EFFECT OF NOZZLE TYPE AND ORIENTATION ON THE APPLICATION OF PROTECTANTS IN PEAR (Pyrus communis L.)
Sergio Behmer1*, Facundo Gonzalez2, y Graciela Colavita2
High radiation and temperature during the growing season causes a physiological damage in pear (Pyrus communis L.), and other fruit species, called ‘sunburn’, which results in important losses in exportable fruit. One of the management techniques suggested to reduce the incidence of sunburn is the application of reflective films on the fruit by using hydraulic fruit sprayers with vertical nozzle bar. The objective of this study was to evaluate the amount of deposits and the thermoprotective effect of a sun protectant under different application techniques. For this, flat-fan nozzles of different flow rates and application angles were tested against hollow cone nozzles, using a laboratory mobile bench, and spraying on pear fruit of commercial size. The flat-fan nozzles of larger droplet size, regardless of their orientation, obtained greater deposit on the fruit surface than the cone nozzles, reaching the required 0.25 mg cm-2 to obtain a decrease of 1° C in the fruit skin temperature. However, these differences were not sufficient to improve the thermoprotective effect obtained by hollow cone nozzles.
Key words: Fruit sprayers, sunburn, application quality.
1 Departamento de Producción, Mecanización Agrícola, Facultad de Ciencias Agrarias, Universidad Nacional del Comahue, cc 85 (8303) Cinco Saltos, Rio Negro, Argentina.
2 Departamento de Biología, Fisiología Vegetal, Facultad de Ciencias Agrarias, Universidad Nacional del Comahue, cc 85 (8303) Cinco Saltos, Rio Negro, Argentina.
* Autor para correspondencia E-mail: [email protected]