LEAF ANALYSIS SERVICE AND STANDARDS FOR NUTRIENT LEVELS 



William J. Lord 

 Department of Plant and Soil Sciences 



Leaf analysis is an effective guide to more economical and 

 efficient fertilizer practices; and as an aid in diagnosing 

 specific problems in individual orchards. The accuracy of 

 diagnosis depends upon accuracy of sample collection. Thus, 

 it is important that the procedures described below are followed. 



The leaves are analyzed for nitrogen, potassium, phosphorous, 

 calcium, magnesium, manganese, iron, copper, boron, zinc and 

 sodium. Nutrient sprays of calcium, manganese, zinc, copper, and 

 boron leave residues which make analyses for these micronutrients 

 meainingless without carefully washing the leaves prior to wilt- 

 ing, to remove the residue. Washing procedures to remove this 

 residue require specific laboratory procedures which cannot be 

 provided by or compensated for by this service. Therefore, 

 leaves from trees sprayed with these micronutrients cannot be 

 used for micronutrient analyses. 



Sampling Procedure 



1. Sampling Individual Trees to Diagnose Problem. ( Leaves from 

 each tree constitute the sample . ) 



Select a minimum of 3 trees of the same variety in a block 

 showing the condition in question. Then as an aid in diag- 

 nosing, select a minimum of 2 trees of this variety not 

 showing the condition in question. Now sample each tree 



separately the leaves from each tree will constitute a 



sample. A leaf sample consists of: apple trees (50 leaves 

 per tree); peach tree (80 leaves per tree). 



Analysis of leaves from individual trees in a block is more 

 expensive, but is more meaningful than a composite sample 

 from several trees . 



2. Composite Sample to Diagnose Problem. ( Leaves from several 

 trees are combined into one sample ) . 



Obtain 10 leaves from each of 5 or more trees of the same 



variety in a block showing the condition in question and put 



them together as one sample. Then, obtain a similar sample 

 from trees not showing the condition in question. 



