The object of this work was to simulate the total number of leaves issued, by using two mathematical models; one to consider the linear effect, and one the nonlinear effect of air temperature on leaf appearance in the cassava. Two versions of each model were used, one version for the mean daily air temperature and the other for the daily minimum and maximum air temperatures. The Wang-Engel model for the cassava was also validated. For the linear model, the phylochron model was used and for the nonlinear, that of Wang-Engel. To estimate the coefficients of the models, a data-set of the number of leaves on the main stem and on the first and second order sympodial branching of the cassava, variety Fepagro RS 13, was used, the data being collected in experiments conducted during the 2005/2006 and 2007/2008 growing seasons. Evaluation of the models was carried out using independent data collected in the 2006/2007, 2008/2009, 2009/2010 and 2010/2011 seasons. The Wang-Engel model gave a better estimate for the number of leaves in the cassava, with lower values for the root mean square error compared to the phylochron model.
Manihot esculenta; Number of leaves; Air temperature
