Effectiveness of Sinorhizobium Inoculants on Annual Medics

Crop Science ◽  
2011 ◽  
Vol 51 (5) ◽  
pp. 2249-2255 ◽  
Author(s):  
Sindy M. Interrante ◽  
Ruchi Singh ◽  
M. Anowarul Islam ◽  
Jimmy D. Stein ◽  
Carolyn A. Young ◽  
...  
Keyword(s):  
Annual Medics

Evaluation of pasture legumes sown into a prepared seedbed at Tamworth, New South Wales. 2. Seed production and seed reserves

1993 ◽  
Vol 33 (3) ◽  
pp. 299 ◽  
Author(s):  
GM Lodge
Keyword(s):  
Seed Production ◽  
New South ◽  
New South Wales ◽  
Pasture Legumes ◽  
South Wales ◽  
Medicago Scutellata ◽  
Seed Reserves ◽  
Annual Medics ◽  
Perennial Legumes ◽  
Seed Yields

Plots sown in 1983 were used to examine the seed production and reserves (residual hardseeds) of 15 annual legumes over 5 years at Tamworth in northern New South Wales. Seed production characteristics were measured in 1983 for these annuals, and for 6 perennial legumes. After the annuals had set seed in 1983, an area of the plots was sprayed to prevent flowering in subsequent years, and the rates of decline in seed reserves were compared with those from areas that seeded annually. Seed yields of the perennials were often significantly lower than those of the annuals except Trifolium glomeratum. Seed yields of T. subterraneum var. subterraneum cvv. Seaton Park and Woogenellup were significantly higher than those of cv. Nungarin and T. subterrarzeum var. brachycalycinum cv. Clare. Seed numbers were lowest for Medicago scutellata cv. Sava among the annual medics, and for Nungarin among subterranean clovers. There was little relationship between the mean number of seeds produced from 1983-86 and maturity grading, and between seed numbers and relative dry matter yield. Seed reserves decreased over 5 years by more than 90% in the sprayed treatments of all species. This decrease was not continuous, with the largest declines occurring from December 1983 to August 1984. In the sprayed treatments of Seaton Park, Woogenellup, and Clare, and in both treatments of Astragalus hamosus cv. Ioman, Vicia dasycarpa var. villosa cv. Namoi, and T. hirtum cv. Hykon, none of the original 1983 seed was recovered in 1987. For the annual medics and Nungarin, the number of residual hardseeds in the sprayed treatments in 1987 was about 3-5% of the seed produced in 1983. From 1983 to 1987, seed numbers in the unsprayed treatments declined by 7040% for the annual medics and by 85-95% for Seaton Park, Woogenellup, and Clare. Long-term persistence of annual medics and Nungarin depended on seed production in most years and the maintenance of a high number of residual hardseeds in the soil. In contrast, the mid- and late-maturing subterranean clovers Woogenellup and Clare had low seed reserves and were dependent on seed production in most years for their continued regeneration.

scholarly journals Agronomic and Acetylene Reduction Evaluation of Three Annual Medics

1983 ◽  
Vol 36 (1) ◽  
pp. 55 ◽  
Author(s):  
Mark A. Smith ◽  
Arden A. Baltensperger
Keyword(s):  
Acetylene Reduction ◽  
Annual Medics

Factors influencing transmission of alfalfa mosaic virus through seed of annual medics (Medicago spp.) and the genetic control of seed transmission rate

1997 ◽  
Vol 48 (7) ◽  
pp. 989 ◽  
Author(s):  
W. Pathipanawat ◽  
R. A. C. Jones ◽  
K. Sivasithamparam
Keyword(s):  
Mosaic Virus ◽  
Genetic Control ◽  
Transmission Rate ◽  
Alfalfa Mosaic Virus ◽  
Seed Transmission ◽  
Virus Concentration ◽  
Rate Condition ◽  
Reciprocal Crosses ◽  
Transmission Rates ◽  
Annual Medics

Factors likely to influence rates of transmission of alfalfa mosaic virus (AMV) through seed to seedlings of annual medics (Medicago spp.) and genetic control of the magnitude of its seed transmission rate were investigated in plants from 17 early-flowering accessions of M. polymorpha and in progenies of crosses involving M. murex cv. Zodiac × accession 5320 as parents. Plants were graft-inoculated when 6 weeks old to ensure successful and uniform infection. To exclude variation in seed transmission rates due to virus isolate or temperature, only 1 AMV isolate was used and the plants were kept under uniform temperature conditions. In M. polymorpha, significant differences were found between accessions in the levels of AMV transmitted through seed to progeny seedlings, SA 8250 giving the highest mean level of seed transmission (52%) and SA 4188 the lowest (3%). Neither virus concentration nor symptom severity influenced the rates of seed transmission obtained. However, part of the variation in seed transmission rates found in these accessions was related to their flowering times, seed transmission rates increasing as the interval between inoculation and owering increased. In seed samples collected from individual graft-inoculated plants of M. murex from (i) the F2 generation from crosses and reciprocal crosses, and (ii) the backcross progenies, the rates of transmission of AMV through seed to seedlings ranged from 0 to 77% and showed a continuous pattern of variation. Also, there was evidence of transgressive segregation for the low seed transmission rate condition. This indicates that the low seed transmission rate condition for AMV in medics is quantitatively inherited and under polygenic control. In contrast, when the pods from F2 progeny plants from the crosses and reciprocal crosses were examined, the segregation ratios obtained revealed that the smooth pod character from parent accession 5320 was controlled by a single recessive gene, for which the name sp is proposed. The presence in a plant of gene sp, or of its spiny pod-determining allele from the other parent cv. Zodiac, was not correlated with low seed transmission rates of AMV. It is concluded that selection for low rates of seed transmission and a population breeding approach can be used to produce improved M. polymorpha and M. murex cultivars with good resistance to seed-borne AMV

Flowering responses to vernalization and photoperiod in annual medics (Medicago spp.)

1975 ◽  
Vol 26 (5) ◽  
pp. 831 ◽  
Author(s):  
NM Clarkson ◽  
JS Russell
Keyword(s):  
High Temperature ◽  
Flowering Time ◽  
Vernalization Requirement ◽  
Vernalization Response ◽  
The Third ◽  
Long Day ◽  
Temperature Requirement ◽  
New Finding ◽  
Annual Medics

The three processes thought to control flowering times in annual medics (Medicago spp.) are a vernalization requirement, a long day requirement and a high temperature requirement. To examine the first two processes, seed of seven cultivars of six species was vernalized at 1�C for periods of up to 11 weeks, then grown to flowering under three photoperiods in a glasshouse. To study the third process, the time to flowering of selected treatments from this expcrirnent was compared with flowering data from plants grown in the field at a range of temperatures lower than in the glasshouse. Vernalization and photoperiod caused large shifts in flowering time but the effects varied widely among species. M. scutellata was almost insensitive to both factors but in M. rugosa acceleration of up to 91 days was caused by treatment. Vernalization and short dark periods were additive in accelerating flowering and largely able to substitute for each other. Species flowered almost simultaneously when given their most favourable conditions for flowering. High temperature accelerated flowering in all species studied. However, in species other than M. scutellata it was necessary for a vernalization requirement to be met before this effect was observed. A new finding was that the vernalization response in M. truncatula and M. littoralis was largely reversed after more than 7 weeks of vernalization. This suggests a previously undetected flowering mechanism in these species.

Plant attributes leading to persistence in grazed annual medics (Medicago spp.) growing in rotation with wheat

1992 ◽  
Vol 43 (7) ◽  
pp. 1559 ◽  
Author(s):  
PS Cocks
Keyword(s):  
Principal Component Analysis ◽  
Multiple Regression ◽  
Seed Bank ◽  
Principal Component ◽  
Frost Tolerance ◽  
Late Flowering ◽  
Grazed Pasture ◽  
Short Internodes ◽  
Annual Medics ◽  
Sun Light

Attributes of 84 accessions of 12 medics (Medicago spp.) were measured in nursery rows in two successive years. Multiple regression, principal component, and cluster analyses were used to relate 14 attributes of the medics to persistence in the seed bank of grazed pasture growing in rotation with wheat. Principal component analysis distinguished between the attributes of the species. For example, M. rigidula had short petioles, high frost tolerance, many seeds per pod, and large leaves and seeds; while M. polymorpha had long petioles, low frost tolerance, few seeds per pod, and small seeds and leaves. M. noeana produced many flowers per raceme, small pods and seeds, long peduncles, and was hard-seeded and late flowering; while M. aculeata produced few flowers per raceme, large pods and seeds, short peduncles, and was soft-seeded and early flowering. M. trulncatula and M. rotata were intermediate. Long peduncles and high levels of hardseededness were the attributes most closely associated with persistence of the medics in grazed pasture. It was concluded that (1) long peduncles place the flowers above the canopy in spring where they are in full sun light, and (2) hardseededness levels of up to 90% protect seeds against germination in the cereal year. The results also suggest that small leaves and short internodes and petioles protect young plants against over-grazing in winter, and small pods and seeds are less likely than large pods and seeds to be selected and digested by grazing sheep in summer.

Patterns of seed softening and seedling emergence of nineteen annual medics during three years after a single seed crop in southern Queensland

1997 ◽  
Vol 37 (7) ◽  
pp. 767 ◽  
Author(s):  
D. L. Lloyd ◽  
G. B. Taylor ◽  
B. Johnson ◽  
K. C. Teasdale
Keyword(s):  
Seedling Emergence ◽  
Soil Surface ◽  
Farming Systems ◽  
The Other ◽  
Research Station ◽  
Hard Seed ◽  
Diurnal Cycles ◽  
Wide Range ◽  
Burr Medic ◽  
Annual Medics

Summary. To produce seed to determine the rates of seed softening of annual medics in the subtropics, 8 lines of barrel medic (Medicago truncatula), 3 lines of burr medic (M. polymorpha), 4 lines of snail medic (M. scutellata), and 1 line of each of button medic (M. orbicularis), strand medic (M. littoralis) and gama medic (M. rugosa) were grown at Warra in southern inland Queensland, in 1993. Seed of a fourth line of burr medic, a naturalised line, was harvested from Hermitage Research Station at that time. Pods were placed on the soil surface and buried at a depth of 7 cm, both in flywire envelopes and as free pods. Residual hard seed numbers were determined each year for 3 years from the envelopes, and seedlings were counted and removed from the free pods after each germination event. Patterns of softening of seeds from the same seed populations were also determined after placing them in a laboratory oven with a diurnal temperature fluctuation of 60/15° C for periods of 16, 40 and 64 weeks followed, after each time period, by 4 diurnal cycles of 35/10°C. More than 90% of the original seeds were hard. Seed softening at the soil surface ranged from 26% after 3 years in button medic to almost complete softening in the gama medic after only 2 years. Burial had little effect on the rate of softening of the button medic but about halved the rate of softening of the other lines. The barrel medics were vulnerable to losses of large numbers of seedlings which softened and germinated in January–February and the snail medics from seedlings emerging in August–December. The proportion of soft seeds recovered as seedlings in the buried compared with the surface pods was higher in the larger-seeded medics, snail and gama, and lower in the other, smaller-seeded medics. Laboratory techniques effectively ranked the medic lines for their rate of seed softening in the field and provided some insight into their seasonal patterns of seed softening. A wide range of seed softening patterns is available for fitting the requirements of various farming systems. The most appropriate pattern of softening will depend on the variability of medic seed production between years and the need for self regeneration of the medic after a cereal crop.

Residual effect of some herbicides on Medicago species in the Victorian Mallee

1972 ◽  
Vol 12 (55) ◽  
pp. 181
Author(s):  
GJ Wells
Keyword(s):  
Residual Effect ◽  
High Toxicity ◽  
Residual Toxicity ◽  
Application Rates ◽  
Annual Medics ◽  
Chemical Fallow ◽  
Medicago Species ◽  
Low Rate ◽  
Chondrilla Juncea

The use of soil persistent herbicides for controlling skeleton weed (Chondrilla juncea) on fallows and in crops might lead to problems of residual toxicity towards establishing medic pastures. Data from 1967 to 1969, taken from both chemical fallow and crop spray experiments on light soils in the Mallee, Victoria, are presented which show the extreme persistence of picloram applied at very low rates and its high toxicity towards both annual medics and lucerne. Other herbicides studied (an atrazine-amitrole mixture, fenac and 2, 4-D) had little or no effect at moderate application rates. It is considered that the very low rainfall in 1967 was largely responsible for the low rate of herbicide decomposition.

Differential tolerance of annual medics, Nungarin subterranean clover and hedge mustard to broadleaf herbicides

1992 ◽  
Vol 32 (1) ◽  
pp. 49 ◽  
Author(s):  
RR Young ◽  
KJ Morthorpe ◽  
PH Croft ◽  
H Nicol
Keyword(s):  
Sodium Salt ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Effective Control ◽  
Medicago Littoralis ◽  
Annual Medics ◽  
Seed Yields ◽  
Test Plants ◽  
Degree Of Recovery

The tolerance of 5 species of annual medics (Medicago spp.), Trifolium subterraneum cv. Nungarin, and hedge mustard (Sisymbrium orientale) to a range of post-emergence broadleaf herbicides was tested over 2 years. The least damaging to M. truncatula was 2,4-DB, which provided more consistent and effective control of hedge mustard than the other chemicals tested, including the less expensive tank mix of 2,4-DB + diuron. MCPA amine or sodium salt (300 g a.i./ha), bromoxynil (420 g a.i./ha), and tank mixes containing MCPA amine (150-175 g a.i./ha) severely damaged annual medics, particularly M. truncatula, with flowering delayed by up to 21 days, and dry matter and seed yields often significantly (P<0.05) reduced. Seed yields of most test plants indicated a degree of recovery from herbicide damage assessed visually after 10 days. Hedge mustard was not always as severely damaged by MCPA amine as was M. truncatula. Nungarin subterranean clover and M. aculeata SAD 2356 were more tolerant than the M. truncatula cultivars of MCPA amine, MCPA sodium salt, MCPA tank mixes, and bromoxynil, and less tolerant of 2,4-DB. Medicago littoralis, M. polymorpha and M. laciniata were severely damaged by bromoxynil but were more tolerant of MCPA than M. truncatula.

Sign in / Sign up

Export Citation Format

Share Document