Great job. Spring can't get here soon enough for me.
As for the yellow plants. When you pull the plants, try to pull out as much of the root system as possible. Look at it closely and see if there are any knots or tuber looking things growing in the roots.
I'm thinking you might have nematodes. Nematodes affect areas like what you have and are usually not found in an entire field. The other thing that might be the problem is and old chemical spill in that spot, but without seeing the roots, it's a tough call.
As for the yellow plants. When you pull the plants, try to pull out as much of the root system as possible. Look at it closely and see if there are any knots or tuber looking things growing in the roots.
I'm thinking you might have nematodes. Nematodes affect areas like what you have and are usually not found in an entire field. The other thing that might be the problem is and old chemical spill in that spot, but without seeing the roots, it's a tough call.





