Tolerance of Phalaris aquatica L. lines and some other agricultural species to excess manganese, and the effect of aluminium on manganese tolerance in P. aquatica

1985 ◽  
Vol 36 (5) ◽  
pp. 695 ◽  
Author(s):  
RA Culvenor

Tolerance to excess manganese in 13 Mediterranean accessions and 3 Australian cultivars of phalaris was determined in solution culture with manganese concentrations from 0.5 to 210 ppm. The effect of aluminium (0, 2.5, 5-0 ppm) on the response of two accessions to excess manganese was studied in a second experiment. Phalaris was very tolerant to excess manganese. Shoot yield at 150 ppm manganese ranged from 25 to 50% of the maximum yield, which was achieved at 0.5 ppm in some lines and at 40 ppm in others. The cultivars Australian and Sirosa were among the most tolerant types. With one exception, Algerian accessions were the least tolerant. These accessions were of similar tolerance to Egret, the most tolerant wheat cultivar examined. All phalaris lines were much more tolerant than Isis wheat, Clipper barley, Woogenellup subterranean clover and Jumbuck rape. Variation in tolerance of high internal manganese levels was the principal determinant of relative tolerance within phalaris. Shoot manganese concentrations causing 10% yield reduction ranged from 730 to 2200 8g g-1 dry wt. The greater tolerance of phalaris compared with the other species was due to lower manganese uptake and higher internal tolerance. Presence of aluminium in the solution did not increase the susceptibility of phalaris to manganese toxicity. Aluminium strongly reduced manganese uptake in phalaris. It is concluded that selection for manganese tolerance need be only of low priority in developing a phalaris cultivar with improved tolerance of acid soils.

2000 ◽  
Vol 51 (8) ◽  
pp. 1031 ◽  
Author(s):  
Vele P Ila'ava ◽  
Pax Blamey ◽  
Colin J Asher

There were strong relationships between exchangeable aluminium (Al) and relative top yield, and between soil pH and relative top yield in the Garret and Bisinella soils. Sweet potato plants produced maximum top yields at soil exchangeable Al <3.0 cmol ((+)/kg, with a 10% yield reduction coinciding with a value of approximately 5.0 cmol (+)/kg. The value was lower for the Bisinella soil than the Garret soil. In the case of pH, maximum yield in both soils was evident at a soil pH of 5.0 with 90% of maximum yield being achieved at about pH 4.7. These results suggest that soil pH would be a good index for Al toxicity. The close relationships between sweet potato growth and both exchangeable Al and soil pH need to be explored further to determine whether it will hold across a wide range of acid soil groups.


Soil Research ◽  
1989 ◽  
Vol 27 (4) ◽  
pp. 663 ◽  
Author(s):  
EA Close ◽  
HKJ Powell

This paper examines the use of short extraction times, and the determination of aluminium with chrome azurol S (CAS), for the estimation of 0.02 M CaCl2-soluble aluminium in soils. It reports the correlation between CAS-reactive aluminium in 5 min extracts and percent maximum yield of white clover (Trifolium repens) for a series of acid soils. The reactivity of soluble and colloidal aluminium species with the metallochromic reagent CAS has been assessed. ~ l ( a q ) ~ + , simple hydroxy species and complexes of weakly binding ligands (salicylic acid, tannins) are CAS-reactive (2 rnin). In contrast, complexes of strongly binding ligands (citric acid, fulvic acid) are not CAS-reactive ([Al] ~ [L] ~ [CAS] ~ 1-2~10-5 M). For a series of six limed phosphated topsoils and subsoils (pH 4.2-5.5), 0.02 M CaCl2- soluble aluminium, as determined with CAS, was negatively correlated against the percent maximum yield of white clover; r2 = -0.73** (5 min extraction), n = 20. This correlation is similar to that for yield against total aluminium as determined by atomic absorption spectroscopy after 60 min extraction (r2 = -0.77**). However, the colorimetric analysis is more convenient and sensitive; further, it does not measure colloidal and polymeric aluminium species (which may not be plant-available). The satisfactory correlation achieved for short extraction times suggests use of CAS for a rapid field method for aluminium toxicity in soils.


Author(s):  
Michele Maglie ◽  
Costanza Baldisserotto ◽  
Alessandra Guerrini ◽  
Alessandra Sabia ◽  
Lorenzo Ferroni ◽  
...  

AbstractThe biotechnological potential of microalgae has gained considerable importance in many applied fields: biomass production for food and feed, cosmeceutical and pharmaceutical products, energy and phytoremediation. The driving force that inspires the progress in microalgae production is the need for new cultivation systems to obtain simultaneously the maximum yield, reduction of water and nutrients use, and production of economically interesting molecules, such as pigments, fatty acids and polysaccharides. We aim to test, for the first time, the co-cultivation in saline medium of Tisochrysis lutea (Haptophyta) and Nannochloropsis oculata (Ochrophyta) to obtain valuable compounds, i.e. pigments and lipids characteristic of each species, using a single culture process. Mono-cultures of each strain were used as controls. The two strains showed an increase in the concentration of chlorophylls and carotenoids in co-culture. At the end of the experiment, the fatty acid profile was analysed by gas chromatography–mass spectrometry. The lipids in the co-cultivated cell extracts were mainly attributable to N. oculata, which represented 97% of the total cells (ca. 83% of the total biomass) at the end of the experiment. Nevertheless, the ω-3 characteristic of T. lutea (DHA and SDA, absent in N. oculata) was also detectable. Although the co-cultivation of these two phylogenetically different species of microalgae did not show positive effects on the growth and on the total lipid production, however, this process resulted in a reduction of the production costs and a lower consumption of water and nutrients.


1986 ◽  
Vol 26 (6) ◽  
pp. 681 ◽  
Author(s):  
A Pinkerton ◽  
JR Simpson

Previous studies on soils from old pastures in southern New South Wales have demonstrated that nutrients have accumulated at the soil surface, but that the 40-100-mm depth layer in many profiles has become strongly acidic (e.g. pH 4.7), and high in extractable aluminium. Poor growth of subterranean clover has occurred on such soils during dry periods and may be associated with poor root growth in the acidic, nutrient-poor subsurface layers. Possible nutritional causes of these observations were investigated using reconstituted soil profiles. The root and shoot growth of subterranean clover, wheat, oats and lucerne were compared in unamended profiles and in profiles amended by applying nutrients or calcium carbonate (lime) to correct the more obvious deficiencies of the subsurface layers. Subterranean clover grew well as long as the surface soil remained moist, so that plants could utilise the nutrients potentially available within it. When the surface (0-40 mm) was allowed to dry but the subsurface layers remained moist, growth was poor unless phosphate was applied to the moist layer. Subsurface application of lime alone was ineffective. Nitrogen application increased clover growth in the presence of added phosphate or surface moisture, but nitrogen alone did little to alleviate the effects of surface drought. Wheat, and to a lesser extent oats, responded to subsurface lime when the surface was moist, and both responded to subsurface phosphate when the surface was dry. Lucerne responded to subsurface phosphate similarly to subterranean clover but the response was more than doubled in the presence of additional borate and lime. Lime without borate was not effective. When the surface was maintained moist, liming both the surface (0-40 mm) and subsurface layers improved the response over liming the subsurface layer only. The results suggest that declining fertility and productivity in old pastures developed on acid soils may not be rectified by liming alone, but that cultivation, ripping or drilling of phosphate, and in some cases addition of borate, may be required to improve the penetration of nutrients, particularly phosphorus, to greater depth.


2001 ◽  
Vol 41 (8) ◽  
pp. 1179 ◽  
Author(s):  
S. R. Walker ◽  
G. R. Robinson ◽  
R. W. Medd

The competitive advantage of barley compared with wheat was quantified for suppressing seed production of Avena ludoviciana Durieu. (wild oats) andPhalaris paradoxa L. (paradoxa grass), and for improving herbicide effectiveness on these major winter grass weeds of the subtropical grain region of Australia. Eight field experiments were broadcast with weed seed before sowing wheat or barley, in which the emerged weeds were then treated with 4 herbicide doses (0, 25, 50, 100% of recommended rates). Yield reduction from untreated weeds was on average 4 times greater in wheat than in barley, with greater losses from A. ludoviciana than P. paradoxa. Barley did not affect weed emergence, but suppressed weed tiller density and, to a lesser extent, the number of weed seeds per tiller. Seed production was, on average, 4340 and 5105 seeds/m2 for A. ludoviciana and P. paradoxa, respectively, in untreated wheat compared with 555 and 50 seeds/m2 in untreated barley. Weed seed production following treatment with 25% herbicide rate in barley was similar or less than that after treatment with 100% herbicide rate in wheat. Overall, 25% herbicide rate was optimal for both conserving yield and minimising weed seed production in barley. For wheat, maximum yield was achieved with 50% herbicide but weed seed production was lowest with 100% herbicide rate. This indicates that weeds can be effectively controlled in barley with considerably less herbicide than required in wheat, highlighting the importance of including barley as a part of weed management strategies that aim to reduce herbicide inputs.


1959 ◽  
Vol 12 (4) ◽  
pp. 205 ◽  
Author(s):  
William A. Williams ◽  
Burgess L. Kay

1991 ◽  
Vol 31 (6) ◽  
pp. 777
Author(s):  
MDA Bolland

The effect of superphosphate applications (0, 25, 50, 75, 100 and 125 kg P/ha to the soil surface) on the dry matter (DM) herbage production of dense swards of subterranean clover (Trifolium subterraneum cv. Junee) and yellow serradella (Ornithopus compressus cv. Tauro) was measured in a field experiment on deep, sandy soil in south-western Australia. The swards were defoliated with a reel mower at weekly intervals from 88 to 158 days after sowing, to a height of 2 cm for the first 9 cuts, 4 cm for the tenth cut and 5 cm for the eleventh cut. Yellow serradella was more productive than subterranean clover. Consequently, for the relationship between yield and the level of phosphorus (P) applied, yellow serradella supported larger maximum yields and required less P than subterranean clover, to produce the same DM herbage yield. Maximum yields of yellow serradella were 12-40% larger. To produce 70% of the maximum yield for yellow serradella at each harvest, yellow serradella required about 50% less P than subterranean clover. However, when yields were expressed as a percentage of the maximum yield measured for each species at each harvest, the relationship between yield and the level of P applied was similar for both species, and they had similar P requirements.


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.


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