About the authors
Coyne, D. Claudius-Cole, A.
Disadvantages: There is the need for specialized equipment and a fuel/energy source; the process is time-
consuming and slow; it may reduce germination of treated material, particularly certain sensitive cultivars (Coyne
et al., 2010).
Chemical seed sett treatment
Cut seed setts immersed in chemical
dip. – D. Coyne
The use of a recommended fungicide-insecticide
combination before planting has provided excellent
results for producing healthy seeds. This is ideally
applied by dipping setts into a liquid suspension, then
leaving them to dry before planting. Studies in West
Africa showed that a combination of a compatible
fungicide and insecticide was most effective in
increasing the yield, quality, and storability of seeds
(Kenyon, 2005). It is important to receive local
information from agro-input suppliers on safe and
suitable products for this use. Chemical dusts can also
be used, but may result in an uneven distribution.
Disadvantages: Care is required to prevent unwanted human and environmental contamination and to ensure
the safe disposal of excess chemicals and packages; this method is not suitable for organic crop production.
The dual combination of hot water treatment followed by chemical dip is also a viable strategy, particularly when
dealing with poor quality initial material.
Tissue culture and vine cuttings
Tissue culture and vine cuttings are other technologies to mass-produce plants that form healthy mini-tubers to
be used as seed material. They allow the elimination of major pests such as nematodes if they are planted on
nematode-free land. However, as for hot water and chemical treatment, viruses cannot be fully eliminated and
plants must be monitored for these symptoms and affected plants eradicated. Research on both new
technologies is ongoing at IITA to optimize the procedures. These include the identification of the most suitable
media for meristem culture and alternatives to rice husks as the rooting media for vine cuttings.
Danny Coyne is a plant
stationed at IITA-Tanzania.
Abiodun Claudius-Cole is a
nematologist and a visiting
scientist at IITA-Ibadan.
Hidehiko Kikuno is a yam
physiologist with IITA-Ibadan.
A B CD
A. Main vine stem cut from the mother plant. B. Vine cutting, with a node and a leaf, excised from the
main stem. C. Vine cutting in the rooting medium. D. Harvested tubers from vine cutting. – H. Kikuno
Vine cuttings give a high multiplication rate without the use of tubers. Depending on the cultivar, size, and type of
mother plants, the multiplication rate of vines (about 20-50 times or more) and the size of tubers harvested will
both vary. The combination of tissue culture and vine cuttings gives even higher multiplication rates, rapid
growth, and clean tubers for seeds. However, there is a need for the validation of the technology with more
species and cultivars in different agro-ecological zones. Nevertheless, it is expected that this technology can be
simplified so that NARIs and seed producing farmers can apply it and produce healthy seed tubers (Kikuno,
Disadvantages: Tissue culture facilities are needed and the availability of rice husks for making carbonized rice
husks as the rooting media is limited in some areas where rice is not cultivated.
This Technical Innovation
Brief is published by:
Coyne, D.L., Claudius-Cole, A.O., Kenyon, L., and Baimey, H. (2010). Differential effect of hot water treatment on whole
tubers versus cut setts of yam (Dioscorea spp.). Pest Management Science 66, 385-389.
Kalu, B.A., Norman, J.C., Pal, V.R. and Adedzwa, D.K. (1989). Seed yam multiplication by the mini-sett technique in three
yam species in a tropical guinea savannah location. Experimental Agriculture 25, 181-188.
Kenyon, L. (2005). Final Project Technical Report for: Evaluation and promotion of crop protection practices for ‘clean’ seed
yam production systems in Central Nigeria (R8278). Crop Protection Programme, NR International, UK.
Kikuno, H. (2009). New yam-growing technique. Appropriate Technology 36:2, 36-37.
SP-IPM Steering Committee Members:
Sikora, R. (Program Chair); Nwilene, F. (AfricaRice); Ramasamy, S. (AVRDC); Staver, C. (Bioversity); Buruchara, R. (CIAT); Nicol, J. (CIMMYT); Kroschel, J. (CIP); Yahyaoui, A.
(ICARDA); Chabi-Olaye, A. (icipe); Sharma, H. (ICRISAT); Narrod, C. (IFPRI); Bandyopadhyay, R. (IITA); Heong, K.L. (IRRI); Bramel, P. (DDG – R4D convening center, IITA);
Hoeschle-Zeledon, I. (Program Coordinator, IITA)