Does Preemergent kill the seed?

[Please_Be_Green]

I know preemergent will keep a seed from germinating...

but will it actually kill the seed?

i.e. put down pre-emergent, keeps seeds in soil from germinating... pre-emergent wears out... is the seed still able to germinate in the proper conditions or has the seed expired?


Thanks...

Specifically, I'm thinking about Poa Annua.

I have a few larger patches that I need to eradicate in 2010, and am trying to think of my 2010 plan. I'm planning on just using ROUND UP on the spots in early Spring before seed head formation... reseed these spots with a 50/50 Rye/KBG blend... hit the lawn with a late summer pre-emergent application through fall 2010 with the hopes that I don't get the patchy light green/darkgreen, look I get in the fall that I have now in these areas.

[ICT Bill]

Pre emergents do not keep the seed from germinating. When the seed germinates it attacks the seedlings roots and de-nuts it basically, no root, no plant

Over time you will deplete the seed pool on the site and get better control, of course a lot comes in on the wind in the winter

This is also why you will hear a term "root pruning" it will attack roots of the existing plants as well. Most but not all do this

[Please_Be_Green]

Thanks... That helps me understand the concept...

[Think Green]

Be Green,
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E.G.-- Prodiamine herbicide mode of action or (site of action).....!!!!
Most of or if not all complete herbicide labels state the chemicals mode of action, half-life, and r.e.i. intervals for safety. IF you do not have the current labels, google them, but be assured that most labels are offered in sample formats. Sometimes, the complete information isn't stated, so be aware..!!