EFFECTS OF IRRADIATION OF THE MOTHERPLANTS ON ROOTING OF PELARGONIUM CUTTINGS

Motherplants of three cultivars of Pelargonium x hortorum Bail. were irradiated from early October till late March at three temperature levels.
Cutting production was strongly enhanced by increasing light intensities.
Long day treatment with incandescent lamps did not increase the cutting production.
Largest number of cuttings were produced at 18°C. At 15°C the growth was too slow, and at 21°C the branching was depressed.

Until February cuttings from non-irradiated plants rooted faster and had more roots than cuttings from irradiated motherplants.
Later this tendency was reversed.

Early in the season cuttings from young motherplants rooted fastest.
Later, the difference between young and old motherplants diminished.

Symposium on Production of Potted Plants and Cut Flowers

Jarle H. Nilsen

https://doi.org/10.17660/ActaHortic.1976.64.8