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Effects of shoot tipping on development and yield of the tuber crop Plectranthus edulis

Published online by Cambridge University Press:  27 September 2011

M. TAYE
Affiliation:
Hawassa University College of Agriculture, P. O. Box 5, Awassa, Ethiopia
W. J. M. LOMMEN*
Affiliation:
Centre for Crop Systems Analysis, Plant Sciences Group, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
P. C. STRUIK
Affiliation:
Centre for Crop Systems Analysis, Plant Sciences Group, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
*
*To whom all correspondence should be addressed. Email: Willemien.Lommen@wur.nl

Summary

Plectranthus edulis (Vatke) Agnew is one of the tuber crops of the genus Plectranthus that is widely cultivated in Africa and Asia. P. edulis produces below-ground tubers on stolons originating from the stems, comparable to the potato (Solanum tuberosum L.). Farmers apply several laborious cultural practices to enhance shoot growth and yield, among which shoot tipping is very common. Tipping (pinching) is the removal of the shoot apex with one or two pairs of leaves from the main stems and branches. The rationale of this practice, especially when repeated more than once during one cropping season, is not fully understood. One similar experiment with two cultivars was carried out at two locations (Awassa and Wondogenet) in Ethiopia to assess and analyse the effects of shoot tipping and its frequency on crop development and tuber production. Tipping treatments included zero tipping, tipping once, tipping twice and tipping thrice, with the first tipping taking place 68 days after planting (DAP), a stage at which most of the stems reached a height of about 0·15 m, and the remainder following at intervals of 44–46 days. Tipping stimulated stem branching; it significantly increased the number of primary, secondary and tertiary stems in both experiments. Soil cover increased with an increase in the frequency of the tipping in Awassa, because of the tipping effects on the different canopy development variables. Tipping also enhanced the soil cover in Wondogenet, but the crop did not gain any extra benefit from a third tipping. Tipping enhanced early stolon formation, but did not consistently affect the number of stolons per hole later in the growing season. The number of tubers increased with an increase in the frequency of tipping in both cultivars in Wondogenet and in one cultivar in Awassa. Tuber dry matter yield increased with an increase in the frequency of tipping at both sites. Fresh tuber yield in the final harvest at 208 DAP was c. 1·9 kg/m2. Tipping on average increased fresh tuber yield by 17% in Wondogenet, whereas the difference was not detectable in Awassa. Because senescence was delayed slightly by tipping, yield effects of tipping might be larger when harvesting later. In general, there was a positive effect of tipping on canopy development and tuber yield.

Type
Crops and Soils Research Papers
Copyright
Copyright © Cambridge University Press 2011

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References

REFERENCES

Allen, E. J., Bean, J. N., Griffith, R. L. & O'Brien, P. J. (1979). Effects of length of sprouting period on growth and yield of contrasting early potato varieties. Journal of Agricultural Science, Cambridge 92, 151163.CrossRefGoogle Scholar
Asfaw, Z. & Woldu, Z. (1997). Crop associations of home-gardens in Welayta and Gurage in southern Ethiopia. SINET, An Ethiopian Journal of Science 20, 7390.Google Scholar
Bremner, P. M. & Taha, M. A. (1966). Studies in potato agronomy I. The effects of variety, seed size and spacing on growth, development and yield. Journal of Agricultural Science, Cambridge 66, 241252.CrossRefGoogle Scholar
Bryan, J. E., Meléndez, G. N. & Jackson, M. T. (1981). Stem Cuttings, a Rapid Multiplication Technique for Potatoes. CIP Slide Training Series: Series I: Rapid Multiplication Techniques. Guide-Book I/3. Lima, Peru: International Potato Center (CIP).Google Scholar
Burstall, L., Thomas, M. N. & Allen, E. J. (1987). Some effects of shading on tuber set and development. Potato Research 30, 142143.Google Scholar
Dun, E. A., Ferguson, B. J. & Beveridge, C. A. (2006). Apical dominance and shoot branching: divergent opinions or divergent mechanisms. Plant Physiology 142, 812819.CrossRefGoogle ScholarPubMed
Greenway, P. J. (1944). Origins of some of East African food plants. Part 1. East African Agricultural Journal 10, 3439.CrossRefGoogle Scholar
Haverkort, A. J., Van de Waart, M. & Bodlaender, K. B. A. (1990). Interrelationships of the number of initial sprouts, stems, stolons and tubers per potato plant. Potato Research 33, 269274.CrossRefGoogle Scholar
Haverkort, A. J., Uenk, D., Veroude, H. & van de Waart, M. (1991). Relationships between ground cover, intercepted solar radiation, leaf area index and infrared reflectance of potato crops. Potato Research 34, 113121.CrossRefGoogle Scholar
Jansen, P. C. M. (1996). Plectranthus rotundifolius (Poiret) Sprengel. In Plant Resources of South-East Asia No. 9. Plants Yielding Non-Seed Carbohydrates (Eds Flach, M. & Rumawas, F.), pp. 141143. Leiden: Backhuys Publishers.Google Scholar
Lommen, W. J. M. & Struik, P. C. (1994). Field performance of potato minitubers with different fresh weights and conventional seed tubers: crop establishment and yield formation. Potato Research 37, 301313.CrossRefGoogle Scholar
Lommen, W. J. M. & Struik, P. C. (2007). The canon of potato science: 26. In vivo cuttings. Potato Research 50, 309313.CrossRefGoogle Scholar
Menzel, C. M. (1981). Tuberization in potato at high temperatures: promotion by disbudding. Annals of Botany 47, 727733.CrossRefGoogle Scholar
O'Brien, P. J., Firman, D. M. & Allen, E. J. (1998). Effects of shading and seed tuber spacing on initiation and number of tubers in potato crops (Solanum tuberosum). Journal of Agricultural Science, Cambridge 130, 431449.CrossRefGoogle Scholar
Olasantan, F. O. & Salau, A. W. (2008). Effect of pruning on growth, leaf yield and pod yields of okra (Abelmoschus esculentus (L.) Moench). Journal of Agricultural Science, Cambridge 146, 93102.CrossRefGoogle Scholar
Smith, T. M. (2003). Production Guidelines for Four Crops: Osteospermum, Angelonia, Calibrachoa and Ornamental Sweet Potato (Ipomoea batatas). Fact Sheet. Department of Plant and Soil Sciences, University of Massachusetts, Amherst, USA. Available online http:// www.umass.edu/umext/floriculture/fact_sheets/specific_crops/newcrops.html (verified 9 August 2011).Google Scholar
Taye, M., Lommen, W. J. M. & Struik, P. C. (2007). Indigenous multiplication and production practices for the tuber crop Plectranthus edulis in Chencha and Wolaita, southern Ethiopia. Experimental Agriculture 43, 381400.CrossRefGoogle Scholar
Van der Veeken, A. J. H. & Lommen, W. J. M. (2009). How planting density affects number and yield of potato minitubers in a commercial glasshouse production system. Potato Research 52, 105119.CrossRefGoogle Scholar
Westphal, E. (1975). Agricultural Systems in Ethiopia. Agricultural Research Reports 826. Wageningen, The Netherlands: Centre for Agricultural Publishing and Documentation (PUDOC).Google Scholar