The result of 4 weeks without any additional watering.
I have had this avacado growing from seed, perhaps 3 or 4 years now. It has always grown well. I could leave it in the window for 2 weeks and at worse, it would wilt badly. With water, it would be good as new. Before being left alone, it was well watered with the blinds closed but this time it was left for 4 weeks, with apparently dire results. The stem, with bark on the bottom 20 cm of the ca. 1m tall plant, looks fine, but everything at the top looks dry and shriveled. The question, what to do now?