Articles
IMPROVING HIPPEASTRUM PROPAGATION AND BULBIL YIELD BY CUTTING AND INCUBATION TECHNIQUES
The growth in terms of the numbers of bulbs produced and the overall area cultivated demands optimization of the propagation method and a shortening the growing period.
Various bulb cutting techniques, incubation, and growing methods were studied for the purpose of producing propagules in one growing season, that are capable of developing into marketable bulbs after only one additional growing season.
‘Red Lion’ bulbs were cut into ‘chips’ (12 segments/bulb) or ‘half-chips’ (24 /bulb) and planted immediately in a greenhouse which was soil heated to 20°C. The results of 11 months’ growth indicate the superiority of the ‘half-chip’ method in which 28.5 bulbils developed per cut bulb compared with 20.4 bulbils obtained by the ‘chip’ method.
Approximately 80% of the bulbs produced by both techniques were of size 12+ (cm in circumference). "Outer" half-chips gave higher yields than the "inner" halves (16.2 and 12.3 bulbils/bulb respectively). Incubation of ‘twin-scales’, ‘chips’ and ‘half-chips’ in vermiculite (4.5 months at 23°C) followed by spring planting in a screen-house, was compared with direct planting in the greenhouse.
Ten months after bulb cutting, direct planting and pre-incubation yielded averages of 40.3 and 30.4 bulbils/bulb, respectively.
Direct planting yielded larger bulbs then the incubation method.
The percentage of bulbs larger than size 12 was in direct planting 17.5, 46.5 and 54 for ‘twin-scales’, ‘half-chips’ and ‘chips’ respectively, and after pre-incubation 0, 1.0 and 57%, respectively.
The results demonstrate an advantage in the use of the ‘half-chip’ technique followed by direct planting.