Methods and systems for the prevention of citrus greening by application of liquid sugar to citrus leaves to otherwise inhibit, reduce and or eliminate the ability of psyllids to transmit the bacteria responsible for citrus greening. Liquid sugar, in either undiluted or diluted solutions, can be directly or indirectly applied to citrus leaves to treat psyllids at various stages of development. The use of liquid sugar to combat citrus greening can also increase the amount of caloric energy directly available to the citrus tree for photosynthesis, and provide energy to the soil to enhance microbial activity within the soil. Furthermore, the use of liquid sugar to prevent citrus greening is non-harmful to bees and can encourage the return of commercial beekeepers to citrus groves.
