I've been hand pollinating some fruit trees this year, there haven't been that many bees around and some trees(pear, feijoa) don't attract them anyway. But I usually only have time to do this in the late afternoon and evening. I don't know if this is a waste of time and instead should always be done in the mornings or midday.

How I can tell when the pollen is viable and ready to go. I'm sure it varies with the type of tree but is there a standard way to tell if the pollen is ready...I have a good hand magnifier/microscope so I can look closely at the pollen if that's necessary.

Along the same line, can the stigma still be receptive after the pollen (on that particular flower) has turned brown and dried up? When hand pollinating, I notice the stigmas are straight and strong looking (feijoa=pineapple guava in this case) for a while after the stamen(s) has dropped off. Does this mean anything from a pollination point of view?

It would be nice to hear any kind of information about this.

John