Keeping this in consideration, why use an orchard ladder?
Orchard ladder is used by landscapers as well as fruit pickers to prevent injuries and falls. This type of ladder is portable and durable. This is not the type of ladder that can be used anywhere. It is designed with tripod pole and a flared base that can provide support to an uneven and soft ground.
Similarly, how do you secure a ladder to a tree?
Secure the top of the ladder to the tree so it allows access above the branch being cut. Allow for any upward movement of the branch once the branch is cut. Never stand on the top three rungs of an extension or straight ladder. Always face the ladder and hold onto the side rails with both hands when going up or down.
Never operate a chainsaw on a ladder, and never cut limbs that are higher than your shoulder. (If you're looking to cut something higher, consider an altogether different tool: a manual rope saw.)