Weed Control in Alfalfa (Medicago sativa) Grown for Seed

Weed Science ◽  
1985 ◽  
Vol 33 (3) ◽  
pp. 411-414 ◽  
Author(s):  
John Waddington
Keyword(s):  
Medicago Sativa ◽  
Weed Control ◽  
Seed Yield ◽  
Growing Season ◽  
Taraxacum Officinale ◽  
Bromus Inermis ◽  
Smooth Brome ◽  
Alfalfa Seed

Applications of 1.6 kg ai/ha of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] to established alfalfa (Medicago sativaL. ‘Rambler’) at the start of each growing season for 4 yr increased seed yield by 68% and controlled established dandelion (Taraxacum officinaleWeber. in Wiggers ♯ TAROF) and smooth brome (Bromus inermisLeyss. ♯ BROIN). A lesser amount of metribuzin was not sufficient for smooth brome control, and a greater amount damaged the alfalfa. Hexazinone [3-cyclohexyl-6-(dimethylamino)-methyl-1,3,5-triazine-2,4(1H,3H)-dione] applied at 1.0 kg ai/ha also controlled dandelion and smooth brome and produced increases in alfalfa seed yield. Mixtures of terbacil (3-tert-butyl-5-chloro-6-methyluracil) with reduced rates of metribuzin or hexazinone controlled dandelion well, but gave only fair control of smooth brome. Alfalfa seed yield was negatively correlated with the smooth brome population.

Chemical Control of Dandelion (Taraxacum officinale) and Perennial Sowthistle (Sonchus arvensis) in Alfalfa (Medicago sativa) Grown for Seed

Weed Science ◽  
1980 ◽  
Vol 28 (2) ◽  
pp. 164-167 ◽  
Author(s):  
J. Waddington
Keyword(s):  
Medicago Sativa ◽  
Seed Yield ◽  
Chemical Control ◽  
Growing Season ◽  
Taraxacum Officinale ◽  
Alfalfa Seed ◽  
Visible Effect ◽  
Sonchus Arvensis ◽  
Dichlorophenoxy Acetic Acid ◽  
Seed Yields

Applications of 2,4-D [(2,4-dichlorophenoxy)acetic acid] at 1.1 kg/ha at the start of each growing season severely damaged established alfalfa (Medicago sativaL. ‘Beaver’) and reduced seed yield 32% over a 4-yr period. Dandelion (Taraxacum officinaleWeber) populations were reduced but perennial sowthistle (Sonchus arvensisL.) increased in frequency. Dichlobenil (2,6-dichlorobenzonitrile) applied at 2.1 kg/ha controlled both dandelion and perennial sowthistle. Alfalfa was damaged initially but rapid recovery resulted in an increase in seed yield in 2 yr out of 4. Terbacil (3-tert-butyl-5-chloro-6-methyluracil) applied at 1.1 kg/ha also controlled dandelion and perennial sowthistle. No alfalfa damage was evident and seed yields were increased 34% over a 3-yr period. Seed yield increased 30% where asulam (methyl sulfanilylcarbamate) was applied at 4.5 kg/ha, but there was no visible effect on the growth of either alfalfa or weeds. Simazine [2-chloro-4,6-bis (ethylamino)-s-triazine], propham (isopropyl carbanilate) + PCMC (p-chlorophenyl-N-methyl carbamate), pronamide [3,5-dichloro(N-1,1-dimethyl-2-propynyl)benzamide], and diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea], did not affect alfalfa seed production significantly, although simazine and diuron did reduce dandelion populations.

MON-37500 for Weed Control and Alfalfa Seed Production

2004 ◽  
Vol 18 (3) ◽  
pp. 810-815 ◽  
Author(s):  
Clayton D. Myhre ◽  
Heather A. Loeppky ◽  
F. Craig Stevenson
Keyword(s):  
Weed Control ◽  
Seed Yield ◽  
Organic Matter Content ◽  
Residual Activity ◽  
Matter Content ◽  
Management Tool ◽  
Early Season ◽  
Perennial Weed ◽  
Herbicide Treatments ◽  
Alfalfa Seed

Alfalfa seed producers have a limited number of herbicide options to manage weed problems. MON-37500 (proposed name sulfosulfuron) is a sulfonylurea herbicide that controls dandelion and quackgrass, two common weeds in alfalfa fields. A study was conducted in two alfalfa fields at Valparaiso and Carrot River, Saskatchewan, Canada, from 1999 to 2001 to evaluate perennial weed control and alfalfa production responses with 0.5×, 1×, and 1.5× label-recommended rates of MON-37500 and also 2,4-DB and hexazinone. MON-37500 applied at the 1× and 1.5× rates at both locations reduced mid-May alfalfa vigor from 100% to between 80 and 90% and increased early-season control of dandelion and quackgrass by about 10 to 40 percentage units, when compared with other herbicide treatments. Improved weed control with 1× and 1.5× MON-37500 rates was sustained into mid-June only at Carrot River and was completely eliminated (100% vigor and 0% weed control), or almost so, by mid-July. MON-37500 did not control Canada thistle. Improved early-season weed control with the 1× MON-37500 rate apparently compensated for the loss of alfalfa vigor at Valparaiso, thus resulting in 27% (57 kg/ha) greater seed yield than with the other herbicide treatments. At Carrot River, hexazinone generally provided levels of weed control similar to MON-37500 but did not injure alfalfa. Consequently, alfalfa yields were highest and the proportion of dead (decaying) seed was least with this treatment. The 0.5× MON-37500 rate often resulted in inferior weed control relative to the 1× and 1.5× rates and never was among the herbicide treatments providing the greatest seed yield. Managing the residual activity of MON-37500 and its negative effect on alfalfa growth, especially at locations with soils having coarse texture and low organic matter content, represents the greatest challenge in making MON-37500 a reliable weed management tool for alfalfa seed producers.

Water potentials of seeds of Bromus inermis and Medicago sativa imbibed on media of various osmotic potentials

1976 ◽  
Vol 54 (17) ◽  
pp. 1997-1999 ◽  
Author(s):  
W. T. McDonough
Keyword(s):  
Polyethylene Glycol ◽  
Medicago Sativa ◽  
Bromus Inermis ◽  
Smooth Brome ◽  
Thermocouple Psychrometer ◽  
Water Potentials ◽  
The Media ◽  
Medicago Sativa L ◽  
Brome Grass ◽  
Osmotic Potentials

Seeds of smooth brome grass (Bromus inermis Leyss.) and alfalfa (Medicago sativa L. cultivar Ladak) were allowed to imbibe in water or solutions of polyethylene glycol (Carbowax 1540), mannitol, or sodium chloride. Seed water potentials were determined over a 72-h period after transfer of seeds to thermocouple psychrometer chambers. Seed water potentials were lower than osmotic potentials of the media, but these two potentials were not clearly related to each other. Possible reasons for the lack of gradation in response are discussed.

EFFECTS OF ESTABLISHMENT METHOD AND A RAPESEED COMPANION CROP ON ALFALFA SEED YIELD

1987 ◽  
Vol 67 (1) ◽  
pp. 263-266 ◽  
Author(s):  
J. WADDINGTON ◽  
N. MALIK
Keyword(s):  
Medicago Sativa ◽  
Seed Production ◽  
Seed Yield ◽  
Brassica Campestris ◽  
Establishment Method ◽  
Alfalfa Seed ◽  
Medicago Sativa L ◽  
Companion Crop

In two experiments at Melfort using alfalfa (Medicago sativa L. ’Beaver’) seeded at a rate of 2 kg ha−1 with and without a Polish rapeseed (Brassica campestris L. ’Candle’) companion crop seeded at 5.5 kg ha−1, rapeseed yields in the establishment year were maximum when alfalfa and rapeseed were mixed and planted in 15-cm rows. Alfalfa showed no consistent seed yield differences between broadcast seeding, seeding in 15- or 61-cm rows, or seeding with or without the companion crop.Key words: Alfalfa, rapeseed, Brassica campestris, seed production

Weeds in New Seedings of Alfalfa (Medicago sativa) for Seed Production: Competition and Control

Weed Science ◽  
1982 ◽  
Vol 30 (1) ◽  
pp. 20-25 ◽  
Author(s):  
J. H. Dawson ◽  
C. M. Rincker
Keyword(s):  
Medicago Sativa ◽  
Seed Yield ◽  
Weed Management ◽  
Management Systems ◽  
Mixed Species ◽  
Dense Population ◽  
Alfalfa Seed ◽  
Labor Inputs ◽  
Annual Weeds ◽  
And Control

Alfalfa (Medicago sativaL. ‘Vernal′) seeded in April in rows 55 cm apart and kept free of weeds produced 820 kg/ha of seed during the year of seeding. Competition from a dense popualtion (40 plants/m of row) of mixed species of annual weeds reduced the seed yield to 45 kg/ha. Competition from a dense population (55 plants/m of row) of broadleaf weeds, a light population (4 plants/m of row) of broadleaf weeds, or a heavy population (75 culms/m of row) of barnyardgrass [Echinochloa crusgalli(L.) Beauv.] reduced yields to 80, 310, and 160 kg/ha, respectively. A weed management system, consisting of EPTC (S-ethyl dipropylthiocarbamate) or profluralin [N-(cyclopropylmethyl)-α,α,α-trifluoro-2,6-dinitro-N-propyl-p-toluidine] applied at or before planting, 2,4-DB [4-(2,4-dichlorophenoxy) butyric acid] applied postemergence, trifluralin (α,α,α- trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) incorporated with the soil when the alfalfa was 20 cm tall, interrow tillage, and a modest input of hand labor brought the crop to harvest free of weeds, and the yields of alfalfa seed were similar to those from plots kept weed-free by hand labor only. When weeds within the rows were controlled by hand labor only, labor inputs as great as 930 h/ha were required to bring the crop to harvest free of weeds, whereas labor inputs of 7 to 17 h/ha removed all surviving weeds when effective weed management systems had been applied.

Selective Weed Control from EPTC Applied with Seed of Alfalfa (Medicago sativa)

Weed Science ◽  
1980 ◽  
Vol 28 (5) ◽  
pp. 607-611 ◽  
Author(s):  
J. H. Dawson
Keyword(s):  
Medicago Sativa ◽  
Weed Control ◽  
Greenhouse Experiments ◽  
Alfalfa Seed

In field and greenhouse experiments, liquid or granular formulations of EPTC (S-ethyl dipropylthiocarbamate) applied by hand directly in the row with seed of alfalfa (Medicago sativa L. ‘Vernal’), controlled grass seedlings in bands, usually 5 to 8 cm wide, without injuring alfalfa significantly. Grass was similarly controlled selectively when a mixture of alfalfa seed and clay granules, similar in size to alfalfa seed and containing 10% EPTC, was seeded mechanically.

Alfalfa (Medicago sativa) Seed Yield Loss Due to Canada Thistle (Cirsium arvense)

1991 ◽  
Vol 5 (4) ◽  
pp. 723-728 ◽  
Author(s):  
James R. Moyer ◽  
G. Bruce Schaalje ◽  
Peter Bergen
Keyword(s):  
Medicago Sativa ◽  
Linear Equation ◽  
Seed Yield ◽  
Yield Loss ◽  
Linear Equations ◽  
Cirsium Arvense ◽  
Average Yield ◽  
Canada Thistle ◽  
Southern Alberta ◽  
Alfalfa Seed

Alfalfa seed yield and Canada thistle densities were measured in 10 fields in southern Alberta to assess the effect of thistles on seed yield. Thistle density and seed yield from each field were fitted to the Weibull, hyperbolic, and linear equations and a random coefficient and linear equation were used to obtain an “average yield loss curve”. Estimated average losses in alfalfa seed yield were >34% and >48% at thistle densities of 10 and 20 shoots m–2, respectively.

EFFECTS OF INITIAL HARVEST DATE ON PRODUCTIVITY AND PERSISTENCE OF ALFALFA AND BROMEGRASS

1972 ◽  
Vol 52 (5) ◽  
pp. 801-804 ◽  
Author(s):  
J. D. McELGUNN ◽  
D. H. HEINRICHS ◽  
R. ASHFORD
Keyword(s):  
Nitrogen Fixation ◽  
Medicago Sativa ◽  
Taraxacum Officinale ◽  
Bromus Inermis ◽  
Harvest Date ◽  
Mixed Stands ◽  
Medicago Sativa L ◽  
Made In

Alfalfa (Medicago sativa L.), bromegrass (Bromus inermis Leyss.), and a mixture of the two were grown on irrigated land and subjected to six defoliation schedules in which the initial cutting date varied in time. Delaying the initial defoliation until mid-June resulted in greatest seasonal yield even though the last cutting in this schedule was made in the 1st week of September, usually considered somewhat late for cutting in Saskatchewan. Nitrogen at the rate of 112 kg/ha doubled the yield of bromegrass but did not increase the yield of the alfalfa–bromegrass mixture, indicating that nitrogen fixation was adequate for the crop. Alfalfa and the alfalfa–bromegrass mixtures yielded about 50% more forage than the N-fertilized bromegrass and three times as much as unfertilized bromegrass. At the end of the experiment, dandelions (Taraxacum officinale Weber) had invaded pure stands of alfalfa but not mixed stands of alfalfa and bromegrass.

Effects of row spacing and plant growth regulation on alfalfa seed yield (Medicago sativa L.)

2020 ◽  
Vol 52 (5) ◽  
Author(s):  
Duro Pajcin ◽  
Savo Vuckovic ◽  
Vera Popovic ◽  
Aleksandar Simic ◽  
Sandra Popovic ◽  
...  
Keyword(s):  
Plant Growth ◽  
Medicago Sativa ◽  
Seed Yield ◽  
Growth Regulation ◽  
Row Spacing ◽  
Plant Growth Regulation ◽  
Alfalfa Seed ◽  
Medicago Sativa L

scholarly journals The Effect of Foliar Boron Application on Seed Production of Alfalfa (Medicago sativa L.)

2020 ◽  
Vol 1 (2) ◽  
pp. 60-64
Author(s):  
Wurentuya ◽  
Lingling Chen
Keyword(s):  
Medicago Sativa ◽  
Seed Production ◽  
Seed Yield ◽  
Foliar Application ◽  
Pollen Viability ◽  
Positive Effects ◽  
Yield And Quality ◽  
Alfalfa Seed ◽  
Medicago Sativa L

Boron (B) is an essential micronutrient for plant reproductive growth and seed setting. A better understanding of the reasonable application rate of B could provide guidelines for improving seed yield and quality. In this study, we used five B concentrations (0, 400, 800, 1200, and 1600 mg B L-1) to study the effect of foliar application of B on seed yield and quality of alfalfa (Medicago sativa L.) in northern China. Our results indicated that foliar B application increased the pollen number, pollen viability, and dry weight and B concentration of alfalfa reproductive organs. The effect of B on alfalfa seed yield can be attributed to affecting the number of inflorescence and the seeds per pod. Foliar application with 800 mg B L-1 made quantitative and qualitative improvements in seed yield and quality of alfalfa. These results help to explain the positive effects of B on alfalfa seed production.

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