The effects of ammonium phosphate and boron on alfalfa (Medicago sativa L.) seed production and vegetative growth /

In field plot experiments conducted in southern Alberta over a 6-yr period, highest seed yields of alfalfa (Medicago sativa L. cv. Beaver) were obtained with one or two irrigations in the first half of the growing season. In outdoor lysimeters protected from rain, moisture stress for more than 8 days before seed ripening severely reduced seed production. Under field conditions, stored soil moisture from irrigation during the vegetative stage of growth plus occasional rain in July and August permitted irrigation of alfalfa for seed to be stopped at the bud to early bloom stage (June to early July).

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Relationships between inbreeding, meiotic irregularity, and fertility in alfalfa

Canadian Journal of Genetics and Cytology ◽

10.1139/g86-017 ◽

1986 ◽

Vol 28 (1) ◽

pp. 130-137 ◽

Cited By ~ 6

Author(s):

S. E. Smith ◽

R. P. Murphy

Keyword(s):

Medicago Sativa ◽

Seed Production ◽

Inbreeding Depression ◽

Pollen Mother Cell ◽

Mother Cell ◽

Pollen Parent ◽

Meiotic Behavior ◽

Negatively Associated ◽

Meiotic Irregularity ◽

Medicago Sativa L

Fertility (seed production) in alfalfa (Medicago sativa L.) is severely depressed by inbreeding; however, little is known of the factors directly responsible for this depression. Irregularities in meiotic behavior could be partially responsible for the inbreeding depression in fertility observed. This study considered relationships between fertility, inbreeding, and irregularity in microsporogenesis. Fertility declined markedly with inbreeding in the materials examined (S0–S3). Irregularity in microsporogenesis, as measured by the percent irregular quartets, (i.e., quartets with micronuclei, supernumerary microspores, or irregular cytokinesis) increased significantly with inbreeding. Increases in quartet irregularity were associated with increases in the number of univalents per pollen mother cell observed at metaphase I. Considering all materials studied, the percentage of irregular quartets was negatively and significantly correlated with fertility as both a seed and a pollen parent. In more detailed analyses, it was observed that the percent irregular quartets was negatively associated with fertility as a pollen parent only when levels of irregularity were relatively high. No association was observed between the percent irregular quartets and fertility when levels of irregularity were relatively low.Key words: Medicago, microsporogenesis, seed production, breeding, fertility.

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

Canadian Journal of Plant Science ◽

10.4141/cjps87-037 ◽

1987 ◽

Vol 67 (1) ◽

pp. 263-266 ◽

Cited By ~ 1

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

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EFFECT OF GENERATION AND LOCATION OF SEED PRODUCTION ON GROWTH HABIT AND ANTHRACNOSE RESISTANCE IN ARC ALFALFA

Canadian Journal of Plant Science ◽

10.4141/cjps86-078 ◽

1986 ◽

Vol 66 (3) ◽

pp. 585-589

Author(s):

J. H. ELGIN Jr. ◽

C. M. RINCKER

Keyword(s):

Medicago Sativa ◽

Seed Production ◽

Growth Habit ◽

The Other ◽

Anthracnose Resistance ◽

Field Growth ◽

Medicago Sativa L ◽

Growth Habits ◽

Fall Growth

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

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