Reduction of Seed Set in Nodding Thistle (Carduus nutans) by the Seed-Fly, Urophora solstitialis, in Australia

2020 ◽  
pp. 165-169
Author(s):  
T. L. Woodburn
Keyword(s):  
Seed Set ◽  
Author(s):  
I.W. Forster

One honeybee or bumblebee working on each square metre of white clover or red clover gave adequate pollination. This could be obtained with one hive of honeybees to each three hectares of flowering clover. Lucerne seeding averaged only 10% of the potential maximum in open fields with honey- or bumblebees. In cages where honeybees were forced to gather pollen, this was raised to 30% but it was not possible to increase seed set significantly in the fields.


2006 ◽  
Vol 7 (3) ◽  
pp. 248-252 ◽  
Author(s):  
Kazuki Ariyoshi ◽  
Emily Magnaghi ◽  
Mark Frey
Keyword(s):  
Seed Set ◽  

2005 ◽  
Vol 58 ◽  
pp. 140-147 ◽  
Author(s):  
M.R. McNeill ◽  
C.J. Fletcher

Nodding thistle receptacle weevil Rhinocyllus conicus and gallfly Urophora solstitialis attack the capitula of nodding thistle Carduus nutans L Between 31 October and 15 December 2003 the phenology of both R conicus and U solstitialis was studied at a dryland site in Canterbury Adult R conicus were more numerous than U solstitialis on capitula throughout the experiment Larvae of R conicus were first found on 11 November (15 of capitula infested) and peaked on 2 December with 53 of capitula infested Only 3 of capitula were infested by U solstitialis Adult R conicus or U solstitialis emerged from 79 of the selected primary and secondary capitula The majority of infested capitula (81) contained only R conicus 2 contained only U solstitialis while 17 contained both insect species Parasitism of R conicus by the braconid parasitoid Microctonus aethiopoides was low and occurred when most weevil eggs had been laid


1970 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Bista ◽  
G. B. Khattri ◽  
B. D. Acharya ◽  
S. C. Srivastava

To find out the ability of Orobanche seeds to germinate immediately after seed set, seeds were germinated periodically at an interval of three months for one year in GR24. Some Orobanche seeds were capable of germination immediately after seed set but most required about nine months as after ripening or incubation period to be able to germinate. The phenomenon of after ripening in Orobanche seeds could be taken as an ecological measure to dormant over following unfavorable wet summer season. The growth hormone studies on Orobanche seed germination have shown that GA3 at a concentration of 100 ppm substantially enhanced seed germination when applied during pre-conditioning period. NAA showed some stimulatory effect at 0.5 - 1.0 ppm when applied during post-conditioning period but the hormone if applied during pre-conditioning period inhibited the germination. Kinetin failed to stimulate the germination at all the concentrations tested. Key words: Germination, root-parasite, hormone. Ecoprint Vol.11(1) 2004.


Author(s):  
Aradhana Phukan ◽  
P. K. Barua ◽  
D. Sarma ◽  
S. D. Deka

Two CMS lines, IR 58025A and IR 68888A along with their maintainers and two fertility restorers, LuitR and IR 36R, were evaluated for flower and plant characters during early ahu (February-June) and kharif (July-November) seasons. IR 58025A showed longer stigmata and styles, and higher spikelet Length/Breadth (L/B) ratio while IR 68888A showed broader stigmata and wider glume opening angle in both the seasons. IR 68888A also exhibited higher pollen sterility during early ahu. IR 36R was characterized with broad anthers. LuitR showed longer and broader anthers with more pollen than others. Plant height, flag leaf length, flag leaf width and area were higher in IR 36R. Panicle exsertion was complete in pollen parents whereas it was 78-80% in CMS lines. The widest flag leaf angle was found in IR 58025B during early Ahu and in IR 36R during kharif. Kharif season was more favourable for growth of the plants with higher seed set percentage while floral traits of the CMS lines were better expressed in early Ahu. Manipulation of the seeding sequence of the parental lines in early Ahu is warranted for better seed set provided the seed crop escapes heavy premonsoon showers during reproductive stage. IR 68888A/LuitR was a good combination for pollen dispersal and seed setting.


2010 ◽  
Vol 2009 (1) ◽  
pp. 21-27
Author(s):  
Wenbo LONG ◽  
Shengbin TU ◽  
Li LUAN ◽  
Xing WANG ◽  
Fanlun KONG ◽  
...  
Keyword(s):  
Seed Set ◽  

1928 ◽  
Vol 20 (7) ◽  
pp. 710-721 ◽  
Author(s):  
D. C. Tingey ◽  
George Stewart
Keyword(s):  

Crop Science ◽  
1966 ◽  
Vol 6 (2) ◽  
pp. 216-218 ◽  
Author(s):  
Arnel R. Hallauer ◽  
J. H. Sears
Keyword(s):  
Seed Set ◽  

Crop Science ◽  
1992 ◽  
Vol 32 (1) ◽  
pp. 269-271 ◽  
Author(s):  
P. Devaux ◽  
T. Adamski ◽  
M. Surma

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