An experiment to study “Response of apple cultivars to different boron levels under the agro-climatic condition of Kalam” was conducted at Kalam Summer Station (KSS) Swat during the year 2016. The experiment was laid out in Randomized Complete Block Design (RCBD) with two factors. Apple cultivars (Golden Smoothee, Jonica, Royal Gala) were assigned as Factor A and Boron level (0, 0.5, 1.0, 1.5%) were considered as Factor B. The purpose of study was to improve the quality and yield of three different apple cultivars for agro-climatic condition of district Kalam. The three cultivars were treated with four different concentrations of boron at pink bud stage. Statistical analysis revealed that boron application at (1.5%) concentration significantly improved the fruit set (19.14%), TSS (11.72 oBrix), TSS Acid Ratio (22.32%), reducing sugars (11.03%) and non-reducing sugars (2.77%). While on the other hand fruit drop (7.44%) and titratable acidity (0.5%) were significantly reduced with 1.5% boron application. Royal Gala was found with minimum percent fruit drop, titratable acidity, Apple cultivar Jonica has maximum reducing sugars and non-reducing sugars. Apple cultivars Golden Smoothee has maximum TSS and TSS acid ratio. It was concluded from the  experiment  that  boron  at  rate  of  1.5%  significantly  increased  fruit  set,  total soluble solids, sugar acid ratio and reducing sugars, while decrease  in  fruit  drop,  titratable  acidity and  non-reducing sugars.

Keywords: Boron, Apple, Cultivars, Agro climatic condition of Kalam