Effect of High Electric Fields on the Germination and Early Growth of Some Vegetable Seeds

Abstract

Seeds of 'Sunny' lettuce, Chinese cabbage, 'Tsumamina', Japanese radish, 'Tokinashi' and 'Kaiware' were exposed to positive- and negative-DC and AC fields with a frequency of 60 Hz. Six intensities of electrical fields, ranging from 18 to 105 kV•m^-1, were ap-plied to seeds held in the dark at 25°C and a relative humidity of 60%. The effect of the treatments on the percentage germination and the mean days to complete germination was recorded.
1. The AC electrical field in an experimental range from 18 to 105 kV•m^-1 hastened germination rate and shortened the mean days of germination for 'Tsumamina', 'Toki-nashi' and 'Kaiware' seeds. The seeds 'Kaiware' daikon were most responsive.
2. The germination rate of 'Sunny' lettuce seeds was stimulated by DC from 65 to 105 kV•m^-1 and all AC electrical fields, but their mean days to complete seed germination was unaffected.
3. Under AC electrical fields of more than 50 kV•m^-1, early growth of the seedlings, especially those 'Tokinashi' and 'Kaiware' daikon, was significantly promoted compared with that of the control. On the other hand, DC positive and negative fields had promo-tive and inhibitory effects depending on the field strengths.