You can definitely model a more realistic apple (or other fruit/flower) to substitute for some of the leaves. Adding to what Antaran says (waves Hi to Antaran!), you can also model full branch/leaf/fruit combinations and load as "leaves" in the plant modeler. I believe that the default uvmap for the Carrara plant modeler trunk and branches has dimensions of 3:1. So if you create procedural shaders or tiled trunk/branch texture maps, you may get better results using height to width tiling to 3:1 or 1:3 when applied to trees created with the plant modeler. The other tip I would give for the plant modeler is to look in the leaves tab for the place to adjust the weights of individual "leaves." That is where you can adjust how dense the fruit coverage is compared to the foliage.