Effect of foliar application of micronutrient fertilizers on the technological quality of sugar beet

Today, one of the practical ways to improve the quantity and quality of sugar beet is to use micronutrients in appropriate proportions and in the form of foliar application. For this purpose, 14 micronutrient fertilizer treatments in four replications were applied on Latatia cultivar in a randomized complete block design in Roshtkhar and Zaveh cities of Khorasan Razavi in 2017. Results showed that fertilizer treatments had a significant (P<0.01) effect on sugar yield, white sugar yield, extraction coefficient of sugar, and sugar content in Roshtkhar field. However, the effect of fertilizer treatment on potassium (P<0.01), molasses sugar percentage (P<0.01), and extraction coefficient of sugar (P<0.05) were also significant in Zaveh field. The highest white sugar yield obtained in Roshtkhar and Zaveh fields was 8.5 (in fertilizer No. 1) and 7.61 t ha-1 (in fertilizer No. 3), respectively. The highest root yield (51.47 tha-1) and the lowest sugar content (18.29%) were obtained in fertilizer treatment No. 1 in Roshtkhar field. In Roshtkhar and Zaveh fields, fertilizer composition number 7 (19.16 %) and number 8 (20.01 %) were resulted in the highest sugar content, respectively. Studies showed that the most effective elements in increasing sugar yield and white sugar yield are molybdenum, boron and manganese and the most effective elements in increasing sugar content, white sugar content, extraction coefficient of sugar, and molasses sugar content are iron, zinc, manganese and magnesium. The most effective elements for extraction coefficient of sugar are magnesium, copper and molybdenum. The general conclusion of this study is that the combination of micro- and macronutrient elements containing less nitrogen had positive and significant effect on production quality and sugar efficiency and the proper combination of iron, manganese, zinc, magnesium and molybdenum with macro elements containing less boron and chlorine percentage have the greatest effect on increasing extraction coefficient of sugar, white sugar yield, and root yield.