According to the university, the so-called alternation is problematic for producers. In order to work around the fluctuations, fruit growers are dependent on elaborate mechanical or chemical methods; but these often only have a limited effect. The researchers therefore pursued different approaches to investigate the underlying mechanism of the alternation. One theory is that the ripening fruits were suspected of using a hormone to suppress the formation of flowers the following year.
According to the University of Hohenheim, the scientists plan to investigate this approach with the help of a rare apple variety. The variety "Spencer's Seedless" forms fruit without seeds, because they are normally not pollinated due to missing petals. The scientists plan to compare the yields of two groups of this variety, one group being artificially pollinated to produce fruit with seeds. In this way, the hypothesis that the sought after hormone is formed in the seed will be tested.
A further research approach is based on competition within the tree; it is assumed that growth and flowering were contesting for nutrients. In experiments in this context, a strong fluctuation in yield could also be induced by a very slight change.
The project is funded by the Deutsche Forschungsgemeinschaft (DFG) [German Research Association] and also by the Australian horticultural society, "Horticulture Innovation Australia Limited" who are contributing approximately 615,000 euros.
Source: Proplanta
