Effects of irrigation withholding at reproductive stages and vermicompost and nano ‎silicon application on quantitative and qualitative yield and grain filling period of ‎safflower

the aim of ‎this study was to investigate the effects of silicon and vermicompost on quantitative and ‎qualitative yield and grain filling period of safflower.

an experiment was conducted as factorial based on RCBD with three replications in research farm of University of Mohaghegh ‎Ardabili during 2020. Factors experiment were included irrigation levels (full irrigation‏ ‏as ‎control, irrigation withholding in 50% of heading bud and flowering stages as severe and ‎moderate water limitation respectively) based on 55 and 65 BBCH code, foliar application ‎nano silicon (foliar application with water as control, application of 25 and 50 mg.L-1 nano ‎silicon) and application of vermicompost (no application of vermicompost as control, ‎application of 4 and 8 ton.ha 1).‎

The results showed that both application of vermicompost and foliar ‎application 50 mg.L-1 nano silicon under full irrigation increased chlorophyll index ‎‎(450.2%), number of head per plant (40%), number of gain per head (40%), 1000 grain ‎weight (45%), grain filling period and effective grain filling period (40.9 and 31.9% ‎respectively) in comparison with no application of vermicompost and nano silicon under ‎irrigation withholding in heading bud stage. Also, the highest vermicompost level under ‎full irrigation increased grain yield and oil percentage (119 and 26.2% respectively) in ‎comparison with no application of vemicompost under irrigation withholding in heading ‎bud stage. Based on the results, it seems that vermicompost and nano silicon application ‎can increase grain yield of safflower under water limitation condition due to improving ‎yield componenets and grain filling components.‎