat plants. After treatment 94–98 and 2–6 per cent of the total activity were found in the CCC and choline fraction respectively without significant variation throughout the experimental period (Table 1 and 2).
• 3. A great part of the CCC sprayed on the plants in the juvenile stage was leached by rain during the vegetation period (Fig. 1).
• 4. The mobility of CCC in the plants is low. Only a small part of the CCC amount applied to the leaves moves to the stalks and ears and to the leaves developed after CCC application (Fig. 2).

     

Einfluß von Stickstoffernährung und Wuchsstoffapplikation auf die Knolleninduktion bei Kartoffelpflanzen

Influence of nitrogen nutrition and application of growth regulators on tuber initiation in potato plants In water culture the effect of continuous and discontinuous N-nutrition on tuber initiation was investigated. Additional applications of growth regulators on growing stolon tips were carried out. Continuous supply of nitrate or ammonium inhibited completely the tuber initiation in S. tuberosum varieties ?Ostara”? and ?Clivia”?, The inhibition was compensated by application of CCC and ABA on the stolon tip. In contrast to this stolon application of kinetin and root application of CCC were ineffective. Temporarily damaging of the root system led to tuber initiation even when nitrogen was supplied continuously. In S. andigena grown under short day continuous N supply only delayed the tuber initiation but could not prevent it. Discontinuous N supply promotes tuber initiation in S. tuberosum. A sudden increase in N supply caused ?re-growth”? of the tuber, i.e. a stolon was formed on the tuber apex. GA₃ application on the growing tuber had the same effect. The effect of N nutrition on tuber initiation can be explained via changing the balance of endogenous growth regulators in general and the physiological aging of the leaves in particular. Discontinuous N supply seems to reduce cytokinin production in roots and therefore accelerates the aging of the leaves. This in turn favours the formation of inhibitors and/or presumably reduces the GA production in the shoot, which will change the balance of the growth regulators in the stolon tip in favour to tuber initiation.     

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.     

Ammoniakemissionen aus alternden Pflanzen und bei der Zersetzung von Ernterückständen

Ammonia emissions from senescing plants and during decomposition of crop residues NH₃ emissions from plant stands, measured under simulated environmental conditions with the wind tunnel method, ranged between 0.8 and 1.4% of the N content of the shoot, equivalent to 1.1 to 2.9 kg NH₃-N ha^?1. The highest emissions were observed in faba beans whereas the emissions in winter wheat, spring rape and white mustard were lower. The total NH₃ emissions were not affected by removing a part of the ears (sink reduction), but emissions occurred earlier, as did the plant senescence. This suggests that the NH₃ emissions are closely related to senescence. NH₃ emissions from decomposing crop residues ranged from 0.9 to 3.7% of the N content. The emissions from sugar beet leaves and potato shoots with high water content reached from 8.6 up to 12.6 kg N ha^?1, whereas the emissions from field bean straw with high dry matter and N content were relatively low. (3.1 kg N ha^?1, or 0.9% of the N content). The NH₃ emissions from sugar beet leaves were reduced by 81% by ploughing and 63% by mulching.     

Aufnahme und Verlagerung von Natrium bei zwei Sorten von Lolium perenne

Uptake and translocation of sodium in two cultivars of Lolium perenne The uptake and translocation of Na was investigated in two Lolium perenne cultivars (Dolewi and NFG). With increasing Na⁺ concentration in the nutrient solution (0, 1, 2 and 4 mMNa) the Na⁺ uptake per pot increased from 1.4 to 11.9 me/1 Na⁺ for Dolewi and from 1.1 to 6.9 me/l Na⁺ for NFG. The higher Na uptake by Dolewi can only partly be explained by better growth, the higher Na⁺ selectivity playing also an important role. In another experiment plants of both types were grown in solution cultures for 41/2 weeks at 15°C and 25°C, respectively. Hereafter the plants were supplied with 1.25 mM ²⁴NaCl for six hours under equal conditions. Again the higher Na uptake and also a higher Na translocation (of about 20%) was found in Dolewi, whereas only 10% of the ²⁴Na uptake had been translocated by NFG. When plants were grown in a nutrient solution with a lower temperature (at 15°C) the root lipids showed a higher linolenic acid and oleic acid content than the plants grown in a medium at 25°C. At the same time the 24Na uptake was higher in the plants grown at the lower temperature, yet the relationship between root lipids and Na uptake still remains to be elucidated.     

Methoxylgehalt,PSR und Farbreaktionen bei Wurzel- und Strohlignin von Triticum

Methoxyl content, PSR and color reactions on root and straw lignin The wet chemical measured content of methoxyl groups is in lignin from up to 13 cm long roots and straw with ～ 11,5 % nearly indentical. Lignin in roots contains more keto groups. This was proved by psr-spectroscopy (δ = 8 ppm) and by various color reaction with o–dianisidine/HCl, diphenylamine, acridine, barbituric acid, p-anisidinhydrochloride, sulfanilic acid and aniline. Root lignin has also more benzolic protons (δ = 5,35 – 5,45 ppm) and by far higher part of highly shielded aliphatic protons (δ = 1,33 ppm). The last diminished to a large extend after having react with diazomethane. From this informations could even be concluded that lignin in roots has more methylable structures. Against that protons in the side arms are to find more in the lignin of straw.