ABSTRACT


Gonzalo Sepúlveda R.1 y Jorge Valenzuela B.2
 

A field experiment was designed to study the effects of GA on yield and herry size of the grape cultivar "Moscatel Rosada". The trial wasconducted at the Vicuña Experiment Substation located at Vicuña, Northern Province of Coquimbo.
Four doses of GA, 0-20-35 and 50 ppm, were sprayed to the clusters a few days after berry set. On haIf of each plot a cluster thinning work was overimposed.
Treatments were arranged as a factorial experiment with 2 replications and 6 plants per replicate.
Yield per plant was increased with GA spray applieations. This was particularly noticeable with GA 35 ppm and without cluster thinning which produced a 52.5 - 71.3% yield increase over the check treatments. With the above dosis, the treatment without cluster thinning showed a larger yield than with thinning.
AIso, GA 35 ppm presented a larger clus ter weight at harvest than the other treatments and a 69% increased over the check.
GA at 20 and 35 ppm produced a higher percentage of medium-sized berries and a lower percentage of small herries than 0 and 50 ppm., Natural small herry condition of Moscatel Rosada cv. was therefore commercially reduced.
Soluble solids percentage was reduced by GA applications in comparison to untreated plants. No differences among doses were found New experiments are needed on this subject hecause of its importance on the development of, the Pisco industry.

Keywords:
1Ing. Agr., Programa Frutales y Viñas. Subestación Experimental Vicuña. Instituto de Investigaciones Agropecuarias (INIA), Casilla 73, Vicuña, Chile.
2Ing. Agr., Ph. D., Programa Frutales y Viñas. Estación Experimental La Platina, INIA, Casilla 10, La Granja, Santiago, Chile.