ETHREL IN THE COLORATION AND MATURATION OF THE FLAME SEEDLESS CULTIVAR ON THE COAST OF HERMOSILLO, SON.

Abstract

At the Costa de Hermosillo, Sonora, Mexico, about 10,500 ha are planted with grapevine (Vitis vinifera L.) , from wich about 20% is planted with table grapes. Flame Seedless, a recently introduced red cultivar has been well accepted in the market. However, the low intensity of coloration in the berry reduces the marketable yields. Results obtained in other countries indicate that application of Ethrel (2-chloroethylphosphonic acid) have improved the intensity of color. Therefore, an experiment was carried out to test the effect of Ethrel on the cultivar Flame Seedless, under the environmental conditions of this area.

In 1983, Flame Seedless plants were sprayed with Ethrel 48 at rates of 0, 200,400, 600 and 800 ppm, at the beginning of color development, covering the crop with 1200 liter/ha of solution. A linear effect was observed between the rate and the berry coloration since as the concentration increased a better coloration was obtained. Besides, the maturity time tended to be accelerated by Ethrel. Soluble solids (⁰ Brix), however, were Iower in the treated clusters. These results shouÌd be used cautiosly, since it is reported that at higher Ethrel concentrations, the firmness of berries might be reduced; this variable was not measured in this study.