Intervenal chlorosis in a leaf is attributed to inadequate supply of which nutrient?

1. Chlorosis is the yellowing of leaves and can follow a shortage of several nutrients, so the pattern matters. 2. Inadequate magnesium leads to intervenal chlorosis, the yellowing between the veins. 3. Magnesium deficiency also produces general yellowing of the foliage. 4. That fits the role of magnesium in the photosynthetic process, since a failing photosynthetic apparatus shows in the leaf colour. 5. Calcium deficiency instead shows as blossom end rot in fruit, which is a quite different symptom. 6. Boron, sulfur and nickel are not the elements tied to this particular leaf pattern. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 31 "Soil and Plant Nutrition", section 31.1 Nutritional Requirements of Plants_