scholarly journals STUDIES ON THE STIMULATION OF CATALPA BIGNONIOIDES WALT. SEED GERMINATION

2021 ◽  
Vol 10 (20) ◽  
pp. 172-178
Author(s):  
Daniela-Sabina Poșta ◽  
Sándor Rózsa ◽  
Tincuța-Marta Gocan
Keyword(s):  
North America ◽  
Seed Germination ◽  
Exotic Species ◽  
Humid Climate ◽  
Methods And Techniques ◽  
Temperate Soils ◽  
Individual Trees ◽  
Stimulation Of ◽  
Compact Shape

Catalpa is a tree with an attractive ornamental value and compact shape. Catalpa bignonioides Walt., is a tree with heights of up to 35 meters and a large trunk. It is an exotic species in North America areal. It grows well in a warm and humid climate, on alluvial, fertile, deep, temperate soils. It has a light temperament, withstands winter frosts well, but is sensitive to late frosts. The degree of germination varies both between species and within them. Within batches of seeds of the same species varies depending on the origin, year of harvest and individual trees. There are different methods and techniques for overcoming drowsiness depending on the seeds. Various pre-treatments are used such as scarification and hot and cold aeration to stimulate the embryo. The paper presents the stimulation of seed germination at catalpa, using different concentrations of Nitragin: 0.1%, 0.3%, 0.5%, 0.7%, 0.9% and following the seed germination interval.

scholarly journals Swailing affects seed germination of plants of European bio-and agricenosis in a different way

2017 ◽  
Vol 12 (1) ◽  
pp. 62-75 ◽  
Author(s):  
Renata Bączek-Kwinta
Keyword(s):  
Seed Germination ◽  
Agricultural Practice ◽  
Seedling Vigour ◽  
Habitat Composition ◽  
Indirect Impact ◽  
Wild Thyme ◽  
Plant Habitat ◽  
Seed Testa ◽  
Stimulation Of

AbstractSwailing as a part of agricultural practice is an illegal habit in many European countries. The indirect effect of swailing is the emission of volatiles (SGV), hence the aim of the study was to identify their impact to seeds of different species occurring or grown Europe. It was carried out on seeds of 29 species of 10 botanical families within the angiosperms. The response to SGV was more or less differentiated within a family, and even within the species, e.g. in the case of tomato. The stimulation of germination and/or increased seedling vigour was established in celery, green- and red-leafed basil, white and red cabbage, white clover and wild thyme. The same effect was noticed for the seeds of stratified broadleaf plantain and the positively photoblastic seeds of German chamomile germinated in darkness. The inhibition of seed germination and/ or reduced seedling vigour was demonstrated in case of caraway, dill and forget-me-not. Similar results were obtained in the experiments carried outin vitroand in the soil, hence it can be assumed that the indirect impact of SGV on plant habitat composition is likely. The interaction of SGV compounds with seed testa and seed phytohormones is discussed.

Stimulation of seed germination in South African species of Restionaceae by plant-derived smoke

1994 ◽  
Vol 15 (1) ◽  
pp. 93-100 ◽  
Author(s):  
N. A. C. Brown ◽  
H. Jamieson ◽  
P. A. Botha
Keyword(s):  
Seed Germination ◽  
South African ◽  
African Species ◽  
Stimulation Of

Stimulation of Common Cocklebur (Xanthium pensylvanicum) and Redroot Pigweed (Amaranthus retroflexus) Seed Germination by Injections of Ethylene into Soil

Weed Science ◽  
1980 ◽  
Vol 28 (5) ◽  
pp. 510-514 ◽  
Author(s):  
G. H. Egley
Keyword(s):  
Seed Germination ◽  
Laboratory Tests ◽  
Seedling Emergence ◽  
Amaranthus Retroflexus ◽  
Redroot Pigweed ◽  
Plastic Bags ◽  
Viable Seeds ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Stimulation Of

The effects of ethylene upon germination of common cocklebur (Xanthium pensylvanicumWallr.) and redroot pigweed (Amaranthus retroflexusL.) seeds were studied. In laboratory tests with seeds in sealed flasks in the dark, 10 μl/L ethylene increased germination of redroot pigweed seeds from 7% to 52% at 30 C, and increased germination of large and small common cocklebur seeds from 30% and 0% to 100% and 90% respectively, at 25 C. At least 12 h of exposure to ethylene was necessary for appreciable stimulation of germination. In growth chamber studies with known numbers of seeds in pots of soil, ethylene at 11 kg/ha was injected into the soil, and the pots were enclosed in plastic bags for 24 h. One such injection at 2 weeks after planting, and successive injections at 2, 3, and 4 weeks, significantly increased redroot pigweed seedling emergence, and significantly decreased the numbers of dormant, viable seeds remaining in the soil. When pots were not enclosed, injections did not significantly effect redroot pigweed seeds, but significantly increased common cocklebur seedling emergence and decreased the number of viable common cocklebur seeds remaining in the soil.

scholarly journals Migration of exotic species of ammonites during highstands of sea level

1992 ◽  
Vol 6 ◽  
pp. 324-324
Author(s):  
Keith Young
Keyword(s):  
North America ◽  
South America ◽  
Exotic Species ◽  
Sea Level ◽  
South Atlantic ◽  
Horn Of Africa ◽  
Mozambique Channel ◽  
The North ◽  
North And South ◽  
Early Late

In northeastern Chihuahua and Trans-Pecos Texas, in the early Late Albian zone of Hysteroceras varicosum occurs the Boeseites romeri (Haas) fauna with B. romeri (Hass), B. perarmata (Hass), B. aff. barbouri (Haas), B. cf. howelli (Haas), B.proteus (Haas), Prohysteroceras cf. P. hanhaense Haas, Elobiceras sp., and Dipoloceras (?) sp. B. perarmata has also been collected at Cerro Mercado, near Monclova, Coahuila. Haas originally described this fauna from Angola. Now, from rocks in the same zone in the Sierra Mojada, Coahuila, Mexico, there is a form related to if not identical with Hysteroceras famelicum Van Hoepen, also originally described from Angola and also from the zone of Hysteroceras varicosum.These fossils are known only from southern North America and Angola; they have not been described from the European Tethys. In 1984 I suggested that during the highstand of sea level of the early Late Albian (Hysteroceras varicosum zone) these ammonites migrated from Angola to Mexico and Trans-Pecos Texas via an epeiric seaway extending across the sag between South America and Africa proposed by Kennedy and Cooper. This would be twelve to fifteen million years prior to an oceanic connection between the North and South Atlantic.I would now ask, can similar epeiric seas and highstands of sea level explain the migration of successive European, Tethyan, Jurassic ammonite faunas down the Mozambique Channel and around the horn of Africa into the Neuquen Basin of Argentina before Africa and Antarctica separated, as proposed by Spath.

scholarly journals Challenges, tactics and integrated management of emerald ash borer in North America

2019 ◽  
Author(s):  
Deborah G McCullough
Keyword(s):  
North America ◽  
Integrated Management ◽  
Management Strategies ◽  
Emerald Ash Borer ◽  
Interspecific Variation ◽  
Agrilus Planipennis ◽  
Local Conditions ◽  
Ash Trees ◽  
Invasion Impacts ◽  
Individual Trees

Abstract Emerald ash borer (EAB) (Agrilus planipennis Fairmaire), discovered in southeastern Michigan, USA in 2002, has become the most destructive and costly invasive forest insect in North America. This phloem-boring beetle has also invaded Moscow, Russia and continued spread of EAB potentially threatens European ash (Fraxinus spp.) species. This review summarizes EAB life history, including interspecific variation in host preference, invasion impacts and challenges of detecting new infestations and provides an overview of available management tactics. Advances in systemic insecticides, particularly emamectin benzoate products applied via trunk injection, have yielded effective and practical options both to protect individual trees and to slow EAB population growth and ash decline on an area-wide basis without disrupting natural enemies. Economic costs of treating ash are substantially lower than removal costs, retain ecosystem services provided by the trees, reduce sociocultural impacts and conserve genetic diversity in areas invaded by EAB. Girdled ash trees are highly attractive to EAB adults in low-density populations and debarking small girdled trees to locate larval galleries is the most effective EAB detection method. An array of woodpeckers, native larval parasitoids and introduced parasitoids attack EAB life stages but mortality is highly variable. Area-wide management strategies that integrate insecticide-treated trees, girdled ash trap trees and biological control can be adapted for local conditions to slow and reduce EAB impacts.

Modes of union and interaction between parasite and host in the Loranthaceae. II. Phoradendreae

1957 ◽  
Vol 146 (924) ◽  
pp. 320-338 ◽  
Keyword(s):  
North America ◽  
Vascular System ◽  
Lower Side ◽  
Large Genus ◽  
Large Primary ◽  
Stimulation Of

The large genus Phoradendron includes not only species like those of North America already described and Ph. fanshawei from Trinidad, with cortical strands and sinkers comparable especially with those of Viscum capense , but also others with very different modes of attachment. Some have much enlarged primary haustoria, with subordinate cortical strands and sinkers ( Phoradendron trinervium on some hosts) or without them ( Ph. hartii, Ph. flavens ). Ph. trinervium on Calophyllum lucidum , in contrast with its behaviour on other hosts, forms no major wedge but the cortical strands show an exaggerated development with anastomosis of the strands and the formation of numerous sinkers. In Phoradendron crassifolium and Ph. tetrapteron the haustorium simply spreads against the host wood to form a saddle-like attachment. In Ph. perrottetii also the haustorium spreads against the host wood, occasionally girdling it completely, forming downward branches, sometimes twenty or more, which run parallel and in their older parts fuse. Dendrophthora inaequidentata forms a very large primary haustorium, with slender cortical strands. The growth of the haustorium in width is accompanied by conspicuous hypertrophy of host wood on the lower side of it, the vessels and other elements of which abut on the haustorium, linking up with the parasite vascular system and without continuity with host wood above the haustorium. Tangential enlargement of the haustorium with stimulation of the adjoining cambium and annexation of the wood it forms occurs also though less conspicuously in some species of Phoradendron , particularly Phoradendron trinervium (on Rollinia mucosa ) and Ph. flavens .

Variation in Piceaglauca seed germination associated with the year of cone collection

1993 ◽  
Vol 23 (7) ◽  
pp. 1306-1313 ◽  
Author(s):  
G.E. Caron ◽  
B.S.P. Wang ◽  
H.O. Schooley
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Storage Period ◽  
White Spruce ◽  
Germination Percentage ◽  
Degree Days ◽  
Seed Maturity ◽  
Individual Trees ◽  
Collection Time

The effects of cone storage period and pregermination treatment on seed maturity and dormancy were compared for cones of white spruce (Piceaglauca (Moench) Voss) collected from individual trees in 1984 and 1988. Seeds were extracted from cones and germinated after 2 or 6 weeks of cone storage in 1984 and after 2, 4, 6, 10, or 14 weeks in 1988. Based on cumulative degree-days, seeds were more mature at collection time in 1988 than in 1984. Seeds from 1984 cones stored for 6 weeks matured during storage, and both germination percentage (GP) and rate of germination (GR) were significantly improved. In contrast, storage up to 14 weeks in 1988 did not increase GP and GR, as seed had attained maturity prior to cone collection. Seed dormancy was present in both 1984 and 1988. Significant improvements in GP and GR were achieved in 1984 with a pregermination treatment even before seed maturity was attained. Prechilling of seed after 6 weeks of cone storage increased GP from 60 to 95% in 1984 and 64 to 89% in 1988.

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