RESEARCH FINDINGS FROM OTHER AREAS 



Potassium Aids in Developing Better Apple Color 



The September-October issue of Ohio Farm and Home Research contained an 

 article by Dr. J. M. Beattie, Ohio Agricultural Experiment Station, Wooster, 

 Ohio, titled, "Potassium Aids in Developing Better Apple Color". The informa- 

 tion obtained in this article should be of interest to the apple growers of 

 Massachusetts because the results presented by J. M. Beattie are similar to 

 the findings of Dr. W. D. Weeks, University of Massachusetts in his work on 

 Mcintosh Apple Tree Nutrition. 



"Better colored apples - the kind modern consumers want - are being grown 

 at the Ohio Experiment Station. Experiments are showing that naturally red apples 

 develop better color if ample amounts of potassium are supplied to the trees. By 

 raising the level of potassium in the leaves of Rome Beauty apple trees well above 

 one per cent, not only was fruit color but also total yields and shoot growth 

 improved. 



"The eight-year-old trees used in the experiment grew on a site where another 

 orchard had been removed. These original trees were known to be abnormally low 

 in potassium. Foliage analysis showed this to be true. This situation afforded 

 an excellent opportunity to study methods and rates of potassivmi fertilizer appli- 

 cation under conditions of known deficiency of this element. 



Three Treatments 



"Trees received one of these three fertilizer treatments: 



1. Nitrogen plus muriate of potash at the rate of one-fourth pound per 

 year of tree age. 



2. Nitrogen plus four sprays of potassium sulfate applied to the foliage. 



3. Nitrogen only. 



"The foliar sprays were made by dissolving 16 pounds of potassium sulfate in 

 100 gallons of water. They were applied at 10-day intervals starting the last 

 week of May. 



"Leaf samples taken each year since 1952 showed that the soil potassium 

 treatment was the most effective in raising the leaf content of potassium. Foliage 

 sprays of potassium sulfate also helped to raise leaf potassium levels over check 

 trees, but not as high as the soil applications. Average potassium content of the 

 leaves for six years was 1.78 per cent for the trees receiving soil applications of 

 potassium; 1.36 per cent for trees receiving foliar sprays; and 1.04 for check trees. 

 A leaf concentration of one per cent potassium has been generally considered as the 

 level at or below which response from applications of potassium fertilizers can be 

 expected. These results suggest the fruit color improvement can be obtained by 

 raising leaf potassium well above this one per cent level. 



Yields in Order 



"The yields of trees ran in a corresponding order. In fact, trees fertilized 

 with nitrogen and muriate of potash produced almost twice as many apples as the 



