10 



SUGGESTIONS FOR FERTILIZATION OF PEACH TREES 



William J. Lord 

 Department of Plant and Soil 



Sciences 



Tree growth is the best guide to how your fertilizer program fulfills 

 the needs of peach trees, if soil moisture is not a limiting factor. Since 

 flower buds of the peach are formed along the new shoot growth, it is essen- 

 tial to produce adeguate growth by use of a nitrogen (N) fertilizer. Young 

 peach trees should make about 18 inches of new terminal growth annually; 

 12-15 inches are sufficient for mature trees. Growth in excess of these 

 amounts may result in poor fruit color and excessive cold injury, and will 

 increase the amount of pruning required. 



In some orchards, N is the only fertilizer required. However, leaf 

 analysis in conjunction with visual observations of tree growth and fruit 

 quality are the best criteria by which to determine required amounts of fer- 

 tilizers (Table 1). In Massachusetts, N needs are usually met with an 

 application of ammonium nitrate or a "complete fertilizer." Foliar sprays 

 of urea to supply N are ineffective on peach trees because the leaves do not 

 absorb N as efficiently as do apple leaves. 



Table 1. Standards for nutrient levels in peach leaves. 



Element 



Nitrogen 



Potassium 



Calcium 



Magnesium 



Boron 



Copper 



Manganese 



Zinc 



Shortage^ 

 fless than1 



3.00% 



1 . 25% 



1 . 35% 



0.25% 



25 ppm 



5 ppm 



25 ppm 



15 ppm 



^Shortage: Corrective measures needed. 



^Optimum: Applications should be continued at present rate or adjusted 

 according to anticipated crop size. 



•^Excess: Amount applied should be decreased or eliminated. 



