Interveinal chlorosis and bright yellowing develop first on older leaf margins and tips and spreads back to the main vein. The leaves often have a characteristic herringbone pattern of chlorosis on new season’s growth. Symptoms are normally most obvious later in the season during fruit
Magnesium deficiency
Lack of magnesium results in reduced photosynthesis leading to smaller leaves that are lighter in color, as well as poor flowering, reduced fruit size and significant fruit drop.