Effect of Sowing Date and Plant Density on Bolting and productivity in Sugar Beet (Beta vulgaris L.) in Homs Governorate

Waeel Sabsabi, GCSAR, Crops Research Administration, Sugar Beet Research Department.
Aleppo University, Faculty of Agriculture.
2010

Abstract

An experimental field trial was conducted at Homs Agriculture Research Center, during 2007/2008 and 2008/2009 seasons. Four sugar beet varieties were used, tow monogerm varieties i.e., Parade and Etna, and tow multigerm varieties i.e., Nadir and Mammut. The varieties were sown in three dates, begins from 15/9 till 15.10, with interval 15 days between the dates. Three plant densities were applied (133000, 100000 and 80000 plant/hec). Randomized Completely Block Design with split split plots was used with three replicates. The sowing dates were allocated in the main plots, while the varieties were in the sub-plots, but the densities were distributed in the sub sub-plots. The experimental plot area was 35m2, thte length was 7m, while the width was 5m, 50 cm the distance between rows, and (15, 20 and 25) was the distance between plants within the row. The results exhibited:

The sowing date 15/10 (control) was superior in yield traits (root, vegetative and biology yields) and quality traits (brix and purity) and growth traits (100 seedlings weight after thinning, plant fresh weight after 240 days of sowing and the percent of top weigh to root weight after 75 and 240 days after sowing). This date 15/10 also, reduced bolting percent and its all types (early, medium and late), and decreased the length of the bolter, as compared with the early sowing dates, 15/9 and 1/10. But the sowing date 1/10 gave the highest sucrose percent and sugar yield.

Increasing the distance between plants within the row, leads to the increment in the weight of 100 seedlings after thinning, fresh weight of the plant after 75, 120 and 240 days after sowing, and the top to root weight percent. The recommended plant density (100 000 plant / hec) was superior in root ant sugar yields and sucrose percent, as compared with the other densities, but the density 133 000 plant / hec reduce the bolting percent and the length of the bolters.

Results of stability analysis for root and sugar yields and sucrose percent, according to Kang method (1993), indicated that Parade (monogerm) was the most stable variety in different environment conditions (years, sowing dated and plant densities), and appeared tolerances to bolting as compared with the other varieties, with the respect of that we recommend to use this variety in growing in Homs governments, autumn sowing.