[member=467]sabrina[/member]
Ah! Bramley is a triploid variety (with 3 sets of chromosomes rather the normal 2, ie. diploid) and is self-infertile and cannot pollinate other apples: as things stand you will have been dependent on insects passing on pollen gathered from any diploid apples (wild or otherwise) in surrounding area. However, your new James Grieve (a partially self-fertile diploid variety) should sort things out as it is should blossom at about the same time thereby pollinating itself and the Bramleys. However, planting yet another diploid variety (whether self-fertile or self-infertile) in flowering group 3 or 4 (I would suggest) will help ensure the JG crops well in due course and of course also contribute to pollinating the Bramleys while being pollinated itself by the JG.
Regarding rootstock: the type of rootstock will affect the potential for first cropping on young trees. I doubt very much that your Bramleys are on very dwarfing rootstock and would bet they are grafted onto M106 rootstock (for medium size reduction), but they might be on something like M25 for a larger tree. On M106 you are probably in the “window” for 1st cropping (as long as you have a donor tree for pollen nearby); on something like M25 rootstock cropping might be a bit iffy just yet on the younger trees.
You should definitely be pruning all your trees routinely and from the outset: a winter pruning as standard, but I personally recommend a summer pruning also (late July say), particularly for vigorous varieties like Bramley. Summer pruning is traditionally reserved for trained apples, e.g. espalier training, but I recommend a summer hair-cut for free-standing trees also. It helps the sun get in for fruit ripening (when you have some!) and can induce tree to turn more of this year’s new buds into flowering buds for next year. To note, Bramley is semi-tip bearing so will produce some flowering buds on the end (or near the end) of shoots as well as on established fruiting spurs – so, to help maximise cropping, go light on pruning-out new Bramley shoots, particularly lateral shoots anything less than about 8 to 9”, except where you want to thin out to avoid congestion or to maintain shape or to contain tree size. JG is a spur bearer so you can prune new growth without worrying quite so much about where you want fruit buds/spurs to develop in future.
Finally, I’m going to throw in a partial counter to cloddopper’s regime for feeding apple trees: if a fruit tree is too happy with its lot in life, it might not bother much about “reproducing” itself via the production of fruit/seed. ‘Tis said that a stressed or diseased/dying tree will put more of its resources into producing fruit/seed than into producing more vegetative growth. On the other hand, stressing a tree too much will reduce its ability to fight off diseases naturally.
[I would mention that I have gardening clients with apples and black currants growing side by side very successfully - I don't think that is any part of your problem.]