Seedling chlorosis

Seedling chlorosis is a physiological disorder occurring when young plants fail to produce sufficient chlorophyll, causing leaf tissues to turn pale green, yellow, or even white. It is primarily a non-infectious condition driven by environmental factors or nutrient availability rather than a pathogen invasion.

This condition affects a vast array of plant species, particularly during the sensitive stage of early development. It is especially notable in peach (Prunus persica) seedlings, which are highly susceptible to iron-deficiency chlorosis when grown in soils with alkaline pH, making precise soil management essential for nursery success.

The primary symptom is interveinal chlorosis, where the area between the veins turns yellow while the veins themselves remain green. As the condition worsens, the entire leaf may fade, growth becomes stunted, the internodes shorten, and in severe cases, the leaf margins may necrosis, eventually leading to the death of the seedling.

Development and spread are triggered by unfavorable environmental factors such as high soil pH, excessive soil moisture causing root suffocation, compacted soil, and low ambient temperatures. These factors restrict the roots' ability to uptake essential nutrients like iron, magnesium, or zinc, regardless of their presence in the substrate.

The economic impact of seedling chlorosis is significant, often resulting in high mortality rates and weakened plant vigor that persists even after transplanting. Effective protection involves maintaining optimal pH levels, improving soil drainage, and applying chelated micronutrients through foliar sprays to ensure rapid absorption during the critical early growth phases.