1. Department of Statistic, Federal University of Santa Maria, Santa Maria, RS, Brazil
2. Department of Plant Protection, Federal University of Pelotas, Pelotas, RS, Brazil
3. Department of Statistic, Federal University of São Carlos, São Carlos, SP, Brazil
4. Federal University of Pampa, São Gabriel, RS, Brazil
5. Brazilian Agricultural Research Corporation, Embrapa Temperate Agriculture, Monte Bonito, Pelotas, RS, Brazil
6. Brazilian Agricultural Research Corporation, Embrapa Rice & Bean, Fazenda Capivara, Santo Antônio de Goiás, GO, Brazil