Journal of Plant Process and Function

The objective of this study was to evaluate the nutritional role and efficiency of nano and micro Si on photosynthetic parameters and pigments of potato leaves (Agria cv.) in soil less culture. The factorial experiment based on randomized complete block design with three replications was conducted at the research greenhouse, Ferdowsi University of Mashhad in 2013. Treatments were included two sizes of sodium silicate particles (nano and micro) and three concentration levels (0.3, 0.6 and 0.9 mM) and control. The results showed that concentration effect and effect of interaction between of particle size and concentration was significant on chlorophyll a, chlorophyll b, total chlorophyll, a/b ratio, cartenoides, net photosynthesis, intercellular carbon dioxide, stomatal conductivity, instantly water use efficiency and mesophyll conductivity. In most of traits, Si concentration of 0.3 Mm had a positive effect. But, negative effect of silicon was observed at higher concentrations and nano particles in compared to micro particles imposed severe negative effects on traits. A significant correlation between photosynthesis, mesophyll conductivity, instantly and water use efficiency, concentration of chlorophyll a, b and total chlorophyll was observed. In contrast, intercellular carbon dioxide showed a negative correlation with all above mentioned traits.