Effect of Micronutrients Application on the Quantitative and Qualitative of Sugar Beet Seed and Root Yield.

Considering the importance of growth and feeding condition of maternal plants on seed vigour, germination and growth habit, the experiment was conducted in three years (2001-2004) in Ardabil (seed production) and Karadj (root production). Eight treatments including control (no-micronutrient), applying B + Mn + Fe combination, applying them separately and applying them two-by-two were exerted on sugar beet seed plants in Ardabil based on a Completely Randomized Block Design with three replications in two years (2001-2002) and the effect of applying these elements on plant morphological characteristics and qualitative and quantitative seed yield were studied. In Karadj, seeds produced in Ardabil were divided into six categories [including (1) Fe and Zn (low), (2) Fe (low) and Zn (moderate), (3) Fe and Zn (moderate), (4) Fe (moderate) and Zn (high), (5) Fe and Zn (high) and (6) control (sum of seeds of control plots in Ardabil)] and were compared as split plots based on Completely Randomized Block Design with four replications in two years (2002-2003). Main plots included two levels of applying and not-applying microelements (B + Zn + Mn + Fe combination). The results of cluster analysis of sugarbeet seed chemical composition showed that Fe and Zn level was varied in the ranges of 1.46-4.60 and 0.28-0.40 ppm, respectively. According to the results, spray of Fe + B during vegetative and regenerative growth stages of seed-bearing plants increased saleable and germinable standard viable seed yield by 69.9 and 72.3% compared to control, respectively. On the other hand, the application of Fe and Fe + B combinaton decreased the portion of undersize seeds (3.5 mm)to the half and one-third of control and increased the share of standard seed (3.5-4.5 mm) to about one-fourth and that of oversize seed (4.5 mm) to one-third. Applying micronutrients led to the decrease in unkernel seed percentage (8.120-9.224%) and increase in thousand-germ seed weight from 8.712 g in control to about 10.513 g by applying Fe. Spray of Fe + B treatment was an acceptable treatment for enhancing seed yield and controlling vegetative growth of sugarbeet seed-bearing plants in addition of increasing grain dry weight to 35.4% compared to control (100.795 g/plant) and regardless of decreasing harvest index by 0.5% (38.56% compared to 39.139%). In Karaj, although micronutrients application did not have a significant effect on root yield and sugar content, their application led to the increase in raw sugar (12.091 t/ha) by 106 kg/ha compared to no-micronutrient application (p0.05) due to non-significant increase in sugar content resulting from applying these micronutrients and regardless of decrease in root yield; while the variation of Fe and Zn concentration in sugarbeet seed did not significantly affect qualitative and quantitative characteristics of sugarbeet production.