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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Using Bombus impatiens Cr. as a pollinator of greenhouse sweet peppers (Capsicum annuum L.)

Meisels, Susan. January 1997 (has links)
The pollination of greenhouse sweet pepper (Capsicum annuum L. var. grossum cv. Superset) by Bombus impatiens Cr. was investigated in Ste. Scholastique, Quebec for two periods, 27 June-15 July and 4-18 August, 1995 to determine the pollination effectiveness of B. impatiens compared to a mechanical method (vibration wand) and natural greenhouse ventilation (NGV) and to determine the foraging activity of B. impatiens throughout the pollination period. B. impatiens pollination resulted in a significantly greater number of seeds per fruit and a greater percent marketable fruit, due to a positive quadratic relationship between seed number and fruit weight, than both vibration wand and NGV. Both B. impatiens and NGV resulted in a significantly greater fruit set than vibration wand. Per fruit, an extra profit of $0.06 for green and $0.13 for red sweet peppers could be made by B. impatiens pollination over NGV, due to greater marketable fruit and greater mean fruit weight. B. impatiens pollination was more effective than both vibration wand and NGV even though both the daily activity of the insect at the hive (hive traffic) and their foraging on plants (greenhouse foraging) decreased throughout the pollination period and attained a maximum of only 3 B. impatiens foraging in the greenhouse during the second period. It was estimated that a B. impatiens colony of 30-40 workers could optimally pollinate 17475 plants or a greenhouse size of about 9470 m$ sp2.$
22

Cleistogamy and the evolution of Mimulus nasutus

Diaz, Anita January 1994 (has links)
No description available.
23

Diversity, ecology, reproductive biology and conservation of orchids of south east Bangladesh

Huda, Mohammed Kamrul January 2000 (has links)
No description available.
24

Pollination and dispersal of the noxious vine Passiflora mollissima

Beavon, Merodie January 2007 (has links)
Banana passionfruit (Passiflora mollissima) is a noxious weedy vine that is problematic in coastal regions throughout New Zealand. I investigated the pollination and dispersal mutualisms that facilitate its spread, in the Marlborough Sounds. Flower observations revealed that visits were almost exclusively from introduced honey bees and bumble bees, indicating an invasive mutualism. I investigated the pollination system of banana passionfruit by comparing fruit set, fruit size, seed set, germination success and the effects of inbreeding depression on seedlings when grown in competition, between hand-selfed, handcrossed, bagged and open flowers. Fruit set was significantly reduced when pollinators were excluded (3.0%) indicating reliance on pollinators for reproduction. While banana passionfruit is partially selfcompatible, fruit set was significantly reduced in selfed flowers (17.5%) compared to crossed flowers (29.5%), and we found significant pollen limitation (natural [18.0%] was significantly lower than crossed). A significant degree of inbreeding depression was apparent in germination success but not in fruit size, seed set or seedling growth and survival. Surprisingly, open flowers had significantly lower germination success (10.1%) than the other three treatments (crossed = 16.5%, selfed = 15.0%, bagged = 25.3%). Overall, natural flowers produce more seedlings per flower (1.7) than bagged flowers (0.9), but less than hand-selfed (3.0) and crossed (5.3) flowers. To investigate dependence on dispersal, germination success was compared between hand-cleaned seeds, fleshy seeds and intact fruits in the field and glasshouse. Seeds germinated readily in all treatments, with no significant difference between cleaned and fleshy seeds, so seeds do not require frugivore handling to germinate. In the field, tagged fruits were removed quickly after ripening. Significantly fewer fruit were wholly removed from off-road locations than locations on road edges, but removal rate was high in both cases (93% and 70%) indicating dispersal by both humans and wild animals. I found no evidence of dispersal by birds. Infra-red camera evidence revealed possums and rats consuming fruits in the field. In addition, 2818 seeds were extracted from 1.5 kg of pig excrement collected from Te Weu Weu Bay in February 2006. Seeds readily germinated following extraction from pig and possum droppings with a final germination success, in the glasshouse, of 45.6% and 53% respectively. None of the few intact seeds excreted by rats germinated. Therefore, together with direct weed control, limiting the spread of banana passionfruit through the control of pigs and possums may improve management success and reduce the spread of banana passionfruit.
25

Floral biology of cashew (Anacardium occidentale L.) in relation to pollination and fruit set /

Wunnachit, Wijit. January 1991 (has links) (PDF)
Thesis (Ph.D.) -- University of Adelaide, Dept of Horticulture, Viticulture and Oenology, 1991.
26

Pollination processes - maternal and offspring performance /

Holmén Bränn, Kristina, January 2007 (has links)
Diss. (sammanfattning) Stockholm : Stockholms universitet, 2007. / Härtill 4 uppsatser.
27

Pollination and seed production studies in inbred and hybrid onions

Erickson, Homer T. January 1953 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1953. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 41-43).
28

The effects of a widespread, showy invasive plant (Rubus armeniacus) on pollinator visitation rates, pollen deposition, and seed set in a rare native wildflower (Sidalcea hendersonii) /

Johnson, Natasha S. Peterson, Merrill. January 2010 (has links)
Thesis (M.S.)--Western Washington University, 2010. / Includes bibliographical references (leaves 56-63). Also issued online.
29

Pollination and seed production studies in inbred and hybrid onions

Erickson, Homer T. January 1954 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1954. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 91-93).
30

Community effects of introduced honeybees (Apis mellifera) on native bee fauna and plant pollination

Roberts, Guinnevere E. January 2001 (has links)
Thesis (Ph. D.)--University of Hawaii at Manoa, 2001. / Heading on electronic reproduction: Roberts, Guinnevere Ellen. Includes bibliographical references (leaves 104-131). Also available on microfiche.

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