The leaf loses color between veins, then progresses to brown dead areas. The mottling of tissue that loses green color is a common sign. Leaf edges lose color and the interiors near the veins stay green. It can show up as yellow stripes on leaves such as grasses and corn. It is relatively abundant in seeds and leaves.
Magnesium deficiency is a common problem and it affects the size of roots and fruits.
Tomato leaves are brittle and curl upwards, this is seen on lower leaves first. The lower leaves on cabbages become puckered. P425 Remedy for magnesium deficiency Magnesium nitrate spray may be more effective than magnesium sulfate. Can spray with magnesium borax, magnesium bordeaux. If a soil, media or nutrient is strongly acidic, limestone or dolomite lime must be added to release calcium and magnesium.