Magnesium deficiency (Mg)
Typical early symptoms of magnesium deficiency include chlorosis between the leaf veins which is rather diffuse (cf. Zinc deficiency where the stripes are more defined). This occurs first on older leaves and later the whole plant is affected with leaf curling, severe chorosis/necrosis starting at the leaf tips and eventually leaf death.
Treatment: Foliar application of EPSO Top®, EPSO Microtop® or EPSO Combitop®. Emphasis should be on supplying sufficient soluble Mg to the soil right before or after sowing.