Influence of Iron, Potassium, Magnesium, and Nitrogen Deficiencies on the Growth and Development of Sorghum (Sorghum bicolor L.) and Sunflower (Helianthus annuus L.) Seedings

Plant mineral nutrition is a vital area of research to understand the mineral needs of plants, especially crops, and increase crop yields. The objective of this study was to investigate the impact of iron (Fe), potassium (K), magnesium (Mg), and nitrogen (N) deficiencies on the growth and development of sorghum and sunflower. Fe-deficient sorghum and sunflower plants had slightly reduced plant height, root length, and leaf numbers. Leaf chlorosis and necrosis is extreme in sorghum leaves compared to sunflower leaves which exhibited slight leaf chlorosis and necrosis limited to their edges. K-deficient sorghum and sunflower plants exhibited slightly reduced plant height and leaf number but highly reduced root length. Mg-deficient sorghum plants had similar plant heights, leaf number, and root length; however, their leaves were chlorotic with necrotic spots. In contrast, Mg-deficient sunflower plants had highly reduced plant height, leaf number, and root length, and had stunted growth, brown, necrotic, and chlorotic leaves. N-deficient sorghum and sunflower plants had severely reduced plant height, leaf number, and root length. These plants exhibited extreme stunted growth and leaf chlorosis. The symptoms obtained here are in agreement with characteristic symptoms of plant mineral nutrition deficiencies for Fe, K, Mg, and N reported in the previous studies. The results presented here are very important to a better understanding of the impact of mineral deficiency on sunflower and sorghum plants.