TITLE:
Effect of Curing Treatments on Seven Key Farmers’ Yams (Dioscorea spp.) in Ghana
AUTHORS:
Charles Tortoe, Solomon Dowuona, Nanam Tay Dziedzoave, Deborah Rees
KEYWORDS:
Yam, Dioscorea spp., Curing, Water Loss, Temperature, Humidity, Jute Sack, Grass Straw, Polypropylene
JOURNAL NAME:
Agricultural Sciences,
Vol.5 No.12,
October
29,
2014
ABSTRACT: Curing of freshly harvested yams (Dioscorea spp.) is a process for wounded yams during harvest to heal. In this work
the effectiveness of straw, polypropylene and jute sack on curing of seven key
farmers’ yam varieties over a duration of 7, 14 and 21 days was studied. Seven
key farmers’ yam varieties identified as Pona, Lariboko, Dente, Mutwumudoo, Serwah belonging to D. rotundata, Matches and Akaba belonging to D. alata were
studied under different curing treatments. The percentage weight loss of yam
tubers varied among the treatments over curing period. Curing under jute sack
showed all yam varieties had weight losses less than 2.0%, within 7 days of
curing. Five different varieties had weight loss less than 2.0% except Dente under the straw treatment. Mutwumudoo variety showed the highest
water loss (8.4%) for polypropylene sheet and 6.9% for Lariboko in the control treatment. During 7 days curing the control
and polypropylene treatment did not support yam curing. After 14 days of curing
of tubers, similar tends were observed as in 7 days curing. After 14 days of
curing under jute sack, percentage weight loss of the tubers ranges from 2.0% -
3.7%. In the straw treatment, the percentage weight loss ranges between 1.0% -
4.7% in all other varieties except Dente
(D. rotundata) (8.2%). Polypropylene sheet treatment showed the highest
percentage weight loss in Mutwumudoo variety (18.4%). A similar trend was observed for the yam tubers cured for
21days as percentage weight loss of tubers under jute sacks was 2.5 – 9.8%.
Curing temperature and humidity ranged between 27°C - 40°C and 87% - 100% rh
for yam tubers under the three different treatments of polypropylene, jute and
straw. However, the control treatment recorded lower humidity of 60% - 80% rh.
Curing material, duration, climatic conditions and yam varieties influenced
curing and Serwah variety, which is a D. rotundata is the best bet yam
variety to cure under jute sack for 7, 14 and 21 days of curing.