Two pot experiments were conducted during two glowing seasons, ~OO1-
2002 at greenhouse of National Research Centre, Dokki, Cairo, Egypllo Slu~y the
influence or Thlobencarb herbicide and Sitosterol on rice plant (Oryza saliva L.) e«.
G'I77 . Thiobencarb herbicide concentrations (2,4 and 6 mill) were applied at days
from transplanting. Sitosterol concentralions{100 and 200 mgIl) were sprayed after 7
days from Thiobencarn application the main finding could be summarized as
following: Thiobencarb $ign\1ican\1y cecreaseo reot and vegetative characteristics,
yield, photosynthetic pigments of nag leaf, sugars, protein and indoles con lent of all
rice plant orsrans . However, it increased free amino acids and total p enole
contents at leaf tube and grain ripe stages. Sitosterol applicatlon had stimulatory
improvement the previous characters . Thiobencarb and Sitosterol combinations
significantly improved root , vegetative and yield and its components compar~tI with
Thiobencarb treatment alone espedally 2mIA Thiooencarb and 200 mg/l Sitosterol .
Sitosterol at 200 myll significantly improved all growth characters of root, 'leg tafive
and yield of rice plant . Also ,these treatments significantly increaSed root soluble
sugars , total phenols at leaf lube stage and decreased free amino acids contenl .
There were signiftcant increases in sugars, protein, rree amino acids and folal phenol
contents of vegetative growth, photosynthetic pigments of nag leaf and grain
biochemical contents at the physiological stages. Sitosterol at 200 mg with
TI\ioberlcarb levels was more effective on root and vegetative growth.