440 MANAGING ORCHARD SOILS AND FERTILIZING TREES 



tion, growth of fruit spurs and terminals would probably be 

 very short, and few fruit buds would be formed. Since very 

 little growth is taking place, carbohydrates would probably 

 accumulate in the tissues. Such trees would be in Class IV, 

 and it is readily apparent that heavier applications of nitro- 

 gen, cultivation of the soil, and a heavier pruning would be 

 beneficial. Such a treatment would cause such trees to ap- 

 proach Class III, resulting in better growth and fruiting con- 

 ditions. 



In some sections, especially in parts of New York and New 

 England, difficulty has been encountered with the development 

 of what has been termed '^internal cork'^ in the flesh of the 

 apple — large brown areas not noticeable on the surface. Many 

 of the affected fruits drop prematurely. The condition is 

 accentuated by drought conditions during the growing season. 



The difficulty seems to lie in a deficiency of boron in the 

 soil. When the supply falls below a certain level, the symp- 

 toms described appear. 



Treatment of the soil with borax has given almost complete 

 control. Apply it at about the season of the delayed-dormant 

 spray application in a circle about 2 feet wide under the outer 

 tips of the branches. Measure amounts carefully and dis- 

 tribute them evenly. A treatment once in three years seems 

 adequate. Do not treat normal trees showing no evidence of 

 the disease. Amounts for trees of varying sizes are given in 

 Table 47. 



COMMUNITY STUDIES 



1. Make a survej^ of the orchards in your community and determine 

 the different methods of soil management being used. 



2. Which method of soil management results in best tree growth and 

 yield? 



3. Determine the time of the year when the cover crops are seeded. 

 Which cover crop seems most satisfactory under your conditions? Why? 



4. How much organic matter (green weight per acre) is produced by 

 the different cover crops? 



5. How much does the seed of the different cover crops cost per acre? 



