CLASSIFICATION OF RICE GRAINS OF LOWLAND CULTIVARS GROWN UNDER FLOOD IRRIGATION AND SPRINKLER IRRIGATION

ABSTRACT The objective of this study is to analyze the classification of rice grains of lowland cultivars grown under flood and sprinkler irrigation. The study was carried out in the agricultural years 2011/2012 and 2014/2015 using a completely randomized block design with split plots. In 2011/2012, the treatments were three lowland rice cultivars grown under flood irrigation system and five sprinkler irrigation depths with four replications. In 2014/2015, the experimental design was maintained but flood irrigation was not performed. After harvest, the samples were processed in a rice testing machine, including peeling, polishing and classification. Whole and broken grains were weighed to calculate hulling and milling yield. The classifications followed the guidelines described in Normative Instruction No. 6 of the Ministry of Agriculture, Livestock, and Supply of Brazil. In 2011/2012, there was interaction between sprinkler irrigation depths and the cultivars on hulling and milling yield, and in 2014/2015, there was significant difference in hulling yield between the cultivars. Genetic characteristics and water availability affected the classification of rice grains grown under sprinkler irrigation. In two sprinkler irrigation depths, the quality of the grains was similar to flood irrigation system. The highest milling yield was obtained in cultivar IRGA 417.