North American Fruit Explorers mailing list at ibiblio

[Doug Woodard <dwoodard@becon.org>]

To spell things out a bit:

Japanese plums are even more sensitive in size than most fruits to fruit 
set and I prsume to other factors affecting available resources for the 
fruit., like the division of resources between growth and fruiting on 
the part of a young tree. The growth of a given fruit depends on what 
was there before, so factors affecting early growth (drought?) are 
crucial (thinning late has less effect on the remaining fruit than 
thinning early). I have read that calcium moves into apples mostly in 
the early stages of the fruit's development (affecting the development 
of bitter pit if it is lacking later), and I suppose that this might 
apply to other nutrients in other species.

The size of your Wicksons could be a function of circumstances of 
culture and  weather *this year* as well as to the situation of your 
tree, so be cautious in drawing general conclusions.

Doug Woodard
St. Catharines, Ontario, Canada


Lon J. Rombough wrote:
> Another factor? Temperatures around and just after bloom time have an 
> effect. If it's warm, there is more cell division in the developing 
> fruit, and with more cells, the fruit will be larger when it ripens. 
> Cold weather at bloom and in the first few weeks means less cell 
> division and fewer cells, hence smaller fruit at ripening.
> -Lon Rombough
> Grapes, writing, consulting, my book, *The Grape Grower, *at 
> http://www.bunchgrapes.com Winner of the Garden Writers Association 
> "Best Talent in Writing" award for 2003.
> For even more grape lessons, go to http://www.grapeschool.com
> For growing supplies and more; http://www.grapegrowersolutions.com
>
> On Jul 30, 2007, at 2:39 PM, Lisa Almarode wrote:
>
> Besides thinning fruit, what factors affect fruit size? nutrients,
> grass competition... I know these affect tree size, etc., but I was
> under the impression that fruit size was mostly genetics.
>
> My Wickson plums are quite small (it sets very heavily, thinned to
> 1 in 10 but not enough), and friend's Shiro are cherry size; granted
> her tree was planted this spring.
>
> Lisa in Ashland Oregon
> ------------------------------------------------------------------------
>
>