Effect of fruit sampling and handling procedures on the percentage dry matter, fruit mass, ripening and skin colour of 'Hass' avocado

The accuracy of the avocado dry-matter maturity index may be influenced by fruit sampling procedures. This research investigated the effects of avocado (Persea americana Mill; cv. Hass) fruit location in the tree, fruit size, the presence of damage on the fruit, and of holding fruit after harvest at differing relative humidities (r.h.), on the fruit percentage dry matter (DM) and quality. Fruit aspect in the canopy had no effect on the percentage DM or days to ripeness (DTR) in this trial, although fruit from the eastern side of the tree were larger. Smaller fruit and damaged fruit had higher percentage DM and ripened more quickly, suggesting that they were more mature. Damaged fruit (with ring neck or sunburn) were also smaller. Holding fruit at 60% r.h. or lower for 4 d increased the percentage DM of the fruit after the holding period by almost 1.5%, and reduced the DTR, compared with storage at 98% r.h. There were significant differences in the average fruit percentage DM and DTR between trees, suggesting an important effect of rootstock on fruit quality. These results indicate that fruit sampling procedures can have an important effect on the percentage DM test, and may result in immature fruit being harvested.