I am playing Mission 6, where I have to produce 50 food crates. I am growing some trees and shrubs, but I cant produce the crates. I have read to right-click on the trees or shrubs but nothing happens. What am I doing wrong?

The plant produced varies according to the soil. You have to tweak it by setting the moist and heat levels. I suggest you play the corresponding tutorial mission, so you learn how to control the biodeck.

For food plants, go for high heat and high moisture soils. The workers will produce the plants.

And this article on the wikia has some additional information: [url=]http://startopia.wikia.com/wiki/Bio_deck[/url]