Ahmad AL-Jordi
General Commission for Scientific Agricultural Research-
Homs Research Center
Al-Ba’th University, Faculty of Agriculture
 2009

Abstract

This study was conducted in Scientific Agricultural Researches Centre at Homs on monogerm sugar beet plant-Parade. CV; which accredited for planting under Homs conditions, in winter sowing date of 2007 and 2008 seasons.
The experiment was designed by split randomized plots with two main treatments (main plots): Irrigation Time and Cutoff Duration, the first treatment contain 3 times: a-2 days between one irrigation and another, b- 4 days between one irrigation and another,  c-6 days between one irrigation and another, while the second contain 3 Cutoff Durations: a- 12 days before harvest, b- 18 days before harvest,  c- 24 days before harvest.
The research goals were:
–    Study the effect of irrigation time and cutoff duration on growth attributes of monogerm sugar beet plant-Parade. CV.
–    Study the effect of irrigation time and cutoff duration on yield and quality characteristics.
–    Study the effect of irrigation time and cutoff duration on sucrose accumulation dynamism.
–    Identification the optimum irrigation time and cutoff duration, when drip irrigation applied.
Results show:
1- The foliage fresh weight decreased with increasing leaves dry matter % at harvest in each irrigation treatment and by increasing cutoff duration, while they increased by increasing irrigation times.
2- The average root weight increased by cutoff durations increase, and by increasing irrigation times, and the root  dry matter increased by increasing irrigation times and cutoff durations, so the treatment (6 days irrigation time + 24 days cutoff) was significantly  surpassed, and The root yield increased upon irrigation treatment itself by increasing cutoff duration, and the treatment (6 days irrigation time + 24 days cutoff) was significantly  surpassed.
3- By tracing sugar accumulation dynamism in roots, it was found that the highest increasing were since early July till harvest (the time of cutoff irrigation), so plant thirstiness helps sugar percentage to increase in roots.
the highest increasing were since cutoff till harvest, and it was in the treatment (6 days irrigation time + 24 days cutoff), while the lowest were in the treatments (2 days irrigation time), so sugar percentage increased by increasing of  both factors.
4-Quality attributes values (total soluble solids TSS%, sugar percentage, juice sugar percent%, purity%)  upon irrigation treatment itself by increasing cutoff duration, and the treatment (6 days irrigation time + 24 days cutoff) was significantly  surpassed. Both of total and extractable sugar quantities increased upon irrigation treatment itself by increasing cutoff duration, and it increased between treatments by increasing irrigation times. and the highest increasing was in the treatment (6 days irrigation time + 24 days cutoff).
5- the highest value of water use efficiency was in the  treatment (6 days irrigation time + 24 days cutoff), so it reached (9.9 kg roots /m³, 2.3 kg dry matter /m³, 1.24 kg sugar /m³).