5. What kind of fertilizer do you use in bearing apple orchards 

 (a complete fertilizer, ammonium nitrate or \\rhat)? 



Fifty-six percent of the growers applied a complete fertilizer 

 and 301 of the growers used calcium nitrate (CaCNO,)-^. 



Perhaps some growers like the convenience of obtaining and 

 applying a complete fertilizer rather than purchasing a "bulk" 

 mix containing nitrogen, potassium and minor elements such as 

 boron. However, cost could be reduced by using fertilizer con- 

 taining no phosphorous (P) since there is no evidence that our 

 apple trees need this element beyond what is present in the 

 soil . 



P deficiency can reduce tree growth and yield and in several 

 parts of the world it has been shown to be associated with 

 fruit breakdown in storage. Nevertheless, there has been very 

 little evidence of P deficiency in fruit. In fact, Drake and 

 Bramlage of our Department of Plant and Soil Sciences recently 

 found that high levels of P in apples, especially in combination 

 with low levels of calcium, greatly increased breakdown of apples 

 during storage. 



Soil applications of Ca(NO,)-, are being used to enhance the Ca 

 levels in fruit. Nevertheless, we have no evidence that 

 Ca(NO^)-;> in comparison with ammonium nitrate (NH^NO^) or pot- 

 assium nitrate will increase fruit Ca levels. Ca(NO^)^ unlike 

 NH.NO, will not acidify the soil but NH.NO^ is a more economical 

 source of nitrogen (N) . We believe that tne cost and the amount 

 of N applied to apple trees is more important than the source 

 except under unusual situations. 



6. Do you apply calcium chloride sprays to improve the calcium level 

 in your trees and fruit (yes or no)? 



Changes in cultural practices frequently are slow, thus it was 

 a pleasant surprise to note that 11% of the growers are using 

 calcium chloride sprays. 



7. Do you have early maturing apples (yes or no)? If the answer is 

 yes, have you applied ethephon (Ethrel*) within the last 2 years 

 to advance the maturity of your early maturing apples (yes or no)? 



Of the growers having early maturing varieties, 471 used ethephon 

 to advance their maturity. 



8. Have you used within the last 2 years ethephon (Ethrel*) to advance 

 the maturity of Mcintosh apples (yes or no)? What % of your 

 Mcintosh crop was treated? 



The author was surprised to find that more growers (641) were 

 applying ethephon to Mcintosh than to early maturing varieties. 



