Pakistan Gardening Forum

Hi all,

Till now i had always thought that every water soluble fertilizer can be used as foliar spray but recent 2 incidents changed my mind.

1 - A member of forum Mr umar from DHA lahore used 5:15:45 NPK fertilzer in powder form, water soluble. Foliar spray did not yield much results but as a drench it worked great. I agree, i also used same packet and was not satisfied with foliar spray, drench was effective.

2- J Arthur's multi purpose liquid plant food with sea weed extract. It is in liquid concentrated form. I emailed to info@william-sinclair.co.uk and asked about its foliar spray and their reply was following

"Hi,

The liquid plant food is only a drench and it must be avoided getting it on the foliage as this may damage the leaves.

Kindest Regards

Mrs Christine Burnett
HORTICULTURAL ADVISOR"

Which means unless and until stated explicitly for foliar use, not every water soluble fertilizer is suitable for foliar spray.

It depends on the ingredients, chelates are better absorbed..

Izhar wrote:It depends on the ingredients, chelates are better absorbed..

How do i know if ingredients are chelated or not? And which ingredients are poorly absorbed?

It is usually mentioned on the label. Most of the compounds which are readily water soluble are suitable for foliar sprays..

Like for:

Nitrogen: Ammonium Sulfate, Urea
Phosphorus: Diammonium Phosphate, Mono Potassium Phosphate
Potassium: Potassium Nitrate, Mono Potassium Phosphate

Well then the following composition of my liquid plant food should be foliar as the ingredients are following:
Potassium Nitrate, urea, mono ammonium phosphate, trace elements and a seaweed extract.

But the company says otherwise. Is it the chance that they do not want us to use foliar so that it is used more and more purchases are made?

I use urea as foliar on lawn grass.I mix some urea granular with trace elements in 18 liter pump & spray it on forthnightly bases.The results are dramatic!

Khabbab I think you are right that water soluble fertilizer can potentially be used as a foliar spray but the manufacturers always add additional components (chelating agents) to facilitate absorption by leaves. The most delicate components are trace elements in foliar fertilizers. The chelating agents protect those trace elements and ensure that they are in a absorbable form by the leafs. Secondly, the fertilizer concentration has to be adjusted in such a way that on evaporation, there is no leaf burn either by chemical action or by osmosis. Recall, that whenever we sprinkle salt on fruits or food products, it extracts water out of food. If we try our homemade recipes, we will probably end up in leaf burn.