The physiological assessment of the nutrient status of plants. I. Preliminary experiments with phosphorus

1962 ◽  
Vol 13 (5) ◽  
pp. 791 ◽  
Author(s):  
D Bouma ◽  
EJ Dowling
Keyword(s):  
Leaf Area ◽  
Complete Solution ◽  
Subterranean Clover ◽  
Nutrient Status ◽  
Response Patterns ◽  
Simple Method ◽  
Subsequent Response ◽  
Low Phosphorus ◽  
Phosphorus Status ◽  
Phosphorus Levels

Subterranean clover plants of different phosphorus status, obtained from pastures or raised in the glass-house, were transferred to nutrient solutions. These included a complete solution, and others each lacking a different element. Subsequent response patterns were defined by leaf area changes. Plants raised at low phosphorus levels showed considerably smaller increases in leaf area in the solutions without phosphorus than in the other solutions. These differences were discernible as early as 2 days after transfer. There was little difference between the control treatments and treatments omitting elements other than phosphorus. Plants raised at a more adequate phosphorus level did not show differences between treatments till much later. The results are discussed, and their use as a basis for a simple method of determining the nutrient status of plants is indicated.

The physiological assessment of the nutrient status of plants. II. The effect of the nutrient status of the plant with respect to phosphorus, sulphur, potassium, calcium, or boron on the pattern of leaf area response following the transfer to different nutrient solutions

1966 ◽  
Vol 17 (5) ◽  
pp. 633 ◽  
Author(s):  
D Bouma ◽  
EJ Dowling
Keyword(s):  
Leaf Area ◽  
Subterranean Clover ◽  
Premature Death ◽  
Nutrient Status ◽  
Response Patterns ◽  
Physiological Assessment ◽  
Five Elements ◽  
Series Of Experiments ◽  
Nutrient Solutions ◽  
Area Response

In a series of experiments, young subterranean clover plants were raised at several levels of phosphorus, sulphur, potassium, calcium, or boron respectively, and then transferred to complete nutrient solutions and to solutions without the previously varied element. Response patterns based on relative leaf area increases revealed quantitative relations with the nutrient status of the plants at transfer in the experiments with different phosphorus, potassium, or boron levels. In the sulphur experiment the response pattern indicated only the presence or absence of stress. In the calcium experiment the picture was somewhat obscured by premature death of leaves following collapse of the petioles. In a second series of experiments it was shown that the presence or absence of specific stresses could be determined from the patterns of leaf area response after transfer of plants to complete solutions and to solutions each without one of the five elements.

The physiological assessment of the nutrient status of plants. IV. The effect of the interaction between nutrient elements of leaf area responses

1967 ◽  
Vol 18 (2) ◽  
pp. 223 ◽  
Author(s):  
D Bouma ◽  
EJ Dowling
Keyword(s):  
Leaf Area ◽  
Subterranean Clover ◽  
Nutrient Status ◽  
Simple Relation ◽  
Qualitative Assessment ◽  
Nutrient Elements ◽  
Response Patterns ◽  
Physiological Assessment ◽  
Area Response ◽  
Complete Solutions

Experiments were carried out with subterranean clover in water cultures to study the effect of interactions between phosphorus, sulphur, and nitrogen. These elements were varied in pairs, and leaf area responses measured after transfer to complete solutions and to solutions without one of the two previously varied elements. Leaf area responses after transfer of plants deficient in phosphorus as well as in sulphur revealed both deficiencies when they had been of approximately equal intensity. When elements were deficient to differing degrees, leaf area responses depended on the relative intensities of the deficiencies. With deficiencies of sufficiently differing intensities, leaf area response patterns after transfer showed a deficiency of only one element because its supply had been low enough to mask the effect of the other deficiency. Transfer of plants deficient in only one element confirmed that there is no simple relation between the nitrogen status of the plant and the induced leaf area responses. The results also confirmed the feasibility of at least a qualitative assessment of the phosphorus or the sulphur status of plants.

The physiological assessment of the nutrient status of plants. III. Experiements with plants raised at different nitrogen levels.

1966 ◽  
Vol 17 (5) ◽  
pp. 647 ◽  
Author(s):  
D Bouma ◽  
EJ Dowling
Keyword(s):  
Leaf Area ◽  
Leaf Growth ◽  
Subterranean Clover ◽  
Nutrient Status ◽  
Response Patterns ◽  
Combined Nitrogen ◽  
Nitrogen Levels ◽  
Relative Differences ◽  
Area Response ◽  
Complete Solutions

Young subterranean clover plants were raised at several levels of nitrogen supply, and then transferred to complete solutions and to solutions without nitrogen Subsequent leaf area response patterns were not related to the supply of combined nitrogen before transfer. The relative differences m leaf area between the two solutions were thought to depend on differences In nodulation caused by differences In the supply of combined nitrogen before transfer. Further experiments showed that the rates of leaf area Increase of inoculated and well-nodulated plants In solutions without nitrogen were similar to those of corresponding plants receiving combined nitrogen Plants that had not been inoculated showed markedly smaller leaf growth rates after transfer to solutions without nitrogen than in complete solutions Even when the previous supply of combined nitrogen had been adequate, plants transferred to solutions without nitrogen were unable to maintain leaf area Increases at rates comparable with those of the corresponding plants in complete solutions for more than 3 days. Reasons for the marked differences between these results and those of experiments with phosphorus, sulphur, potassium, and boron are discussed

Effects of phosphorus and sulphur on dark respiration of subterranean clover leaves

1971 ◽  
Vol 22 (5) ◽  
pp. 723 ◽  
Author(s):  
D Bouma
Keyword(s):  
Dark Respiration ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
The Other ◽  
Phosphorus Level ◽  
Respiration Rates ◽  
Phosphorus Status ◽  
Whole Plants ◽  
Complete Solutions ◽  
Phosphorus Levels

Respiration rates in the dark (oxygen uptake) of leaves sampled from subterranean clover plants (Trifolium subterraneum L. cv. Mt Barker) increased with the phosphorus supply in the culture solutions in which the plants were grown. Over a period of 3 hr no differences were detected in respiration rates when leaves of these plants were placed in Warburg flasks containing complete solutions or solutions without phosphorus. However, when whole plants were transferred to complete and no-phosphorus solutions, the differences in respiration rates of leaves sampled from the two groups of plants depended on the phosphorus status of the plants at transfer. Leaves from plants raised at an adequate phosphorus level showed no differences over a period of 96 hr after transfer, but leaves from plants raised at suboptimal phosphorus levels before transfer to complete and no-phosphorus solutions showed significant differences in respiration rates as early as 18-19 hr after transfer. Similar results were obtained for leaves sampled from plants raised at different sulphur levels when transferred to complete solutions and to solutions without sulphur. However, these differences took longer to develop than in the phosphorus experiments. When phosphorus-deficient plants were transferred to complete solutions and to other solutions each without a different element, the respiration rates of the leaves sampled from the plants in the solutions without phosphorus were much lower than for the leaves of plants in the other solutions.

A comparison of growth rates and phosphorus distribution in a range of pasture species

1969 ◽  
Vol 20 (6) ◽  
pp. 1023 ◽  
Author(s):  
EF Biddiscombe ◽  
PG Ozanne ◽  
NJ Barrow ◽  
J Keay
Keyword(s):  
Growth Rates ◽  
Phosphorus Content ◽  
Subterranean Clover ◽  
Early Growth ◽  
Unit Weight ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Low Phosphorus ◽  
Low Levels ◽  
Phosphorus Levels

Relative growth rates (RGR) of nine annual pasture species and lucerne were compared in two experiments. During the first 4 weeks of growth the RGR of the clovers tended to be slower than that of the herbs and grasses, especially at low levels of applied phosphate. This situation was reversed towards maturity. Slow RGR of the tops of the clovers at low phosphorus levels was associated with the development of large root systems relative to tops; but at least in subterranean clover, the RGR of the roots was also slow. Other associated characteristics of the clovers, a month from emergence and at low phosphorus levels, were low phosphorus concentrations in the tops relative to non-legumes, and a low proportion of their total phosphorus in the tops. The phosphorus content per unit weight of clover roots was low under these conditions. Differences between species in early growth rate were maintained on different sods, even though the soil solution contained widely different concentrations of phosphate. Establishment of species In the field, particularly during the seedling stage, is discussed in relation to growth rates at low and optimal levels of phosphorus.

Phosphorus nutrition of beef cattle. 2. Relation of pasture phosphorus to phosphorus content of blood, hair and bone grazing steers

1973 ◽  
Vol 13 (60) ◽  
pp. 5 ◽  
Author(s):  
RDH Cohen
Keyword(s):  
Phosphorus Content ◽  
Correlation Coefficients ◽  
Inorganic Phosphorus ◽  
Beef Steers ◽  
Grazing Cattle ◽  
Low Phosphorus ◽  
Phosphorus Status ◽  
The Relationship ◽  
Phosphorus Levels ◽  
Do So

The phosphorus content was measured every three months in pasture and in blood, hair and bone of beef steers that had grazed pastures of low phosphorus content for 12 months. This was done to determine the effect that changes in pasture phosphorus levels had on the phosphorus content of animal tissue. The correlation coefficients between pasture phosphorus content and either the phosphorus content of hair or the concentration of inorganic phosphorus in plasma were not significant. The relationship between the phosphorus content of pasture (x) and dry fat-free rib-bone (y) was given by the equation y = 9.5 + 33.3x (r = 0.97; P < 0.05). It was concluded that bone phosphorus content could provide the best estimate of the phosphorus status of grazing cattle because it significantly reflected variation in the phosphorus content of pasture whereas blood and hair failed to do so.

Phosphorus status of subterranean clover: a rapid and simple leaf test

1982 ◽  
Vol 22 (119) ◽  
pp. 428 ◽  
Author(s):  
D Bouma ◽  
EJ Dowling
Keyword(s):  
Total Phosphorus ◽  
Field Experiments ◽  
Relative Yield ◽  
Subterranean Clover ◽  
Critical Value ◽  
Sand Culture ◽  
Molybdenum Blue ◽  
Phosphorus Status ◽  
Extractable Phosphorus ◽  
Phosphorus Levels

A simple and rapid method is presented for the assessment of the phosphorus status of subterranean clover. The method rests on extracting fresh leaf tissue (400 mg) with five drops 10 N H2SO4 and measuring phosphorus in the filtered extract by a molybdenum blue colour method, visually or calorimetrically. No special skills or equipment are required and the method is therefore potentially suitable for use by advisers and farmers. Two standard blue colours would be sufficient for a visual separation between non-deficient, moderately deficient or severely deficient plants. The method was tested in early spring with leaf samples obtained from two field experiments (five phosphorus levels), a sand culture experiment, and a pot experiment with phosphorus deficient soil (five phosphorus levels in each). Close relations were obtained between relative yields (yields as a percentage of the maximum in each experiment) and extractable phosphorus (R2 = 0.93). The curve fitted to the relation had a clearly defined inflexion point, indicating a critical value of 150 ppm extractable phosphorus at 90% of the fitted asymptote for relative yield. The relation for total phosphorus and yields was not as close (R2=0.77) and the critical value not clearly defined. Extractable phosphorus was closely related to total phosphorus below the critical value for extractable phosphorus, but not above this value. Likely physiological are discussed.

Phosphorus compounds measured in a rapid and simple leaf test for the assessment of the phosphorus status of subterranean clover

1984 ◽  
Vol 24 (125) ◽  
pp. 213 ◽  
Author(s):  
GCJ Irving ◽  
D Bouma
Keyword(s):  
Leaf Tissue ◽  
Rapid Test ◽  
Subterranean Clover ◽  
Exchange Chromatography ◽  
Phosphorus Compounds ◽  
Fresh Leaf ◽  
Organic Phosphates ◽  
Phosphorus Status ◽  
Colour Development ◽  
Hydrolysis Of

Experiments were done to determine what proportion of the phosphate extracted from fresh leaf tissue by five drops of 10 N H2SO4 represents inorganic tissue phosphate, and to what extent hydrolysis of organic phosphates during and after the extraction, and during the development of the blue phosphomolybdate complex, could contribute to the values obtained. The extraction is the basis of a simple and rapid test for the assessment of the phosphorus status of subterranean clover (Bouma and Dowling 1982). Extraction of leaf tissue of subterranean clover and sunflower with 0.2 M HClO4 at O�C, which was shown to extract inorganic leaf phosphorus without causing significant hydrolysis of organic phosphates, gave values not significantly different from those in H2SO4 extracts. The rate of hydrolysis of endogenous organic phosphates in tissue, extracted and left at room temperature for periods of up to 40 min. after adding H2SO4, did not differ significantly from zero. Errors due to hydrolysis during the 30 min. previously recommended for colour development are reduced to negligible proportions by reducing the time for colour development to 10 min. and by adding citric acid at this point. Anion-exchange chromatography of 10 N H2SO4 and 0.2 M HClO4 extracts confirmed the similarity of their composition and provided estimates of the various phosphate compounds present. The extraction of fresh leaf tissue with 10 N H2SO4 provides a satisfactory estimate of the endogenous inorganic phosphorus content.

The influence of seed size and depth of sowing on pre-emergence and early vegetative growth of subterranean clover (Trifolium subterraneum L.)

1956 ◽  
Vol 7 (2) ◽  
pp. 98 ◽  
Author(s):  
JN Black
Keyword(s):  
Leaf Area ◽  
Seed Size ◽  
Vegetative Growth ◽  
Dry Matter ◽  
Relative Rate ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Total Leaf Area ◽  
Pot Culture

Changes in the pre-emergence distribution of dry matter in subterranean clover (Trifolium subterraneum L.) variety Bacchus Marsh were followed at 21°C, using three sizes of seed and three depths of sowing, ½, 1¼, and 2 in. Decreasing seed size and increasing depth of sowing both reduce the weight of the cotyledons a t emergence. Seed of the three sizes were sown a t three depths in pot culture a t staggered intervals so that emergence was simultaneous. Dry weight in the early vegetative stage was proportional to seed size, and total leaf area and leaf numbers showed similar trends. Plants of each seed size grew at the same relative rate. No effect of depth of sowing could be detected, and this was shown to be due to the cotyledon area a t emergence being constant for any given seed size, regardless of varying depth of sowing and hence of cotyledon weight. It was concluded that seed size in a plant having epigeal germination and without endosperm is of importance: firstly, in limiting the maximum hypocotyl elongation and hence depth of sowing, and secondly, in determining cotyledon area. Cotyledon area in turn influences seedling growth, which is not affected by cotyledon weight. Once emergence has taken place, cotyledonary reserves are of no further significance in the growth of the plants.

Sign in / Sign up

Export Citation Format

Share Document