<H1>Preventive Methods</H1> <P><UL> <LI><H2>State and federal laws </H2> </UL><UL> <LI><H2>Weed-free seed, plant material </H2> </UL><UL> <LI><H2>Topsoil (no nutsedge) </H2> </UL><UL> <LI><H2>Clean equipment </H2> </UL><UL> <LI><H2>Field borders</H2> </UL></P> <P></P> <P>