In some embodiments the invention provides a unit for delivery of agrochemicals to the roots of a plant comprising: one or more root development zones optionally one or more agrochemical zones and a pesticide wherein the agrochemical zones are formulated to release at least one agrochemical into the root development zones in a controlled release manner when the root development zones are swelled and wherein the dry weight ratio of the root development zones to the agrochemical zones in a dry unit is 0.05: 1 to 20: 1 or wherein the total volume of the root development zones in the unit is at least 0.2 mL when the unit is fully swelled.