AGR 3102 Principles of Weed Science Unit 5: Methods of Weed Control Integrated Weed Management (IWM) Muhammad Saiful Ahmad Hamdani

Methods of Weed Control

Integrated Weed Management (IWM) Definition: combination of multiple management methods to reduce weed population to an acceptable level while preserving the quality of existing habitat, water, and other natural resources.Definition: combination of multiple management methods to reduce weed population to an acceptable level while preserving the quality of existing habitat, water, and other natural resources. Involves 2 critical elements:Involves 2 critical elements: -using multiple control tactics (cultural, mechanical, biological, and chemical control methods). -integrating a knowledge of weed biology and ecology into the management system.

IWM - Rice Critical period of weed control DAS Cultural method1)Healthy and highly competitive variety 2)Flooding 3) High density Mechanical method1)Land preparation (ploughing) 2)Hand weeding 3)Rotary weeder Chemical methodApply pendimethalin 1.0kg/ha on 5 DAS or Pretilachlor + safener (Sofit) 0.45kg/ha on the day of receipt of soaking rain, and apply Nominee (bispyribac-sodium) 0.35kg/ha at 7-15 DAS) Biological methodRelease Tilapia spp. to control aquatic and floating weeds such as Azolla and Salvinia RemarksCan also include preventive method: 1) Certified seeds 2) Clean planting and tilling machines

IWM - Maize Critical period of weed control 3 to 6 weeks after germinating Cultural method Mechanical method One hand weeding on days after sowing Chemical method1.Pre-emergence application of Atrazine (1-2 kg ai/ha) 2.Combined application of Alachlor (2 kg/ha) and atrazine (1kg/ha) is more effective and have wider spectrum of control Biological method

IWM - Sugarcane Critical period of weed control 4 to 5 months after planting Cultural methodHigh density planting Mechanical methodRemove the weeds along the furrows with hand hoe. along the ridges on 25, 55 and 85 days after planting for removal of weeds and proper stirring Chemical method1.Pre-emergence herbicides like atrazine (2 to 3 kg/ha), Simazine (2 to 3 kg/ha), Alachlor (1.3 to 2.5 kg/ha) etc. will generally last for 8 to 12 weeks 2.To obtain best results, sequential application of preemergence and post emergence herbicides like Glyphosate (0.8 to 1.6 kg/ha) Paraquat (0.4 to 0.8 kg/ha). Biological method

Can develop a long-term weed management plan, that considers all available management control techniques to control weeds. Likely to hinder the adaptation of weeds to any single control tactic, i.e. chemical control-herbicide resistance. IWM takes a common-sense approach to weed control (helps reduce hazards to people, animals and the environment). IWM works well for agricultural, home, garden and workplace environments. Advantages of IWM*

Avoid unknown problems in the future i.e. some biological agent may become invasive spp., insect may mutate and change their diet attack other crops and plants; mechanical will reduce soil nourishment and cause erosion; water scarcity is a major issue nowadays. Consists of a series of evaluations, decisions, and control practices which focus on economical and effective control of weed with consideration of ecological conservation. Most important, IWM helps decrease herbicide use. Advantages of IWM cont…

Principle of IWM: “THE RIGHT COMBINATION OF DIFFERENT WEED CONTROL METHODS FOR THE RIGHT CROP & ENVIRONMENT AT THE RIGHT TIME”

Future weed control - the super IWM???