sensa
Why is there an optimal time for its use?
Both the male and female flower bud primordia (bud tissue in its earliest recognizable stage of development) are sensitive to alteration of their programmed genetic “blueprint” during certain time-frames. If you apply Sensa-Spray™ plant hormone too soon, the plant will not be physiologically able to respond properly and little effect from your application will be seen.
If sprayed too late, male flowers are already locked into their development pathway as males. However, when sprayed at the right time, Sensa-Spray™ plant hormone will exert pressure on your male plants to produce female flowers. Of course it will not affect your female plants – they will be female anyway. Also, you will undoubtedly have some bisexual plants (both male and female flowers on the same plant), but who cares – you win both ways!
I haven't tried either products but I found the above excerpt from Sensa if that is of any use.
