INFLUENCE OF AUXIN NAA AND ETHEPHON ON YIELD QUALITY OF APPLE (Malus domestica Borkh.) 'SAMPION' CV

The experiment was carried at the Experimental Station of Garlica Murowana near Krakow in 2006 and 2008. In 2007 the experiment was not conducted due to frost damages. The objects of the experiment were fourteen-year-old apple trees 'Sampion' cv. on MM. 106 rootstock. The aim of the experiment was to evaluate the influence of ethephon (2-chloroethylphosphonic acid) and auxin NAA (naphthalene acetic acid) used in two terms and concentrations on the yield and fruit quality. First treatment was carried out at the end of flowering (80 % the falling petals), second when fruitlets' diameter was 12 mm. Two concentrations: 20 and 60 mg NAA . dm(-3), and 200 and 600 mg ethephon . dm(-3) were used each time. Controlled trees were not sprayed. After fruit harvest total yield with division into five classes: apple blush, flesh firmness, extract content, acidity and pH were estimated. Experiments showed that used preparations increased the number of fruit with more than 12 cm diameter and decreased the amount of small fruit in total yield. All used combinations increased pH of fruit juice in comparison with control. Used compounds did not show clear influence on fruit juice's extract contents. Used compounds did not have influence on fruit storage ability assessed.