181-23 Effects of Provenance, Growth and Storage Agroecology on the Timing of Sprouting In Yam (D. rotundata Poir.).



Tuesday, October 18, 2011: 3:30 PM
Henry Gonzalez Convention Center, Room 213A, Concourse Level

Elsie I. Hamadina, Department of Crop and Soil Science, University of Port Harcourt, Port Harcourt, Nigeria, Peter Craufurd, ICRISAT, Hyderabad, AP, India and Robert Asiedu, IITA, Ibadan, Oyo State, Nigeria, Nigeria
Provenance, growth and storage environments are hypothesized to control the timing of sprouting of yam (Dioscorea spp.) tubers. A factorial (provenance X storage 1 X growth X storage 2) experiment was conducted to determine the effect of provenance on the timing of sprouting  of D. rotundata tubers and quantify the effects of growth and storage environments on the timing of sprouting . Tubers of eleven landraces were collected from three agroecological zones in Nigeria (Guinea savannah -GS, Moist savannah transition -MS and the Humid forest-HF) and grown, to multiply tubers, at a location (Abuja-GS, Ibadan-MS and Onne-HF )representing their respective agroecological zones. A third of the harvested tubers of each landrace(provenance) was stored at one of the three locations (i.e., in storage 1). In the subsequent growth and then storage 2 levels of the study, tubers were also crisscrossed. Sprouting time was not signifacantly (p=0.05) influenced by provenance. Thus, neither provenance per se nor the difference in the timing of the start of the rains at these agroecologies may be cue for sprouting time. Storage and growth agroecology modulates sprouting time slightly (10 - 20 d). Sprouting occurred 18 d earlier when tubers are stored at Onne than at Abuja. Sprouting occurred 11 d earlier when yams were grown at Onne than at Abuja and their combined effect was additive, with sprouting occurring earlier by 36 day of year (DOY) when grown and stored at Onne compared with 66 DOY when grown and stored at Abuja.  The effect of storage location could not be explained by a linear function of sprouting DOY and thermal time (oCd) using average temperature. After removing the effects of storage 2 and growth environment, sprouting time was not affected by storage 1. Thus, yam may not keep memory of the effect of a previous storage.
See more from this Division: ASA Section: Agronomic Production Systems
See more from this Session: General Agronomic Production Systems: I