I have fifty three 55-gallon drums setting under the gable of two of my barns to collect rain water, and a pump system that pumps the water into my greenhouse. I use only pure rain water to water my trees and other plants, as my well water contains twice the safe limit of bicarbonates.. When I water my entire greenhouse it takes about 300 gallons of water to complete the entire watering of all my trees and misc. plants.

Rain water does not contain any calcium, and my trees are planted in an organic medium (CHC/peat). This medium does not provide calcium to my plants. What I do, for my container trees to provide calcium is: after 3 or 4 applications of Jack's fertilizer, I apply a cal-mag fertilizer for the fifth application. For me it seems to work well as I have never had a calcium deficiency. On my 10 in ground trees, I only use 25-5-15 W/TM . - Millet

I did not check on the completeness of the link to "Understanding pH Management For Container Grown Crops", that I posted above, I just assumed that it was a posting of the entire book. After reading helpmycitrus's comment, I went back and checked out the link. As it turns out it is only a very very very small portion of the entire book.

Millet
Dietrick Bonhoffer Hero

I wonder if you could give me a quote or two from the series (which are not in the pdf we already found) that seems unlikely to appear in lots of places on the net so that I could search for pdfs from the series?

I see that the series is from Greenhouse Grower in 2001 and I do have access to a library but the full text from 2001 is not available.

I suspect it's somewhere online but would need some quotes to find it.

Thanks!

I have been a long time subscriber to the magazine "Greenhouse Grower". I find the magazine somewhat helpful, and would rate the magazine as OK. Give me a day or so, and I will provide you with some quotes, from the actual book.
Millet

helpmycitrus, Sorry for the delay answering your last request. I forgot about this post. Below are a couple sentences from the book, in hopes that you can locate it on line, if the complete book is even on line.

From Chapter One --- Overview
Certain species are very efficient at taking up the iron and manganese from the soil solution and have been termed "iron-efficient species."

Chapter Three ---Monitoring pH And Nutrition
There are only a few situations in which one testing method is better than another

Chapter Six --- Correcting Low pH Problems
Over-acidification of irrigation water (100 ppm to 120 ppm alkalinity is the usual target when acidifying a high-alkalinity water).

Chapter Eight --- Examples Of Growers Who Do It Right
In contrast, growers who run into pH problems often lack a consistent growing medium.

Millet
Dietrich Bonhoeffer
(4 February 1906 - 9 April 1945)

Thanks for getting back to me with the quotes. I found some of the articles (or think I did) and some I didn't. I may just end up ordering the book.

Do you know a source for ultra low biuret urea? I'm having difficulty finding one - the best I can do locally is 2% which I gather is too much biuret for foliar application to citrus (I am still working on the pH using sulfuric acid but I'd like to get some Mn to the plants in the mean time).

If you know an online source that would be great. A brand name without a source might also be helpful.

Thanks!

I do not use Urea for foliar applications, I prefer to use Potassium Nitrate instead. As I have never used, or purchased urea, I am unaware of a good source for a low biuret product. Citrus is more sensitive than most crops to biuret, an impurity that can be present in urea fertilizer created by excessive heating of chemical reactants during urea manufacture. Toxicity can result from either soil or foliar spray applications of urea with an elevated biuret concentration. If urea is used as a nitrogen source for citrus, it should contain not more than 0.25 - 0.40% biuret by weight. - Millet (216 BO-)

I have ready access to potassium nitrate as well. Do you have suggested rates per gallon of water for both potassium nitrate and EDTA Mn?

Hrm from my reading it looks like EDTA Mn might not work. The molecule size might be too large for foliar application? I ordered some MnSO4...

Citrus: Potassium Nitrate (KNO3) can be applied foliar at a 1 to 4 percent concentration. (I use a 2% spray concentration. - I have never used a 4% spray)

1-3 applications: pre-bloom (1 normally spray one to two months prior to the expected start of blooming),--- post-bloom ( some people spray post-bloom, I never have), --- during fruit growth (three - four months after bloom).

I've read that KNO3 foliar sprays somehow raise the Mn content in the leaves. I've never looked into the scientific reason for this.

Millet (215 BO-)