Selfsufficientish.com

1. Some of my apples are developing nicely, some drop off very easily as I check them and some of them are wrinkly, but the ones that come off easily are not necessarily the wrinkly ones.
2. The pear tree has always had that rust spot thing on the leaves. Now it's got something dark brown or black on them, mainly in one area of the tree.
3. The currants on one side of the shrub look like they are drying, there's something wrong with them. For a few years now, the shrub has produced currants without any trouble.
Any advice would be appreciated. Could it be something to do with the unusually hot weather?

Without pictures it's difficult to tell what's going on but I'm guessing watering will rectify some of your issues. Even well-established shrubs won't like sustained drought - if that's what you're experiencing. I don't know how old any of your trees/shrubs are but younger ones will definitely need more help in hot, dry weather.

I think most apple trees will shed some of their apples, they'll only grow what they can sustain on the nutrients/water available. Unless there looks like any sort of disease, just water and let them get on with it.

If you can remove and dispose of the blackened areas of the pear tree, I think it's probably a good idea. If it's some sort of infection/infestation that may stop it spreading to the rest of the tree or elsewhere. Again a bit of TLC - water food - while it's recovering won't hurt it. Don't put the stuff you've cut off in the compost. It would probably be best burned, but that might be problematic unless you can contain it safely.

Did you prune the currant bush? It may just be too crowded. Currants like an open airy structure. Unless, again, it looks like some sort of infection, water it and after fruiting give it a prune of old wood.

AS GA mentioned, much of the problem stems from water and feeding. Like people, plants that are incorrectly nourished become susceptible to disease so check watering and nutrition; avoid getting too much nitrogen in the mix and look to the micro-nutrients. If your patch has been overused / abused by previous tenants there could be some problems. I would advise soil tests but these can be pricey and you need to know what tests YOU want and exactly how to sample - we test for our broadacre systems and have found that different testing and sampling can give widely variable results. Early shallow (0-50mm) sampling (basic industry standard) showed us a significant lack of the "normal" NPK macro-nutrients and a fairly even balance of most micro-nutrients - more recent deeper sampling( 150-200mm & much more comprehensive) shows us we actually have an abundance of nutrients but that these are not in plant available forms - so our solutions are to increase soil biology, not to add fertilisers (except calcium in our case). However, soil tests do give us a baseline from which to build up. Costs for lab work and interpretation work out at about $A160 per sample but we have saved much more than this in useless fertiliser purchases.

The bottom line is that most impacts from pests and diseases (remembering that there is always a background level of these) can be effectively managed by proper plant nourishment and mixed species plantings.

These are the blackened leaves on the pear tree. Normally, there are lots of leaves with the orangey bits on, but there are only a few of those this year and more of the black bits.

And these are the normal blackcurrants as they have always been and the ones that have something wrong with them, but on one side of the shrub only.

It looks like some sort of fungal infection or blight on the pear tree. You can get antifungal treatments - I don't know of any other treatment. Depending how much of the tree is infected, I'd be thinking of removing it and starting again, maybe somewhere else.

I think you could just cut of those dying currant branches. It's got a good crop otherwise.