During the 2019 and 2020 seasons, Sultani fig trees were sprayed two times (at 1st week of April and 1st week of May) with two levels of potassium silicates (1 and 2 %), two levels of Calcium nitrate (1 and 2 %) and kaolin at 5 %. The study focused on the effect of foliar application of kaolin, silicon and Calcium on vegetative growth, tree nutritional status, number of fruits per tree yield and fruit quality.
Results showed that applications of 1% or 2% potassium silicate, 1% or 2% calcium nitrate and 5% kaolin were very effective in enhancing the main shoot number, main shoot length, main shoot thickness, number of leaves/shoot, leaf area and percentages of N, P, K, Ca and yield as well as fruit quality relative to the check treatment. The promotion was associated with using 5% kaolin, 1% calcium nitrate, 1% potassium silicate, 2% calcium nitrate and 2% potassium silicate in ascending order. Using potassium silicates and Calcium nitrate was preferable to using kaolin in this respect.
Treating Sultani fig trees two times (1st week of April), and (1st week of May) with 2% potassium silicate was suggested to be beneficial for promoting yield quantitively and qualitatively.