Nitrogen fertihzation in apple trees. I. Effect on production and fruit quality

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.