1. Crop Sciences Department; Federal University of Piauí; Campus Professora Cinobelina Elvas Bom Jesus Piauí Brazil
2. Agricultural, Environmental and Biological Sciences Center; Federal University of Recôncavo da Bahia; Cruz das Almas Bahia Brazil
3. Embrapa Semiárido; Petrolina Pernambuco Brazil
4. Agronomy Department; UNESP; Campus de Ilha Solteira Sao Paulo Brazil