1. Department of Agronomy, Federal Rural University of Pernambuco, Serra Talhada, Brazil
2. Department of Agronomy, Federal Rural University of Pernambuco, Recife, Brazil
3. US Department of Interior, Bureau of Land Management, National Operations Center, Denver, CO, USA
4. Department of Biology, Federal Rural University of Pernambuco, Serra Talhada, Brazil
5. Department of Research, Agronomic Institute of Pernambuco, Recife, Brazil