root yield and quality of sugar beet in relation to foliar application of micronutrients

In order to investigate the effects of micronutrients on quantitative and qualitative yield traits of sugar beet, an experiment was performed during growing season of 2013-2014in the Esfarayen region, located in the North-East of Iran. Treatments consisted of three levels of mixture of micronutrients (spraying with 0, 1, 2 L ha-1) and the number of applications (once 45 days after planting; twice, 45 and 75 days after planting; three times, respectively 45, 75 and 105 days after planting). The results revealed the highest root yield was obtained with the spraying 2 L ha-1 of the micronutrients. Foliar spraying of micronutrients significantly increased content of sucrose and refined sugar compared to the control. The highest percentage of sucrose and refined sugar (75% and 74.45%) was recorded by spraying of mixture of micronutrients twice at the rate of 2 L ha-1. Micronutrient concentrations and the number of applications as well as their interaction effect had significant effects on the content of molasses forming substances. The highest amount of these compounds occurred in the control treatment and reduced by applying the micronutrient. Foliar spray of micronutrients added to the refined sugar yield so that in all times of application the highest refined sugar yield was obtained by 2 L ha-1 spraying. Generally, it could be recommended that fertilizing sugar beet plants by spraying 2 L ha-1 of the micronutrients at 45, 75 and 105 days after planting produce the highest productivity and quality of sugar beet under this study.