If tobacco plants exhibit dark green color, severe stunting, and yellow flecks in lower leaves, what is the likely cause?

The symptoms described—dark green color, severe stunting, and yellow flecks in the lower leaves—often indicate a condition related to nutrient imbalances or deficiencies in the soil. Inadequate soil may refer to a lack of essential nutrients or poor soil structure that affects root development and nutrient uptake.

When soil lacks necessary nutrients or has a poor physical structure, it can hinder plant growth, leading to symptoms such as stunting and discoloration in the leaves. The dark green color indicates that the plant is possibly experiencing nutrient stress, often associated with an excess of certain resources without the balance of others. This often leads to the accumulation of chlorophyll, contributing to dark green leaves. The yellow flecks can be a sign of nutrient deficiency or toxicity, conditions that often manifest in the lower leaves as the plant reallocates resources away from less vital areas for its survival.

In this case, residual herbicides or diseases like blue mold tend to have different symptom profiles, and excess nitrogen typically would not cause lower leaf yellowing but rather a general lush growth with potential for delayed maturity and susceptibility to other issues. Therefore, inadequate soil quality directly causing these specific symptoms aligns most accurately with the situation presented.