งานนำเสนอเรื่อง: "Principle of weed management Prevention : cleaning, quarantine, weed laws Eradication : complete suppression, removal to total elimination a weed species."— ใบสำเนางานนำเสนอ:
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)
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 –Mycoherbici des –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 Dormant weed seed bank Active weed seed Crop Biological factors Physical factor Cultural management factor Weed reproductive yield Losses due to Limiting factor Cultivation Predation Toxic herbicides Crop yield Alter crop sp. Crop rotation Invasion of other weed sp.
Non chemical methods of managing weeds and the ecological principles Ecological principle 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