Flowering, initial fruit set, fruit retention, fruit characteristics and yield of olive trees cv. Manzanillo under the conditions of El-Maghara region, North Sinai Peninsula as affected by soil mulching around the trunk (using Polyvinyl acetate 1:1 v/v) and foliar spay of potassium chloride (0, 1 and 2 %) were studied in the two seasons of 2003 and 2004. The results obtained revealed that, soil mulching treatment significantly increased the mean flower number per inflorescence, inflorescence number per meter length, initial fruit set, fruit retention but did not affect the perfect flower percentage. Meanwhile, fruit weight, volume and flesh weight increased significantly by soil mulching, especially during the second season, while fruit shape index, flesh/fruit % and flesh thickness did not differ significantly compared to control. Foliar spray of 2 % KCl increased the mean flower number and inflorescence number per meter. However, foliar spray of 2 % KCl followed by 1 % KCl increased significantly initial fruit set, fruit retention compared with control trees. 2 % KCl spray enhanced significantly fruit and flesh weight compared with both of 1% KCl and control during the second season. Moreover, 1 % and 2 % KCl increased significantly flesh thickness compared with control. Concerning the interaction between soil mulching and foliar spray treatments, mean flower no., Initial fruit set and fruit retention were increased significantly by soil mulching and 2 % KCl. However, fruit volume and weight, flesh weight and flesh thickness increased significantly by soil mulching and 2 % KCl during the second season.
                Soil mulching and KCl foliar spray enhanced tree yield significantly. However, Generally the yield in the second season was greatly increased than that obtained during the first season.