PROGRAMMATION OF CUT FLOWER PRODUCTIONS FOR CHRYSANTHEMUM IN POLYETHYLENE TUNNELS

The aim of the experiment was cut flower production of Chrysanthemum X hortorum programmed for October-November and grown in large polyethylene tunnels.
This type of plastics structure has been chosen on account of economy : less expensive investment and less expensive antifreeze heating.

Two types of cultivars were put to the test : large flower ("Spider") and little flower ("Daisy"). We applied three photoperiodic treatments :

1. Natural short days.

2. Artificial short days by total darkening of plants from 18 h to 8 h, one month after planting until flower bud colouring.

3. Treatment similar to n° 2 but the beginning of darkening was two weeks after plantation.

The results show that programmed flowering is very possible ; moreover the date of the beginning of short days has a very clear effect upon the length of flower stems.

Carried out during several years with different types and cultivars these trials show that programmed flower production is possible by making use of common tunnels heated against frost under + 4°C. We may be led to use this heating from 1st October in some parts of France.

Symposium on Chrysanthemum

H. VIDALIE

https://doi.org/10.17660/ActaHortic.1982.125.19