RESPONSE OF SEEDS TO DRY HEAT

1977 ◽  
Vol 57 (1) ◽  
pp. 305-307 ◽  
Author(s):  
M. A. MAUN

The seeds of alfalfa (Medicago sativa L.) were more sensitive to heat than the other species tested. The germination of barnyard grass (Echinochloa crusgalli (L.) Beauv.) caryopses was significantly reduced by exposure for 1 h to temperatures of 100 C or over. Downy brome (Bromus tectorum L.) and Kentucky bluegrass could withstand temperatures of up to 120 C for 1 h without any loss in germination.

1997 ◽  
Vol 11 (2) ◽  
pp. 277-282 ◽  
Author(s):  
Robert G. Wilson

Two experiments were conducted near Scottsbluff, NE, to evaluate the efficacy of fall-and spring-applied herbicides for downy brome control in established alfalfa. Downy brome was effectively removed from established alfalfa, and alfalfa yield increased with fall applications of hexazinone, metribuzin, pronamide, and terbacil. Regression analysis indicated a linear relationship between alfalfa yield and downy brome biomass. Glyphosate or paraquat suppressed downy brome when applied to dormant alfalfa in the spring. If glyphosate or paraquat application was delayed until after alfalfa had resumed spring growth, injury was observed. Alfalfa yield did not increase following spring applications of glyphosate or paraquat.


Weed Science ◽  
1978 ◽  
Vol 26 (2) ◽  
pp. 151-153 ◽  
Author(s):  
D. G. Swan

Six herbicides, simazine [2-chloro-4,6-bis(ethylamino)-s-triazine], propham (isopropyl carbanilate), terbacil (3-tert-butyl-5-chloro-6-methyluracil), carbetamide [D-N-ethyllactamide carbanilate (ester)], pronamide [3,5-dichloro(N-1,1-dimethyl-2-propynyl)benzamide], and secbumeton [N-ethyl-6-methoxy-N′(1-methylpropyl)-1,3,5-triazine-2,4-diamine] were applied annually for four years to establish forage alfalfa(Medicago sativaL. ‘Washoe’). Downy brome(Bromus tectorumL.) control ranged from 80 to 100%. The average control of broadleaf weeds was 90 to 100% with simazine, terbacil, and secbumeton, compared to 30 to 40% with propham, carbetamide, and pronamide. Only simazine and terbacil were phytotoxic to the alfalfa. Based on weed control and crop tolerance, secbumeton performed best on the coarsetextured soil in this experiment.


1988 ◽  
Vol 39 (3) ◽  
pp. 447 ◽  
Author(s):  
JM Scott ◽  
GJ Blair

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.


Weed Science ◽  
1988 ◽  
Vol 36 (5) ◽  
pp. 583-588 ◽  
Author(s):  
Albert J. Fischer ◽  
Jean H. Dawson ◽  
Arnold P. Appleby

Barnyardgrass [Echinochloa crus-galli(L.) Beauv. #4ECHCG] and pigweeds (mixture ofAmaranthus retroflexusL. # AMARE andA. powelliiS. Wats. # AMAPO) seeded separately with alfalfa (Medicago sativaL.) in mid-August suppressed alfalfa severely before frost killed them in October and November. Some alfalfa was killed, and yield of alfalfa forage was reduced in each of three harvests the following year. These weeds did not harm alfalfa seeded in mid-September. Downy brome (Bromus tectorumL. # BROTE) and tumble mustard (Sisymbrium altissimumL. # SSYAL) suppressed alfalfa seeded in August and September. They reduced alfalfa stands and reduced yield of alfalfa forage in each of three harvests the following year. Alfalfa seeded August 27 and allowed to compete with a mixture of these species for various periods was injured most by weeds that emerged with the alfalfa and remained uncontrolled until forage harvest in May. These weeds did not reduce alfalfa yields if removed by 36 days after alfalfa emergence. Thereafter, yield decreased as the period of weed interference increased. Interference was most damaging in early spring, when growth of winter annual weeds was rapid and vigorous. Weeds seeded 65 or more days after alfalfa emergence did not reduce alfalfa yields but sometimes produced enough biomass to reduce the quality of the first-cutting alfalfa hay.


2007 ◽  
Vol 87 (2) ◽  
pp. 267-272 ◽  
Author(s):  
J. Diane Knight

Because of its small seed size, alfalfa (Medicago sativa L.) typically is seeded at a shallow depth, putting Rhizobium inoculated onto the seed coat at a high risk of desiccation. Granular inoculants may provide a superior delivery formulation for Rhizobium because the inoculant can be placed deeper in the soil than the seed, where it is protected from desiccation. Sinorhizobium meliloti cv. Beaver delivered as (1) pre-inoculated alfalfa seed from the inoculant manufacturer, (2) commercial peat-based, self-sticking inoculant applied on-site, and (3) granular inoculant placed with the seed or (4) banded below and to the side of the seed was evaluated against uninoculated alfalfa controls at three field sites in Saskatchewan. Overall, alfalfa inoculated with the granular formulation placed below and to the side of the alfalfa seed was among the highest biomass producer in the establishment year, although it did not exhibit superior nodulation or biological N fixation compared with the other treatments. Any advantage conferred by the granular inoculant in the establishment year did not persist through the first and second production years. Under the conditions of this study, the delivery formulation had no long-term affect on alfalfa productivity, nodulation and biological N fixation. Furthermore, none of the inoculant treatments were consistently superior to the uninoculated controls. Key words: Alfalfa, granular inoculant, peat inoculant, pre-inoculated seed, Medicago sativa L., Sinorhizobium meliloti


Weed Science ◽  
1999 ◽  
Vol 47 (3) ◽  
pp. 256-257 ◽  
Author(s):  
Carol Mallory-Smith ◽  
Paul Hendrickson ◽  
George Mueller-Warrant

A Bromus tectorum L. (downy brome) biotype with cross-resistance to sulfosulfuron has been identified. The resistant biotype was selected with primisulfuron in Poa pratensis L. (Kentucky bluegrass) plots near Madras, OR. The plots received two treatments of 20 g ai ha−1 primisulfuron in the fall of 1993, 1994, and 1995. In 1995, control of B. tectorum decreased and greenhouse studies confirmed that the biotype was resistant to primisulfuron. Cross-resistance to sulfosulfuron also was confirmed in greenhouse studies. Metabolism of sulfosulfuron rather than an insensitive site of action is the likely cause of the cross-resistance.


1986 ◽  
Vol 66 (3) ◽  
pp. 585-589
Author(s):  
J. H. ELGIN Jr. ◽  
C. M. RINCKER

Thirty-one seedlots of Arc alfalfa (Medicago sativa L.), produced between 1971 and 1974 at Prosser, Wash.; Stanfield, Oreg.; and Shafter and Tehachapi, Calif., were evaluated for shifts in field growth habits (regrowth after cutting, winter injury, and date of flowering) and greenhouse anthracnose resistance. Seedlots represented one (Syn 2), two (Syn 3), and three (Syn 4) generations of increase beyond the original Syn 1 lot, grown under four diverse environments. Results indicated a tendency for shift in regrowth rate among the Syn 3 and Syn 4 generation seedlots produced at Shafter, Calif. No shift in regrowth rate was observed for the other locations and no significant trends away from the original lot were observed for winter injury, date of flowering or anthracnose resistance.Key words: Medicago sativa L., seed production, genetic shifts, anthracnose resistance, fall growth, regrowth


2007 ◽  
Vol 21 (2) ◽  
pp. 411-420 ◽  
Author(s):  
George W. Mueller-Warrant ◽  
William C. Young ◽  
Thomas G. Chastain ◽  
S. Caprice Rosato

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
M. Raeeszadeh ◽  
P. Mortazavi ◽  
R. Atashin-Sadafi

Nicotine is one of the most important compounds in cigarette which can cause changes in the concentration of neurotransmitters and damage to the nervous system. The aim of this study was to investigate the effect of the hydroalcoholic extract of Medicago Sativa L. (alfalfa) on controlling nicotine-induced brain damage and anxiety behaviour in rats. Forty-two male Wistar rats were randomly divided into six equal groups and treated daily as follows: a control group, T1 and T2 groups where animals were subcutaneously injected 250 and 500 mg/kg alfalfa extract, respectively, T3 and T4 groups where animals were injected subcutaneously 0.2 mg/kg nicotine and 250 and 500 mg/kg alfalfa extract, and T5 group in which only nicotine at the dose of 0.2 mg/kg was injected. At the end of the period after weighing, the elevated plus-maze test was taken from the animals. Serum assay was conducted to measure TCA, IL-1, and TNFα, and half of the brain tissue was used to measure oxidative stress parameters (GPx, SOD, TAC, and MDA) and the other parts were used for histopathological studies. Body weight in the T5 group was significantly different from that of the other groups. The time and number of open arms reduced in the T5 group. The duration and number of times in the open arm significantly decreased in the treated groups in a dose-depended manner. Malondialdehyde concentration was the highest in the nicotine group and the lowest in T2. The concentration of GPx and SOD was significantly increased in the presence of alfalfa extract in nicotine groups. TNFα and IL-1 in the T5 group showed a significant increase compared to the other groups. Moreover, the number of neurons and the level of necrotic neurons and gliosis significantly decreased and increased in the nicotine group, respectively, while these histopathological damages improved by treatment with alfalfa extract in T3 and T4 groups. Alfalfa extract can have a significant dose-dependent therapeutic effect on inducing oxidative damage and inflammatory responses of nicotine in the brain and reducing anxiety behaviours.


Weed Science ◽  
1992 ◽  
Vol 40 (4) ◽  
pp. 517-521 ◽  
Author(s):  
Robert A. Buman ◽  
David R. Gealy ◽  
Alex G. Ogg

Root absorption of subtoxic levels of metribuzin and its ethylthio analog (ethyl-metribuzin) by downy brome, jointed goatgrass, and winter wheat increased by a factor of three to five times as temperature increased from 10 to 20 C. Absorption of ethyl-metribuzin per gram dry weight was similar for all three species. Absorption and distribution of ethyl-metribuzin, but not metribuzin, were similar per gram dry weight in downy brome and jointed goatgrass. Absorption of metribuzin per gram dry weight was lower for winter wheat than for the other two species at 20 C. In general, the ratio of absorbed ethyl-metribuzin detected in shoots to that in roots was less in winter wheat and jointed goatgrass than in downy brome. The absorption by roots of14C-herbicides relative to water was similar for winter wheat and jointed goatgrass. Absorption of both14C-herbicides by winter wheat and jointed goatgrass was nonpreferential with respect to water absorption at 10 and 15 C. However, at 20 C14C-herbicide absorption was reduced 5 to 30% with respect to water absorption. Downy brome absorption of14C-herbicides with respect to water was 30 to 50% less than that of the other two species.


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