Effect of competition by white clover on the seed production characteristics of subterranean clover

1979 ◽  
Vol 30 (4) ◽  
pp. 597 ◽  
Author(s):  
RCG Smith ◽  
MC Crespo
Keyword(s):  
Seed Production ◽  
White Clover ◽  
Subterranean Clover ◽  
Plant Size ◽  
Individual Plant ◽  
Plant Seeds ◽  
South Wales ◽  
Seed Population ◽  
Initial Seed ◽  
Total Seed

During the third year following establishment, the production, hard-seededness and dormancy of subterranean clover cv. Woogenellup when grown along and in association with white clover was studied in commercial pastures on the Northern Tablelands of New South Wales. The pasture containing only subterranean clover produced 757 mg seed dm-2, whereas in competition with white clover only 34 mg dm-2 was produced. A study was made of seed production by subterranean clover grown in competition with white clover. As the level of competition increased there was a marked decline in individual plant size, flowers per plant, seeds per burr and total seed production per plant, whereas no significant effects on seed dormancy and hard-seededness were apparent. A study of the seed and seedling population of the pure subterranean clover paddock revealed a recovery of 13% of the initial seed population as surviving plants and 32% as viable hard seeds at the beginning of winter. These observations suggest that competition from white clover could be a significant factor in some situations influencing the persistence of subterranean clover on the Northern Tablelands, and selection of cultivars with better ecological combining ability with white clover might be a worth-while objective.

Increased seed production of subterranean clover pastures in response to fertilizers supplying calcium

1974 ◽  
Vol 14 (71) ◽  
pp. 749 ◽  
Author(s):  
PG Ozanne ◽  
KMW Howes
Keyword(s):  
Seed Production ◽  
Calcium Concentration ◽  
Field Experiments ◽  
Seed Set ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Unit Weight ◽  
Gypsum Plaster ◽  
Total Seed ◽  
Seed Yields

The effects of four common fertilizers containing calcium on seed production in subterranean clover (Trifolium subterraneum) were measured at six locations over five years in a total of fifteen field experiments. Calcium as a sulphate, carbonate or phosphate salt was applied to subterranean clover pastures either at the start of the growing season (autumn) or at flowering (spring). Gypsum, plaster of Paris, or lime gave large increases in seed yield per unit area and also per unit weight of tops. Spring applications of superphosphate increased seed yields in only two out of four experiments. Gypsum applied in spring at 200-500 kg ha-1 was as effective as 2,000 kg ha-1 of lime applied in autumn. Applications of lime in spring were much less effective. Increased seed yields were due to increases in burr yield, seed number per burr, and mean weight per seed. They were usually accompanied by increases in calcium concentration in the seed. Responses in seed production to calcium applications were obtained in all three sub-species of Trifolium subterraneum. In two experiments, newly sown on a soil type on which subterranean clover regeneration and persistence is commonly very poor, applied calcium doubled or quadrupled seed set. In 13 experiments using soils on which subterranean clover had persisted as the major component of the pasture for several years, calcium in the year of application increased the total seed bank by 6 to 31 per cent, and the current seed set by a greater amount.

Seed and seedling studies of three Trifolium subterraneum var. brachycalycinum lines, in a predominantly summer rainfall environment

1995 ◽  
Vol 35 (8) ◽  
pp. 1101
Author(s):  
GM Lodge
Keyword(s):  
Seed Production ◽  
Field Experiments ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Trifolium Subterraneum ◽  
Summer Rainfall ◽  
Sowing Time ◽  
Buried Seeds ◽  
Initial Seed ◽  
Total Seed

Field experiments were conducted in a predominantly summer rainfall environment to investigate burr burial, seed production, seed characteristics, seedling emergence and survival, and the effects of time of sowing on 3 Trifolium subterraneum var. brachycalycinum lines (cv. Clare and 2 local lines). Each line produced more surface than buried burrs; surface burrs were 59% (range 56-62%) of the total number of burrs recovered and produced 59% of the total seed number. Numbers of seeds per burr were similar for surface and buried burrs, however, buried seeds were 0.97 mg heavier (P<0.05) than surface seeds. Storage for 5 months at 25/60�C decreased hardseed content of surface seed by 50% and buried seed by 70%. Surface and buried seeds stored at 25/25�C for 3 months prior to sowing in trays had a total emergence of <10%, compared with 70% emergence for seeds stored at 25/60�C before sowing. These emergence differences reflected their levels of hardseededness. Numbers of seeds recovered from the soil were not significantly different among lines, declining from about 4200 seeds/m2 after initial seed set to 150 seeds/m2 by the following winter, a 97% decrease. Seed production in the second year increased seed reserves to about 8730 seeds/m2. With no further seed production, levels had declined by 93% in June 1990 and by 99% in May 1991. These data confirm the importance of annual seed production for persistence. Total seedling emergence in summer-autumn accounted for only 10% of the estimated seed production in each year. Seedling survival in summer-autumn 1988-89 was 92.7%, more than double the survival in 1989-90. The effect of sowing time on flowering was always significant, with time to first flower being highest (196 days) for the earliest sowing in March (P<0.05), progressively decreasing (P<0.05) to 108 days for the latest sowing in July. In March, April and May sowings, inflorescence numbers on the first day of flowering were similar at about 120/m2, but increased markedly (P<0.05) for sowing in June or July. However, for the March and July sowings, number of inflorescences at the 9 November 1990 count, were lowest (P<0.05). May or June sowings had the highest number of burrs and seeds (P<0.05), indicating that these may be the best sowing times for maximum seed production in these Trifolium subterraneum var. brachycalycinum lines.

Survey of the productivity, composition and estimated inputs of fixed nitrogen by pastures in central-western New South Wales

2004 ◽  
Vol 44 (12) ◽  
pp. 1165 ◽  
Author(s):  
A. M. Bowman ◽  
W. Smith ◽  
M. B. Peoples ◽  
J. Brockwell
Keyword(s):  
White Clover ◽  
N2 Fixation ◽  
Dry Matter ◽  
New South ◽  
Perennial Grass ◽  
New South Wales ◽  
Subterranean Clover ◽  
Legume Species ◽  
Forage Production ◽  
South Wales

Total productivity and legume nitrogen fixation (N2 fixation) in dryland pastures were examined in a 2 year study (1999–2001) on 118 farms in central-western New South Wales. Pasture exclosure cages, placed at 217 on-farm sites, were harvested on 7 occasions and the foliage hand-sorted according to species in order to measure shoot dry matter (DM). The separated legume shoot material collected in spring 1999 (52 different legume samples) and 2000 (76 different legume samples) from a subset of representative pastures (41 cages on 28 different farms in 1999, 32 cages on 25 different farms in 2000) was also analysed for concentration of nitrogen (%N) and 15N natural abundance. These data were subsequently used to calculate the proportion of the legume shoot N derived from atmospheric N (%Ndfa), comparative measures of the relative efficiency of N2 fixation (kg N fixed/t DM accumulated) and the amounts of shoot N fixed (kg N/ha). The survey encompassed 8 common pasture types, and 5 others that were less common, ranging from native perennial grass pastures with little legume content to lucerne (Medicago sativa L.) pastures with and without companion clovers. Fifteen legume species were found in the pastures, some only occasionally. Lucerne and white clover (Trifolium repens L.) were the only perennials. Mean spring estimates of %Ndfa were similar in 1999 and 2000 for lucerne (72 and 81%, respectively), rose clover (T. hirtum All., 82 and 77%) and annual medics (Medicago spp., 89 and 86%). For the remaining 12 legume species, measures of %Ndfa ranged from 64 to 95% and averaged 83%. Shoot %N contents were greater for lucerne than for the other 14 legumes and this was reflected in the comparative measures of N2 fixation which ranged from 14.5 kg N/t DM for rose clover to 25.7 kg N/t DM for lucerne in 2000. The most productive pasture type comprised lucerne plus balansa clover [T. michelianum Savi var. balansae (Boiss.) Azn.], white clover or arrowleaf clover (T. vesiculosum Savi), but all pasture types that contained lucerne were highly productive. Spring was the most productive season and summer the least. Lucerne was overwhelmingly the most productive legume and was responsible for >83% of the fixed N in those pastures that contained both lucerne and other legumes. Lucerne productivity was approximately uniform throughout the year whereas, for other pastures, especially those based on rose clover or subterranean clover (T. subterraneum L.), there were sharp peaks in spring and little or no dry matter production over summer. The presence of lucerne in pastures significantly (P<0.05) reduced broadleaf weeds. It was concluded that, where there are requirements in central-western New South Wales agriculture for uniform forage production throughout the year and a high input of fixed N, lucerne is substantially superior to other species.

Izmir subterranean clover (Trifolium subterraneum L. var. subterraneum)

2007 ◽  
Vol 47 (2) ◽  
pp. 226 ◽  
Author(s):  
P. G. H. Nichols ◽  
G. A. Sandral ◽  
B. S. Dear ◽  
C. T. de Koning ◽  
D. L. Lloyd ◽  
...  
Keyword(s):  
Seed Production ◽  
Seed Set ◽  
New South ◽  
South Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Good Seed ◽  
Improvement Program ◽  
South Wales ◽  
Pasture Legume

Izmir is a hardseeded, early flowering, subterranean clover of var. subterraneum (Katz. et Morley) Zohary and Heller collected from Turkey and developed by the collaborating organisations of the National Annual Pasture Legume Improvement Program. It is a more hardseeded replacement for Nungarin and best suited to well-drained, moderately acidic soils in areas with a growing season of less than 4.5 months. Izmir seed production and regeneration densities in 3-year pasture phases were similar to Nungarin in 21 trials across southern Australia, but markedly greater in years following a crop or no seed set. Over all measurements, Izmir produced 10% more winter herbage and 7% more spring herbage than Nungarin. Its greater hardseededness and good seed production, makes it better suited to cropping rotations than Nungarin. Softening of Izmir hard seeds occurs later in the summer–autumn period than Nungarin, giving it slightly greater protection from seed losses following false breaks to the season. Izmir is recommended for sowing in Western Australia, New South Wales, Victoria, South Australia and Queensland. Izmir has been granted Plant Breeders Rights in Australia.

Productivity of pasture legumes and chicory in central New South Wales

2002 ◽  
Vol 42 (1) ◽  
pp. 15 ◽  
Author(s):  
D. R. Kemp ◽  
D. L. Michalk ◽  
M. Goodacre
Keyword(s):  
White Clover ◽  
New South ◽  
New South Wales ◽  
Subterranean Clover ◽  
Summer Rainfall ◽  
Annual Rainfall ◽  
Summer Drought ◽  
Potential Yield ◽  
Pasture Legumes ◽  
South Wales

Seven experiments were established across a range of environments (latitude 33°S) in central New South Wales to evaluate 52 legume cultivars and lines against currently recommended cultivars. Plots were grazed by either sheep or cattle after each harvest. Criteria for inclusion were that lines were either commercially available or in the process of being registered. Three experiments also included chicory. Sites had from 600 to 900 mm annual rainfall and were at altitudes of 440–1000 m. The 4-year program included the dry summer of 1990–91. White clover and subterranean clover were the most productive species over time. Among subterranean clovers, the subspecies subterraneum cultivars were more productive than the yanninicum or brachycalycinum subspecies. Other species such as balansa, Persian, strawberry, red and crimson clovers, lotus major and murex medic were more variable in production. These legumes often grew well in the establishment year, but failed to persist. Lucerne was in general, not as productive as white or subterranean clover. Caucasian clover and yellow serradella should be evaluated further as conclusive judgements could not be formed. Chicory was often the most productive species in the experiments, especially over the warmer 6 months of the year. It persisted under a 6-week harvest regime and during the drought year. The newer subterranean clover cultivars, Leura, Goulburn and Denmark all exceeded the production from the previously recommended cultivars, Woogenellup and Karridale, even though no major disease was evident in the later group. The lines 89820D and 89841E were sufficiently productive to warrant further evaluation and possible development as cultivars. In contrast, while Huia, Tahora, Bonadino and Tamar were often as productive as the recommended white clover cultivar Haifa, they were not consistently better. Where summer rainfall occurs and the annual rainfall exceeds 650 mm, the greater potential yield of white clover compared with subterranean clover justifies its use. However, no white clover cultivars survived the summer drought in 1990–91 as intact plants. Further work is needed to develop more drought-tolerant cultivars.

Clover root-nodule bacteria in the New England region on NSW.

1955 ◽  
Vol 6 (1) ◽  
pp. 15 ◽  
Author(s):  
KJ Baird
Keyword(s):  
New England ◽  
White Clover ◽  
New South ◽  
Subterranean Clover ◽  
Significant Negative Correlation ◽  
Mixed Inoculum ◽  
South Wales ◽  
Clover Root ◽  
Unsterilized Soil ◽  
Successful Inoculation

Most of the cultures isolated from the New England Region of New South Wales were able to form effective associations with white clover. Associations with red, crimson, and subterranean clovers were of doubtful effectiveness, or definitely ineffective. Isolates from plants growing in the drier ayeas were the most effective symbionts with crimson and subterranean clovers, but those from plants in the wetter areas proved best with red and white clovers. This locality effect seemed to be related to the field host from which the isolate was obtained. Those from clustered and subterranean clover were more effective on crimson and subterranean clovers than were those from white clover. On the other hand white clover isolates were the most effective symbionts for white and red clovers. There was a similarity in the effectiveness of isolates of red and white, subterranean and crimson clovers. There was a significant negative correlation with all other pairs. An unusually large number of cultures was inconsistent in nodulation (29 per cent.) or failed to nodulate any of the four clover hosts (6 per cent.). There were initially only about 5 clover rhizobia per gram in the two soils examined but no difficulty was experienced in obtaining growth of bacteria in sterilized soil or successful inoculation of seed of subterranean clover sown in unsterilized soil in pots. A pure culture of each of the five strains was capable of forming nodules, but strains 297 and 298 were responsible for most of the nodules produced from a mixed inoculum. While the relative success of the strains in producing nodules appeared to be independent of their rate of multiplication in sterilized soil, it was affected to some extent by the type of soil.

Pasture establishment on a granite soil on the northern tablelands of New South Wales

1965 ◽  
Vol 5 (16) ◽  
pp. 23 ◽  
Author(s):  
BR Watkin ◽  
PJ Vickery
Keyword(s):  
New England ◽  
White Clover ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Factors Affecting ◽  
South Wales ◽  
Heavy Grazing ◽  
Second Year ◽  
Phosphorus And Potassium ◽  
Granite Soil

Factors affecting the establishment and yields of legumes (Trifolium repens L., Trifolium subterraneum L., Meticago sativa L.) on unimproved pasture were studied on a granite soil in New England. Treatments included methods and times of sowing, pre-sowing grazing managements, and fertilizer applications. Sod seeding and discing increased the establishment of clover as did late sowing when the seed was broadcast. Pre-sowing grazing managements had no significant effects. Nitrogen application improved clover establishment. The percentage establishment for subterranean clover was consistently higher than that for white clover, but this was not related to subsequent yield. Sod seeding resulted in increased clover yields. Interactions between yields and pre-sowing grazing managements occurred with species ; light grazing before sowing resulted in maximum white clover yield whereas heavy grazing resulted in maximum subterranean clover and lucerne yields. Significant responses in the yield of white clover were obtained from phosphorus and potassium applications with a significant interaction (P x K). In the second year there were responses to phosphorus and sulphur, largely with repeat applications. The response to potassium declined in the second year. There was a significant increase in clover growth early in the second year from the application of lime and this interacted with potassium.

scholarly journals Tall Waterhemp (Amaranthus tuberculatus) and Palmer amaranth (Amaranthus palmeri) Seed Production and Retention at Soybean Maturity

2016 ◽  
Vol 30 (1) ◽  
pp. 284-290 ◽  
Author(s):  
Lauren M. Schwartz ◽  
Jason K. Norsworthy ◽  
Bryan G. Young ◽  
Kevin W. Bradley ◽  
Greg R. Kruger ◽  
...  
Keyword(s):  
Seed Production ◽  
Plant Size ◽  
Palmer Amaranth ◽  
Weed Seed ◽  
Great Opportunity ◽  
Weed Biomass ◽  
Seed Retention ◽  
Loose Soil ◽  
Soil Seedbank ◽  
Total Seed

Two of the most problematicAmaranthusspecies in soybean production today are tall waterhemp and Palmer amaranth. This study determined the percentage of tall waterhemp and Palmer amaranth seed that was retained by the weed at soybean maturity to assess the likelihood of using at-harvest weed seed control tactics for soil seedbank management. Palmer amaranth plants were collected from fields in Arkansas, Tennessee, Illinois, Missouri, and Nebraska, and tall waterhemp plants were collected from fields in Nebraska, Missouri, Wisconsin, and Illinois. Collected plants were assessed for at-harvest weed seed retention in 2013 and 2014. Within 1 wk of soybean maturity,Amaranthusplants were harvested and the loose soil and debris beneath the plants were swept into a pan with a hand broom to collect any shattered seed. Percent seed retention ranged from 95 to 100% for all states both years, regardless of species. There was a strong correlation between weed biomass (g) and total seed production (no. plant−1) in that the larger the plant, the more seeds it produced. However, there was no correlation between percent seed retention and weed biomass, which indicates that regardless of plant size and likely time of emergence, seed retention is high at the time of crop maturity. Overall, this study demonstrated that there is great opportunity for Palmer amaranth and tall waterhemp seed capture or destruction at soybean harvest. It is likely that nearly all of the seeds produced for bothAmaranthusspecies passes through the combine during harvest to be returned to the soil seedbank. Thus, there is continued need for research focused on developing and testing harvest weed seed control tactics that aim at reducing the soil seedbank and lowering risks for evolution of herbicide resistance.

Effects of waterlogging and soil salinity on irrigated agriculture in the Murray Valley: a review

1986 ◽  
Vol 26 (6) ◽  
pp. 761 ◽  
Author(s):  
AM Grieve ◽  
E Dunford ◽  
D Marston ◽  
RE Martin ◽  
P Slavich
Keyword(s):  
Soil Salinity ◽  
White Clover ◽  
New South ◽  
New South Wales ◽  
Subterranean Clover ◽  
Economic Losses ◽  
Deep Drainage ◽  
Winter Cereals ◽  
South Wales ◽  
Loss Coefficients

A physical model was used to assess the effects of surface waterlogging and soil salinity on the productivity of winter cereals and irrigated dairy pastures on irrigation farms in the Berriquin and Wakool Irrigation Districts of the Murray Valley region of New South Wales. Parameters describing the physical properties of major soil types were combined with statistically derived estimates of rainfall excess over evapotranspiration to establish the incidence of waterlogging. Soils predisposed to waterlogging occupy 150000 ha of Berriquin District (45% of District) and 24 800 ha of Wakool District (73%). Estimates of yield losses from waterlogging ranged from 12.5% in annual subterranean clover-based pastures, 20% in winter cereals, to 25% for perennial ryegrass-white clover pastures. The relationships between yield and soil salinity were determined for barley, wheat, white clover, subterranean clover, and irrigated annual and perennial pastures growing under existing management practices in shallow watertable areas of the 2 Districts. Response functions were applied to soil salinity frequency distributions to derive production loss coefficients. Surveys showed that average soil salinities were lower in Berriquin than in Wakool. In 1984, 43% the soils in shallow watertable areas of Berriquin could be classed as saline, whereas, in 1982 the corresponding figure for Wakool was 72%. A further survey taken in 1984, 2 years after the inception of a deep drainage scheme, showed that saline soils in Wakool had decreased to 46% of the total area.We assessed economic losses associated with soil salinity and waterlogging by applying the derived loss coefficients to achievable yields for known production areas. Total annual losses for the 2 Districts exceeded $A13 million, or 16% of the 1984 value of the District's agricultural production. This figure underestimates real losses because we excluded livestock enterprises other than dairying, as well as summer cropping, from the study. Losses due to waterlogging ($A10 million overall) were more serious than those due to soil salinity (nearly $A4 million), particularly in Berriquin where shallow watertables were less extensive. In Wakool, 2 years' operation of the deep drainage scheme reduced losses due to soil salinity by $A750 000.Thus surface waterlogging and soil salinity cause serious economic losses in the irrigated areas of southern New South Wales. Research into appropriate techniques for on-farm irrigation management may reduce these losses, and delay further development of shallow watertables and soil salinisation, with sub of stantial economic and environmental benefits.

scholarly journals Integrated management of vulpia in dryland perennial pastures of southern Australia

2009 ◽  
Vol 60 (1) ◽  
pp. 32 ◽  
Author(s):  
K. N. Tozer ◽  
D. F. Chapman ◽  
P. E. Quigley ◽  
P. M. Dowling ◽  
R. D. Cousens ◽  
...  
Keyword(s):  
Seed Production ◽  
Integrated Management ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Summer Rainfall ◽  
Annual Rainfall ◽  
Herbicide Application ◽  
South Wales ◽  
Fertiliser Application ◽  
Western Victoria

Vulpia (Vulpia species C.C. Gmel.) are annual grass weeds that can reduce pasture quality and stock-carrying capacity of perennial pastures throughout southern Australia. To develop more effective strategies to control vulpia, an experiment was established in western Victoria (average annual rainfall 565 mm) in phalaris (Phalaris aquatica L.) pastures comparing the effects of control methods [comprising combinations of fertiliser addition (Fert), a single herbicide (simazine) application (Sim), and pasture rest from grazing (Rest)] on vulpia populations. A further herbicide treatment [paraquat-diquat (SpraySeed®)] was imposed on some of these treatments. Measurements included botanical composition, phalaris and vulpia tiller density, seed production, and number of residual seeds in the soil. Vulpia content remained unchanged in the Sim-Rest treatment but increased in all other management treatments over the duration of the 3 year study and especially where paraquat-diquat was applied, despite paraquat-diquat causing an initial reduction in vulpia content. Vulpia content was lowest in the Fert-Sim-Rest treatment. The Fert-Sim treatment and in some cases paraquat-diquat application reduced vulpia tiller production. Vulpia seed production and the residual seed population were not influenced by any of the management treatments, while the single paraquat-diquat application increased vulpia seed production 18 months after application. Phalaris content was enhanced by the Sim-Rest and Fert-Sim-Rest treatments and initially by paraquat-diquat. No treatment affected phalaris tiller production and basal cover. The subterranean clover (Trifolium subterraneum L.) content declined during the experiment, but to a lesser extent where paraquat-diquat was applied. Volunteer species content was initially suppressed in the year following paraquat-application, although populations recovered after this time. Of the two Vulpia spp. present (V. bromoides (L.) S.F. Gray and V. myuros (L.) C.C. Gmelin), V. bromoides was the most prevalent. Results show how a double herbicide application can increase vulpia fecundity and rate of re-infestation of herbicide-treated sites. Pasture rest shows some promise, but to a lesser extent than in the New South Wales tablelands, where summer rainfall may increase the growth of perennial species. In lower rainfall, summer dry areas, responses to pasture rest may be slower. Despite this, integrated management (which combines strategies such as pasture rest, herbicide application, and fertiliser application) increases the perennial content and reduces vulpia seed production, thus improving vulpia control.

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