The cobalt status of Tasmanian soils. II The recovery of applied cobalt in pot experiments

1964 ◽  
Vol 15 (4) ◽  
pp. 609 ◽  
Author(s):  
KD Nicolls ◽  
JL Honeysett

In glass-house experiments, cobalt was added at rates corresponding to 18, 32, or 36 oz CoSO4.7H2O per acre to 27 soils, mostly krasnozems. This treatment raised the cobalt content of subterranean clover tops significantly on only 13 soils, and on only five of the 13 by more than 0.05 p.p.m. Cobalt in control plants ranged from 0.05 to 0.32 p.p.m. The largest recovery of applied cobalt, by two successive crops of subterranean clover, was 4% of that applied. Mechanical contamination of plant material was avoided by adding the cobalt before sowing the first crop. Perennial ryegrass and white clover gave similar results, over four or five harvests. The implications for the practice of top-dressing pastures with cobalt salts are discussed. Cobalt application at the 36 oz rate increased cobalt in subterranean clover more than the 18 oz on three of the four soils tested at the two rates. There was some evidence for a greater recovery of applied cobalt from the more acid soils, over a pH range of 4.9 to 6.2.


2000 ◽  
Vol 53 ◽  
pp. 436-440 ◽  
Author(s):  
N.W. Waipara ◽  
S.K. Hawkins

A preliminary survey of pastures sprayirrigated with dairyshed effluent revealed a significant increase in the population of plant pathogenic Pythium species isolated from both soil and roots In vitro pathogenicity tests showed the majority of these isolates to be pathogenic when inoculated onto the seedlings of white clover subterranean clover and perennial ryegrass although both clover species were more susceptible to Pythiuminduced disease than ryegrass



Author(s):  
R.J. Townsend ◽  
J.E. Radcliffe

Lambs were rotationally grazed with ewes in a 'sheep only' system and with low, medium, and high proportions,of wether goats from October to March on dryland perennial ryegrass-white clover pastures in Canterbury. Lambs grazed with ewes and goats until they were weaned; then they grazed ahead of other stock. Treatment ratios of adult stock on a per head basis were 3 ewes:1 goat ('low goats'), 3 ewes:2 goats ('medium goats') and 3 ewes:3 goats ('high goats'). The ewe:lamb ratio was 1:1.35 on all treatments. Lamb growth rates (g/day) were 152 for 'sheep only', and 169, 185 and 203 for low, medium and high goat treatments respectively. As each treatment lamb reached a target draft weight, it was replaced by a lighter lamb for finishing. In comparison with the 'sheep only' treatment, an extra 1.6 lambs/ha were drafted off the 'medium goat' and an additional 2.6-lambs/ha off the 'high goat' treatment by the end of January. Increasing the proportion of goats:ewes increased the supply of white clover in pastures especially after lambs were weaned. Examination of faecal plant material showed 30% clover in the diet of lambs in a 'sheep only' system, increasing as the goat:sheep ratio increased to 60% clover in the 'high goat' treatment. Keywords white clover, perennial ryegrass, goats, sheep,grazing management, diet, lamb



1974 ◽  
Vol 14 (66) ◽  
pp. 49 ◽  
Author(s):  
CR Kleinig ◽  
JC Noble ◽  
AJ Rixon

Herbage yield, herbage nitrogen, and soil nitrogen accumulation were followed over a five-year period (1958-63) under irrigated annual and perennial pastures established initially with different clovergrass proportions. Species sown in the annual pasture treatments were subterranean clover (Trifolium subterraneum cv. Tallarook) and annual ryegrass (Lolium rigidum cv. Wimmera). Those used in the perennial mixtures were white clover (T. repens cv. Irrigation) and perennial ryegrass (L. perenne cv. Victorian). In the treatments sown to annual or perennial ryegrass only, nitrogenous fertilizer as urea was applied annually at four rates. Total soil nitrogen (mat + 0-91 cm of soil) after five years did not differ significantly for annual pasture and bare ground. In contrast, total soil nitrogen under all perennial pasture treatments, particularly those with a white clover component, was significantly greater than for bare soil (5365 cf. 4181 kg ha-1). Where white clover was sown, nitrogen accumulated at the rate of 258 kg ha-1 per annum compared with 101 kg ha-1 per annum under subterranean clover, the latter barely matching the accumulation rate under perennial ryegrass sown alone without applied nitrogen (105 kg N ha-1 p.a.). Nitrogen accumulation (soil plus mat) was related to both legume and non-legume nitrogen. Perennial pasture, particularly if white clover was present, generally outyielded annual pasture. The total yield of white clover over five years was 29,970 kg ha-1 compared with 11,614 kg ha-1 for subterranean clover. Annual and perennial ryegrasses showed similar yield responses to applied nitrogen. Irrespective of the rate of urea application, nitrogen recovery was low (21-23 per cent).



1971 ◽  
Vol 22 (5) ◽  
pp. 707 ◽  
Author(s):  
KR Helyar ◽  
AJ Anderson

Preliminary pot culture experiments indicated that the yield of phalaris relative to that of perennial ryegrass was poor on the less productive soils, particularly on some of the soils of pH <5.0 as measured in 115 soil/water suspensions. On an infertile acid soil with a high content of exchangeable aluminium, lucerne and phalaris plants responded to lime in pot experiments while subterranean clover, white clover, and perennial ryegrass were depressed by liming. The evidence, including that based on chemical analyses of extracted soil solutions and of lucerne plants, indicates that where adequate nitrogen had been applied, aluminium toxicity depressed the growth of lucerne and phalaris on this acid soil. The plant roots did not show the stunting which is obvious in cases of more severe aluminium toxicity. Subterranean clover, white clover, and perennial ryegrass resisted the toxicity. There was little evidence of a negative interaction between lime and phosphate on yields through their effects on aluminium toxicity. In general, responses to phosphate increased as the level of lime increased. Where suboptimal levels of nitrogen were applied there were responses to lime which were not clearly attributable to the alleviation of aluminium toxicity. Where nitrogen was adequate and there was no effect of lime in counteracting aluminium toxicity, in most cases lime caused a decrease in the concentration of phosphorus in the plants as well as a decrease in the yield. Lime also caused a decrease in the phosphorus level in the extracted soil solutions. However, in some cases where lime counteracted aluminium toxicity it increased the concentration of phosphorus in the tops of the plants. The significance of the results in relation to the problem of the diagnosis of aluminium toxicity is discussed.



1997 ◽  
Vol 48 (1) ◽  
pp. 31 ◽  
Author(s):  
S. J. McKirdy ◽  
R. A. C. Jones

Leaf samples of white clover were collected from 19 irrigated white clover (Trifolium repens) pastures in the south-west of Western Australia and tested for virus infection by enzyme-linked immunosorbent assay. Clover yellow vein virus (CYVV) was found in 16 pastures at infection levels of up to 23% and white clover mosaic virus (WCMV) in 10 at levels up to 83%. None of the white clover pastures with a high incidence of WCMV had been resown with white clover within the last 10 years, whereas those resown within the last 5 years had little or no infection. As previously reported in tests on different white clover pastures in the same irrigation area, widespread infection with alfalfa mosaic virus (AMV) and occasional infection with subterranean clover red leaf virus (SCRLV) was also found. Two or more viruses were found within 16 of the pastures with at least 3 having all 4 viruses. AMV and WCMV were detected in flatweed (Hypochaeris glabra) and AMV was detected in clustered dock (Rumex conglomeratus), both commonly occurring weeds in the pastures. In tests on the perennial ryegrass (Lolium perenne) component of 18 white clover pastures, infection with barley yellow dwarf virus was found in 14 at levels up to 5%. In addition, 11 of the pastures contained a virus which reacted with potyvirus-specific monoclonal antibodies, presumably ryegrass mosaic virus (RyMV), which was detected at levels up to 34%. Live aphids were trapped at 8 different times during 1995 in one pasture that was infected with WCMV, CYVV, AMV, and SCRLV. Blue-green aphid (Acyrthosiphon kondoi) and oat aphid (Rhopalosiphum padi) were the only species caught, both reaching peak populations in midwinter, but only the latter was found in summer. No virus transmission was detected when the aphids caught were fed individually on subterranean clover (T. subterraneum) indicator plants. It is concluded that WCMV poses a threat to the productivity of white clover within irrigated pastures, especially when present in mixed infection with AMV. CYVV is also commonly found but normally not at high enough incidences to pose a serious threat. RyMV may pose a threat to the productivity of the perennial ryegrass component within white clover-based pastures.



Author(s):  
Mj Macfarlane ◽  
G.W. Sheath

Subterranean clover and white clover plant material was collected from 85 sites located in summerdry northern North Island hill country. Plants of both species originating from this collection were grown and typed at Whatwhata Hill Country Research Station. Using several cultivars and selections as standards, measurements were made of morphological, flowering and reseeding characteristics. The subterranean clover population consisted of 44% Mt Barker type, 28% Tallarook type and the remainder an undetermined intermediate type. Mt Barker types in the collection tended to flower later and for longer than their Mt Barker standard, while Tallarook types tended to flower earlier and for longer than StandardTallarook. White clover plants were smaller and more densely leaved than 'Grasslands Huia', the population mean being similar to 'Grasslands Tahora'. A vast majority (7035%) of plants flowered earlier and yielded more seed than Huia and Tahora. An apparent shift in plant type has occurred within clover populations in summerdry hill country, the most notable being the development of a more flexible reseeding pattern. This type can be a future guide to breeding clovers suitable to these environment . Keywords: white clover, subterranean clover, flowering, seeding, morphology, type hill country



Agronomie ◽  
2003 ◽  
Vol 23 (5-6) ◽  
pp. 503-510 ◽  
Author(s):  
Florence Paynel ◽  
Jean Bernard Cliquet


Author(s):  
D.W.R. White

Cell culture and genetic engineering techniques can be used to develop improved pasture plants. To utilise these methods we have developed procedures for regenerating plants from tissue cultures of perennial ryegrass and white clover. In both, the plant genotype influences regeneration capacity. There was significant genetic variation among regenerated perennial ryegrass plants in a wide range of characteristics. Most of the regenerants were resIstant to crown rust and this trait was highly heritable. This rust resistance is being used to breed a new ryegrass cultivar. A system for introducing cloned genes into white clover is described. This capability is bemg used to incorporate genes with the potential to improve nutritional quality and pest resistance. Other possibilities for engineering genetic improvements in white clover, genes conferring herbicide tolerance and resistance to white clover mosaic virus, are briefly outlined. Keywords: Lolium perenne, Trifolium repens, cell culture, somaclonal variation, crown rust resistance, transformation, cloned genes, nutritional quality, proteinase inhibitors, Bt toxins, pest resistance, WCMV viral cross-protection, herbicide tolerance, Agrobacterium, Bacillus thuringenisis.



Author(s):  
W.M. Williams ◽  
L.B. Anderson ◽  
B.M. Cooper

In evaluations of clover performances on summer-dry Himatangi sandy soil, it was found that none could match lucerne over summer. Emphasis was therefore placed on production in autumn-winter- early spring when lucerne growth was slow. Evaluations of some winter annual clover species suggested that Trifolium spumosum, T. pallidum, T. resupinatum, and T. vesiculosum would justify further investigation, along with T. subterraneum which is already used in pastures on this soil type. Among the perennial clover species, Kenya white clover (7'. semipilosum) showed outstanding recovery from drought and was the only species to produce significantly in autumn. However, it failed to grow in winter-early spring. Within red clover, materials of New Zealand x Moroccan origin substantially outproduced the commercial cultivars. Within white clover, material from Israel, Italy and Lebanon, as well as progeny of a selected New Zealand plant, showed more rapid recovery from drought stress and subsequently better winter growth than New Zealand commercial material ('Grasslands Huia'). The wider use of plant material of Mediterranean origin and of plants collected in New Zealand dryland pastures is advocated in development of clover cultivars for New Zealand dryland situations.



Sign in / Sign up

Export Citation Format

Share Document