When to cut Oncidium Flower spike?

[claypot]

I have always cut my oncidium spikes once they start to fade. Most Oncidiums put so much energy into producing a substantial spike I just feel that when the flowers begin to fail the plant is saying "i am tired and had enough". I cannot see how a plant can suddenly decide that it is time for no more growth so I'll suck goodness what goodness is left for another time. It seems more likely to me that the plant just decides to hut down goodness flow to the spike. Now leaves are quite different in taking in energy. Some people even cut flower spikes off very early from Oncidiinae especially on young plants to conserve energy. I guess either way you are not going to make much difference on a mature plant. Again, some people hold that some species oncidiinae might even exert so much energy that they flower themselves to death and the pseudobulbs just shrink away.