Germination and emergence of citrus and tomato seeds in relation to temperature

SummaryTemperature had little effect on final percentage germination (radicle protrusion) or emergence (epicotyl appearance) of citrus and tomato seeds over the range 11°-30°C, but at about 35° there was less germination of citrus and no germination of tomato seed which showed thermodormancy. However, the rates of germination and emergence of citrus increased linearly and the time span between germination of the first and last seeds decreased with temperature (ll°-30°). The germination rate of tomato seed was related to temperature by a parabolic function. Small seeds had a lower percentage germination, but a faster rate, than large seeds. The minimum and optimum temperatures for citrus appeared to be about 6°-10° and 30° respectively, and for tomato about 11° and 25°C.