in the last month or two my tree started to thin its heavy crop of avocados. I thought it was normal and ignored it. now, the fruit is shriveling ,turning very black, while its still on the tree. then it drops off. i was told to water more. The tree is growing in the ground, near orange citrus, on a slight in cline. what can i do?
It could be fruit or stem rot. These references should help pinpoint the problem and how to manage it:
http://ipm.ucanr.edu/PMG/C008/m008fpfrtdmg.html
https://www.gardeningknowhow.com/edible/fruits/avocado/avocado-pests-and-diseases.htm
We would like to purchase small avocado trees and grow them indoors in containers under artificial lighting. Have indoor gardeners been able to successfully grow avocadoes on trees grown indoors? If so, who can provide me with information on how to successfully do so?
Yes, you can grow them indoors, but start with dwarf, grafted trees. Avocados grown from seed may not produce fruit.
Here are the basics. You can get more information from your local extension office (see below).
https://www.gardeningknowhow.com/edible/fruits/avocado/indoor-avocado-plant-care.htm
https://www.gardeningknowhow.com/edible/fruits/avocado/repotting-an-avocado.htm
https://www.gardeningknowhow.com/edible/fruits/avocado/how-to-fertilize-avocados.htm
https://www.gardeningknowhow.com/garden-how-to/info/what-is-extension-service.htm
I don’t know why are the leaves on my avocado tree turning yellow with brown spots.
It's likely due to insects feeding on the leaves. They suck the sap out. It looks like aphids - the tiny, dark brown things. You can treat them with Neem oil or insecticidal soap.
https://www.gardeningknowhow.com/plant-problems/pests/insects/homemade-aphid-control.htm