Wireless Sensor Network (WSN) is a variant of Mobile Ad-hoc Network which has strict resource constraints. In WSN, sensor nodes are scattered in the sensor field. These nodes sense parameters like humidity, pressure, sound etc and report it to the sink node. These direct form of data transmission takes significant amount of energy also nodes may sense correlated data and may report redundant data back to the sink. This book aims to identify efficient data aggregation protocol and further enhance it for achieving better network life time also to use this aggregation protocol for automation of an application like automation of water sprinklers(where based on the humidity present into the soil water will be supplied automatically). Hardware implementation of data aggregation with very small network of 3 nodes is also done using arduino micro controller. In these small experimental setup nodes can sense amount of humidity present into the soil, generates results accordingly and report it to the aggregator node. To use this approach in real time application like automation of garden water sprinklers, model for automation is also presented.