Phosphorus seed coatings for pasture species. I. Effect of source and rate of phosphorus on emergence and early growth of phalaris (Phalaris aquatica L.) and lucerne (Medicago sativa L.)

1988 ◽  
Vol 39 (3) ◽  
pp. 437 ◽  
Author(s):  
JM Scott ◽  
GJ Blair
Keyword(s):  
Medicago Sativa ◽  
P Uptake ◽  
Early Growth ◽  
Phalaris Aquatica ◽  
Early Seedling Growth ◽  
P Content ◽  
Early Seedling ◽  
Medicago Sativa L ◽  
Germinating Seeds ◽  
P Sources

Seed coatings containing phosphorus (P) can be an effective way of promoting early seedling growth in P-deficient soil, but there is insufficient information available on the P sources and rates which are both safe to germinating seeds and effective in supplying P. A growth chamber experiment was undertaken to study the effect on the emergence and early growth of phalaris (Phalaris aquatica L.) and lucerne (Medicago sativa L.) of seed coatings containing one of three P sources (mono-[MCP], di-[DCP], or tricalcium phosphate [TCP]) at three rates (0.625, 1.25 or 2.5 mg P seed-1). The emergence of lucerne was markedly delayed (as measured by fitted Mitscherlich functions) by increasing rates of MCP, whilst that of phalaris was only slightly delayed. DCP and TCP had only slight effects on the emergence of both species. Leaf number (at 27 days after sowing [d.a.s.]), dry matter yield and P content of shoots of both species (at 35 d.a.s.) were increased by all P sources. With phalaris, MCP was approximately four times as effective per unit of P as DCP, which in turn was approximately four times as effective as TCP, whereas, with lucerne, MCP was twice as effective as DCP, which in turn was twice as effective as TCP. The results show that whilst emergence was most affected by soluble P sources at high rates, these same sources were most effective in promoting early P uptake per unit of P applied.

Phosphorus seed coatings for pasture species. II. Comparison of effectiveness of phosphorus applied as seed coatings, drilled or broadcast, in promoting early growth of phalaris (Phalaris aquatica L.) and lucerne (Medicago sativa L.)

1988 ◽  
Vol 39 (3) ◽  
pp. 447 ◽  
Author(s):  
JM Scott ◽  
GJ Blair
Keyword(s):  
Medicago Sativa ◽  
Plant Height ◽  
Early Growth ◽  
The Other ◽  
Fertilizer Treatment ◽  
Seed Coating ◽  
Phalaris Aquatica ◽  
Medicago Sativa L ◽  
Application Methods ◽  
P Sources

The relative efficiency of phosphorus (P) seed coatings and drilled and broadcast applications of P was investigated in a glasshouse experiment conducted with phalaris (Phalaris aquatica L.) and lucerne (Medicago sativa L.) in P-deficient soil. Two P sources (monocalcium phosphate [MCP] and dicalcium phosphate [DCP]) were used at three rates in seed coatings (0, 5 and 10 kg P ha-1) or at six rates each of drilled or broadcast applications (0, 2.5, 5, 10, 20 and 40 kg P ha-1). MCP coatings severely reduced lucerne emergence and hence yield, but had little effect on phalaris emergence. No other fertilizer treatment affected emergence. The height of phalaris plants at 27 days after sowing (d.a.s.) was increased as much by seed coatings containing MCP at 5 kg P ha-1 as by drill or broadcast applications of MCP at 20 kg P ha-1. Plant height of the MCP seed coating treatments was also less variable than the other application methods, suggesting that the coatings provided more uniform access to P. Seed coatings containing DCP at 10 kg P ha-1 increased phalaris plant height more than did drilled or broadcast applications at 40 kg P ha-1, but there was no effect of any DCP treatment on lucerne growth at 27 d.a.s. The relatively large differences observed in plant height between different application methods at 27 d.a.s. diminished over time until, at 57 d.a.s., only small differences were evident. The dry matter yield and P content of both species were increased by increasing rates of MCP, but DCP had little effect at any rate. The reduced differences between the seed coating treatments and the other application methods at harvest may have been due to the limited soil volume of the pots used; further work is necessary in larger soil volumes to determine the significance of the early growth advantage conferred on phalaris by the phosphorus seed coatings, and to find ways of protecting lucerne from soluble P sources during germination.

Nitrogen fixation by subterranean clover (Trifolium subterraneum L.) growing in pure culture and in mixtures with varying densities of lucerne (Medicago sativa L.) or phalaris (Phalaris aquatica L.)

1999 ◽  
Vol 50 (6) ◽  
pp. 1047 ◽  
Author(s):  
B. S. Dear ◽  
M. B. Peoples ◽  
P. S. Cocks ◽  
A. D. Swan ◽  
A. B. Smith
Keyword(s):  
Medicago Sativa ◽  
N2 Fixation ◽  
Pure Culture ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Shoot Biomass ◽  
N Fixation ◽  
Mineral N ◽  
Phalaris Aquatica ◽  
Medicago Sativa L

The proportions of biologically fixed (Pfix) plant nitrogen (N) and the total amounts of N2 fixed by subterranean clover (Trifolium subterraneum L.) growing in pure culture and in mixtures with different densities (5, 10, 20, or 40plants/m2) of newly sown phalaris (Phalaris aquatica L.) or lucerne (Medicago sativa L.) were followed over 3 years in a field study using the 15N natural abundance technique. The amount of fixed N in subterranean clover was linearly related to shoot biomass. Over the 3-year period, subterranean clover fixed 23–34 kg N/t shoot biomass compared with 17–29 kg N/t shoot biomass in lucerne. Based on above-ground biomass, pure subterranean clover fixed 314 kg N/ha over the 3 years compared with 420–510 kg N/ha by lucerne–clover mixtures and 143–177 kg N/ha by phalaris–clover mixtures. The superior N2 fixation by the lucerneŒsubterranean clover mixtures was due to the N fixed by the lucerne and the presence of a higher subterranean clover biomass relative to that occurring in the adjacent phalaris plots. In the first year, 92% of subterranean clover shoot N was derived from fixation compared with only 59% of lucerne. The reliance of clover upon fixed N2 remained high (73–95%) throughout the 3 years in all swards, except in pure subterranean clover and lucerne in August 1996 (56 and 64%, respectively). Subterranean clover usually fixed a higher proportion of its N when grown in mixtures with phalaris than with lucerne. The calculated Pfix values for lucerne (47–61% in 1995 and 39–52% in 1996) were consistently lower than in subterranean clover and tended to increase with lucerne density. Although lucerne derived a lower proportion of its N from fixation than subterranean clover, its tissue N concentration was consistently higher, indicating it was effective at scavenging soil mineral N. It was concluded that including lucerne in wheat-belt pastures will increase inputs of fixed N. Although lucerne decreased subterranean clover biomass, it maintained or raised Pfix values compared with pure subterranean clover swards. The presence of phalaris maintained a high dependence on N2 fixation by subterranean clover, but overall these swards fixed less N due to the lower clover herbage yields. Perennial and annual legumes appear compatible if sown in a mix and can contribute more N2 to the system than where the annual is sown alone or with a perennial grass. These findings suggest that increases in the amount of N2 fixed can be achieved through different legume combinations without interfering greatly with the N fixation process. Different combinations may also result in more efficient use of fixed N2 through reduced leaching. Further work looking at combinations of annuals possibly with different maturity times, different annual and perennial legume combinations, and pure combinations of perennial (e.g. lucerne) could be investigated with the aim of maximising N2 fixation and use. Grazing management to encourage clover production in mixtures with phalaris will be necessary before the potential of subterranean clover to contribute fixed N2 in these swards is fully realised.

Effect of seed source and seed phosphorus content on the growth and yield of wheat in north-eastern Victoria

1997 ◽  
Vol 37 (2) ◽  
pp. 191 ◽  
Author(s):  
V. F. Burnett ◽  
P. J. Newton ◽  
D. R. Coventry
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Seed Source ◽  
Growth And Yield ◽  
Dry Matter Production ◽  
Early Seedling Growth ◽  
Matter Production ◽  
P Content ◽  
North Eastern ◽  
Early Seedling

Summary. Wheat (Triticum aestivum L.) seed was grown at 2 locations differing in phosphorus (P) status (low and high) in north-eastern Victoria (36°S, 146°E), with applied superphosphate (kg P/ha: 0, 12, 24, 100 and 200), to produce seed of different P content. This seed was used in field and glasshouse experiments in 1993 and 1994 to investigate the effects of seed source and P content on the growth and yield of wheat. Wheat seed grown at the low P status site was smaller than seed grown at the high P status site, irrespective of the amount of applied P. Seed from the low P status site produced less early dry matter in both field and glasshouse experiments in 1993, but there was no effect of seed source on grain yield in either experiment. High seed P content either had no effect or reduced seedling emergence in the field experiments. In the glasshouse, low P content in seed from the low P status site resulted in reduced emergence. Increases in dry matter production and grain yield with higher seed P content were only observed in the drought season of 1994. Application of P resulted in increased emergence, dry matter production and grain yield at most seed P content levels but there were no significant interactions between seed P content and applied P. Application of N did not affect dry matter production in either year, but increased grain protein in both years and grain yield in 1993. Seed from low P status environments can affect early seedling growth but in average growing seasons, or in glasshouse conditions, wheat growth compensates so that differences in grain yield are not observed. However, in order to avoid risk of poor early seedling growth and possible yield penalties when the crop is stressed, wheat seed should be collected from adequate soil P status sites.

Effect of phalaris (Phalaris aquatica L.) and lucerne (Medicago sativa L.) density on seed yield and regeneration of subterranean clover (Trifolium subterraneum L.)

2000 ◽  
Vol 51 (2) ◽  
pp. 267 ◽  
Author(s):  
B. S. Dear ◽  
P. S. Cocks ◽  
A. D. Swan ◽  
E. C. Wolfe ◽  
L. M. Ayre
Keyword(s):  
Medicago Sativa ◽  
Seed Yield ◽  
Seed Bank ◽  
Seed Set ◽  
Basal Area ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Phalaris Aquatica ◽  
Medicago Sativa L ◽  
Clover Seed

A mixture of 3 subterranean clover (Trifolium subterraneum L.) cultivars (cvv. Goulburn, Seaton Park, and Dalkeith) was grown with 5–40 plants/m2 of phalaris (Phalaris aquatica L.) or lucerne (Medicago sativa L.) for 3 years at Wagga Wagga, NSW (147°21´E, 35°03´S). Clover seed yield was assessed each year, the number of regenerating clover seedlings was counted, herbage yield of clover and the perennials was measured, and the change in perennial density recorded. The influence of perennials on water availability in spring and light during clover seed set was also examined. The impact of perennial density on clover was assessed using regression analyses. In each of the 3 years, subterranean clover seed yield was negatively related to perennial density, but phalaris suppressed clover seed yield more than equivalent densities of lucerne in 2 of the years. Clover seed yield was positively related (R2 = 0.30–0.85) to clover biomass in spring in all 3 years (except for subterranean clover in phalaris in 1994) and to the proportion of total photosynthetically active radiation reaching the clover canopy beneath the perennial (R2 = 0.33–0.83) in 2 of the 3 years. There was a positive relationship between clover seedling regeneration in autumn and size of the summer seed bank in both years in lucerne (R2 = 0.40–0.76) and in 1 year in phalaris (R2 = 0.76) and a negative association between perennial density and clover seedling regeneration. The rate at which the surface profile (0–37 cm) dried in spring was independent of phalaris and lucerne density over the 3 years and did not differ from that of pure clover. The late season clover cultivar, Goulburn, constituted between 57% and 79% of the seed bank following seed set, substantially more than the earlier flowering cultivars, Seaton Park and Dalkeith. Neither perennial density nor species changed the relative competitiveness of the 3 cultivars. The high seed yield of Goulburn and the lack of a perennial-induced change in surface soil water in spring suggest that growing perennials in association with subterranean clover does not increase the level of moisture stress during clover seed set. The good performance of Goulburn is attributed to superior competitive ability for light in late spring. The basal area occupied by lucerne and phalaris increased with perennial density in each of the first 2 years. However, in the third year, phalaris basal area was similar at all densities. The findings suggest that sowing low densities of lucerne should assist in promoting seed yield and regeneration of subterranean clover. Management of phalaris, which has the capacity to substantially increase plant size at low densities, may require additional strategies such as more frequent grazing in spring.

EFFECTS OF VEGETATION DECOMPOSITION AND CARBOFURAN ON ESTABLISHMENT AND YIELD OF SOD-SEEDED ALFALFA

1983 ◽  
Vol 63 (2) ◽  
pp. 421-427 ◽  
Author(s):  
P. M. DOWLING ◽  
D. L. LINSCOTT
Keyword(s):  
Medicago Sativa ◽  
Early Growth ◽  
Botanical Composition ◽  
Canopy Architecture ◽  
Application Time ◽  
Decomposition Time ◽  
Medicago Sativa L ◽  
Herbicide Glyphosate

The effect of varying degrees of sward decomposition and carbofuran at 1.1 kg a.i./ha on establishment and yield of sod-seeded alfalfa (Medicago sativa L. ’Iroquois’) was assessed at Ithaca, N.Y. during 1980 on four sites differing in botanical composition and canopy architecture. Differential decomposition was achieved by applying the herbicide glyphosate (2.2 kg a.i./ha) at three sequential times before a late May seeding. The influence of lime and charcoal on alfalfa establishment was also evaluated. Seedling numbers generally increased with progressively earlier killing of vegetation, though the pattern differed at each site. Seedling numbers were lowest on the quackgrass sod and highest on the haysod sites. Carbofuran application increased seedling numbers, particularly at the latest glyphosate application time. Lime and charcoal had little effect. The influence of decomposition time was not transient since treatment differences up to 1 yr after planting were still apparent. The data presented suggest that allelopathic factors and to a lesser extent arthropod activity limit seedling numbers and the early growth of sod-seeded alfalfa.Key words: Decomposition, carbofuran, sod-seeding, alfalfa

scholarly journals Assessment of Barley Genotypes Response to Salinity Stress at Early Seedling Growth Stage

2020 ◽  
Vol 63 (3) ◽  
pp. 179-186
Author(s):  
Hossein Askari ◽  
Seyed Kamal Kazemitabar ◽  
Hamid Najafi Zarrini ◽  
Mohammd Hossein Saberi
Keyword(s):  
Dry Matter ◽  
Growth Stage ◽  
Early Growth ◽  
Stability Parameters ◽  
Early Seedling Growth ◽  
Matter Production ◽  
Nacl Concentration ◽  
Early Seedling ◽  
Tolerance Indices ◽  
Barley Genotypes

 This study was performed to assess several indices for identifying barley genotypes at early growth stage with the best performance in salinity conditions. The effect of salinity treatments was studied through an analysis of the dry matter production, results showed significant differences among genotypes. The majority of used tolerance indices indicated that ESBYTM8910, 4 Shori and MBS8715 were the best barley genotypes showing the highest stress resistance for the greatest NaCl concentration. It is based on used stability parameters that the genotypes MBS8712 and Jo torsh were the most phenotypically stable. In general, the tolerant genotypes showed the least stability based on mostly of stability parameters  

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