Re: CULT:Nutrients

--- In iris-talk@y..., lmmunro@h... wrote:
> I notice the same exact thing with my pear tree: One year it is 
full of pear flowers and pears; the next year I usually get a single 
> (huge) pear  or two. Then the cycle repeats itself."

This is a typical problem with all apple/pear relatives.  The cycle, 
once set in motion, such as by a frost year with a near wipe-out, is 
a mixture of nutrition and effects of growth regulating hormones, 
with the hormonal factor the dominant one.  Small green fruit produce 
growth hormones that suppress blossom development for the following 
year.  The tips of rapidly growing upright sprouts produce hormones 
that inhibit the formation of fruiting spurs and of competing 
sprouts.  Ordinarily all this is in dynamic tension--and the 
hormonally balanced plant produces enough of both green sprouts and 
fruit spurs to continue the balance into the coming year.

I suspect there are similar hormonal controls at work in iris.

In fruit trees, there are ways to get the tree showing alternate-year 
bearing habit back into control.  Early and heavy thinning is one of 
the main tools.  Control of the N-P-K balance is more difficult.  
Upright, too-rapidly growing sprouts in the no-fruit year can 
be "bent and twisted"--a Japanese horticultural technique that gets 
the sprout leaning or curving away from the vertical.  That reduces 
the control-hormone production and allows more buds to set--for the 
second year hence.

To "thin" an iris should be possible---for one thing, not setting 
pods on a plant that is needed for increase is a good idea.  Also, it 
is possible to break out the developing bloomstalk as soon as it is 
seen bulging in the base of the blooming fan.  This will maximize the 
possibility of increase--at the expense of part of the current year's 
bloom.

Neil Mogensen   zone 7a in western NC



------------------------ Yahoo! Groups Sponsor ---------------------~-~>
Make good on the promise you made at graduation to keep
in touch. Classmates.com has over 14 million registered
high school alumni--chances are you'll find your friends!
http://us.click.yahoo.com/n4HqaC/DMUCAA/4ihDAA/VTJVlB/TM
---------------------------------------------------------------------_->

 

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index