With maturity, deficiency symptoms expand to leaves closer to the top of the canopy. It’s not uncommon to find K deficiency symptoms near the plant tops in isolated field areas with intense soybean aphid pressure. In this case, the deficiency isn’t necessarily related to a deficiency of K in the soil. The symptoms of a phosphorus (P) deficiency can easily be seen on fast-growing stem plants. Very slow growth and shoot tips decreasing in size are typical. Some aquatic plants may turn darker or even a violet color. Frequently, a phosphorus deficiency can cause an increase in spot algae. In a planted aquarium, phosphate concentrations of about Scope. This editorial paper gives an overview of the latest aspects related to iron nutrition presented at the 18th International Symposium on Iron Nutrition and Interaction in Plants: (i) Iron chemistry and dynamics in soils; (ii) Agronomic practices to correct Fe deficiency, from diagnosis to fertilizer development and genetic approaches A sulfur deficiency is often caused by no fertilization or a low supply of soil. Smaller plants are more susceptible. Burning vegetation, saturating the soil and heavy rainfalls often result in a sulfur deficiency in the soil. Sandy or weathered soil and soil with a high concentration of iron can cause a sulfur deficiency. Iron chlorosis is a result of a lack of chlorophyll, the leaves' green pigment. Affected trees and shrubs’ leaf veins will be yellow while the rest of the leaf will remain green. To help mildly symptomatic trees, add iron or compost to the soil. For trees with severe iron deficiency, trunk injections can provide rapid results within the same Iron chlorosis is the result of the inability of the plant to extract sufficient iron from the soil. Utah soils are typical of arid and semiarid soils around the world with lime or calcium carbonate in most of the soil profile. These soils are alkaline with pH ranging between 7.2 and 8.3. Iron chlorosis is common in these soils and is If the plant does not obtain iron, the symptoms become more severe, and the deficient leaves become pale yellow to white in color. Chlorophyll–protein complexes in the chloroplast require iron and the absence of usable iron perpetuated this condition. Young tissue displays deficiency symptoms first because iron is mostly immobile within plants. Deficiency Symptoms. Yellowing of Young Leaves: Unlike most other nutrient deficiencies, sulfur deficiency first appears on the newer, upper leaves. Stunted Growth: Plants may exhibit slowed growth rates due to reduced chlorophyll production. Brittle Leaves and Stems: Leaves may become brittle, and stems can be thin due to impaired protein Stunted growth of the plants. How to Treat Iron Deficiency: Testing kits for iron will allow you to determine the amount of iron in your system. Readings of 3.0 ppm or below show iron deficiency. To supplement iron in your aquaponics system, you need to add iron that the plants can absorb. This means using chelated iron. Young leaves of most plants should contain about 50 parts per million (ppm) Fe, or greater on a dry weight basis (Table 1). Deficient plants will have leaves with less than 30 ppm Fe and will likely exhibit the chlorosis typical of Fe-deficient plants. Iron deficiency symptoms generally consist of a yellowing or chlorosis of the youngest leaves. em3VIZe.