ABSTRACT
Nitrogen sources and levels applied to unirrigated Pedro Jiménez grape - vines. III. Effects over concentration and seasonal trends of N, P, K, Ca and Mg

Arturo Lavín A.1 y Jorge Valenzuela B.2
 

At the Cauquenes Exp. Sta. (INIA), over unirrigated Pedro Jiménez grape - vines, submitted to sources and levels of N, shoot and root samplings were made, in four phenological stages of the annual growth (1974/75), as to characterize levels and seasonal trends of N, P, K, Ca and Mg in these tissues. Nitrogen and P levels were not affected by either sources or doses of N. Seasonal trend indicated a decline unti)l veraison and an increase towards harvest. Amonium nitrate induced lower levels of K in shoots and roots. Potassium in the shoots declined through the season, while in the roots did not vary; however, levels in both tissues were higher than those previously reported for the area. No effects of sources or doses of N were found on Ca or Mg levels, neither in shoots or roots. The seasonal treod was to decline untill full bloom, and then to increase towards harvest.

Keywords:
1 Subestación Experimental Cauquenes (INIA), Casilla 165, Cauquenes, Maule, Chile.
2 Estación Experimental La Platina (INIA), Casilla 439, Correo 3, Santiago, Chile.