An agricultural sprayer, comprising: at least one nozzle (176, 210, 215, 310, 360, 412, 414, 610, 802) configured to receive a fluid and direct atomized fluid to an agricultural surface; characterized in that a radio-frequency transmitter (312, 430, 620, 804) is disposed to generate an RF signal that passes through a dispersal area, wherein the RF signal is detectably changed when interacting with droplets of the atomized fluid; a first RF receiver (314, 510, 560, 570) is disposed to receive the RF signal after the RF signal passes through the dispersal area, the first RF receiver providing an output indicative of the RF signal; and a controller is coupled to the first RF receiver (314, 510, 560, 570) and configured to detect plugging of the at least one nozzle based on the output of the first RF receiver (314, 510, 560, 570) and on comparing attenuation of the received signal with reference, wherein the at least one nozzle (176, 210, 215, 310, 360, 412, 414, 610, 802) comprises a plurality of nozzles, the sprayer further comprising a second RF receiver (314, 510, 560, 570), wherein the first RF receiver (314, 510, 560, 570) is disposed to receive the RF signal after passing through the dispersal area of a first nozzle (176, 210, 215, 310, 360, 412, 414, 610, 802) of the plurality of nozzles, and the second RF receiver (314, 510, 560, 570) is disposed to receive the RF signal after passing through the dispersal area of a second nozzle (176, 210, 215, 310, 360, 412, 414, 610, 802) of the plurality of nozzles and wherein the controller is configured to detect plugging by comparing the output of the first RF receiver (314, 510, 560, 570) to an output of the second RF receiver (314, 510, 560, 570). at least one nozzle (176, 210, 215, 310, 360, 412, 414, 610, 802) configured to receive a fluid and direct atomized fluid to an agricultural surface; characterized in that a radio-frequency transmitter (312, 430, 620, 804) is disposed to generate an RF signal that passes through a dispersal area, wherein the RF signal is detectably changed when interacting with droplets of the atomized fluid; a first RF receiver (314, 510, 560, 570) is disposed to receive the RF signal after the RF signal passes through the dispersal area, the first RF receiver providing an output indicative of the RF signal; and a controller is coupled to the first RF receiver (314, 510, 560, 570) and configured to detect plugging of the at least one nozzle based on the output of the first RF receiver (314, 510, 560, 570) and on comparing attenuation of the received signal with reference, wherein the at least one nozzle (176, 210, 215, 310, 360, 412, 414, 610, 802) comprises a plurality of nozzles, the sprayer further comprising a second RF receiver (314, 510, 560, 570), wherein the first RF receiver (314, 510, 560, 570) is disposed to receive the RF signal after passing through the dispersal area of a first nozzle (176, 210, 215, 310, 360, 412, 414, 610, 802) of the plurality of nozzles, and the second RF receiver (314, 510, 560, 570) is disposed to receive the RF signal after passing through the dispersal area of a second nozzle (176, 210, 215, 310, 360, 412, 414, 610, 802) of the plurality of nozzles and wherein the controller is configured to detect plugging by comparing the output of the first RF receiver (314, 510, 560, 570) to an output of the second RF receiver (314, 510, 560, 570).