Chemical control of swamp morning glory (Ipomoea aquatica Forsk) in drainage water bodies.
In field trials conducted at Maruteru during 1988-89, the effects were evaluated of 2,4-D at 2.0 kg/ha, 2,4-D + urea at 2.0 kg + 2%, 2,4-D + paraquat at 4.0 + 1.0 kg, paraquat at 2.0 kg, paraquat + urea at 2.0 kg + 2%, and paraquat + 2,4-D at 4.0 + 1.0 kg for the control of I. aquatica in drainage canals. All herbicide treatments decreased weed biomass production 25 d after spraying from untreated control values of 6500 kg/ha to 800-5300 kg. All weed control treatments reduced weed growth by 18-99%, and reduced resprouting of I. aquatica from control values of 100% to 1.4-65.3%. Paraquat + 2,4-D at 4.0 + 1.0 kg resulted in the greatest decrease in weed growth and resprouting.