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Efficiency of early selection in Calycophyllum spruceanum and Guazuma crinita, two fast-growing timber species of the Peruvian Amazon

Jonathan P. Cornelius, Roger Pinedo-Ramírez, Carmen Sotelo Montes, L. Julio Ugarte-Guerra, John C. Weber
Canadian journal of forest research 2018 v.48 no.5 pp. 517-523
Calycophyllum, Guazuma, agroforestry, capital, cost effectiveness, discount rate, early selection, field experimentation, forest trees, genetic improvement, germplasm, income, plant improvement, plantations, Amazonia, Peru
Bolaina (Guazuma crinita Mart., Malvaceae) and capirona (Calycophyllum spruceanum (Benth.) Hook. f. ex K. Schum., Rubiaceae) are fast-growing Amazonian timber trees. In Peru, they are increasingly being used in agroforestry systems and plantations, and interest in developing improved germplasm is growing. However, tree improvement incurs both direct costs and interest costs on investments; because of this, early selection is of interest. We examine the efficiency of early selection 13 or 17 months after field trial establishment. These are compared with selection after 49 or 53 months using two efficiency metrics: one based on discounted response to selection per unit of present value of cost, and the second on net discounted revenues, using discount rates of 5%, 10%, and 15%. Our metrics differed from those used in previous studies by taking into account direct costs, as well as costs of capital. We found that in most scenarios, early selection was attractive, partly due to direct cost savings. We conclude that in evaluating the efficiency of early selection, lack of consideration of direct costs may produce erroneous results. We also explore some general implications of the results.