Hi Vee the Hessayon book on fruit growing says that browning on fruit tree leaves can be due to shortage of one of the elements in the soil. Such as magnesium or potassium or phospherous, more a yellowing if iron. If in a pot, repot to larger pot, as much fresh soil as possible and water well and fertilise after reading the label, or asking at a good garden centre. In soil in the garden just try more water plus fertiliser. In grass it works the same, probably best with dissolved fertiliser to avoid damaging already drought scorched grass if it is a lawn.