Barbara, I think if the chinaberry wood was allelopathic you'd be seeing a lot more problems with your veggies by now. Maybe it's just the leaves that fall under the chinaberry tree that suppress other plants. The wood breaking down under the soil probably wouldn't secrete enough of the stuff to affect your veggies on the surface. Plus if you are watering your veggies as I'd imagine probably daily, the allelopathic agents would be washed downwards away from your plants.
I'd proceed with optimism and keep an eye out - you have a built-in excuse for any failures now, too!
