North American Fruit Explorers mailing list at ibiblio

["Donna &/or Kieran" <holycow@cookeville.com>]

Yes, raising pH and organic matter make boron less available.  We did it, 
and it sure did a job on things that needed boron.  Mind you, southern clays 
are seriously deficient in boron to start with, but when we got done, beets 
would not grow, period.  We also managed to make Mn less available by doing 
both of those things PLUS God provided some heavy rainfall.  I couldn't stop 
the rain, wouldn't have wanted to reduce the organic matter even if I could 
have, so only the pH was under my control.  I'd add sulfur and the yellow 
stripes on the corn leaves would disappear within days.  I rescued the corn 
like this every summer for about 5 years.  Unfortunately the effects of 
severe boron deficiency can't be easily gotten rid of; stunted warped growth 
that looks like a virus infection, cracked apples.  Neil Kinsey in his book 
HANDS ON AGRONOMY says that a foliar boron spray greens up crops so fast 
that a farmer can quit anywhere in the field, go home for lunch, and the 
line between green plants and yellow plants will tell him right where he 
quit.  Their level of deficiency was obviously minor compared to ours. 
Donna

P.S.  Though calcium can prevent Boron uptake, boron controls calcium 
transport in the plant.  Without boron, the plants show Ca deficiency 
symptoms.  Since Calcium slows the spread of viruses, I have bugged some 
rose nuts to throw borax around wild multifloras infected with rosette virus 
to see if it stops the "virus" or maybe a real virus.  It looks like a very 
exaggerated version of what happened to my tomato plants in the bad old low 
boron days.