A method and system of improving the growth of plants belonging to the family Solanaceae by providing a plant nutrient solution about the plant roots and a gas mixture circulating about the plant shoot； by selecting the gas mixture and plant nutrient solution temperature independently of the other； and providing a plant nutrient solution to gas mixture temperature differential of approximately at least approximately 10° F. during different phases of plant development. The method and system improves plant development to improve a desired plant organ for industrial, scientific, and medical purposes. A method of improving the growth and development of Solanaceae plants by providing a shoot-to-root temperature differential to treat or prevent infection by a plant pathogen and/or infestation by pests.
