As you've learned, electronic high frequency sound emitters don't work.

Traps do. But you must bait them with a choice morsel (small piece of nut) wired to the bait holder, the topped with a small dab of peanut butter.

And wire the trap to something heavy -- perhaps a concrete block -- so that a partially trapped rat won't leave with trap attached.

Keep the dog out of the area. Devise a fence if needed.

put poison in something with an opening big enough for a rat but small enough so dog can't get in ,sometimes the rat only wants the moisure from the fruit

i used to get rats in OC Cali but bought rat food boxes from Orange County Farm Supply (Chris)in Orange and these green squares - rat poison - put one in my yard along the top of the fence and one in the neighbors who has fig trees I also bought T-REX rat traps (could be sturdier) and use old uncooked bacon or peanut butter one last thing made for insect repellent that deters rats and possums is hot wax - where used to see 24+ rats running the neighbors trees at night maybe see 3-4 and my tomatoes not chewed on - oh by the way I have 2 Brussells Griffons and the female finds them and the little male has killed 8 rats

if you have never been to Orange County farm supply you should check it out - they have all the great stuff and prices too - they stock PRO-Mix BX the planting plug mix and more - plain or with fungicide or micorrhizae and texas tomato cages
tell him Dennis sent you - my user name is supposed to be mtbigfish need to get it changed