Wireless Sensor Networks (WSNs) consist of multiple unassisted embedded devices which process and transmit data collected from different on-board physical sensors (temperature, humidity, pressure, etc.,). There are several applications in WSN such as agriculture, industrial monitoring, etc.,. In agriculture, plant diseases are regularly monitored by WSN. This survey paper explains about the existing methods and new methods and the development of WSN. Plant monitoring with the image processing and sensor networks using Field Programmable Gate Array (FPGA) based control is the new method. The figures in this paper consist of the development and progress in WSN.