S5rmptoms of X disease not normally associated 

 with K deficiency. 



Magnesium (Mg) 



Mg deficiency often occurs on sandy soils, or 

 in orchards that have received heavy applica- 

 tions of K. Symptoms include marginal 

 chlorosis. Chi orotic tissue may die, resulting in 

 necrosis of leaf margins. The center of the leaf 

 remains green in an inverted-V pattern. The 

 oldest leaves are most severely affected and 

 usually fall in late summer, leaving shoot bases 

 bare, but tufts of green leaves at shoot tips. 

 These symptoms may be confused with X 

 disease (see above), iron deficiency (see 

 description below), or manganese deficiency. 

 Manganese deficiency, however, results in 

 more interveinal chlorosis. 



Manganese (Mn) 



Mn deficiency is not commonly found on 

 peaches, but has been observed. Sjonptoms 

 include interveinal chlorosis fi*om midrib to leaf 

 margin. Bands of green remain along the veins, 

 resulting in a herringbone appearance to the 

 leaves. Symptoms appear throughout the tree. 

 These s5rmptoms may be confused with Mg 

 deficiency (see above), iron deficiency (see 

 below), or zinc deficiency (see below). 



Boron (B) 



B deficiency has been observed on peaches 

 in other sections of the United States. Since 

 peaches are highly sensitive to excess B, 

 however, boron has not normally been applied 

 to peach orchards. Symptoms of deficiency 

 include terminal dieback of twigs with weak 

 growth below the affected terminals. Buds do 



not break in spring. These sjonptoms may be 

 confused with winter injury. 



Iron (Fe) 



Fe-deficiency symptoms are common when 

 pH is too high (sometimes referred to as lime- 

 induced chlorosis). Symptoms include 

 interveinal chlorosis with distinct green veins. 

 Leaves may turn almost totally white. 

 Terminal leaves are affected first. Symptoms 

 may be confused with Mn deficiency, Mg 

 deficiency, or Zinc deficiency. Symptoms of Fe 

 deficiency are more widespread throughout the 

 tree than those of Mn deficiency, and symptoms 

 of Mg deficiency are more prevalent on older 

 leaves rather than terminal leaves as with Fe 

 deficiency. 



Zinc (Zn) 



Zinc deficiency is fairly common, especially 

 in California. Symptoms include chlorotic, 

 Interveinal mottling on older leaves. As 

 severity increases, leaf and shoot growth are 

 stunted, resulting in a rosetting of little leaves. 

 Leaves may also show wavy, crinkly margins. 

 Symptoms may be confused with Mn deficiency 

 (see above). 



Any suspected nutrient deficiency should be 

 confirmed by leaf analysis. Since deficiency 

 symptoms can be similar for different 

 nutrients, leaf analysis is the only definitive 

 method of confirmation. Note also that 

 weather factors (for example, drought), 

 overapplication of certain nutrients, as well as 

 pH can each affect availability and uptake of 

 other nutrient elements. 



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Fruit Notes, volume 61 (Number 4), FaU, 1996 



