Compétition entre la spargoute des champs (Spergula arvensis) et la sétaire glauque (Setaria glauca). II. Production de graines

C. Lemieux; J. M. Deschênes; P. Morisset

doi:10.1139/b84-253

Compétition entre la spargoute des champs (Spergula arvensis) et la sétaire glauque (Setaria glauca). II. Production de graines

Canadian Journal of Botany ◽

10.1139/b84-253 ◽

1984 ◽

Vol 62 (9) ◽

pp. 1858-1863

Author(s):

C. Lemieux ◽

J. M. Deschênes ◽

P. Morisset

Keyword(s):

Seed Production ◽

Intraspecific Competition ◽

Unit Area ◽

Long Term Changes ◽

Setaria Glauca ◽

Mixed Populations ◽

Viable Seeds ◽

Number Of Seeds ◽

Slight Advantage

Seed production of corn spurry (Spergula arvensis L.) and yellow foxtail (Setaria glauca (L.) Beauv.) was studied in various situations of competition. Intraspecific competition affected both species in the same way; each plant produced fewer seeds when the density was increased. In such situations, the overall seed production (seeds per square metre) also increased. However, seed production of yellow foxtail (seeds per square metre) reached a plateau. Interspecific competition affected seed production of corn spurry and yellow foxtail in different ways. Firstly, for corn spurry, the number of seeds produced per plant increased with interspecific pressure while for yellow foxtail it decreased. Secondly, the total number of seeds produced per unit area is larger for corn spurry than for yellow foxtail. This suggests that corn spurry may dominate mixed populations. However, at high density, yellow foxtail seed production per unit area seems to suffer less from interspecific pressure than does corn spurry. At this level, yellow foxtail obtain a slight advantage. However, conclusion on long-term changes of the populations cannot be drawn without a study of viable seeds.

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Effect of crop canopy and herbicide application on kochia (Bassia scoparia) density and seed production

Weed Science ◽

10.1017/wsc.2020.23 ◽

2020 ◽

Vol 68 (3) ◽

pp. 278-284

Author(s):

Elizabeth G. Mosqueda ◽

Charlemagne A. Lim ◽

Gustavo M. Sbatella ◽

Prashant Jha ◽

Nevin C. Lawrence ◽

...

Keyword(s):

Sugar Beet ◽

Seed Production ◽

Spring Wheat ◽

Unit Area ◽

Crop Canopy ◽

Herbicide Treatment ◽

Herbicide Treatments ◽

Sites Of Action ◽

Germinable Seed

AbstractUnderstanding the effects of crop management practices on weed survival and seed production is imperative in improving long-term weed management strategies, especially for herbicide-resistant weed populations. Kochia [Bassia scoparia (L.) A.J. Scott] is an economically important weed in western North American cropping systems for many reasons, including prolific seed production and evolved resistance to numerous herbicide sites of action. Field studies were conducted in 2014 in a total of four field sites in Wyoming, Montana, and Nebraska to quantify the impact of different crop canopies and herbicide applications on B. scoparia density and seed production. Crops used in this study were spring wheat (Triticum aestivum L.), dry bean (Phaseolus vulgaris L.), sugar beet (Beta vulgaris L.), and corn (Zea mays L.). Herbicide treatments included either acetolactate synthase (ALS) inhibitors effective on non-resistant B. scoparia or a non–ALS inhibiting herbicide effective for both ALS-resistant and ALS-susceptible B. scoparia. Bassia scoparia density midseason was affected more by herbicide choice than by crop canopy, whereas B. scoparia seed production per plant was affected more by crop canopy compared with herbicide treatment. Our results suggest that crop canopy and herbicide treatments were both influential on B. scoparia seed production per unit area, which is likely a key indicator of long-term management success for this annual weed species. The lowest germinable seed production per unit area was observed in spring wheat treated with non–ALS inhibiting herbicides, and the greatest germinable seed production was observed in sugar beet treated with ALS-inhibiting herbicides. The combined effects of crop canopy and herbicide treatment can minimize B. scoparia establishment and seed production.

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Seed production in woodland and isolated trees of Eucalyptus melliodora (yellow box, Myrtaceae) in the South Western Slopes of New South Wales

Australian Journal of Botany ◽

10.1071/bt99058 ◽

2000 ◽

Vol 48 (6) ◽

pp. 681 ◽

Cited By ~ 25

Author(s):

G. E. Burrows

Keyword(s):

Seed Production ◽

Seed Weight ◽

Physical Parameters ◽

Mixed Mating ◽

Isolated Trees ◽

South Wales ◽

Large Numbers ◽

The Mean ◽

Viable Seeds ◽

Number Of Seeds

Seed production in woodland and isolated Eucalyptus melliodora Cunn. ex Schauer trees was investigated. Measurement of physical parameters such as mean capsule weight, mean seed weight and mean ratio of the weight of the capsule contents to the weight of the empty capsule showed no significant differences between woodland and isolated trees. In contrast, reproductive output as measured by mean number of seeds per capsule, mean number of seeds per 10 g of capsule contents and mean seed weight as a percentage of the weight of the capsule contents, was significantly lower (45–48% less) in isolated trees than in woodland trees. Mean percentage seed germination was also significantly lower (14% less) in the isolated trees and the mean number of viable seeds per 10 g of capsule contents was only 38% of the woodland trees. These results indicate that E. melliodora, like many eucalypts, has a mixed mating breeding system with preferential outcrossing but is also capable of self pollination leading to a reduction in seed yield and viability. The woodland and isolated trees produced a mean of 4.6 and 2.1 seeds per capsule, respectively. It would be relatively easy to collect large numbers of seeds from isolated trees of E. melliodora and subsequently propagate potentially genetically inferior plants.

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The influence of defoliation on the components of seed yield in swards of subterranean clover (Trifolium subterranean L.)

Australian Journal of Agricultural Research ◽

10.1071/ar9610821 ◽

1961 ◽

Vol 12 (5) ◽

pp. 821 ◽

Cited By ~ 9

Author(s):

RC Rossiter

Keyword(s):

Seed Production ◽

Seed Yield ◽

Unit Area ◽

Control Level ◽

Subterranean Clover ◽

Supplementary Data ◽

Promotive Effect ◽

Grazed Swards ◽

Practical Implications ◽

Number Of Seeds

Six defoliation treatments were imposed on two strains of subterranean clover (Dwalganup and Yarloop) grown in dense swards. Seed yield (weight per unit area) was increased by 27% over controls by July, or July plus early September, defoliations. With progressively later defoliation, yields fell to the control level, then to 15% below it. The number of seeds per unit area showed an increase of almost 40% with early defoliation, whereas with later defoliation the numbers fell to the control level. The increase was due primarily to larger numbers of inflorescences per unit area and a greater proportion of buried burrs. Supplementary data from grazed swards confirmed the promotive effect of early defoliation on seed production. The promotive and detrimental effects of defoliation are discussed, and brief consideration is given to practical implications.

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Effects of 2,4-D on Seed Production and Embryo Development of Curly Dock

Weed Science ◽

10.1017/s0043174500054746 ◽

1969 ◽

Vol 17 (4) ◽

pp. 533-536 ◽

Cited By ~ 16

Author(s):

M. A. Maun ◽

P. B. Cavers

Keyword(s):

Acetic Acid ◽

Seed Production ◽

Lithium Salt ◽

Seed Viability ◽

Rumex Crispus ◽

Viable Seeds ◽

Almost All ◽

Dichlorophenoxy Acetic Acid ◽

Days After Anthesis ◽

Number Of Seeds

Lithium salt of (2,4-dichlorophenoxy)acetic acid (2,4-D) (1000 ppm) was sprayed on plants of curly dock (Rumex crispus L.) 12 days before anthesis, at an thesis, 7 days after anthesis, and 34 days after anthesis. Treatment 12 days before anthesis completely prevented the formation of viable seeds. Two percent of the seeds had minute embryos after treatment at anthesis, but even these seeds did not germinate. Embryos were present in 91% of the seeds from plants treated 7 days after anthesis. These embryos ranged in size from 0.5 to 2.5 mm. The total weight of seeds obtained was significantly less than the control and only 5 to 15% of these seeds were capable of germination. Spraying the inflorescences 34 days after anthesis did not affect the number of seeds produced or seed viability. Almost all plants remained alive after the harvest.

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