6. 



Fruit Ca levels were analyzed in 1978 and 1979. Fruit Ca 

 was higher on trees fertilized with Ca(N03)2 on April 12, 1978(93 

 ppm),than those from trees that received NH4NO3 on May 22, 1978 

 (84 ppm) , otherwise N source and time of application has not 

 influenced fruit Ca levels. 



Influence of Time of N Application on Elements in Leaves 



We suggest that nitrogenous fertilizers be applied as early 

 as possible in the spring. Among the several things early appli- 

 cation accomplishes is early absorption of N rather than late ab- 

 sorption which could cause higher levels of this element at harvest, 

 reduced red color of fruit, and delayed maturation. However, 

 our data showed that with the exception of leaf N in 1974, the 

 level of this element and Ca, K and Mg were similar in mid-July 

 for the 2 timings of fertilization. The fertilizer application 

 on April 12, 1974 was followed by 0.7 inches of rain on April 14, 

 thus it probably was more rapidly dissolved and carried to feeder 

 root depth than the May 15 application which was followed by 0.3 

 inches and 1.1 inches of rain on May 24 and June 1, respectively. 



Influence of N Source on the Incidence of Bitter Pit 



The trees commenced bearing in 1974, but it was 1976 before 

 cropping was considered sufficiently uniform among trees to exa- 

 mine the fruits for bitter pit. A frost eliminated the crop in 

 1977. However, in 1976, 1978 and 1979 N source did not influence 

 the amount of bitter pit (Table 4) , which gives further evidence 

 of the lack of differential Ca response to N source. 



Table 4. The influence of N source on the incidence of bitter pit 



Bitter pit (I): 



Nitrogen At harvest At harvest After storage 



source 1976 1978 1979 1978 1979 



KNO3 lla^ 17a 9a 22a 13a 



NH4NO3 8a 14a 6a 18a 9a 



Ca(N03)2 7a 16a 6a 21a 11a 



z 

 Numbers in a column followed by a different letter are significantly 



different at odds of 19 to 1. 



