Where symptoms begin
Boron and copper are framed on the poster as new-growth nutrients, so symptoms show first on young leaves and meristems.
Molybdenum is presented as an old-growth nutrient, so symptoms appear first on older leaves as the plant reallocates resources.
Boron and copper progression
Boron early stage
brittle thickened new leaves, slight malformation and slowed growth
Boron mid to late stages
necrotic tip dieback, dead meristems, malformed growth and hollow stems
Copper early stage
dark bluish foliage with a metallic cast on young leaves; later stages show hooked tips, necrotic margins, wilted shoots and loss of apical dominance
Molybdenum progression
Early stage
twisting and interveinal yellowing on older leaves
Mid stage
general chlorosis, cupping and brittle older leaves while veins stay greener
Late stage
severe chlorosis, edge necrosis and stunting with a presentation that can resemble nitrogen deficiency
Poster takeaways
The boron panel stresses meristem damage and brittle malformed new growth.
The copper panel centers on bluish wilt and shoot dieback.
The molybdenum panel warns that it can mimic nitrogen deficiency on older leaves.