A new avocado variety, ‘KB1 ’, was discovered in Chincha, Peru. The ‘KB1 ’ variety when used as a rootstock is notable for its prolific and vigorous feeder root growth ability that results in rapid canopy volume and early productivity of the ‘Hass’ avocado scion cultivar, and induces larger fruit sizes of the ‘Hass’ cultivar and is an alternative for locations where ecologic conditions tend to produce small fruit.