How to improve dog's recall when I don't have her ball?

So after a few walks recently whereBella's recall hasn't been great(not bad, but not instant if other distractions where there),and resorting to her long lead again,today we went to the park. We were on our own on the field,so I let her off lead to play ball. And her recall was wonderful. Even when another dog appeared and ran up to her,she recalled instantly,and did a wonderful "Down Stay" till the other dog ran back to it's owner. I was so proud of her .
Anyway....it then occured to me that her recall is much better when I have her ball !!!! It's so true! The times she has been dodgy with recall have been times in the wood etc when I hadn't taken her ball.
Now her ball is her most favourite thing ever, and obviously holds greater attraction than other temptations......
So my question is how can I improve her recall without her ball? I don't want to always bring her ball cause I like her to have some walks without chasing a ball,and if she knows I've got it she expects me to throw it! I do always practice her recal on walks by calling and treating etc....but it seems they are just not as tempting as her ball ! Any ideas????

Stick a ball in your pocket?

She KNOWS though LOL She can sense the ball, and if I have one anywhere on my person she circles me and jumps up at me the whole walk waiting for me to throw it.....and sometimes (like in the woods) I like her to sort of just sniff and explore a bit rather than chase a ball.....
Thing is....she is just much more ball/play motivated than food motivated....guess that's the collie in her.....

Daisy does the same. And she`s GSD. I use the ball to train her so we always have it. She carries it round on walks. If training it stays in my pocket. It`s a good tool.
But I`ve no idea how you`d get that sort of response without using a ball. Sorry. I have tried using a higher value ball as well (one on a rope) but life gets a bit complicated then as you juggle between the two.
A friend had a GSP who worked for a glimpse of a small fabric mouse. Just the sight of it made him ecstatic. But Daisy`s not as daft as that!

You are lucky she is ball focused, it will make training her very easy. She needs to learn that although you have the ball, you will decide when it comes out of your pocket, not her. My GSP never takes his eyes off me and has a gold plated guaranteed recall, because he lives in hope the ball will come out. Sometimes when he comes back I will chuck it to him to catch a couple of times, sometimes I won't, he never knows...

Tilly's the same & will recall fine if I have the ball - if I don't have the ball, a piece of cheese string does the trick

Lucky you - I would LOVE ball focus!!

A few things I would do
Make her understand that the ball is something she has to work for - ask for behaviours like sit and down before you chuck the ball

For the next wee while always have the ball with you. Often just take it out in your pocket but never take it out of your pocket - you can even give a command like 'all gone' if she bugs you then ignore any attempts to get the ball for the rest of the walk, she will learn that when you say your word there is no chance of the ball comming out (dont crumble, if you say the word the ball never comes out - not even if she runs after a deer)
Then once she is used to you having the ball in your pocket not meaning anything and on a day you havent said your 'all gone' one time recal her and when she comes back reward her with the ball, then ball away 'all gone'
do this every few days or a while and then only pull the ball out for better than normal recals - more distraction, faster, whatever
She will learn that comming back to you is amazing because the ball might magically appear if she does it well

Thanks all, great ideas!
We have just been on a long ramble in the woods.I was working a lot on her recall(I didn't have her ball) and tried to only call her when she looked like she would respond,then treating with peices of sausage!She was fairly good most of the time, but then a couple of times she heard a noise,picked up a scent or got distracted by something just more interesting than sausage and ignored me She will always come eventually,just sometimes in her time not instantly and after she has explored whatever has caught her attention
Will try to use her ball then I think like you suggest Ben
Good idea about leaving it in my pocket.I have recently started getting her to Sit or Down before throwing it actually. Trouble is at one point she decided that was just too much effort and so walked off with the ball in her mouth and wouldn't bring it back to me(normally she is great at retreiving and dropping)....so need to make sure I can get it back off her, otherwise she will just carry on with her ball and ignore me anyway LOL
Gosh dogs can be hard work LOL But so worth the effort

very intrested in this topic my dog has a fav ball and as you say recall everything brill if hes allowed it only problem, i have is hes obsessed with that toy and wont play with anything else no idea what im gonna do when it eventually breaks, and also hes started to wonder of once he has the ball so he doesnt have to give it up and then hell lay down and chew it meaning i have to go fetch him and put him on his long line on then he is fine again till i stop holding long line any ideas

I also have have this problem when am training Astra. She prefers the ball more that a treat. But sometimes if she obeys she gets the ball and sometimes not. Anyhow the ball helps me get her attention towards me. She listens to me when I have treats in my hand, but not as much as when i hold the tennis ball.