GENERAL SUGGESTIONS 5 



REPLACEMENT BY USEFUL PLANTS 



The success or failure of control measures depends not only on 

 the extent to which weeds are eliminated but also on the kind, qual- 

 ity, quantity, and duration of the new plants that come in their 

 place. Where useful plants are already present in a suppressed 

 state, removal of weed competition is frequently all that is neces- 

 sary to ensure satisfactory improvement. Thus, in a Maryland 

 locality dominated by cattails, control by mowing resulted in good 

 volunteer growths of wild millet, wildrice, and rice cutgrass for 

 about a decade. However, satisfactory replacement cannot always 

 be left to nature. Sometimes, seeding or planting is necessary 

 soon after control operations to assure a good crop of useful plants 

 and prevent rapid reestablishment of weeds. 



