Low Calcium Treatment Research Articles

Effect of calcium, pH and nitrogen on the growth and chemical composition of some tropical and temperate pasture legumes. II.* Chemical composition (calcium, nitrogen, potassium, magnesium, sodium and phosphorus)

The chemical composition of tops and roots of nodulated and non-nodulated plants of some tropical and temperate pasture legumes grown in sand culture is reported and discussed in relation to nodulation efficiency and dry matter production, and nutrient interaction. In most species, increasing pH raised the nitrogen concentrations in the tops of nodulated plants; calcium treatment had little effect. Increasing the calcium concentration of the nutrient solution from 0.125 to 2.0 mM markedly increased the calcium~ concentration in the tops of all species, but in the roots to only a minor extent. Concentrations in tops differed between species. Concentrations in the tops of modulated plants were increased as a result of increasing pH, particularly at the low calcium treatment and for those species sensitive to low pH (Glycine wightii, Medicago species). Increasing the calcium concentration lowered the magnesium concentration, but the total cation content was not significantly affected. In the tropical species, phosphorus concentrations in the tops were increased by reducing pH at both calcium treatments; values were higher at the low calcium treatment than at the high calcium treatment. Roots accumulated inore phosphorus than the tops. Differences in the response of the species cannot be directly related to their mineral composition. With respect to nodulation and dry matter production, it is considered that the pH is the dominant factor and operates in the nodule initiation phase and in subsequent nitrogen production. _______________ *Part I, Aust. J. Agric. Res., 27: 611 (1976).

Response of two soya bean cultivars to manganese toxicity as affected by pH and calcium levels

Two cultivars of soya bean (Glycine max) were grown in nutrient solution to test their response to manganese toxicity as affected by pH and calcium levels in the medium. Increasing calcium levels consistently decreased manganese concentration in the shoots, but only decreased manganese toxicity symptoms and increased yields between moderate and high levels of substrate calcium. It is suggested that the higher ammonium/nitrate ratio associated with the low calcium treatments, where part of the calcium nitrate was replaced with ammonium nitrate, more than nullified the effect of increased manganese in the shoots obtained from the low calcium treatments. pH had little effect on concentrations of manganese, iron or calcium in the shoots or on the development of manganese toxicity symptoms. However, as pH increased at high substrate manganese levels, total dry matter yields significantly decreased and levels of manganese in the roots markedly increased. At least part of the greater root manganese at higher pH could have been in the precipitated form, while the increased retention of calcium in the roots may also have influenced manganese retention. Reasons for decreased yields at higher pH are discussed. Environmental conditions appear to have had sonic effect on cultivar response to manganese toxicity.

Effect of calcitonin on experimental osteolathyrism. (II). Action of calcitonin on collagen metabolism.

In order to study the effect of calcitonin on the bone collagen metabolism in osteolathyrism, male Wistar rats were placed on 0.1% aminoacetonitrile diet for 9 days. Porcine calcitonin dissolved in gelatin was concurrently administered in a dose of 0.1 MRC U/100g body weight for 8 days and on the 9th day 0.75 MRC U/100g body weight was given 3, 2 and 1hr respectively before sacrifice. Both bone collagen formation and maturation were examined by the determination of specific and total activities of 3Hhydroxyproline in bone collagen, and collagen resorption was examined by the estimation of the amount of hydroxyproline released into the incubation medium from metaphyses. Treatment of lathyritic rats with calcitonin diminished the concentration of serum calcium, phosphate, and rate of collagen resorption, but did not affect collagen formation and collagen maturation. Inhibitory effect of calcitonin on collagen resorption was more pronounced in osteolathyrism than under normal condition. It seemed that parathyroid glands did not play a vital role in the collagen resorption induced by osteolathyrism, since the resorption was not affected by parathyroidectomy. On the other hand, administration of calcitonin (every 0.8 MRC U/rat, 60 and 30min before sacrifice) also counteracted collagen resorption which was induced by low calcium diet and treatment with parathyroid hormone (PTH, 70 USP units).It is concluded that the effect of calcitonin on collagen metabolism resulted in primary inhibition of collagen resorption in osteolathyrism, and that calcitonin counteracted both PTH-dependent collagen resorption and PTH-independent collagen resorption induced by osteolathyrism.

Calcium concentration in tomato fruits in relation to the incidence of blossom-end rot

Tomato fruits (CV. Grosse Lisse) were grown in sand cultures irrigated with nutrient solutions containing either normal- (120-160 p.p.m. Ca) or low-calcium (40 p.p.m. Ca) levels. Data were collected from the first five trusses, and restricted to fruits arising from the first three flowers of each truss. A greater yield of fruit and fewer fruit affected by blossom-end rot (BER) were produced by the normal than the low calcium treatment. Irrespective of treatment or BER incidence, the calcium concentration was higher in the stem end than the calyx end, and the concentrations of calcium and potassium were greater in trusses 1 and 2 than 4 and 5. BER affected the largest fruit in the normal, but the smallest in the low calcium treatment. Within the same trusses affected fruit had a lower calcium concentration in the stem end than did healthy fruit. For all fruits the ranges in calcium percentage (on dry basis) recorded were : Healthy fruits-stem end 0.086-0.029, calyx end 0.057-0.018 ; affected fruits-stem end 0.072-0.022, calyx end 0.045-0.020. Differences in magnesium and potassium concentrations in stem or calyx ends between healthy and affected fruits were recorded. The K: Ca ratio was higher in affected fruits, but the incidence of BER was unrelated to the Mg : Ca ratio. For both calcium and magnesium the stem end : calyx end concentration ratio was lower in affected than healthy fruit.

Mevinphos and Phosphamidon: Influence of Plant Nutrition on Uptake and Effectiveness12

The uptake of mevinphos and phosphamidon by bean plants was altered when the supply levels of phosphorus, potassium, magnesium, nitrogen, sulphur, and calcium were varied. The influence of the uptake on the acaricidal effectiveness and the phytotoxic action were studied. Increased effectiveness of mevinphos and phosphamidon were associated with increased supply levels of phosphorus, potassium, and magnesium. Decreased effectiveness of mevinphos was associated with increased supply levels of nitrogen and sulphur, but effectiveness of phosphamidon was increased at increased supply levels of these 2 minerals. Greater effectiveness of mevinphos was associated with increased supply levels of calcium. In general as the acaricide-absorbing capacity of the plants increased, the acaricidal effectiveness of plants also increased. The phytotoxicity of mevinphos and phosphamidon was accentuated in the plants receiving low-nitrogen, high-phosphorus, potassium-deficient, low-calcium, high-magnesium, or sulphur-deficient treatments. The low concentration of mevinphos and phosphamidon increased the fresh and dry weights of the plants under conditions of low-phosphorus supply.

Nucleotides of Sugarcane: Increased Nucleotide Content of Leaves as a Function of Nutritional Stress

Nucleotide analyses were conducted with sugarcane subjected to decreasing levels of nitrate, phophorus, potassium, and calcium over a period of 16 weeks in sand culture. In each instance of nutritional stress, abnormally high levels of sucrose appeared in leaf tissues. This study was motivated by the theory that abnormal nutritional status might induce added nucleotide synthesis, with the concurrent formation of sucrose precursors. Lyophilized leaf samples were extracted with trichloroacetic acid, and nucleotide preparations were analyzed by anion exchange plus paper chromatography. Total nucleotide content was higher in each of the near deficient plant sources as compared with those receiving adequate nutrient supply. Nucleotide increase was greatest among low-calcium and low-nitrate treatments, and least increase was found in low-potassium samples. Increased nucleotides of low nitrate and phosphorus samples were removed from anion-exchange resins by pH 2.9 formic acid-sodium formate elution. Low-Ca induced nucleotides were retained at pH 2.9, but were removed from resin columns by 6 N formic acid. Nucleotide preparations from nitrate- and phosphorus-treated plants contained high levels of reducing sugar, inorganic phosphorus, and organic phosphorus. More than fivefold increases of organic phosphorus were obtained in both treatments. Low-potassium and low-calcium treatments induced high sucrose without accumulating high organic phosphorus. The nucleosides adenosine and cytidine were present in all samples. Guanosine was found in nitrate-, phosphorus-, and potassium-deficient plants only. The possibility is discussed that an azaguaninelike endogenous antimetabolite is formed as a consequence of nutritional stress, accounting in part for growth retardation and abnormally high nucleotide content.

Calcium nutrition in relation to the occurrence of internal browning in Brussels sprouts

Brussels sprouts, cv. Long Island, grown in sand cultures supplied with either normal or low-calcium nutrient solutions, were used to study the relationship between internal browning of sprouts and the calcium regime of the plants. The interaction of ammonium, magnesium, and potassium ions with calcium nutrition, and the susceptibility of four locally selected strains of Brussels sprouts to the disorder, were also investigated. No symptoms, in either the sprouts or the growing points, were found in plants grown under normal calcium nutrition, but each of the low-calcium treatments, irrespective of other cations, induced a significant amount of internal browning in sprouts. The incidence was greatest in the low-calcium high-magnesium, and least in the low-calcium high-ammonium treatments. Calcium deficiency symptoms of the growing points were most severe in the low-calcium high-magnesium treatment, and only this treatment significantly reduced plant yield. Internal browning occurred in the four strains when grown under the low-calcium high-magnesium treatment. Two strains (Bepi and original early) were more severely affected and developed symptoms earlier than the other two (Sartori and mid-season). However, the Sartori strain was the only one in which low calcium nutrition reduced yield. The calcium content in the sprouts decreased from the wrapper to the meristematic region. In leaves, the calcium content was highest in the leaf margin in all strains except mid-season. Low calcium nutrition greatly reduced the calcium content in sprouts and leaves.

Bitter pit in the apple variety Sturmer in a pot experiment using low levels of major elements

The results of a pot experiment showing the influence of low calcium, low magnesium, and complete fertilizer on the pit incidence and mineral content of Sturmer apples are reported. Low calcium treatment resulted in high incidence of pit, low levels of calcium and high levels of potassium, magnesium, phosphorus, and nitrogen in the fruit compared to complete fertilizer and low magnesium treatments. In the ash, though the proportion of calcium was significantly lower, the proportions of potassium, magnesium, and phosphorus did not change. The difference in the characteristics examined between pitted and sound fruit in the three treatments were in the same direction as those between fruit from low calcium and complete fertilizer treatments, and the differences in calcium level were significant. The response to low calcium treatment was a much greater relative molar increase in nitrogen, potassium, magnesium, and phosphorus than the molar decrease in calcium. The evidence supports an hypothesis that the primary cause of pit is low calcium status which under water stress in the leaves and fruit induces an increase in nitrogen, respiration rate, and mineral content but gives no indication which of these causes the lesions.

IDIOPATHIC HYPERCALCÆMIA OF INFANTS LOW-CALCIUM TREATMENT

IDIOPATHIC HYPERCALCÆMIA OF INFANTS LOW-CALCIUM TREATMENT