About the fertilizer.

Being in New England, I'm not familiar with the nutritional requirements of tangerine vines.

Calcium availability is dependent on soil pH, with low pH decreasing the availability, although organic soils are better at providing calcium than mineral soils.

There should not be any real problem using calcium and nitrogen at the same time. Calcium nitrate is used as a fertilizer. On the other hand, an application of too much fertilizer could cause root injury which would be reflected in the general plant health, not just in the fruit.

Are you sure that your fruit has a chemical injury or could it be some other problem?

misato wrote:

Other way around, surely?

Nope. Although again, it depends...

Hi Sandy,

decreasing the

dps are right about this, calcium do started reduce the availability when PH are below 6.0.

Regards, Wong

-- Latitude: 06.10N Longitude: 102.17E Altitude: 5m

My information was taken from "Knott's Handbook for Vegetable Growers", by Lorenz and Maynard, second edition, 1980. Their tables showing nutrient availability as a function of pH are on pp 86-87 in that edition and reference "Changing Patterns in Fertilizer Use", Soil Science Society of America, Madison WI, (1968), L.B. Nelson, ed. and also "Relationships between pH values of organic soils and availability of 12 plant nutrients", R.E. Lucas and J.F. Davis, Soil Science

I should have said that organic soils are *slightly* better at providing calcium than mineral soils.

The statement was actually peripheral to the question about tangerines.

Sandy wrote:

Thank you for your web reply!

I'm beginner of raising tangerine trees and studing little by little about it. I hadn't got any other idea of the tree ploblem . Yes, there would be couse of the ploblem or I just don't know how to distingush a chemical injury from the other ploblems.... your comments are really instructive for me.

Thanks.

misato

Konnichi-wa Misato-san:

Where in Japan are you growing your tangerine (mikan) trees?

Henry