In this article:

The percentage of fruitful buds on sultanas is shown to be closely related to the weather over 3 weeks in late November and early December–that is, during the period when the inflorescence primordia are differentiated.

The two factors concerned are the hours of bright sunshine and the sum of daily maximum temperatures from 82 to 90oF.

An estimate of the start of the period for which these weather elements are effective can be made by summing mean temperatures from bud burst.

Fruitfulness can be forecast within practical confidence limits from a regression developed for fruitfulness from 1954 to 1962 on sunshine and maximum temperatures.

The Relation between Weather and Fruitfulness of the Sultana Vine

1964, April 30th Australian Journal of Agricultural Research, vol 15, pages 920 – 928

csiro 024

Please note accessing PDF may be slow, thank you.