Lenticel are slightly sunken blotches that result in underlying tissue drying out and becoming brown and spongy. Its occurrence is more prominent than that of bitter pit. Lenticel blotch is associated with hot summers, late harvests and excessive use of nitrogen. Pitting is always associated with a lenticel.
Crop Nutrition and Lenticel Blotch
Calcium
Fruit sprays of calcium, along with soil supply, will help reduce lenticel blotch incidence in apples. The greater the number of sprays the better the fruit quality. It is important to continue spraying right through to harvest.
Manganese
In trials, foliar manganese, applied at least twice in the spring, has proven to be most effective at minimizing leaf drop and lenticel blotchiness.