Taro (Colocasia esculenta) and tanier (variously known as malanga, otoy, otoe, cocoyam, tannia, tannier, yautía, among other names; Xanthosoma spp.) are two tropical root crops of the arum family (Araceae). They are grown for their corms and cormels (starchy underground stems). Although global production is modest, the crops are locally important, especially in subsistence agriculture.
Early modeling of the two crops by the DSSAT community was based on the SUBSTOR model (Goenaga et al., 1991; Prasad et al., 1991; Singh et al., 1998). In 2004, the model was incorporated as the AROID module of Cropping System Model (CSM; Jones et al., 2003), enabling use of the shared soil water, nitrogen, and carbon dynamics and other features.
Growth is simulated on a daily basis using a CERES-type radiation use efficiency approach. The model calculates the number of leaves, suckers, and cormels produced. All plant components are reported as dry weights. Seven developmental stages are recognized, including specific onset and end of corm growth, the latter followed by maturity. These stages are not as well defined as in seed crops and merit further investigation. Both temperature and photoperiod may affect development. The model allows planting from transplants and calculates a transplant shock using the approach developed for CSM-CERES-Rice.
Data sets for model calibration and evaluation are limited. There is a single dataset for tanier (from Isabela, Puerto Rico) and five for taro (Isabela, Puerto Rico). As a process-based model, the AROID module can be applied to a wide range of research problems, including response to nitrogen and potential response to climate change (Singh, 1992). However, given the limited set of data used to develop and test the model, further testing under field conditions is a high priority.
References
- Goenaga, R., Singh, U., Beinroth, F.H. and Prasad, H. 1991. SUBSTOR‐Aroid: A model in the making. Agrotechnology Transfer 14: 1–4.
- Jones, J.W., G. Hoogenboom, C.H. Porter, K.J. Boote, W.D. Batchelor, L.A. Hunt, P.W. Wilkens, U. Singh, A.J. Gijsman, and J.T. Ritchie. 2003. The DSSAT cropping system model. European Journal of Agronomy 18:235–265.
- Prasad, H.K., U. Singh, and R. Goenaga. 1991. A simulation model for aroid growth and development. Agronomy Abstracts 7, American Society of Agronomy, Madison, Wisconsin.
- Singh, U. (Editor). 1992. Proceedings of the Workshop on Taro and Tanier Modeling. College of Tropical Agriculture and Human Resources, University of Hawaii, Honolulu, Hawaii.
- Singh, U., Matthews, R.B., Griffin, T.S., Ritchie, J.T., Hunt, L.A. and Goenaga, R., 1998. Modeling growth and development of root and tuber crops. In Understanding options for agricultural production (pp. 129-156). Springer, Dordrecht, the Netherlands.
- Singh, U., Tsuji, G.Y., Goenaga, R. and Prasad, H. K. 1992. Modeling growth and development of taro and tanier. Proceedings of the Workshop on Taro and Tanier Modeling. Edited by: Singh, U. pp.45–56. College of Tropical Agriculture and Human Resources, University of Hawaii, Honolulu, Hawaii.