I have been reading about the Sunflower Project.
Since I found that so many of my sunflower seeds were empty, I was very interested when earlysnowdrop left me a comment saying that empty seeds means they have not been pollinated and are an indicator of the health of bee populations in the garden. The Sunflower Project looks at sunflower seed samples to follow bee health.
I made some more seed counts on the same sunflower below.
Four sets of counts, n=30 for each, 120 total seeds. Percentages were 67%, 53%, 43% and 63%. Mean 57%, standard deviation 11, standard error 5.3.
So, just over half of my sunflower seeds were pollinated (about 57%). I don’t think this rate is very good.
This sunflower bloomed early (the end of July) and there weren’t many bees around then. Also, it was very rainy, which probably isn’t good for the bees. We have a lot more bees now and I bet my next sunflowers will have better seed production.