Effect of Oilseed Radish (Rhaphanus sativus oleifera) Rotation as a Trap - Plant on Quantitative and Qualitative Characteristics of Sugar Beet (Beta vulgaris) and Reduce the Severity of Rhizomania Infection

In order to evaluate the rotation potential of different cultivars of oilseed radish (Rhaphanus sativus oleifera) named Adagio, Luna, Colouel and Accent on quantitative and qualitative Characteristics of Sugar Beet (Zarghan cultivar) and reduction of rhizomania infection severity, an experiment was conducted using Latin Square Design with five replications in Zarghan station in 2009-2011 in Fars province. The treatments were applied in first year as 1- no trap plant (check), 2- Adagio, 3- Luna, 4- Colouel, 5- Accent, and in second year Zarghan cultivar was planted in the same plots. Quantitative and qualitative traits and rhizomania infection severity measured after harvest. Results of compound analysis showed that the effect of rotation with trap plant cultivars on qualitative traits in Zarghan cultivars was not significant, but based on Friedman test, rhizomania infection severity in cultivated plots with trap plant was significant in 5% probability level so that in plots that Luna and Accent had been cultivated mean of disease degree was 1.85 and 2.5, respectively, that was less than other treatments. The biomass produced in the trap plant Luna and Accent less than other cultivars and their impact on disease reduction was remarkable. The effect of Trap plant compared to control treatment (without traps planted) on root yield and sugar yield was very evident in Zarghan comparison to control that root and sugar yield was reduced. In the control plot (without trap plant) the lowest root yield (36.65 t/ha) and sugar yield (6.28 t/ha) were included in separate groups. Acording to results it can be said that crop more than two years rotation with trap plant and using relatively tolerant sugar beet cultivars, can use to decrease virus growth potential and increase quantity in sugar beet.