Soybeans and Round-UP ??

How tall do you let round up ready soybeans get before you spray?

 

Read the label!

There are restrictions.

 

But typically hit the weeds before they get over 5".

 

I like your second response better thanks

 

Haha yup! Sooner the better obviously but stuff happens. I'm assuming it doesn't have a pre down so sooner the better or you'll have a big mess!

 

As with most herbicides, the best range is before 8" or so of weed growth. Note that anything that goes to a seed head, there might only be supression verses kill.
Always mix ammonium sulfate with your glyphosate.
You also might want to do insect control at the same time if there is bug pressure. Silencer, warrior or other generics work well.

 

Why mix the ammonium aulfate?

 

Don't add an insecticide without knowing for sure there is a problem. Aphids and spider mites are your only real soybean pest and they will not be a problem yet. I would advise to not add insecticide. All you will do is kill the beneficials.