1962 FERTILIZER RECOMMENDATIONS 



Results of leaf samples obtained from growers' orchards in 1961 indicate 

 that over one-half of the Mcintosh trees were too high in nitrogen for the best 

 development of fruit color. A similar situation was found in 1960. It was 

 suggested that growers reduce nitrogen applications by one third or one half in 

 1961. In the majority of the orchards which were too high in nitrogen, growers 

 had applied nitrogen at rates in excess of the suggested rates for normal 

 applications. In some orchards, both normal and reduced rates produced nitrogen 

 levels which were too high. 



In our fertilizer experiments, we have found that it may take two years for 

 reduced rates of nitrogen to be effective. We have also found that omitting 

 nitrogen applications from trees which were high in nitrogen did not significantly 

 reduce yields below trees receiving normal rates of nitrogen. It appears that it 

 may be necessary in some situations to omit nitrogen in order to bring nitrogen 

 down to the desired level. 



We are suggesting that In 1962 growers should: 



(1) Apply no more than normal rates of nitrogen. 



(2) Omit or reduce nitrogen applications by one half in those 

 blocks which have produced fruit with poor color. 



Suggested rate of fertilizer for normal applications are given in the 

 following table. 



Normal Rates of Fertilizer for Bearing Apple Orchards 



Approximate Amounts per Tree 



Potential bushel 

 yield of tree 



Nitrogen 

 required 



Potash 

 required 



Ammonium 

 Nitrate 



Muriate 



of Potash or 0-15-30 



8-16-16 



Less than 15 

 15 - 25 

 More than 25 



Pounds 



0.66 



0.66-1.00 



1.33-2.00 



Pounds 



1.3 



1.3-2.0 



2.7-4.3 



Pounds 



2.0 



2.0-3.0 



4.0-6.0 



Pounds 



2.1 



2.1-3.3 



4.5-7.9 



Pounds 



4.3 



4.3- 6.6 

 9.0-14.3 



Pounds 



8 



8-12 

 16-25 



The suggested amounts of materials to apply in the table are for hand appli- 

 cations under the spread of the branches. When the materials are broadcast over 

 the entire orchard floor it may be necessary to Increase the rate of application 

 in order to obtain the same tree response as with the band applications. Ferti- 

 lizer materials other than those given in the tables may be used so long as they 

 are applied at rates which provide equivalent amounts of nitrogen and potassium. 



The tree's magnesivim and calcium requirements can best be met by main- 

 taining an adequate dolomitic liming program. The pH of orchard soils should be 

 maintained between 6 and 6.5. If a soil test shov;s that the pH of soil is 5.5 or 

 below, magnesium sulfate sprays should be applied to prevent possible occurrence 

 of magnesium deficiency. It takes from three to five years before dolomitic 

 limestone is effective in correcting magnesium deficiency. When magnesium sul- 

 fate sprays are used apply two to three sprays of epsom salts at the rate of 20 



