This study was carried out during two successive seasons of 2013 and 2014 in order to study the effect of organic acid as salicylic acid (SA) at 0, 100 and 200 ppm on yield and fruit quality of nine  years old "Anna" apple trees(Malus domastica) grown in clay soil. The present goals of the present research were to study the effect of salicylic acid (100, 200 ppm) on fruit set ,yield and fruit quality, mainly, the sugar, pectin, acidity and protein contents, compared with untreated apple trees. Flowering fruit set, yield and fruit quality at each 100 &200 improved by using salicylic acid, compared by untreated trees. It could also noticed that salicylic acid at 200ppm enhanced physical (fruit weight, fruit length. Fruit dimension and firmness) and chemical properties (TSS, total acidity, total sugars, pectin and protein). Milk was fortified with 8 and12 % (w /v ) of apple treated by salicylic acid. The study was to evaluate the chemical, and microbiological qualities of yoghurt variants during storage. The obtained results revealed that total solids (TS), fat, protein and ash contents varied due to variations of manufacturers and type of milk used. The resultant Yoghurt with apple fruit treated by salicylic acid contained an increase of total solids, protein and decreased of acidity and microbiological analysis. Yoghurt also had a good quality for the products.