Propagation, growth and yield of Boweia volubilis L. bulbs as affected by growth regulators, manure and inorganic fertilization

Abstract

Boweia volubilis L. is an endangered indigenous bulb that is highly valued for its medicinal properties
by local communities. A method has been developed for rapid multiplication of B. volubilis L. from
bulbs under nursery conditions. Bulbs of two sizes were cut longitudinally into four quarters, treated
with solutions of varying concentrations of NAA, BAP and kinetin, germinated in river sand and
transplanted into the field. The mean survival rate of the larger bulb quarters (98.1%), their rooting
percentage (91.8%), the number of roots (3.8 roots/bulb quarter) and root dry weight (0.11 g/plant) were
higher than those of smaller ones at 1 to 2 mg L-1
NAA. The percentage of new bulbs formed (98%),
number of bulblets (3.6 bulbs/bulb quarter) and bulblet fresh weight (12.78 g/bulb quarter) were highest
in larger bulbs treated with 2.0 mg L-1
BAP. The combination of manure and inorganic fertilizer gave the
highest fresh weight (66.99 g/bulb) and diameter (66.7 mm) at 8 months of growth. These findings
suggest that larger bulbs should be selected for propagation because they had superior rooting ability
and a high survival rate. It is recommended that BAP at a concentration of 2 mg L-1
be used for
propagation of this species. Although inorganic fertilization combined with manure gave a better yield,
further work is needed to establish their effect on production of phytochemicals that are responsible for
its medicinal uses