【摘要】 在沈阳、庄河两地的田间试验,建立了玉米田苗后有草天数或无草天数与产量损失率间的函数关系模型,明确了辽宁省春玉米田杂草的生态经济防治阈期为玉米出苗后18～65d。在此期间内保持田间杂草少于经济防治阈值,既可确保杂草造成的减产率低于3%,又能充分发挥杂草在生态系统中的积极作用。更多还原

【Abstract】 Field experiments were conducted in two day in Shenyang and Zhuanghe regions of Liaoning province. On this base, fit the functional relationships between the relative weedy or weed-free days after emergence and yield loss rate of spring maize. Made it certain that eco-economic period threshold for weeds controlling in spring maize fields of Liaoning is 18-65 days after maize emergence. To make the grass number the economic threshold,during this term can make the deduce yield under 3 percent , and can make the weeds do its positive work.更多还原