Well you could always put a few UV Lights in your grow room, I'm sure you will pull more resin off the plants. All the big hash producers in the world like Morocco, Afghanistan, Pakistan, and Africa are growing their hash up high in the mountains, why? Well if you think about it they are closer to the sun and the plants are getting more UV light therefore producing more trichs to protect itself.

I think if we used this method and the pinch method rocktheganj suggested, you could simulate an 'attack' on the plant. Even if you topped and cut off a few leaves I think the plant would react as if it were being attacked??

Lots to think about here