Had a 9 acre field just across the road that went down flat about a month ago in a rain storm.We had very humid warm weather for the next 3 weeks and the few short weeds that were underneath the grain took off like a rocket.They grew up completely through the flattened grain field,formed a green mat over most of the top of the crop and became a tangley viney mess.We reluctantly tried to cut it,the augger wrapped and the grain in the bin was full of waxy green leaves.When we tried to unload it,Dad had to turn the unloader on and off while I climbed in the bin to jump it down and back out for him to turn it on to see how much more would come out.Decided to give it a good coat of round up and leave it for a week and a half than tackel it again.About 9 days in,an inspection of the field revieled that only the top half of the weeds were dying while the bottom half was green and thriving.So our last resort tactic was to mow it with the impellor disc mower and combine it after the weeds dried out.The grain stayed fairly well intact,took only 2 days for the weeds to dry.We don't have a pickup head,so had to keep the header very low and let the pickup reel pull it into the head.We mowed it about baling width so it would be easier to pick up.That combine ate alot of clay and the cattle should get their minerals on that bit of grain.We ended up loosing about half of the grain being knocked off by the mower.Wouldn't recomend it to anyone unless it's an absolute last resort,but I figured that half was better than none,was easy straw to bale and now the field is cleaned off.Will spray it again with round up to clean it out before ploughing.