The effects of vermicompost and nano silicon on yield and the trend of changes some ‎physiological traits of rye (Secale cereal L.) in different irrigation regimes‎

Background and objectives: Drought is one of the most important factors limiting crop production. ‎Several methods have been proposed to increase the resistance of crops against water limitation. In this ‎regard, the use of vermicompost and silicon can improve the performance of crop plants under stress ‎conditions. Considering the above fact, thr present study was undertaken to evaluate the effects of ‎nanosilicon and vermicompost application on grain yield and the trend of changes some physiological ‎traits (i.e, chlorophyll index, nitrogen index, relative water content, leaf electrical conductivity and ‎stomatal conductivity) of rye in different irrigation regimes.‎
Materials and methods: a factorial experiment based on randomized complete block design with three ‎replications was conducted under the research greenhouse conditions in 2023. Treatments were various ‎irrigation regimes (normal irrigation as control, irrigation withholding at 50% of booting and heading ‎stages as severe and moderate water limitation, respectively), application of nanosilicon and ‎vermicompost at four levels (no application as control, application of nanosilicon, vermicompost, both ‎application vermicompost and nanosilicon). Vermicompost was prepared from Gilda corporation and ‎silicon from Pishgaman Nanomaterials Company. Nano silicon was with the average of particle size of ‎less than 30 nm. Foliar application of Si was done in stages of tillering and stem elongation (BBCH 21 ‎and 30, respectively).‎‏ ‏Two weeks after irrigation withholding in booting stage, some biochemical and ‎physiological traits were measured on the flag leaf. The trend of changes some traits such as chlorophyll ‎index, nitrogen index, relative water content, leaf electrical conductivity and stomatal conductivity were ‎measured at time intervals every four days from 135 to 150 days after planting.‎‏ ‏Analysis of variance was ‎done by software package SAS v9.12. The main effects and interactions were compared by LSD test at the ‎‎0.05 the probability level, using the SAS version 9.1. ‎
Results: study of the trend of changes some physiological traits showed that in 151 days after planting
under irrigation withholding at of booting conditions, application of vermicompost and nano silicon ‎increased chlorophyll index (47.9%), nitrogen index (47.6%), relative content of flag leaf (30.2 %), ‎stomatal conductance (12.8%), root weight and volume (22.3 and 28.3%, respectively), plant height ‎‎(32.5%), spike length (32.2%), the number of grains per spike (40.2 %) and grain yield (7.3%) as ‎compared to no application of nano silicon and vermicompost at the same level from irrigation levels. ‎Also, under irrigation withholding at of booting stage conditions, no application of nano silicon and ‎vermicompost increased electrical conductivity (13.8%), hydrogen peroxide content (26.7%) and ‎malondialdehyde (9.8%) as compared to application of nano silicon and vermicompost at the same level ‎from irrigation levels.‎
Conclusion: Therefore, with considering of the results of this study, it can be stated that, applying ‎nano silicon and vermicompost were able to compensate part of the yield reduction caused by water ‎limitation by improving some physiological traits of rye.‎