The determination of most suitable planting and harvesting date of sugar beet in Dehloran.

In order to determine of the best sowing (SD) and harvesting (HD) date of sugar beet in Dehloran region, this experiment was conducted during 2002-3,2003-4, and 2004-2005 growth seasons. Experimental design was split plot with four replication. SD and HD were main and subplot respectively. Three SD Sept. 25, Oct. 13 and Nov. 2 and two HD, may 22 and June 7 were first growth season. treatments of Five SD including sept. 8, sept. 22, oct. 12, Nov. 1 and Nov. 17 and five HD including Apr. 8, May 3, May 23, June 14, and July 4 were treatments in second growing season. Two SD sept. 23, and oct. 13 and four HD Apr. 12, Apr. 2, May 14, and June 1 studied in third growing season. The SD and Hd have significant effect on root yield and sugar yield, respectively in first year.The best SD was during sept. 11 to oct. 12.Results showed that SD with the exception of the second year had no significant effect on percent sucrose. Generally,early and late SD had the highest and lowest level of percent sucrose,respectively.First SD in the first year with 16.55% and last SD in the second year with 11.91% had the highest and lowest percent sucrose respectively. The highest sugar yield obtained on SD sept.9 and HD June 7 with 8.7 and 8.2 t/ha repectively. In second year Sd and HD also have significant effect on sugar yield at 1% probability level. The highest and lowest sugar yield produced by sept.8 and nov. 17 7.23 and 3.4 t/ha respectively and the highest sugar yield (7.22 t/ha) for HD produced by june14. there was significant differences between SD and HD for sugar yield in third growth season.The SD sept. 23 and HD June 1 produced the highest sugar yield 6.12 and 6.44 t/ha respectively. Early SD to Oct. 12 have the highest sugar content in three growth seasons.Results of the experiment showed that SD of mid Sep.to mid Oct. and HD of early May to mid June from qualitative and quantitative characteristics and level and rercent bolting in sugar beet point of viewes recommended for Abas Dasht and Dehloran rigions.