First Paragraph: Ethephon enhanced color development in 'Tokay' and 'Emperor' table grapes. The most effective concentrations were 200 ppm for 'Tokay' and 100 to 200 ppm for 'Emperor.' Berry firmness was reduced. The most effective time of application in one of two 'Tokay' vineyards was shortly after color development began. Application when 10 to 80% of the berries showed color was equally effective with 'Emperor.'