cases where fruit calcium is marginal, the symptoms 

 may be apparent only after long periods in storage. 

 If soU calcium levels are low, the soU pH likely is 

 acidic. The cheap, long-term solution to low soU 

 calcium is liming to correct the acidity and to add 

 calcium to the orchard soil; however, regardless of 

 the cause of the fruit calcium problem, foliar calcium 

 sprays are advisable. Foliar sprays of a calcium- 

 containing fertilizer put calcium directly on the fruit 

 where it can be taken up, and will reduce greatly the 

 occurrence of costly blemishes and loss of fruit qual- 

 ity. 



Brand Name Products vs. Salts 



A large number of products are available for 

 applying foliar nutrients. Table 2 lists some of the 

 foliar calcium products available to the apple 

 grower. It is not possible to discuss the qualities of 

 each individual product in a short forum such as this 

 article, but several comparisons can be made be- 

 tween brand name products versus calcium chloride 

 salts. 



Brand name products, when applied to provide 

 the same amount of calcium as provided by calcium 



chloride are no better or worse in their effectiveness 

 in preventing frviit disorders. Thus brand name 

 products are more expensive sources of calcium; 

 however, brand name products may be safer to fhiits 

 and foliage, easier to measure, and more conve- 

 niently packaged. 



Calcium chloride contains oxide impurities that 

 can increase the pH of the spray solution in the tank, 

 thereby reducing the effectiveness of certain pesti- 

 cides. If calcium chloride is to be tank-mixed with 

 pesticides, a small amount of vinegar or buffering 

 agent should be added to prevent this problem. 



Finally, brand name products may contain other 

 nutrients, which may be beneficial, but only if they 

 are nutrients that currently are needed by the tree. 

 It is up to the individual grower to weigh the pros and 

 cons of each product given his or her situation. 

 Similar considerations result when growers make 

 comparisons between brand name products and salt 

 formulations for other mineral nutrients. 



Summary and Tips for Success 



Foliar fertilizers are an important tool for apply- 

 ing micronutrients, correcting acute nutrient defi- 



Fruit Notes, Spring, 1993 



21 



