Pollination (and lack thereof)

Seedless Dorsett

One of the questions I often hear about apple varieties is “is it self-fertile?  Does it need a pollinator?  The answer to both is “yes”, but maybe not for the reasons you’re thinking.

The above photo is of a Dorsett Golden apple, and the contents of the core.  You’ll notice there are no viable seeds, just little specks where the seeds should be.  These are seeds that did not get pollinated; and yet, it still produced an apple.  But I could have told you that there were no seeds in this apple before opening it, as the shape tells all. 

If it had indeed been pollinated, the apple would have been much fatter and almost square as in the photo below; instead, it has this skinny shape. 

Pollinated Dorsett

For an explanation of this, I turn to NAFEX (National Association of Fruit Explorers) member and retired pollination contractor Dave Green’s explanation from a recent post in reply to another member’s question:

“I’m wondering if you are under a common misconception. Trees being loaded are not necessarily a sign of good pollination – if fact loaded trees could be a sign of inadequate pollination of the king bloom.

 The only way to truly evaluate pollination is by seed count. Slice the fruit crossways and count the seeds. Low seed counts indicate a pollination problem – and the fruit will not be top quality.

 If the king bloom is not well pollinated (and that’s the one we want fruit from), oftentimes the fruit will then set in clusters of three – which may or may not be well pollinated. It’s a complex thing with a lot of variables – bee populations/rain/cold/wind/pollenizer availability, etc. but it’s important to rely on accurate evaluations by seed counts rather than simplistic assumptions.

 A lot of people think like computer scientists – that pollination is a binary act – an on/off switch. Pollination with multi-seeded fruits is progressive. The more grains of viable pollen carried into the blossom the better, and that usually means many bee visits, not just one.”

It is not unusual for Dorsett Golden to set a whole tree full of fruit, and not have a single viable seed in the bunch.  That’s because it blossoms so early in the year and the only other tree blossoming at that time that could cross-pollinate it would be Anna.  And so no Anna nearby, no pollination (the same goes for the Anna tree that needs pollinating too).  Having both these trees together will increase the quality of fruit for both, but you will still get fruit from them even if planted by their lonesome.

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2 Responses

  1. How does Pink Lady do without a pollinator? We are in the Phoenix area, AZ.

  2. I don’t know, as we have plenty of pollinators here.

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