EVERYDAY SCIENCE

Detailed explanation-1: -2, 4-D, mecoprop, and dicamba control many broadleaf weeds but remain ineffective against turf grasses. Non-selective herbicides are not specific in acting against certain plant species and control all plant material with which they come into contact.

Detailed explanation-2: -Postemergence herbicides are used to control weeds that have already emerged. The younger the weed, the better a postemergence herbicide will work.

Detailed explanation-3: -Herbicides are a type of pesticide that specifically targets weeds and other unwanted plants.

Detailed explanation-4: -Herbicide reduces the cost and drudgery in weed control. Reports show that herbicidal weed control is much cheaper and gives three to four times much more net benefit than manual weed control. Thus weed control by herbicide has clear economic advantages over manual and mechanical weed control.

Detailed explanation-5: -Examples of contact herbicides are diclofop, dinoseb, diquat, and paraquat. Certain contact herbicides, like diquat and paraquat, are deactivated by soil particles. They must be mixed with clear water and applied directly to the vegetation.