If the relative intensity of red (600-700 m1), green (500-600 m u), blue (400-500 mg), and white (400-700 ma) light is 12 : 30 : 1000 : 30, each spectral region exerts a similar effect for both light break and the reversion of the far-red effect. Low-intensity light of 8 hours or more inhibits flowering when applied before an inductive dark period. The relative intensity of each colored light required to exert maximum inhibition is similar to that obtained for the light-break effect and the

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... rsion of the far-red effect. Maximum inhibition was obtained with 10, 40, 200-1000, and 20 uw/cm2 of red, green, blue, and white light, respectively. Blue light was very inhibitory when given for 8 hours before the dark period and this inhibition was reversed by subsequent exposure to red light. Inhibition caused by low-intensity white, green, or red light was not reversed by red, however. When 15 minutes of blue light (1000 ,uw/cm2) was given at different times in a 24-hour dark period, it was most inhibitory at the 8th hour, and the response was very similar to that caused by red light.