ABSTRACT
IRRIGATION FRECUENCY IN SUNFLOWER (Helianthus annuus L.) BASED ON CRITICAL GROWTH STAGES

Jorge Tondreau A.1, Juan Tosso T.1 y Juan Moroni V.2
 

An experiment was carried out during 1973 at La Platina Experiment Station, Santiago, Chile. The main purpose of this research was to determine the critical growth stages of a sunflower crap in relation to soil moisture status.
It was found that the first irrigation can be delayed to the moment when crop presents 12 - 14 leaves, without showing a significant decrease in yield.
Irrigations during fun flowering, late fIowering and early maturity stages, are important to obtain high grain yields; on the other hand, irrigations during late flowering and early maturity are important to obtain a high oil percentage in the seeds.

Keywords:
1Ings. Agrs. M. S., Programa Riego, Estación Experimental La Platina, Instituto de Investigaciones Agropecuarias (INIA), Casilla 5427, Santiago, Chile.
2Ing. Agr., Universidad Católica de Chile.