Glasshouse studies of inherent root growth of seedling avocado rootstock cultivars

In order to mimic loss of root function caused by Phytophthora cinnamomi, differences in inherent root growth of avocado seedlings of ten different rootstock cultivars across the three ecological races were investigated. A 2-pot root harvesting system was used and roots were harvested at three different intervals to assess tolerance to root removal. Seedling 'Velvick' produced the largest amount of harvested roots. However, when results were standardised by the total area of mature leaves, there were no significant differences found between rootstock cultivars in cumulative, root growth. Relative to total photosynthetic area, cultivars 'Kidd' and 'Fuerte' (produced the most roots in the absence of root trimming. Overall, increased trimming decreased cumulative root output (