Competição por luz no crescimento de raízes de arroz cultivado em competição com arroz vermelho

Abstract

The weed presence reduces the yield of paddy rice therefore compete for resources such as water, light and nutrients. Red rice is considered a mainly weed found in paddy rice fields in Southern Brazil, and this is difficult to control because they belong to the same species of cultivated rice. Red rice has a high size and development than the crop rice emergence, interfering mainly in competition for radiation; however, there are few studies about the impact of competition in the development of plant root system. Therefore, the aim of this study was to evaluate root growth in seedlings of rice and red rice in response to competition for light. The experiment was conducted in the agricultural season 2013/14, in a greenhouse at the Federal University of Pampa campus Itaqui, Rio Grande do Sul. The experimental was conducted in randomized complete block design, with five replicates. The first factor was composed of the red rice biotype Q35B and the IRGA 424, factor B consists absence or presence of light competition with red rice and the C factor was composed of times 0, 14, 21, 28, 35 days after transplantation. Under competition, red rice has a higher number of root tips than crop rice. Red rice has greater length, perimeter and area of root regardless of competition. The light competition reduces the area, perimeter, length and number of root tips in Q35B biotype and rice crop cultivar IRGA 424 from 21 days after transplantation.