Lime tree and lemon tree healthy but little fruit any suggestions please

Thank you for contacting Yates. 

The citrus might needs some extra potassium to help the fruit growth. Try 'Yates Thrive Natural Citrus & Fruit Organic Based Pelletised Plant Food' as a complete, soil-conditioning fertiliser for richer, juicier and more abundant fruit and healthy plant growth. Click here for more info on this product: https://www.yates.com.au/product/garden-fertilisers/organic-based/yates-thrive-natural-citrus-fruit-organic-based-pelletised-plant-food