Fadi Abbas
General Commission for Scientific Agricultural Research-
Homs Research Center
Ba’ath University, Faculty of Agriculture
2007

Abstract

This study was conducted at two both Homs and al-Ghab Research Centers on two monogerm sugar beet cultivars Dita & Rizor seeded in autumn and winter dates of 2004-2005/ 2005-2006.
The study aimed to:
Establish a phenological time-schedule explaining the growth and development attributes of monoseed sugar beet and yield components in the middle region of Syria.
Study the dynamism of leaf area (LA) formation, leaf area index (LAI), specific leaf area (SLA), number of green leaves and its age, photosynthetic potential (PHP), net assimilation rate (NAR), green leaves weight, roots weight, dry matter (%) in leaves and roots and sugar accumulation in the various stages of growth.
Study the effect of ecological variance on technological traits and yield components.
The results have shown that the site effect on growth stages depending on variance in growing degrees day (GDD) at the two sites.
–    LA, LAI, reached the maximum value on late May in autumn date and on middle June in winter date because of variance in season length, LA of autumn date were higher than winter date, higher PHP, NAR, so the yield of autumn date surpasses the winter date.
–    SLA varies by growth stage, its value in winter dates were higher than autumn, its value correlated positively with LA and negatively with dry matter content in leaves.
–    Autumn date gives the lowest number of green leaves but increasing of single leaf area caused increasing plant LA, LAI in this date.
–    Cotyledonary and true leaf pairs age varies by site and sowing date, if correlated with GDD and this age reached its pick in leaves (16-25) in winter date and (11-20) in autumn date. The total number of leaves ranged between 52 (Dita- Alghab) and 56 (Dita- Homs) while in autumn date it ranged between 47 (Dita- Alghab) and 50 (Rizor- Alghab).
–    In winter date: Dita- Homs surpasses significantly in green leaves weight at canopy, roots weight at harvest, differences between cultivars and site were significant in dry matter % in leaves and roots.
–    Autumn date surpasses significantly in PHP, fresh leaves weight, fresh root weight, percent of dry matter in each part and NAR.
–    In winter date Dita- Homs surpasses significantly in root yield, purity, percent of sucrose in juice extractable sugar, total dry matter in area unit and harvest index, the values were respectively: 67.301 ton/ha, 87.75%, 19.5%, 10.546 ton/ha, 18.885 ton/ha, 0.559. While differences were not significant in percent in sucrose in roots and Brix.
–    In autumn date differences were not significant in root sucrose %, Brix, juice sucrose, purity and extractable sugar but differences were significant in root yield and total dry matter, so Rizor- Alghab surpasses by 82.976 ton/ha (yield) and 27.27 ton/ha (total dry matter).
–    According to the previous results, we conclude the possibility of sowing of both cultivars in the two sites with an advantage to Homs site because the extractable sugar were higher than in it 11.229-11.393 ton/ha for Dita and Rizor respectively while in Alghab site it reaches 11.089-10.496 ton/ha respectively.
–    In the two sites autumn date surpasses significantly by root yield, extractable sugar, total dry matter, while winter date surpasses significantly by root sucrose, Brix, purity, harvest index.
Finally, the research records a special database explaining the important growth attributes to give satisfied yield for monoseed sugar beet in each site and sowing date.