A field experiment was conducted during rainy (kharif) season of 1999 and 2000 at Research Farm, Department of Agronomy, Banaras Hindu Univeristy, Varansi, Uttar Pradesh, to study the effect of level and time of silicon application on growth, yield and economics of rice (Oryza sativa L). Different silicon levels led to significant increase in plant height, dry-matter production, panicles/m2, filled grains/panicle, test weight and yield of rice. The maximum grain yield (6,588 kg/ha) was recorded with highest level of silicon, i.e. 180 kg Si/ha. However, the maximum response was observed at 127 kg Si/ha and thereafter decreased with increase in silicon level. Highest net returns and benefit: cost ratio were recorded when silicon was applied @ 120 kg Si/ha full as basal. The apparent silicon recovery and agronomic efficiency were higher at the lowest silicon level (60 kg Si/ha) and decreased with increasing silicon levels. However, the highest nitrogen, phosphorus, potassium and silicon uptake was associated with 180 kg Si/ha. Among the application time, full basal application of silicon at the time of transplanting significantly increased the growth, yield attributes, yield and uptake of nutrients compared with the other time of silicon application.
Silicon level, Application time, Nutrients uptake, Apparent silicon recovery, Agronomic efficiency, Rice
