USING SPRING WEATHER DATA TO PREDICT HARVEST DATE FOR ‘IMPROVED FRENCH’ PRUNE

The Californian dried plum/prune (Prunus domestica) industry is almost entirely dependent on a single cultivar, ‘Improved French’. Thus the entire crop must be harvested over a relatively narrow harvest period of about three weeks with the harvest times of individual orchards varying as a function of location within the state.
The mean fruit maturity dates for the ‘Improved French’ can vary by as much as thirty days from year to year, with weather patterns seemingly becoming more variable annually.
There is a need to be able to predict fruit maturity dates early in the growing season to facilitate planning for orderly harvest and fruit drying.
Recent research with peach and nectarine (Prunus persica), and fresh-market plum (Prunus salicina) cultivars indicate that fruit maturity dates can be predicted reasonably well from full bloom dates and the accumulation of growing degree hours 30 days after full bloom (GDH 30) after the relationship between GDH 30 and the length of the fruit growth period between full bloom and GDH 30 is established from historical records.
Thus bloom and fruit maturity data were analyzed for the ‘Improved French’ cultivar for several years from two locations in California, and there was a clear relationship between the length of the fruit growth period and GDH 30. This relationship has subsequently been used to establish an industry oriented “decision support” system that allows growers and dehydration plant managers to use publicly available weather data for their local area and bloom dates from individual orchards to predict fruit maturity dates after only 30 days after bloom.

IX International Symposium on Plum and Prune Genetics, Breeding and Pomology

C. DeBuse, G. Lopez, T. DeJong

decision support, fruit development, harvest prediction, Prunus domestica, temperature effects

https://doi.org/10.17660/ActaHortic.2010.874.13