YIELD AND QUALITY OF SOME SUGAR BEET VARIETIES AS AFFECTED BY SOWING DATE AND HARVEST AGE

Abstract

Two field experiments were conducted in 2008/2009 and2009/2010 seasons in Sakha Agricultural Research Station, Kafr ElShiekh Governorate. The main goal of this study was to investigatethe response of five multigerm sugar beet varieties (Florima,Cleopatra, Heracule, Avantage and Alamas) to three sowing dates (1stSept., 1st Oct. and 1st Nov.) and three harvest ages (180, 195 and 210days after sowing). A split plot design with four replications wasdevoted for each sowing date where harvest age was allocated in themain plots and varieties in the sub-plots. A combined analysis over thethree sowing dates and two seasons was undertaken.Sowing dates markedly affected sucrose and puritypercentages as well as root and sugar yields/fed. Over both seasons,sugar beet sown early on the 1st of Sept., and/or 1st Oct. recorded atpar the highest root and sugar yields/fed. Sugar beet varieties differedsignificantly in their yield potential. Cleopatra variety recorded thehighest sucrose %, while Florima and Heracule varieties produced thehighest root and sugar yields/fed. Harvesting sugar beet after 210 daysfrom sowing was the proper age to obtain the highest sucrose andpurity percentages as well as root and sugar yields/fed. The interactionbetween sowing dates and varieties exerted a significant effect on rootyield/fed. Florima variety recorded the highest root yield in the earlysowing date (1st of Sept.), while Cleopatra and Avantage varietiesrecorded their maximum root yields when they were planted in thesecond sowing date (1st of Oct.). The interaction between sowing dateand harvest age significantly affected almost all the studied traits.Regarding this interaction effect on sugar yield/fed, theresponse equations indicated the need for more delay in harvest than210 days after sowing particularly for the early sown sugar beet in 1stof September. Under the conditions of this work, sowing Florima andHeracule varieties on the 1st of Sept. or 1st Oct. and harvesting themafter 210 days from sowing can be recommended to obtain the highestroot and sugar yields/fed.