Effects of rootstock on avocado fruit quality – assessment of postharvest disease, major cations and biochemical traits

Abstract

Growth and yield performance of ‘Hass’ and ‘Shepard’ grafted to several commercial and proprietary rootstocks has been assessed annually in field trials established around Australia between December 2004 and May 2005. Since 2008 fruit has been assessed for postharvest anthracnose and stem end rot after ripening at 23°C to favour disease development. Peel and/or flesh samples have been analysed for calcium and nitrogen, and for activities of peroxidase and catalase.
There were significant rootstock effects on disease and skin cations in some cases, for example, at Hampton in 2010, ‘Hass’ fruit from clonal SHSR-03, ‘A10’ and ‘Velvick’ had less anthracnose than from ‘Reed’ and ‘Hass’. At the Walkamin field site in 2011 fruit skin calcium levels were highest in fruit from ‘Shepard’ trees on clonal ‘Velvick’ and seedling ‘SHSR-03’. These rootstocks have typically performed well in terms of conferring resistance to anthracnose, thus thus re-affirming the importance of calcium in disease resistance.