IS THE POOR QUALITY OF LATE SEASON NEW ZEALAND 'HASS' AVOCADO FRUIT RELATED TO FRUIT CHARACTERISTICS AT HARVEST?

New Zealand avocado fruit are harvested from August to March, although towards the end of the season fruit tend to develop increasing amounts of disorders when ripe. An increase in disorders can cause problems for exporters forcing an early exit from export markets. Identifying poor quality fruit at harvest would allow exporters to avoid placing such fruit on the market. A marker of advanced maturity that is related to increased disorder levels is required. Potential markers include the fruit's sugar content, either as the soluble solids content or levels of individual sugars, and the development of the seed. Changes in soluble solids, sugar composition and seed development of 'Hass' avocados were followed in fruit harvested from 2 orchards (designated Orchard 1 and Orchard 2, from the Eastern Bay of Plenty and Far North, respectively) about every two weeks from December through to February. A separate sample of fruit from the same harvests were stored for 4 weeks at 4°C and assessed for disorders immediately out of storage and also when ripe. The association between fruit composition and ripe fruit quality was then assessed. The soluble solids content of unripe fruit was about 7 to 9 ° Brix with a gradual decline over the first 3 harvests for fruit from Orchard 1, but no consistent change for Orchard 2. Total sugars were higher in fruit from Orchard 1 (9-16mg/mL) than Orchard 2 (7-9 mg/mL) with a discrete peak in Orchard 1 but a gradual decline in fruit from Orchard 2. The mos