Elevated Root-zone Temperature Research Articles

Effect of root-zone heating on growth, flowering and keeping quality of Saintpaulia

Two cultivars of Saintpaulia (‘Rhapsody’ Nos. 19 and 49) were subjected to three levels of root-zone temperatures, ranging from 17 to 25°C. High root-zone temperatures accelerated flowering as a result of an enhanced rate of plant growth and a promoted flower development; growth analysis showed an increased LAR, resulting in higher growth rates. The percentage plant dry matter decreased compared to the unheated control. Root-zone heating increased the air temperature around the plant and therefore the leaf temperature and growing-point temperature were also increased. Elevated root-zone temperatures reduced cultivation time by 10–15% without unfavourable effects on plant quality and keepability.