Tillage systems and seed dormancy effects on common waterhemp (Amaranthus tuberculatus) seedling emergence

Weed Science ◽  
2006 ◽  
Vol 54 (6) ◽  
pp. 1037-1044 ◽  
Author(s):  
Ramon G. Leon ◽  
Micheal D. K. Owen
Keyword(s):  
Seed Dormancy ◽  
Seedling Emergence ◽  
Tillage Systems ◽  
Common Waterhemp ◽  
Amaranthus Tuberculatus

Secondary seed dormancy prolongs persistence of volunteer canola in western Canada

Weed Science ◽  
2003 ◽  
Vol 51 (6) ◽  
pp. 904-913 ◽  
Author(s):  
Robert H. Gulden ◽  
Steven J. Shirtliffe ◽  
A. Gordon Thomas
Keyword(s):  
Seed Dormancy ◽  
Seedling Recruitment ◽  
Seedling Emergence ◽  
Conventional Tillage ◽  
Western Canada ◽  
Tillage Systems ◽  
Spring Canola ◽  
Typical Summer ◽  
Different Soils

In western Canada, little is known about the seedbank ecology of volunteer canola. Therefore, integrated recommendations for the management of this weed are limited. In this study, we investigated the seedbank persistence and seedling recruitment of two spring canola genotype groups with different secondary seed dormancy potentials under contrasting tillage systems. The study was conducted at two locations with different soils in the Mixed Moist Grassland ecoregion of Saskatchewan. A single cohort seedbank was established in 1999 and was followed for 3 yr in successive wheat crops. In a separate laboratory study, the six canola genotypes examined were classified as those with high and those with medium potentials for the development of secondary seed dormancy (HD and MD, respectively). After one, two, and three winters, maximum persistence of 44, 1.4, and 0.2% of the original seedbank was observed among the treatments, respectively. In 2001, HD canola genotypes tended to exhibit 6- to 12-fold greater persistence than MD canola genotypes, indicating lower seedbank mortality in HD canola. Seedling recruitment of HD canola also was higher than MD canola when differences were observed between these genotype groups. Therefore, long-term seedbank persistence of canola can be reduced by growing genotypes with low inherent potential for the development of secondary seed dormancy. The proportion of persisting seeds tended to be higher under conventional tillage than under zero tillage because of lower seedbank mortality, but no clear distinction in seedbank persistence in terms of absolute time could be made between these two tillage systems. Volunteer canola seedling recruitment followed the pattern of a typical summer-annual weed, where seedling emergence was observed only during May and June.

Competitive attributes ofA. sativa, T. aestivum, andH. vulgareare conserved in no-till cropping systems

Weed Science ◽  
1999 ◽  
Vol 47 (6) ◽  
pp. 712-719 ◽  
Author(s):  
Anne Légère ◽  
Yuguang Bai
Keyword(s):  
Hordeum Vulgare ◽  
Avena Sativa ◽  
Growth Parameters ◽  
Cropping Systems ◽  
Seedling Emergence ◽  
Biomass Accumulation ◽  
Tillage Systems ◽  
Area Index ◽  
No Till ◽  
Lower Test

The robustness of competitive attributes of cereals such as rapid and uniform seedling emergence, tillering, early biomass accumulation and canopy closure, and height advantage over weeds have not yet been tested under environmental conditions typical of no-till (NT) cropping systems. Our objective was to evaluate the effects or NT practices on growth and productivity ofAvena sativa, Triticum aestivum, Hordeum vulgare, and associated weeds. The experiment was conducted on a Kamouraska clay at La Pocatière, QC, in 1994, 1995, and 1996.Avena sativa, T. aestivum, andH. vulgarewere grown under tilled and NT practices. Cereal growth parameters were measured six (1994) or seven (1995) times between planting and the 11th week after planting but only once in 1996. Grain yields and yield components were determined at crop maturity.Avena sativaandH. vulgarepopulations were little affected by tillage, whereasT. aestivumpopulations were reduced by 16 to 20% in NT systems. Growth in height in NT systems was either similar or greater than in tilled systems in all three cereals. Cereal leaf area index (LAI) and biomass accumulation was also comparable between tillage systems, except forT. aestivumLAI in 1994, which was greater in tilled plots on two sampling dates. Response of annual dicots to tillage was inconsistent in all crops. Annual monocots dominated in some but not all NT systems. Perennial dicots dominated in NT systems, whereas perennial monocots were more abundant in tilled systems in all three cereals.Avena sativaandT. aestivumyields in NT plots were comparable or greater than in tilled plots, in spite of having either lower test weights (A. sativa) or lower 1,000-grain weights (T. aestivum). NTT. aestivumproductivity was maintained in spite of reduced plant establishment.Hordeum vulgareyields were also similar across tillage systems, except in 1995, when yields in tilled plots were greater than in NT plots. The height advantage observed for NTH. vulgaredid not result in improved yields. All three cereals, and particularlyA. sativa, appeared well suited to NT systems, despite the pressure provided by different weed groups, compared to tilled systems. However, results suggest that NT production of cereals could benefit from improved attention to perennial dicot control and crop seedling establishment, particularly forT. aestivum.

Morphophysiological dormancy and germination ecology in diaspores of the subtropical palm Phoenix canariensis Chabaud

Botany ◽  
2021 ◽  
Author(s):  
Lanlan He ◽  
Ganesh K. Jaganathan ◽  
Baolin Liu
Keyword(s):  
Seed Dormancy ◽  
Seedling Emergence ◽  
Primary Root ◽  
Germination Percentage ◽  
Early Summer ◽  
Germination Ecology ◽  
Phoenix Canariensis ◽  
Morphophysiological Dormancy ◽  
Cotyledonary Petiole ◽  
Seed Dormancy And Germination

The timing of germination is a crucial event in a plant’s life cycle. Seed dormancy and germination mechanisms are important factors regulating seedling emergence. Since detailed experimental evidence for germination pattern of Phoenix canariensis colonizing sub-tropical climate is scarce, we investigated seed dormancy and germination ecology of P. canariensis. We found that the embryo is underdeveloped at the time of dispersal and doubles in size before the cotyledonary petiole (CP) protrudes through the operculum. The primary root and plumule emerge from the elongated CP outside the seed. In light/dark at 30/25°C, the CP emerged from 8% of the diaspores within 30 days and from 76% within 14 weeks. Thus, 8% of the diaspores have MD and the others MPD. Removal of the pericarp and operculum resulted in 100% germination within 5 days in light/dark at 30/25°C. Cold and warm stratification as well as treatment with GA3 significantly increased the germination speed, but the final germination percentage was not significantly increased. Seed germination was synchronized in early summer when seed dormancy was released by cold stratification in the soil over winter. A remote-tubular germination type and intricate root system provide an ecological advantage to the seedling establishment.

Seed dormancy and periodicity of seedling emergence in Veronica hederifolia L.

Weed Research ◽  
1978 ◽  
Vol 18 (1) ◽  
pp. 41-48 ◽  
Author(s):  
H.A. ROBERTS ◽  
PATRICIA M. LOCKETT
Keyword(s):  
Seed Dormancy ◽  
Seedling Emergence

Growth Characteristics of Common Milkweed

Weed Science ◽  
1971 ◽  
Vol 19 (3) ◽  
pp. 193-196 ◽  
Author(s):  
Larry S. Jeffery ◽  
Laren R. Robison
Keyword(s):  
Low Temperature ◽  
Seed Dormancy ◽  
Seedling Emergence ◽  
Multiple Shoots ◽  
Growth Characteristics ◽  
Temperature Dependent ◽  
Asclepias Syriaca ◽  
Leaf Pair

Seed dormancy of common milkweed (Asclepias syriaca L.) is broken by a few days of moist low-temperature after-ripening. The duration of low-temperature after-ripening of the seeds is temperature dependent. Seedling emergence is best when the seeds are planted 1 to 2 cm deep and extremely limited when planted 6 cm deep. Seedlings have the capacity to produce new shoots if clipped in the 1 to 1¾-leaf pair stage and multiple shoots if clipped in the 2 to 2½-leaf pair stage. All seedlings reaching the 4 to 4½-leaf pair stage before clipping produced new shoots.

scholarly journals Factors Affecting Seed Dormancy and Germination of Greater Bur-Parsley (Turgenia latifolia)

2018 ◽  
Vol 36 ◽  
Author(s):  
M. REZVANI ◽  
S.A. SADATIAN ◽  
H. NIKKHAHKOUCHAKSARAEI
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
Seed Dormancy ◽  
Seedling Emergence ◽  
Potassium Nitrate ◽  
Germination Percentage ◽  
Dormancy Breaking ◽  
Planting Depth ◽  
Factors Affecting ◽  
Drought And Salt Stresses

ABSTRACT: Our knowledge about seed dormancy breaking and environmental factors affecting seed germination of greater bur-parsley (Turgenia latifolia) is restricted. This study has addressed some seed dormancy breaking techniques, including different concentrations of gibberellic acid (GA3) and potassium nitrate (KNO3), leaching duration, physical scarification as well as some environmental factors effective on seed germination such as salt and drought stresses, pH and seed planting depth. Seed germination was promoted with lower concentrations of KNO3 (0.01 to 0.02 g L-1), while higher concentrations reduced germination percentage. Seed dormancy was declined by low concentrations of GA3 up to 100 ppm. Seeds of greater bur-parsley germinated in a range of pH from 3 to 7. With enhancement of drought and salt stresses, seed germination decreased. Also, there was no seed germination in a high level of stresses. Seedling emergence reduced as planting depth increased. Use of GA3, KNO3, leaching and physical scarification had a positive effect on seed dormancy breaking of greater bur-parsley. The information from the study increases our knowledge about seed dormancy breaking techniques, response of germination to drought and salt stresses and also determination of distribution regions of greater bur-parsley in the future.

Influence of tillage type on vertical weed seedbank distribution in a sandy soil

2000 ◽  
Vol 80 (2) ◽  
pp. 455-457 ◽  
Author(s):  
Clarence J. Swanton ◽  
Anil Shrestha ◽  
Stevan Z. Knezevic ◽  
Robert C. Roy ◽  
Bonnie R. Ball-Coelho
Keyword(s):  
Vertical Distribution ◽  
Sandy Soil ◽  
Soil Structure ◽  
Seedling Emergence ◽  
Tillage Systems ◽  
No Till ◽  
Seedling Emergence Method ◽  
Chisel Plow ◽  
The Vertical Distribution ◽  
Moldboard Plow

The vertical distribution of weed seeds in the seedbank of a sandy soil under three tillage systems (moldboard plow, chisel plow, and no-till) was estimated by a seedling-emergence method. The vertical distribution of the weed seedbank differed with tillage type and depth of tillage. The no-till system had the largest portion (90%) of the seedbank in the 0- to 5-cm layer. Chisel plowing distributed most of the seeds (66%) in the 5- to 10-cm layer. Moldboard plowing concentrated 71% of the seeds at the 10- to 15-cm depth. Our results suggest that the vertical distribution of the weed seedbank will be influenced by tillage type, depth of tillage, and soil type. Key words: Soil structure, moldboard plow, chisel plow, no-till

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