The occurrence of sulphur deficiency on a soil of adequate phoshorus status

1952 ◽  
Vol 3 (2) ◽  
pp. 125 ◽  
Author(s):  
KD McLachlan

Subterranean clover (Trifolium subterraneum L.) grown on a basaltic soil from Cooma, N.S.W., responded markedly to treatment with sulphur, as sulphate. The sulphur deficiency occurring on this soil was uncomplicated by deficiencies of other elements, including phosphorus. Even when the sulphur deficiency had been corrected the phosphorus status of the soil was adequate for normal clover growth.

1955 ◽  
Vol 6 (5) ◽  
pp. 673 ◽  
Author(s):  
KD McLachlan

Subterranean clover (Trifolium subterraneum L.) was grown on 32 virgin soils in pot cultures, and the yield responses to phosphorus, sulphur, and molybdenum were determined for each soil. The soils were collected from a wide area in eastern Australia, extending from south-western Victoria to southern Queensland. Sulphur deficiency occurred almost as frequently as phosphorus deficiency. In fact, 75 per cent. of the soils were deficient in both phosphorus and sulphur. Thirty-one per cent. were deficient in all three elements. The effect of the interaction between the elements on the occurrence and intensity of the deficiencies is shown. Molybdenum responses were obtained only after the other deficiencies had been corrected. A deficiency in one of the elements is no indication of deficiency or sufficiency of either of the other two. There was no correlation between the occurrence or intensity of the deficiencies and the geological origin of the soil parent material, the climate of the regions from which the soils were collected, or such soil characters as colour, organic matter, and texture. Responses to phosphorus were less on the black earths than on the red or yellow podzolic soils; those on the red earths were intermediate. The intensity of sulphur deficiency increased, and the intensity of molybdenum deficiency decreased, with increasing soil pH.


1971 ◽  
Vol 22 (5) ◽  
pp. 723 ◽  
Author(s):  
D Bouma

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.


1985 ◽  
Vol 25 (2) ◽  
pp. 331 ◽  
Author(s):  
EJ Dowling ◽  
D Bouma

A series of field experiments (5 phosphorus levels x 6 replicates) on the southern Tablelands of New South Wales was used, firstly, to confirm the suitability of a modified test for inorganic phosphorus (Pi) concentrations in fresh clover (Trifolium subterraneum) leaves as an index of the current phosphorus status of subterranean clover-based pastures; and, secondly, to evaluate the usefulness of Pi as a predictor of responses to phosphorus applications. A close relation (R2 = 0.910) was found between Pi in healthy green leaf tissue sampled in winter and field responses to phosphorus measured at the same time. The fitted curve had a critical value of 154 ppm Pi at 90% of the fitted asymptote for relative yield. Close relations were also found between total herbage yield measured over the season and Pi in leaf tissue sampled in late autumn and early winter (R2 = 0.896) and in leaves sampled in late winter and early spring (R2= 0.877). Critical values were 160 and 153 ppm Pi respectively. The relation was less close for the third sampling (seed set and flowering, R2= 0.809) and the critical value had declined to 118 ppm Pi. It is concluded that Pi determined in clover leaf samples provides a simple measure of the current phosphorus status of subterranean clover-based pasture, and of its likely response to phosphorus. A critical value of 150 ppm Pi is confirmed for assessing the current phosphorus status, and is also proposed for predictive purposes. The method described for the estimation of Pi is a further simplification of the method presented previously. It is also more rapid and achieves a saving of 80-90% in chemicals. The correlation coefficient for the straight line relationship between the two methods was 0.956 (68 observations).


1951 ◽  
Vol 2 (1) ◽  
pp. 14 ◽  
Author(s):  
RC Rossiter

The visual symptoms of several mineral deficiencies on the Dwalganup strain of subterranean clover are outlined. Phosphorus, nitrogen, and molybdenum deficiencies particularly reduce the rate of leaf production and leaf size. They may be distinguished by leaf colour-dark green in phosphorus deficiency and greenish yellow to pale yellow in nitrogen and molybdenum deficiency. Sulphur deficiency reduces the rate of leaf production after the onset of symptoms. Leaf size was not greatly affected by the degree of sulphur deficiency studied. The older leaves were uniformly lemon yellow in colour. Both potassium and zinc deficiency result in very pronounced reduction in leaf size. Potassium deficiency, in addition, shows marginal necrosis of older leaves, while with zinc deficiency leaf shape is profoundly affected. Copper deficiency particularly reduces seed production. The leaves are lighter green in colour than normal. With calcium (and manganese) deficiency, no prominent symptoms were recorded on the soils used. The advantages and limitations of diagnosis by visual symptoms are discussed.


2000 ◽  
Vol 51 (3) ◽  
pp. 377 ◽  
Author(s):  
G. M. Lodge

Seedlings of 3 perennial grasses, Danthonia linkii Kunthcv. Bunderra, D. richardsonii Cashmore cv. Taranna(wallaby grasses), and Phalaris aquatica L. cv. Sirosa,were each grown in replacement series mixtures with seedlings ofTrifolium repens L. (white clover),Trifolium subterraneum L. var. brachycalycinum (Katzn.et Morley) Zorahy & Heller cv. Clare (subterraneanclover), and Lolium rigidum L. (annual ryegrass). Plantswere sown 5 cm apart in boxes (45 by 29 by 20 cm) at a density of 307plants/m2. Maximum likelihood estimates were usedto derive parameters of a non-linear competition model using the dry matterweights of perennial grasses and competitors at 3 harvests, approximately 168,216, and 271 days after sowing. Intra-plant competition was examined inmonocultures of each species, grown at plant spacings of 2, 5, and 8 cm apartwith plants harvested at the above times.Competition occurred in all perennial grass–competitor mixtures, exceptin those of each perennial grass with white clover and thephalaris–subterranean clover mixture (Harvest 1) and those withD. richardsonii and phalaris grown with white clover(Harvest 2). For D. richardsonii (Harvests 1 and 2) andD. linkii (Harvest 1 only) grown with white clover andthe phalaris–subterranean clover (Harvest 1), the two species in themixture were not competing. In the phalaris–white clover mixture, eachspecies was equally competitive (Harvests 1 and 2). These differences incompetition and aggressiveness reflected differences in individual plantweights in monocultures where there was an effect (P < 0.05) of species ondry matter weight per box, but no significant effect of plant spacing.These data indicated that for successful establishment,D. richardsonii and D. linkiishould not be sown in swards with either subterranean clover or white clover,or where populations of annual ryegrass seedlings are likely to be high.Phalaris was more compatible with both white clover and subterranean clover,but aggressively competed with by annual ryegrass.


2004 ◽  
Vol 94 (5) ◽  
pp. 433-439 ◽  
Author(s):  
S.N. Johnson ◽  
P.J. Gregory ◽  
P.J. Murray ◽  
X Zhang ◽  
I.M. Young

AbstractThis study investigated the ability of neonatal larvae of the root-feeding weevil, Sitona lepidus Gyllenhal, to locate white clover Trifolium repens L. (Fabaceae) roots growing in soil and to distinguish them from the roots of other species of clover and a co-occurring grass species. Choice experiments used a combination of invasive techniques and the novel technique of high resolution X-ray microtomography to non-invasively track larval movement in the soil towards plant roots. Burrowing distances towards roots of different plant species were also examined. Newly hatched S. lepidus recognized T. repens roots and moved preferentially towards them when given a choice of roots of subterranean clover, Trifolium subterraneum L. (Fabaceae), strawberry clover Trifolium fragiferum L. (Fabaceae), or perennial ryegrass Lolium perenneL. (Poaceae). Larvae recognized T. repens roots, whether released in groups of five or singly, when released 25 mm (meso-scale recognition) or 60 mm (macro-scale recognition) away from plant roots. There was no statistically significant difference in movement rates of larvae.


1984 ◽  
Vol 24 (125) ◽  
pp. 213 ◽  
Author(s):  
GCJ Irving ◽  
D Bouma

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.


1956 ◽  
Vol 7 (2) ◽  
pp. 98 ◽  
Author(s):  
JN Black

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.


Author(s):  
H. Neave ◽  
C.H. Hewlett

The information contained in this paper is principally first-hand knowledge extending over a period of six years gained from personal experience from our own "Oakleigh" farm.


1954 ◽  
Vol 5 (4) ◽  
pp. 598 ◽  
Author(s):  
EM Hutton ◽  
JW Peak

A number of varieties of subterranean clover (Trifolium subterraneum L.) were tested with a severe strain of Phaseolus virus 2 Pierce. Northam First Early, Dwalganup, and Pink Flowered gave lethal necrotic reactions while the rest developed mottles and chlorosis of different degrees of intensity. Reductions in the mean fresh weights of plants of five subterranean clover varieties ranged from 26.1 to 76.7 per cent. Epidermal cells of mottled leaves contained irregular aggregates of viroplasts stained by treatment with phloxine-trypan blue. Viroplasts in young tip leaves did not stain if the plants were held at temperatures below 44.6°F while those in mature basal leaves were not so affected. The lethal-reactors Northam First Early, Dwalganup, and Pink Flowered were resistant in the field to Phaseolus virus 2. With hand inoculation in the glass-house an average of 10 per cent. of plants of these varieties remained free from systemic infection, whereas all the plants of mottle-reacting varieties became systemically infected. The virus had a discontinous distribution in plants of lethal-reactors, compared with a continuous distribution in those of mottle-reactors such as Mount Barker. The lethal reaction is heritable in a dominant fashion in most crosses, so that the development of desirable new virus- resistant varieties is possible.


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