Table 1. Shade at different times during the season affects fruit 

 development of Redspur Delicious/M.7. Derived from Rom, C. R. and B. 

 H. Barritt. 1989. Light interception and utilization in orchards, pp. 42- 

 51. In A. B. Peterson (ed.) Intensive Orcharding. Goodfruit Grower, 

 Yakima, WA. 



Shading 

 treatment 

 (days after 

 petal fall) 



Fruit weight 



Fruit Fruit 



set Average Total color 



Starch Soluble 

 rating solids 



Percent of control* 



0-47 



47-93 



93-140 



54 



101 



95 



116 

 81 

 94 



48 

 101 

 100 



100 

 96 

 92 



115 

 100 

 100 



87 

 82 

 83 



*Control is not shaded. Other treatments were give 63% shade during 

 the time specified (140 days after petal fall = harvest). 



conducted to prevent this type of shading in 

 much of the inner portion of the canopy. 



2. Row and canopy arrangement are im- 

 portant. Rows should be oriented north- 

 south to optimize light interception 

 throughout the day. In general, narrow 

 canopies and short trees will intercept more 

 light than wide canopies and tall trees. 



3. Limb arrangement and angle can influ- 

 ence penetration of light into the canopy. 

 Limbs should be angled approximately 45° 

 to 60° from the trunk. Limbs should be 

 spaced from 1.5 to 3 feet apart, arranged 

 spirally around the tree to create light "win- 

 dows." 



4. The tree should be maintained in a coni- 

 cal shape. Any overgrowth of the top will 

 reduce light penetration into the canopy. 



5. Summer pruning can enhance light pen- 

 etration during the mid- and late-season 

 periods. Summer pruning should be per- 

 formed between July 15 and August 30 for 

 Mcintosh. 



6. Maintenance of high quality leaves is 

 the only way to ensure optimal light inter- 

 ception. Damage from nutritional stress, 

 drought stress, insect feeding, or disease 

 infection can reduce a leafs ability to absorb 

 sunlight. 



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Fruit Notes, Summer, 1991 



21 



