Guest post by David L. Green, retired commercial bee keeper, former editor of small newspaper, teacher. You can visit his
website and his
blog
 |
| Partially pollinated cucumbers. © Dave Green, 2013 |
With seven inches of rain in five days, bees had very little time to work.
They delivered enough pollen grains so that the cucumbers did not abort, but
not enough to flesh them out.
The one at left is a total lack of fertilization of the seeds at one end -
that meant that the flesh did not grow, and the cuke had a "tail."
Three more are slightly better. The one at the bottom has few of the incipient
seeds fertilized in the middle, giving a waist to the cuke. These poorly pollinated
cukes grow slowly and quickly get tough, sometimes bitter, as well.
If bee populations are normal, this problem should straighten out when the
weather is more suited to bee flight. If you get very many like this in good
pollination weather, you have a shortage of bees, and may need to work on
increasing bee populations or hand pollinate.
My garden is pollinated by a mix of bees, with the bulk of the workload
carried by bumblebees and honey bees, but we also have green sweat bees, squash
bees, digger (
Anthophora) bees, tiny
Ceratina bees, and leaf cutter bees doing
some of that work.
To make a perfect cucumber, you need to get almost all of the incipient
seeds fertilized. That requires two grains of pollen - one for the embryo and
one for the seed coat, so each perfectly pollinated cuke represents several
hundred grains of pollen delivered to the flower.
A lot of folks think that, if they see a bee in a flower, that pollination
is accomplished. But it's not an on/off switch. It's a progressive thing. It
takes many bee visits to deliver all the pollen needed for multi-seeded fruits.
Every year, more and more gardeners report the symptoms of lack of
pollination in their gardens. The problem seems to be accelerating.
It represents one of our most urgent environmental problems - pollinator
decline. Our bees are disappearing. Some of that is due to habitat loss; some
due to monoculture and its feast or famine pattern of intense bloom, followed by
barrenness; some is from new diseases and parasites; but the worst and most
difficult problem to solve is the loss caused by pesticides.
When cotton blooms, bees focus on those nectar-rich blossoms, and drop by
the millions when the cotton is sprayed. In July clover is in full bloom in the
orchard floor, and more millions of bees die when the fruit is sprayed.
Community mosquito sprays are supposed to be applied when bees are not working,
but this time limit is very poorly observed, and many more bees are dropped
from applications done when they are out. And many gardeners plaster Sevin dust
all over their gardens without thought of the bees.
All four of these cases I mentioned are illegal applications, because the
label directions forbid them, but label enforcement is rare and usually amounts
to a slap on the wrist, if anything.
So, if we do not begin to protect our pollinators - we lose much of the
vitamin C (fruits) in our diet. Food costs will rise; only the rich will be
able to afford many of the most nutrient-rich foods we have. We are left with
grains that do not need bees - but remember that "man shall not live by
bread alone."
© Dave Green, 2013
Retired pollination contractor
