Rafael Ruiz S.1
Between 1981 and 1985,an experiment was carried out with 12 years oid Granny Smith and Richared Delicious gpple trees, growing on a soil low in N. A positive response in yield wes obtained with 125 and 250 kg of N/ha, in both varieties. Granny showed ciearer deficiency symptoms (chiorosis, less vigor, less foliage) and lower potential yield (61%) than Richared (70%), in the test (no N) plots. Also, truit quality (size and coiour) responded positively to N levels, especially in Richared, and Granny showed less colour defects, with N applications. Nitrogen had a very small effect on the occurence of Bitter Pit.
1 Estación Experimental La Platina (INIA), Casilla 439, Correo 3, Santiago, Chile.