P van Rijckevorsel writes
Isn't there any number of fruit trees who need to have a 'male' planted
somewhere near them for them to bear fruit? Maybe I can think of them when
feeling a little less woozy.
PvR

Stewart Robert Hinsley schreef
Apples for a start, though I wouldn't swear that it applies to all
cultivars. Sample URL -

http://www.ontarioprofessionals.com/trees.htm
--
Stewart Robert Hinsley

+ + +
Afraid not. This is an example of a different mechanism, viz
self-incompatibility not based on mechanical principles. Self-incompatibilty
in apples is linked to genetic make-up, which means that an orchard composed
of a single clone (cultivar) won't produce fruit. For that a genetically
different apple is necessary (a different cultivar). Not all apple cultivars
are equally suitable as pollen producers.
PvR