Efficacy of Some Herbicides on Growth, Tuber Production and Viability of Purple Nut-sedge (Cyperus rotundus L.)*

Abstract

An experiment was conducted at the Sugarcane Research
Center, Guneid, during 2004/05 and 2005/06 seasons to evaluate the
efficacy of some foliar herbicides on the growth of purple nutsedge
(Cyperus rotundus L.) and to assess the effect of the treatments on the
production and viability of tubers. The products tested were Krismat 75
WG (Trifloxysulfuron-sodium+ametryn) at three rates (1.79, 2.38 and
2.98 kg product ha-1 ) and Envoke 75 WG (Trifloxysulfuron-sodium) at
three rates (0.025, 0.030 and 0.035 kg product ha-1 ). Ametryn (Gesapax
50 FW) + Atrazine (Gesaprim 50 FW) were used at the recommended
rates (3.81 L + 3.81 L product/ha), as a control. The results showed that
statistically significant control of purple nut-edge was attained by all
chemical treatments compared with the untreated check. Envoke 75 WG
at 0.035 kg product/ha and the standard mixture of Gesapax + Gesaprim
at its recommended rate significantly (P=0.05) reduced the number of
purple nut-sedge compared with the untreated check. Gesapax +
Gesaprim gave the lowest number of green leaves per plant. Envoke 75
WG and Krismat 75 WG showed consistent reductions in tuber
production and sprouting. Therefore, their successive application may
lead to persistence and continuous reduction in the population density of
purple nut-sedge in the fields of sugarcane.