Meadowfoam (cultivar Mermaid) is an entomophilous
winter annual oilseed crop that has historically produced
an average of only two of five seeds per flower. Reference
to inadequate meadowfoam pollination exists in the literature,
but quantitative evidence is lacking. Studies were
undertaken to: 1) quantify meadowfoam pollination requirements
and 2) evaluate the potential of an alternative pollinator.
In vivo pollination biology studies tested pollen
age, stigma age, stylar restriction, and pollen deposition
rate effects on seed set. Yield efficacy of Osmia lignaria
propinqua Cresson, a native wild bee pollinator, was compared
in cages to a honey bee standard and a non-caged
honey bee control. Osmia reproductive potential was also
tested. Pollen 0-5 days old (postanthesis), stored at 3,
18, or 37°C, did not appear to limit seed set. Stigma age
was critical for seed set maximization. Seed set was not
influenced by the number of stigmas pollinated per flower,
but was limited by less than 25 pollen grains deposited per
flower. Seed set and pollen deposition increased with increasing
honey bee visits per flower. It was concluded
that at least three honey bee colonies per acre should be
used for commercial meadowfoam production. Osmia produced
comparable individual plant yields to honey bees. Sixty
Osmia produced similar solid stand yields to 4000 honey
bees. Significantly greater solid stand yields per bee
were obtained from Osmia when compared to the honey bee.
Osmia survival and female production were negatively correlated
with female density, while nest/male/total cell
production was positively correlated with female density.
Osmia demonstrated yield improvement potential as a meadow-foam
pollinator. / Graduation date: 1991
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/37404 |
| Date | 31 July 1990 |
| Creators | Jahns, Thomas R. |
| Contributors | Jolliff, Gary D. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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