CORRELATIONS BETWEEN PERIODICITIES IN GERMINATION OF CHENOPODIUM BOTRYS AND VARIATIONS IN SOLAR RADIO FLUX

Abstract

There were pronounced fluctuations in the percentage germination of seeds of Chenopodium botrys that were kept stored in darkness under carefully controlled conditions of temperature, humidity, and barometric pressure. Germination tests were conducted over a period of more than 2 years in controlled environment cabinets at 30 °C with different photoperiods supplied by fluorescent light. The fluctuations in percentage germination showed no evident correlation with the following factors: relative humidity, barometric pressure, lunar cycle, magnetic intensity.There were highly significant correlations between the fluctuations in germination and solar radio flux (10.7 cm wavelength, indicative of sunspot activity). The best positive correlation between values for solar radio flux and percentage germination suggested that the effect of solar flux on germination (whether direct or indirect) was greatest during the week immediately preceding the wetting of seeds. Periodogram analyses of the periodicity of percentage germination and solar flux has provided two periodograms which have corresponding peaks, showing that the component periods for solar flux are practically the same as those for germination. It cannot yet be stated whether these correlations were indicative of a direct effect of solar radio flux on germination. The present evidence affirms the contention that largely unexamined exogenous factors may influence rhythmic biological processes.