Effects of Harvest Dates and Potassium Rates and Timing of Application, on Sugar Beet Yield and Quality

TWO FIELD experiments were carried out in 2002/2003 and 2003/2004 seasons at Sakha Agricultural Research Station, Kafrel-sheikh Governorate to study the effects of potassium fertilization and harvesting dates on the yield and sugar beet quality. Potassium fertilization treatments included a factorial combination of three rates ( 24. 48 and 72 kg K20/fed) and 7 application times; single dose at sowing or 30 / or 60 DAS. two equal split doses at sowing/30 DAS; sowing, 60 DAS. at 30. 60 DAS and finally at 30/ 90 DAS. Harvesting was done 180 or 210 DAS. Applying 72 kg K20/fed in two equal doses ( 50/50 at 30/60 or 90 DAS) significantly increased percentage of sucrose, purity, sugar extraetable, extractability. Alkalinity coefficient and K in extracted root juice as well as root and sugar yields. The results showed also that delaying harvest from 180 to 210 DAS significantly increased root yield and quality parameters