Iodine Applications in Onion Cultivation

Although iodine is not considered as one of the essential elements in plant nutrition, health problems arise in humans and animals consuming those plants in case of deficiency in plants and trace amounts in plants are beneficial for human health.However, iodine application to plants can have a negative or positive effect on plant growth depending on the species and variety.In this study, the effects of foliar application of iodine on morphological and plant effects and Malondialdehyde (MDA) contents of three onion cultivars grown in nutrient solution were investigated.Foliar iodine applications promoted plant growth in purple and yellow onion, while in white onion, this effect was suppressive in shoots and promotive in roots.MDA levels were higher in white onion where iodine had a suppressive effect on vegetative growth compared to other varieties.It is thought that the suppressive or promotive effect of iodine application on vegetative growth of onion varieties depends on the genotype.