The response of defoliated swards of subterranean clover to temperature

1976 ◽  
Vol 27 (5) ◽  
pp. 593 ◽  
Author(s):  
EAN Greenwood ◽  
BA Carbon ◽  
RC Rossiter ◽  
JD Beresford
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Carbon Dioxide Exchange ◽  
Short Term ◽  
Plant Parts ◽  
Pre Treatment ◽  
Reproductive Phases ◽  
Whole Life Cycle

The objective was to characterize the response of Trifolium subterraneum L. (cv. Daliak) swards to short-term and to long-term changes in temperature at several stages of plant growth. Short-term responses were studied with microswards growing in boxes in the open and defoliated every week to simulate heavy grazing. At seven stages, one subsample of boxes was harvested and three other subsamples were moved to controlled-temperature glasshouses and grown for 14 days at 10/5° (day/night), 17.5/12.5° and 25/20°C respectively, and then harvested. Dry weights and numbers of plant parts, and areas of leaves, height, light penetration and net carbon dioxide exchange of swards were measured. For long-term responses, young, defoliated microswards were transferred to the above temperatures for 9 weeks and cut weekly. On days 32 (pre-treatment harvest), 53, 74 and 95, tops and roots were harvested. The results support three generalizations. Firstly, severely defoliated subterranean clover pastures respond to temperature between 10/5° and 25/20° in a variety of ways over the whole life cycle. However, temperature is of greater importance as a determinant of dry weight of tops during the post-emergence and reproductive phases than it is during the preflowering phase. Secondly, total growth rate (TGR) after the first 8–10 weeks of growth does not increase at temperatures above 10/5°. And thirdly, even with moderately low LAI values of 1–4, temperatures of 25/20° can inhibit TGR after about 8 weeks of growth. The biological and agricultural implications are discussed.

Copper nutrition of subterranean clover (Trifolium subterraneum L. cv. Seaton Park). I. Effects of copper supply on growth and development

1981 ◽  
Vol 32 (2) ◽  
pp. 257 ◽  
Author(s):  
DJ Reuter ◽  
AD Robson ◽  
JF Loneragan ◽  
DJ Tranthim-Fryer
Keyword(s):  
Root Growth ◽  
Growth And Development ◽  
Copper Deficiency ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Growing Season ◽  
Internode Elongation ◽  
Plant Parts ◽  
Lateral Branches

Effects of severe and moderate copper deficiency on the development of leaves and lateral branches, on the distribution of dry weight within the plant, and on seed yield of Seaton Park subterranean clover were assessed as part of three glasshouse experiments. Copper deficiency markedly depressed top and root growth without producing any distinctive symptoms. It retarded phasic development by delaying development of leaves and lateral branches, senescence of plant parts, and flowering: it also depressed the proportion of stem plus petiole in plant tops and decreased internode elongation, pollen fertility and the number of burrs and seeds formed. As a result of its effect in delaying flowering, copper deficiency would depress seed production particularly strongly when low soil water supply shortens the growing season. The need for suitable procedures for diagnosing copper deficiency is emphasized by the lack of specific plant symptoms in this species.

Zinc in subterranean clover (Trifolium subterraneum L. cv. Seaton Park). I. Effects of zinc supply on distribution of zinc and dry weight among plant parts

1982 ◽  
Vol 33 (6) ◽  
pp. 989 ◽  
Author(s):  
DJ Reuter ◽  
JF Loneragan ◽  
AD Robson ◽  
D Plaskett
Keyword(s):  
Zinc Deficiency ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Physiological Age ◽  
Vegetative Development ◽  
Plant Parts ◽  
Zinc Concentrations ◽  
Complex Relationships ◽  
Lateral Branches

Effects of zinc supply on the distribution of zinc and dry weight among plant parts were examined during the first 55 days of vegetative development of Seaton Park subterranean clover grown in a zinc-deficient soil in a glasshouse. Symptoms of zinc deficiency first appeared in young trifoliate leaves. Zinc deficiency decreased the expansion of blades and petioles, delayed the development of leaves and lateral branches, depressed dry weights of roots and shoots, and increased the proportion of plant dry weight in roots and leaf blades. In each treatment and at each harvest, zinc concentrations varied widely amongst plant parts and with their physiological age. Plant parts also differed widely in the response of their dry matter and zinc concentrations to both zinc treatment and harvest time. It is suggested that these complex relationships explain why plant samples consisting of composite plant parts are not suitable for diagnosis of zinc deficiency. In the present experiment, zinc concentration in whole shoots was unsatisfactory for diagnosing zinc deficiency since concentrations were higher in young, zinc-deficient plants than in older, zinc-adequate plants. In young leaf blades of the same physiological age, zinc concentrations showed reasonably constant relationships with plant growth throughout the entire experiment. However, they varied two- to three-fold in leaves of different ages from the same plants. The results show the importance for diagnosis of zinc deficiency of selecting as a sample a single organ of defined physiological age. The youngest open leaf blade is recommended for diagnosis of zinc deficiency in subterranean clover.

Growth of skeleton weed (Chondrilla juncea L.) as affected by growth of subterranean clover (Trifolium subterraneum L.) and infection by Puccinea chondrillina Bubak and Syd

1975 ◽  
Vol 26 (6) ◽  
pp. 975 ◽  
Author(s):  
RH Groves ◽  
JD Williams
Keyword(s):  
Leaf Area ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Root Competition ◽  
Leaf Number ◽  
Root Weight ◽  
Large Reduction ◽  
Plant Parts ◽  
Chondrilla Juncea

Growth of skeleton weed (Chondrilla juncea, form A) and subterranean clover (Trifolium subterraneum) was studied in a glasshouse experiment in which the species were grown alone or together and the resultant effects of shoot and root competition assessed. The leaf number and weight of plant parts of C. juncea were reduced by competition vith subterranean clover, especially when shoots of the two species were competing. The leaf area of C. juncea was reduced, especially when roots of the two species were growing together. Puccinia chondrillina on C. juncea rosettes reduced leaf number, leaf area, and weight of plant parts. Subterranean clover grown with C. juncea infected with P. chondrillina further reduced the size and weight of the weed. The large reduction in leaf area and root weight of C. juncea (form A) plants in the presence of both subterranean clover and P. chondrillina suggests that growth of this form of C. juncea in Australia will be greatly reduced in pastures containing these species. In the long term, densities of this form may possibly be so lowered that a significant level of control will be reached in a cereal cropping-pasture system.

The effect of autotetraploidy in five varieties of subterranean clover (Trifolium subterraneum L.).

1954 ◽  
Vol 5 (3) ◽  
pp. 356 ◽  
Author(s):  
WM Hutton ◽  
JW Peak
Keyword(s):  
Moisture Content ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
The Other ◽  
Seed Setting ◽  
Plant Parts ◽  
Green Matter ◽  
Total Dry Weight

Induced autotetraploidy in the Dwalganup variety of subterranean clover (Trifolium subterraneum L.) resulted in total dry weight increases of 60 and 65.5 per cent. at flowering and maturity respectively. In the other four varieties the tetraploids had decreased yields of dry matter compared with the diploids, although the decreases for leaf weights at flowering were nonsignificant in Mount Barker and Tallarook, as was the total dry weight reduction in Tallarook at maturity. There were no significant differences between the diploids and tetraploids in percentage moisture content. When early development was stimulated by growth in a glass-house, the tetraploids of all varieties showed a significant increase in yield of green matter. The level of increased growth was maintained only in Dwalganup, and decreased in other varieties during flowering. An analysis was made of the way in which the different plant parts mere changed by tetraploidy. Where decreased growth occurred, the leaves and stems were coarser. In all varieties a reduced seed-setting followed autotetraploidy, although in Dwalganup the yield of seed per plant was not affected.

Distribution of zinc and copper in seedlings of subterranean clover (Trifolium subterraneum L.) in solution culture

1956 ◽  
Vol 7 (6) ◽  
pp. 495 ◽  
Author(s):  
DS Riceman ◽  
GB Jones
Keyword(s):  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Solution Culture ◽  
Rapid Decline ◽  
Trifoliate Leaf ◽  
Plant Parts ◽  
Total Dry Weight ◽  
Substantial Change

Changes in the distribution of zinc, copper, and dry matter in seedlings of Trifolium subterraneum L. var. Bacchus Marsh grown in solution cultures which were supplied with copper but not with zinc have been traced during the first 40 days after germination. Increase in total dry weight was accompanied by a rapid decline in the concentration of zinc in the plant parts examined. Symptoms of zinc deficiency were recognizable in the third trifoliate leaf by the time the leaflets opened, 33 days after germination. At that time the concentration of zinc in leaf plus petiole had fallen to 14 p.p.m. in the dry matter. There was a continual net loss of zinc from the cotyledons. A marked increase in the amount of copper present in roots, and in leaf plus petiole, occurred soon after the addition of copper to the cultures 20 days after germination, but no substantial change was observed in the amount of copper present in the cotyledons or in the hypocotyl plus growing point. These latter tissues had previously lost small amounts of copper.

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.

Characteristics of the canopy, root system and grain yield of a crop of Lupinus angustifolius cv. Unicrop

1975 ◽  
Vol 26 (3) ◽  
pp. 497 ◽  
Author(s):  
EAN Greenwood ◽  
P Farrington ◽  
JD Beresford
Keyword(s):  
Carbon Dioxide ◽  
Grain Yield ◽  
Leaf Area ◽  
Time Course ◽  
Dry Weight ◽  
Grain Filling ◽  
Main Axis ◽  
Carbon Dioxide Exchange ◽  
Area Index ◽  
Plant Parts

The time course of development of a lupin crop was studied at Bakers Hill, Western Australia. The aim was to gain insight into the crop factors influencing yield. Weekly measurements were made of numbers and weights of plant parts, and profiles of roots, leaf area and light interception. A profile of carbon dioxide in the crop atmosphere was taken at the time of maximum leaf area, and the net carbon dioxide exchange (NCE) of pods was estimated for three successive weeks. The crop took 10 weeks to attain a leaf area index (LAI) of 1 and a further 9 weeks to reach a maximum LAI of 3.75, at which time only 33% of daylight reached the pods on the main axis. Once the maximum LAI was attained at week 19, leaf fall accelerated and rapid grain filling commenced almost simultaneously on all of the three orders of axes which had formed pods. Measurements of NCE between pods on the main axis and the air suggest that the assimilation of external carbon dioxide by the pods contributed little to grain filling. Grain dry weight was 2100 kg ha-1 of which 30%, 60% and 10% came from the main axis, first and second order apical axes respectively. Only 23% of the flowers set pods and this constitutes an important physiological limitation to grain yield.

Defoliation as a factor in the growth of varieties of subterranean clover (Trifolium subterraneum L) when grown in pure and mixed swards

1963 ◽  
Vol 14 (2) ◽  
pp. 206 ◽  
Author(s):  
JN Black
Keyword(s):  
Agricultural Research ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Light Energy ◽  
Weight Changes ◽  
Agricultural Research Institute ◽  
Large Seed ◽  
Waite Agricultural Research Institute ◽  
High Yielding Varieties

This paper describes two experiments analysing the recovery from defoliation of subterranean clover varieties grown in swards in large seed boxes at the Waite Agricultural Research Institute, Adelaide. The first experiment examined the way in which the six common commercial varieties recovered from a single severe defoliation, and showed that under these conditions they can be placed in three groups: Yarloop and Clare are tall, high-yielding varieties with few, large leaves, recovering slowly from defoliation; Tallarook and Dwalganup are prostrate varieties, lower-yielding, with many small leaves, recovering rapidly after defoliation; Bacchus Marsh and Mount Barker are intermediate in all respects. In the second experiment mixed swards of equal numbers of Yarloop and Tallarook plants were grown under three treatments: A, no defoliation; B, defoliated twice at a height which removed the higher Yarloop canopy but left the lower Tallarook plants untouched; C, defoliated twice at a height which removed the canopies of both varieties. Measurement of dry weight on four occasions after each defoliation showed that in the undefoliated treatment, all Tallarook plants died by the end of the experiment. In the defoliated treatments, the removal of the Yarloop canopy resulted in only a temporary improvement in the illuniination in which the Tallarook plants grew, and their dry weight and plant numbers progressively declined. Dry weight changes in the Tallarook component were shown to be dependent on the light energy available to it, which was in turn determined by the light-absorbing capacity of the superior Yarloop canopy. In mixed swards, the ability of Yarloop to re-establish quickly a leaf canopy above that of Tallarook appeared to explain its success when defoliated.

The short-term effects of rock phosphate and super-phosphate on a subterranean clover pasture.

1955 ◽  
Vol 6 (4) ◽  
pp. 553 ◽  
Author(s):  
RC Rossiter ◽  
PG Ozanne
Keyword(s):  
Rock Phosphate ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Phosphorus Recovery ◽  
Available Phosphorus ◽  
First Year ◽  
Short Term ◽  
Pasture Production ◽  
Total Plant ◽  
Second Year

A 2-year field experiment is described, in which an annual-type pasture was grown on a soil of lateritic origin with various initial rates of rock phosphate and superphosphate. The soil was acutely deficient in plant-available phosphorus at the outset. Application of superphosphate led to the expected increases in total pasture production, but rock phosphate also gave substantial yield increases, even during the first season. Differential species effects were noted; subterranean clover (Trifolium subterraneum L.) and cape-weed (Cryptostemma calendula Druce) responded about equally to superphosphate, but the clover responded to rock phosphate to a greater extent than did cape-weed. Both relative efficiency for total plant growth and percentage utilization of applied phosphorus were much higher with the soluble phosphatic fertilizer than with rock phosphate, especially in the first year. However, phosphorus recovery from rock phosphate was as high in the second year as in the first, whereas there was a marked decrease in the second year from superphosphate.

The significance of petiole length, leaf area, and light interception in competition between strains of subterrranean clover (Trifolium subterraneum L.) grown in swards

1960 ◽  
Vol 11 (3) ◽  
pp. 277 ◽  
Author(s):  
JN Black
Keyword(s):  
Leaf Area ◽  
Leaf Development ◽  
Plant Competition ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Sampling Period ◽  
Dry Weight ◽  
Petiole Length ◽  
Petiole Elongation ◽  
Light Profiles

Three strains of subterranean clover differing in leaf development were grown in pure swards and in all combinations in mixtures. The strain Yarloop has relatively few large leaves held on long petioles; Tallarook has many small leaves and short petioles; Bacchus Marsh is intermediate in all these respects. The swards were grown in boxes and were sampled on four occasions during the period of vegetative growth. Leaf area in each 2 cm layer of the sward was determined separately, and for both strains in the mixed swards, and measurements of the light intensity reaching each layer were obtained. Root weights were determined for all swards and separately for each component of the mixed swards. Examination of the dry weights showed that the growth of the strain having the lesser petiole elongation was suppressed. In the extreme instance Tallarook was so suppressed when grown with Yarloop that in the final inter-sampling period it grew completely in the dark, and lost about half its dry weight. Bacchus Marsh also suppressed Tallarook, but to a lesser extent, while Bacchus Marsh was itself suppressed in competition with Yarloop. The amount of light energy intercepted by the two components of the mixed swards was calculated from the leaf area and light profiles, and confirmed the importance of the spatial distribution of leaves in plant competition. It was concluded that, in the absence of defoliation, the success of a strain under competition was associated with its potential petiole elongation.

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