Balistictip - if you are looking to plant this fall - and get significant fall growth - you can stop trying. Seriously, even fast growing crops like Rye (which is a great planting for cover/bedding - planted this year - for Next June/July) cannot grow fast enough in the fall for cover/growth. Sunflowers or sorghum require 8-10 weeks growth for some height.

Personally, I' d find out what chemical is to be used, and if it has residual that might effect new plantings. Also, even the best laid plans sometimes go awry.

Maybe you you can make a deal with the landowner- if not.......If you have clover plots that maybe you would like to have escape the chemical - if its a glycophosphate - mow it very tight to the ground like 1-2 days before they apply the chemical. Since glycophosphate only works on growing plants, if little green is showing, some will make it through the spraying. Hover, other chemicals are not as forgiving as round-up type.

Good luck -