SILICON APPLICATION IMPROVES GERMINATION AND VEGETATIVE GROWTH IN MAIZE GROWN UNDER SALT STRESS

Salinity stress is a major abiotic factor limiting growth and yield of agronomic crops including maize. The present study was conducted to categorize the latest maize cultivars according to their tolerance against salinity stress and to screen out the salt tolerant and sensitive maize cultivars at different growth stages. Initially 15 maize cultivars were categorized into three classes viz sensitive, medium and tolerant to salinity on the basis of germination parameters under control and 90 mM NaCl salinity. Eight selected cultivars were germinated in petri plates with 90 mM NaCl and 2 mM K2SiO3 in a second experiment. Application of Si increased all germination parameters under salinity stress irrespective of cultivars. Two cultivars contrasting in their salinity tolerance at germination (Syngenta 8441 and EV1089) were selected to evaluate role of Si at vegetative growth stage. Plants were grown in pots with 60 mM NaCl and 2 mM H2SiO3. Significant variation existed in both cultivars for growth and ionic concentration. Cultivar EV1089 performed better in non-saline conditions than Syngenta 8441; however, it could not tolerate salinity in root zone and significant reduction in biomass observed. Silicon application improved growth in both cultivars under salinity stress by reducing Na uptake and improving K uptake. Silicon nutrition management and selection of salinity tolerant cultivars can improve productivity of salt affected lands and more area can be taken under cultivation to feed ever increasing population.