Open Access  Subscription Access

Some native subsistence farmers in South Africa store maize (Zea mays L.) cobs over a fireplace and subject the seeds
to smoke and heat. Taro (Colocasia esculenta L. Schott.) propagules are
maintained in dry pits for one month, in layers separated by grass straw, and
water is prevented from contacting them. These methods have been used together
with others to maintain landraces for centuries, but they have largely been
abandoned with no modern technology replacements. The objective of this study
was to examine the effects of the maize and taro storage methods on the quality
of planting material. Experiments were conducted on three subsistence farms
located in KwaZulu-Natal, and at the University of KwaZulu-Natal, South Africa. Two maize landraces, yellow and white, were subjected to the smoke-over-fire
storage method for five months during the normal off-season period for maize
production in the location. Control maize seeds were stored in unsealed
containers away from fire and smoke. Taro propagules of different sizes (80–100g
corm^–1, 40–60g corm^–1 and 20–30g corm^–1) were
compared for storability in dry pits, in layers separated by grass straw, for
one month. Subsequently, sprouted corms were stored in dry conditions to allow
shoot development. During maize seed storage, water content was determined
monthly. Maize seed quality was determined by viability, germination and
seedling vigour. Sprouting and rooting during taro pit storage, and main shoot
development during air storage were used to determine taro propagule performance
in storage. Seeds that were stored over fire and smoke showed higher
germination and vigour that non-smoked seed. Sprouting and shooting of taro
propagules were better in large propagules and the optimum storage depth was
35cm to 40cm. a-amylase activity
increased during pit storage and declined to almost the pre-storage levels
during shoot growth period outside the pits, in all corm sizes. It is concluded
that smoke and heat storage improve maize seed quality and pit storage enhances
taro propagules by inducing sprouting. Data from this study can be used to
investigate the physiological and biochemical basis of seed and propagule
quality enhancement, and possibly contribute to technological inventions that
are based on indigenous knowledge systems.

South African Journal of Botany
2004, 70(1): 16–23