1. Institute of Tropical Ecology and Environmental Management, Visayas State University, Baybay City, Leyte, 6521-A Philippines
2. School of Agriculture, Forestry and Food Sciences, Bern University of Applied Sciences, Switzerland
3. Department of Agronomy and Soil Science, Visayas State University, Baybay City, Leyte, Philippines
4. Institute of Plant Production and Agroecology in the Tropics and Subtropics, University of Hohenheim, Stuttgart, Germany