200 Gallon sprayer tank pump

[r8f1k]

I have an old, but solid, 200 gallon fiberglass sprayer tank that I used over the years to spray the hay fields. We don't do hay as much anymore, so I removed the booms and I mounted a little Fimco 2 gallon per minute 12 volt sprayer pump that I salvaged off of a 25 gallon sprayer tank. I plumbed the tank to feed right into the sprayer pump, builds 60psi no problem. However, I am spraying around 80 to 90, 200 foot rows of apple trees with it. I wanted to use it to keep the grass/weeds down in the rows with it. It will work great for about 3-4 rows, then it just can't keep up. I assume that I need a more potent pump for spraying the volume that I want to spray. I mixed a tank of 100 gallons of Roundup and I don't think I went though more than 20 gallons of it. I want to lay down a SOLID amount of liquid Roundup in the rows. I am pulling this with a John Deere Gator which allows me to drive with one hand and spray with the other. I have a good 12 volt source, does anyone have a recommendation for a larger pump? I get a really fine mist out of the wand I have, but if I adjust it to give me more volume and a more focused fan pattern, this little pump just dies in seconds. I don't really want to do gas powered and I don't want to do a roller pump off a tractor. I have to be accurate and I like how low to the ground I am with the Gator. Any Ideas?

 

[HCJtractor]

Here’s the pump I’m using. It will deplete my 275 gallon tote easily non stop. I run it off of a regular battery like a trolling motor battery. I used the Fimco switch but need to rewire it with a heavier gauge wire or just rig up a better switch.

 

[r8f1k]

I should add, when I pulled everything off for the 'new' set up, I did not add/put back on a bypass hose. Would that influence what I am doing? Might that be an issue?

 

[r8f1k]

Anyone use one of these?
Amazon.com : SEAFLO 12V 5.GPM 6PSI 51-Series Water Pressure Diaphragm Pumps Self Priming Agricultural Sprayer : Sports & Outdoors