Control of Aquatic and Ditch Bank Weed
a) Weeds in Irrigation Ditches, Canals, and Drains:
i. Mechanical control:
Use of knives and hooks, dredging, ploughing etc.
ii. Chemical Control:
2, 4-D against both submerged and surface aquatic weeds e.g. Water hyacinth, Hydrecotyl sp. Ester, 2, 4-D should be kept away from cotton. Amine salts should not be used in irrigation water to be given to crops.
Most submerged weeds are controlled by Nenachlor. It may be used in lakes, shores where aquatic water interferes man.
b) Weeds in Lakes and Ponds:
Floating masses of summer algae may chok ponds. Liquid sodium arsenate is simplest, cheapest and best for destroying weed species. It is sprayed on pond surface. Also kills submerged vegetation. CuCO4 is effective against algae only @ ½ to 2 ppm spray.