Does the amount of pollen produced by tomato blossoms vary much during the growing season?
Do you mean from variety to variety or within the same variety? As long as each bloom produces viable pollen so it pollinates itself then it is "enough". Any thing more is just waste.
I am asking about within the same variety. The reason I am asking is that I am trying to make crosses and am having trouble with not enough pollen available. I was wondering if there was variation so that I could time attempts at crosses better.
AFAIK no analytic study has been done on the grains of pollen produced by a single bloom at any one time much less a comparison of the pollen production through out the life of a specific variety. It just isn't considered a viable study simply because so little is needed relevant to how much is produced.
One could hypothesize that the smaller the bloom diameter the less the number of pollen grains it produces so only the earliest, largest blooms should be used for CP but I don't know of any evidence to support that hypothesis.
A more likely speculation would be that if you are having insufficient pollen issues the problem lies in your pollen collection methods, in the viability of the pollen when it is collected, or in your CP methods rather than in the amount actually produced by the bloom.
I know from personal experience that when the atmospheric conditions - air temp and humidity - are ideal rapid vibration of a single bloom can produce a small cloud of free pollen that if collected and applied properly would be more than enough to pollinate 100s of additional blooms.
I believe I will have to start earlier next year with crosses because now some days when I use my battery powered toothbrush I get no pollen at all from some freshly opened blossoms. I have been told by some that there is less pollen in the month of July here in Pennsylvania,
As you know with Blossom Drop and its lack of pollination due to excess heat and humidity, the pollen becomes tacky and sticky. So it would be normal this time of year for there to appear to be less pollen. It is still there in the usual amounts but it is a sticky glob and non-viable.
Here is a link that might be useful: Blossom Drop FAQ
The older I get, the dumber I get. I never thought about the temperature and the humidity being the cause of my inability to collect pollen. I think that is the problem Thanks all.
Actually, a thank you to Digdirt as you were the only responder. I appreciate the comeback.
It isn't being dumb. It's just the old "can't see the forest for the trees" syndrome we all get. I don't multitask nearly as well at my age and get tunnel vision on the one thing I'm working on. Lots of head-slapping Duh! moments. :)
Q: How many pollens are needed to do the job ?