Apple Tree Disease Or Extreme Heat

[richardandrewparedes]

Hi everyone. Several weeks ago, I received some bare-root apple trees by courier from a friend in China. Some seem to be ok but some seem to have brown spots on their trunks. Some trees have already wilted after a month, while some have their trunks turning brown. The temperature where I live in the tropics is 36 degrees in the afternoon. I am just not sure if these are apple tree cankers or just trunk imperfections due to pruning or cold damage, etc. I have attached some pics for your reference. Also, I have some old olive trees in my tree collection and i am so scared that these could infect my olive trees. Can apple tree diseases infect olive trees and other trees such as citrus? Your advice would be greatly appreciated. Thanks a lot in advance.

 

[Crazy Diamond]

Apples need some cold rest period in winter to flower and grow well, idk if they are going to do very good in a tropical filipines climate

 

[Shibui]

Apple trees should grow Ok in warmer areas but they may not always fruit as well because flowering and fruit formation is controlled by winter chill. There are different varieties that have different chill requirements and some have been selected for warmer areas.

All the brown areas in the pics seem to be dead sections after pruning. Apples can only bud from old nodes so it a branch is pruned it will almost always die back to the fork below or to a dormant bud on the branch. It is usual to prune then wait for the branch to show where the new growth will be then trim the dead section so the trunk can heal properly.
Now that you can see the difference between live and dead sections you can cut neatly with branch cutter or saw to make these cuts neater.