ABSTRACT


Gonzalo F. Gil1 y Enrique Bruzzone2
 
Richard Delicious apple trees were sprayed one maonth prior to harvest with 2000 ppm Alar (N-dimetilaminosuccinamic acid) and/or 15 ppm NAA (Naphtalene acetic acid). The treatments were: I) Control, 2) Alar, 3) NAA, 4) NAA followed by Alar three days later, 5) Alar followed by NAA three days later, and 6) Alar and NAA together. Prior to harvest, fruits on Alar-treated trees softened at a slower rate than those from the controls but their soluble solids content and final size were the same. Alar treated fruits were still firmer after four and six months storage at 0ºC than those of the control. Fruits harvested from trees sprayed with NAA were not appreciably different from the controls. Fruits treated with a combination of alar and NAA exhibited intermediate effects between those treated with Alar or NAA alone. Alar alone also delayed blooming the following spring.
The effect of Alar as a postharvest treatment was also studied. Mature apples having comparable firmess were selected in a packing house, dipped for 5 and 30 minutes in l 000 or 2000 ppm Alar and then stored at 0°C for six months. After four months and at the end of the storage period, Alar treated fruits were firmer and contained less soluble solids than comparable check fruits and their acid content was the same; therefore, ripening was delayed. The higher rate and the longer dipping period were more effective. The possible role of Alar and its potential use in fruticulture are discussed.
Keywords:
1Ing. Agr., M. S., Profesor del Departamento de Frutales y Viñas. Facultad de Agronomía, Universidad Católica de Chile. Casilla 114-D, Santiago, Chile.
2Ing. Agr., Cooperativa Frutícola de Curicó, Casilla 22 D, Curico, Chile.