What is the most accurate kit to use to check the PH levels?

"Andrew" wrote in message
om...
"James Dawson" wrote in message
. au...
Hi,

I planted a couple of eureka lemons 2 years ago and are situated in full
sun.

This years new growth has predominantly yellow leaves (with dark green
veins).
The trees are fed regularly with a citrus food.
What is the problem?

thanks in advance

-j

While your checking nutrient deficiencies, as per other people's
suggestions, you might want to check your soil pH as well. At high
pH's iron is not readily available to the plant. Similarly at very low
pH's magnesium is not readily available. There's no point adding more
trace elements if the plant can't take them up.