Fadi Abbas *(1) Entessar AL-Jbawi (2) and Mahmoud Al–Hamdan(3)
(1). Scientific Agriculture Research Center of Homs, General Commission for Scientific Agricultural Research (GCSAR), Damascus, Syria.
(2). Sugar beet Research Department, Crops Research Administration, GCSAR, Damascus, Syria.
(3). Natural Resources Directorate, Scientific Agriculture Research Center of Homs, GCSAR, Damascus, Syria.
(*Corresponding author: Dr. Fadi Abbas. E-Mail: firstname.lastname@example.org).
Received: 24/09/2018 Accepted: 14/11/2018
This experiment was conducted at Homs Agriculture Research Center Lab, during 2014, using two monogerm sugar beet varieties (Rival and Semper), to study the effects of drought induced by polyethylene glycol (PEG-6000) on seedling stage, and the role of potassium and foliar spray of methanol in reducing the negative effects of drought. Plants thinned to one plant per polyethylene sac which contains 10 kg of soil. Three osmotic solutions (0, -3, -6 bar) were applied, using three levels of potassium sulfate (0, 1.5, 3 g/plant), besides spraying 25% of methanol (four times), one week after emergence, then one-week interval between treatments. Results showed a significant effect of osmotic potential on growth stages, because of that, the time needed to complete each stage increased with decreasing osmotic potential level. Potassium had no significant effect on the early growth stages (germination, cotyledon pairs), while this factor affected the following stages (first, second and third true leaves pairs) significantly. Methanol had no significant effect on the early growth stages (germination, cotyledon pairs and first true leaves pairs), while it affected the following stages (second and third true leaves pairs) significantly. The values of leaves dry matter, leaves area and net assimilation rate decreased with the reduction of osmotic potential, and the differences were significant. Also, potassium and methanol enhanced growth, and had a positive effect on these attributes significantly. Rival variety surpassed Semper in all of studied attributes.
Key Words: Drought stress, Potassium, Methanol, Seedling, Sugar beet.
Full paper in Arabic: PDF