Iron Deficiency

Iron deficiency in cannabis plants refers to insufficient bioavailable iron in the growing medium, resulting in chlorosis (yellowing of new leaves while veins remain green). This condition typically emerges in alkaline or over-watered soils where iron becomes chemically locked and unavailable for uptake, despite adequate total iron content. Iron is essential for chlorophyll synthesis and electron transport in photosynthesis, making deficiency visually distinctive and agronomically significant. Growers and breeders distinguish iron deficiency from nitrogen deficiency by its characteristic vein pattern and onset on newer growth. Understanding iron deficiency is important for cultivation optimization and breeding programs focused on nutrient efficiency or soil adaptability.

Breeders working in specific soil environments or targeting iron-efficient genetics may select for cultivars showing resilience to iron-limited conditions or responsive root architecture. Lines bred for calcareous or alkaline soil cultivation often incorporate iron-uptake efficiency as a secondary trait.