Effect of Silicon in Control of Leaf Blast of the Rice in Northern Mato Grosso

Abstract

The  application  of  silicon  in  rice  has  shown  effectiveness  in  controlling  diseases  such  as  leaf blastl.  Therefore  this  study  evaluated  the  application  of  foliar  silicon  in  rice  under  the  growthconditions in the state of Mato Grosso, for leaf blast control. The experiment conducted in the field, Socreppa  Munhoz farm, municipality  of Porto  the Gaúchos/MT. The  experimental design was randomized, three treatments with ten replications each. The treatments consisted of foliar application of potassium silicate (Sili-k®, with 171 g Si L-1 and 210 g L-1K2O) dose of 3.0 kg ha-1with an application, two applications, and an untreated control. Evaluation of leaf blast was realized in the four upper  leaves  in the main tillers of the plant on 10 tillers randomly collected in the four central rows of each plot. The severity of leaf blast was determined using a scale of 10 degrees (0; 0.5; 1.0; 2.0; 4.0; 8.0; 16.0; 32.0; 64.0 and 82.0% leaf area affected). Thr ee assessments were made  at  intervals  of  0,  19  and  34  days  after  application  for  calculating  the  area  under  the disease  progress  curve  (AUDPC).  The  best  results  in  reducing  the  AUDPC  were  with  an application of potassium silicate. Flag leaf with two applications resulted in less severity leaf blast.