ABSTRACT
Paclobutrazol effeets on walnuts growth and production

Gamalier Lemus S.1
 

Paclobutrazol applied on the soil in the winter of 1986, at 0.5, 1.0, 1.5, and 2.0 g active ingredient/tree, on 6 years-old walnut trees cv. 'Serr'; planted at 6x6 m, reduced shoot length in the 1986/87, 1987/88, and 1988/89 seasons. Also, the last two crops were better due to the chemical. In the 1987/88 harvest, plants with the highest dosage showed the highest yields.ln 1988/89, the control trees yielded 3.1 ton/ha, while the plants treated with 1.5 g produced 5.2 ton/ha. However, if yield is expressed in relation to the area covered by the canopy, the differences among treated and control trees were more conspicuous, showing and increased productivity with higher rates. Weight of the pruned materials, were differents during the first two seasons, but similar for the 1988/89 season. It was concluded that paclobutrazol depresses significantly walnut vegetative growth, increasing productivity up the thirth year afier treatment. Besides, the use of this chemical makes possible to maintain a high density grove, without shading problems among the trees.

Keywords:
1 Estación Experimental La Platina (INIA), Casilla 439, Correo 3, Santiago, Chile.