Influence of Different Tillage Methods on Root Yield, Yield Components and Some Quality Characteristics of Sugar Beet (Beta vulgaris)

A two years study was carried out at the Research Site of Hamedan Province, Iran to investigate the influence of different tillage methods on yield and quality of sugar beet (Beta vulgaris) during, 2008 and 2009 growing seasons. Tillage treatments were moldboard plow + two passes of disk harrow (MDD) as conventional tillage method; moldboard plow + one pass of rotavator (MR), chisel plow + one pass of rotavator (CR) and two passes of disk harrow (DD) as reduced tillage methods; one pass of rotavator (R) and one pass of tine cultivator (C) as minimum tillage methods and no-tillage (NT). Root yield, yield components i.e., root number per hectare (RNPH), sugar yield, root dry matter (RODM), root length, rim diameter and some quality characteristics of sugar beet such as sugar content, K, Na, alpha-amino nitrogen (ALAN) and molasses were measured for different tillage treatments. Different treatments significantly (P = 0.05) affected RNPH and K, but there was no significant difference in other studied traits. Although effect of different tillage treatments on root yield, sugar yield, RODM, root length, rim diameter, sugar content, Na, ALAN and molasses was not significant, results of the study indicated that tillage operations were useful in improving the yield and quality of sugar beet. The highest values of root yield (82.7 t ha(-1)), RNPH (135412 roots ha(-1)), sugar yield (11.4 t ha(-1)), RODM (23.9%) and sugar content (17.0%) were recorded in the MR treatment, while the highest values of root length (20.5 cm), rim diameter (1.5 cm), K (6.4 mmol/100 g), Na (2.6 mmol/100 g), ALAN (2.5 mg/100 g) and molasses (3.0%) were noted in the NT treatment. In contrast, the lowest values of root yield (71.3 t ha(-1)), RNPH (115000 roots ha(-1)), sugar yield (9.15 t ha(-1)), RODM (20.3%) and sugar content (15.2%) were recorded in the NT treatment, while the lowest values of root length (18.0 cm), rim diameter (1.1 cm), K (4.5 mmol/100 g), Na (1.5 mmol/100 g), ALAN (1.6 mg/100 g) and molasses (2.2%) were noted in the MR treatment. Results also showed that tillage method affected the yield and quality of sugar beet in the order of MR > CR > R > MDD > DD > C > NT. Therefore, the reduced tillage treatments MR and CR and the minimum tillage treatment R were considered as more beneficial and suitable tillage methods in improving the yield and quality of sugar beet. (C) 2011Friends Science Publishers