Abstract: [Objective jAiming to improve the yield and starch content of cassava in order to increase the income of
farmers and the benefit of related enterprises, an experiment was conducted to observe the effects of CPPU and paclobutrazol
on yield in cassava. [Method ]In the first part of experiment, two cassava varieties, viz., Nanzhil99 and SC8 were
treated differently (foliar spray, irrigation and spray + irrigation) with 1%o CPPU solution at the expansion stage of root tuber.
Secondly, the cassava varieties viz., Nanzhil99, SC5, GR911 and SC8 were sprayed with 15% PP333 solution (900 kg/
ha, 1000 mg/L) at seedling stage. [Result]All treatments of CPPU enhanced the perimeter and yield of fresh tuber and its
starch content in both varieties, however, the best effects were observed in plants of Nanzhi 199 treated with spray + irrigation
of CPPU. The yield of tuber and its starch content increased by 105.22 and 36.49% compared to the control, respectively.
Foliar spray of PP333 solution also resulted in enhanced yield and starch content in all varieties. This treatment
resulted in 7.21% yield increase in Nanzhil99 and 44.72% increase in starch content in GR911. [Conclusion JIt was concluded
that both , CPPU and PP333, improved the yield and starch content of root tuber in different cassava varieties,
and their application may be recommended to enhance the cassava production.