There's never been a real scientific study done to my knowledge.
A few refs from
EVIDENCE FOR LUNAR-SIDEREAL RHYTHMS IN CROP YIELD: A REVIEW
(Published in Biological Agriculture and Horticulture, 2001, Vol. 19 pp.247-259).
Nicholas Kollerstrom & Gerhard Staudenmaier
Abele, U. (1973). Vergleichende Untersuchungen zum konventionellen und biologisch-dynamischen Pflanzenbau unter besonderer Berucksichtigung vom Saatzeit und Entitaten. PhD thesis, University of Giessen, Germany.
Abele, U. (1975). Saatzeitversuch zu Radies. Lebendige Erde, 6, 223-225.
Bacon, F. (1627). Sylva Sylvarum. In: The Works of Francis Bacon, Vol.2. (J. Spedding and Ellis, eds.) p. 636, Longmans; London 1887.
Beeson, C. (1946). The moon and plant growth. Nature, 158, 572-3.
Bishop, C. (1977). Moon influence in lettuce growth. The Astrological Journal, 10,1, 13-15.
Bockemühl, J. (1985). Elements and ethers: modes of observing the world. In Towards a Phenomenology of the Etheric World (J. Bockemühl, ed.) Anthroposophical Press; New York, U.S.A., 1-68.
Brown, F. (1960). The rhythmic nature of animals and plants. Cycles, April, 81-92.
Brown, F. & Chow, C.S. (1973). Lunar-correlated variations in water uptake by bean seeds. Biological Bulletin, 145, 265-278.
Dubrov, A. (1996). Human Biorhythms and the Moon. Nova Science Publishers, New York, U.S.A.
Edwards, L. (1993). The Vortex of Life, Nature's Patterns in Space and Time. Floris Press, Edinburgh, Scotland.
Graf, U. (1977). Darstellung verschiedener biologisher Landbaumethoden und Abklarung des Einflusses kosmischer Konstellationen auf das Pflanzenwachstum, PhD thesis, Zurich Technical College, Switzerland.
Graf, U. & E.R. Keller (1979). Zusammenhänge... Schweizerische Landwirtschaftliche Monatshefte, Bern, 57 (1979).
Hachez, M. (1935). The significance for seed-germination of the passage of the Moon through the constellations of the zodiac. Anthroposophical Agricultural Foundation, Notes & Comments, IV, 283-289.
Koepf, H. (1989). The Biodynamic Farm, Agriculture in the service of the Earth and Humanity. Anthroposophic Press, New York, U.S.A.
Koepf, H., Schaumann, W. & Haccius, M. (1996). Biologische-Dynamische Land Wirtschaft. Darmstadt.
Kolisko, E. (1936). The Moon and the Growth of Plants. Stroud, Gloucester.
Kollerstrom, N. (1977). Zodiac rhythms in plant growth: potatoes. Mercury Star Journal, London III, 50-53.
Kollerstrom, N. (1980). Plant response to the synodic lunar cycle: A review. Cycles, Bulletin of the Foundation for the Study of Cycles, 31.3, 61-63.
Kollerstrom, N. (1993). Testing the lunar calendar. Biodynamics, Winter 1993, 44-48.
Kollerstrom, N. & Staudenmaier, G. (1998). Mond-Trigon-Wirkung: eine statistiche Auswertung. Lebendige Erde, November 1998, 478-483.
Kollerstrom, N. & Staudenmaier, G. (2001). Mond in Tierkreis: anders rechnen - andere Ergebnisse. Lebendige Erde, January 2001, 48-49.
Llewellyn's Lunar Organic Gardener (1993). Llewellyn, St Paul, Minnesota, U.S.A.
Lücke, J. (1982) Untersuchungen... (Dissertation). Universitüt Giessen 1982.
Mather, M. (1942). The effect of temperature and the Moon upon seedling growth Journal of the Royal Horticultural Society, 67, 264-70.
Maw, M. (1967). Periodicities in the influences of air ions on the growth of garden cress. Canadian Journal of Plant Science, 47, 499-505.
New Zealand Biodynamic Association (1989). Biodynamics, New Directions for Farming and Gardening in New Zealand, Random Century, Auckland, New Zealand.
Rossignol, M., Tizroutine, S. & Rossignol, L., (1990). Lunar cycle and nuclear DNA variations in potato callus. In Geo-Cosmic Relations. (G. Tomassen, ed.), Pudoc; Wageningen, Holland, 116-126.
Sattler, F. & Wistinghausen, E. (1989, English trans. 1992). Biodynamic Farming Practice. Cambridge University Press, Cambridge, U.K.
Spiess, H. (1990a). Chronobiological investigations of crops grown under biodynamic management. 1. Experiments with seeding dates to ascertain the effects of lunar rhythms on the growth of winter rye. Biological Agriculture & Horticulture, 7, 165-178.
Spiess, H. (1990b). Chronobiological investigations of crops grown under biodynamic management II. On the growth of little radish. Biological Agriculture & Horticulture, 7, 179-89.
Spiess, H. (1993). Haben Lunare Rhythmen Bedeutung fur den Ecologishen Landbau? Stiftung Ecologie und Landbau, 42, 397-403.
Spiess, H. (1994) Chronobiologische Untersuchungen mit besonderer Berucksichtigung lunarer Rhythmen im biologische-dynamischen Pflanzenbau, Darmstadt; 2 vols, I 'Band 3' of 258 pp. , and II 'Band 4 - beschreibung der einzelergebnisse' of 319 pp., the data.
Steiner, R. (1993). Lectures on Agriculture, 1924. translation by C.Creger & M.Gardner, Biodynamic Farming and Gardeniung Association, Kimberton, PA., U.S.A.
Thun, M. (1964). Nine years observation of cosmic influences on annual plants. Star and Furrow, 22 (translated from Lebendige Erde, Jan/Feb. 1963).
Thun, M. & Heinze, H. (1979). Mondrhythmen im Siderischen Umlauf und Pflanzenwachstum. Darmstadt, Germany.
Thun, M. (1991). Work on the Land and the Constellations. Lanthorne Press, Launceston, Cornwall, U.K.
Thun, M. (1999). Gardening for Life - the Biodynamic Way Hawthorne Press; Stroud, Gloucester, U.K.
Thun, M. (2001). Working with the Stars, a Biodynamic Sowing and Planting Calendar. 26th Edn. Lanthorne Press, Launceston, Cornwall, U.K.
Wachsmuth, G. (1932). The Etheric Formative Forces in Cosmos, Earth and Man. Anthroposophic Press; London, U.K.
Wildfeuer, S. (1986). Stella Natura, The Kimberton Hills Agricultural Calendar, 19th edn. Kimberton Hills Publications, Kimberton, U.S.A.
A quick look on online acedemic jornals produced quite a few results too.
including
ISHS Acta Horticulturae 73: I International Symposium on Spices and Medicinal plants
RESPONSES OF LUNAR-PHASES ON THE GROWTH OF ABRUS PRECATORIUS LINN. (LEGUMINOSAE) AND ITS EFFECTS AS CRUDE DRUG ON DISEASES
Author: C.R. Karnick
There is also quite a bit regarding growth and lunar phase influences on animals, including H.H Sapiens.
All in all interesting reading whicever side of the fence one is on.