Principle of weed management Prevention : cleaning, quarantine, weed laws Eradication : complete suppression, removal to total elimination a weed species Control : reduce or suppress of weed (density and species composition of weeds)

7. วิธีการควบคุมวัชพืช methods of weed control โดยไม่ใช้สารเคมี การใช้แรงงาน การใช้เครื่องจักรกล การเขตกรรมและจัดระบบนิเวศของพื้นที่/แปลงปลูกพืช การใช้ไฟ โดยการใช้สารเคมี การใช้ชีววิธี การจัดการวัชพืช การใช้ประโยชน์จากวัชพืช

Tools used for weed control Physical methods of weed control Hand pulling and hoeing Fire, Flame Tillage (cultivation), reduce tillage, no tillage Mowing and shredding Chaining and dredging Flooding Mulches and solarization Cultural methods of weed control Weed prevention :clean seed, manure, equipments & irrigation systems Crop rotation Crop competition Living mulches and cover crops Biological control Natural enemies Grazing Mycoherbicides Allelopathy Chemical control Integrated weed management

Principles for weed management systems Incorporation of ecological principles Use of plant interference / crop-weed competition Incorporation of economic and damage threshold Integration of several weed control measures (techniques)

Conceptual model of a weed community Crop Biological factors Physical factor Cultural management factor Alter crop sp. Crop rotation Invasion of other weed sp. Dormant weed seed bank Active weed seed Weed reproductive yield Losses due to Limiting factor Cultivation Predation Toxic herbicides Crop yield

Non chemical methods of managing weeds and the ecological principles Reduce inputs to and increase output from soil seed bank Allow crop earlier space capture Reduce weed growth and thus space capture Maximize crop growth and adaptability Minimize intra-specific competition of crop, maximize crop space capture Maximize competitive effects of crop on weed Modify environment to render weeds less well adapted Maximize efficiency of resource utilization by crops

Non chemical methods of managing weeds and the ecological principles Weed management Prevention, soil sterilization, weed control before seed set Early cultivation, using crop transplants, choice of planting date Cultivation, mowing, mulching Choice of crop variety, early planting Choice of seeding rate , choice of row spacing (plant density) Planting smother or cover crop Rotation of crops, rotation of control methods Intercropping