Have you been fertilizing? The soil also looks a bit dry.

well....just going back to the basics, here are my recommendations: 1. avos like moist soil (not standing water) 2. feed with a very dilute fertilizer 3. make sure it is getting UV's (not through new E glass)

I have been using Miracle Grow in the same amount as I use on my other avocado plant which is dark green and flourishing. The only difference between the 2 plants is the pot. The healthy plant is in a plastic pot with eight 1/2" dia. drain holes and sits on top of a warm computer tower case. The unhealthy plant was in a pot with no holes and had lost most of its leaves, so about 3-4 weeks ago I drilled drainage holes in the bottom and you are seeing the new growth. Both plants are in a business office under bright floresent lights. The lights burn 3 shifts 24 hours 6 days a week. Lights are off 12 hrs on Sunday. I water the plants heavy once a week on Friday until the soil will not absorb any more water and the excess drains out. Do you think the weak plant my have suffered some root rot from being in a wet pot? It may be having trouble absorbing nutrients?

I think you will be fine now that you have drainage. The only thing that concerns me is the 24 hr light. Plants need dark (rest).

Photo of my healthy avocado plant