Effects of silicon application and irrigation halting on yield, yield components and bending moment of rice (Oryza sativa L.) Tarom Mahalli cultivar

In order to investigate the effects of silicon application and irrigation halting on yield, yield components and bending moment of rice, a field experiment was carried out in split plot in basis of randomized complete block design with three replication at Dashtnaz Agricultural Research field in 2008. Main plot was irrigation halting in four levels including (irrigation halting at start, middle and end of tillering and at 50% flowering stages). Sub plot was silicon application in three levels including (0, 500 and 1000 kg Si ha-1). Results showed that irrigation halting in early tillering stage decreased plant height, panicle length, tiller per hill, fertile tiller, panicle per m2, spikelet per panicle and grain yield (329.22 g.m2) significantly. Irrigation halting in middle of tillering stage also decreased 1000 grain weight (21.11 g). The highest number of tiller per hill, fertile tiller per hill, panicle per m2 and grain yield (408.78 g.m2) were obtained in irrigation halting at 50% flowering stage. Least fourth internode bending moment at irrigation halting were produced in middle of tillering stage with use of 500 kg Si ha-1. Maximum number of panicle per m2 was recorded in response to interaction effects of Silicon and irrigation halting at 50% flowering stage where 1000 kgha-1 Silicon was applied. According to the results obtained in this Study, the beginning of tillering is the most sensitive stage to irrigation halting as caused sever reduction of yield and yield components.