, produção de grãos e peso hectolítrico. A melhor época para se realizar a adubação potássica na cultura do arroz foi na semeadura.
Palavras-chave:Oryza sativa L., potássio, época de aplicação, cultivar.
ABSTRACT. Potassium management in upland rice sprinkler irrigation.The fertilizer use is one of the most important factor on the rice productivity. In the world, the higher productivity is reached by chemical fertilization. There are few researches about potassium fertilization. In this context, the experiment was carried out on a Typic Haplustox, in Selviria, MS, Brazil, with the objective of evaluating two rice cultivars performance (IAC 201 and IAC 202), Oryza sativa L. (Poaceae), as a function of potassium fertilization management (sowing, tillering, panicle differentiation) under sprinkler irrigation. The experimental design was of randomized blocks in a fatorial outline 2x8 with four replicates. The IAC 201 cultivar had higher laying index, on the other hand, the IAC 202 cultivar had the best performance in all of agronomic characters, like plants' height, panicule m -2 , yield and hectolitric weight. The best period to carry out potassium fertilization was seed sowing time.