Wheather Fleck-Air Spot
There are non-parasitic diseases on the tobacco leaf. The most common and known in Turkish tobaccos is "double color". "Wheather fleck-air spotting", a physiological leaf spot disease seen in large-sized tobacco abroad, has also started to be seen in Turkish tobacco. The disease detected in Denizli's Acıpayam (Alaattin Town and some villages) and Tavas (especially Nikfer Town-Barza Plain) districts can be confused with other disease symptoms due to its newly recognized symptoms.
Non-parasitic spot disease was first reported in the United States in 1920. Since then, it has mainly caused damage to tobacco types.
Weather fleck is seen for the first time in mature and lower leaves. 1–3 mm on the lower and upper surface of the non-uniform white leaf that looks like paint splashes. The spots are usually circular and seen on both sides of the middle vein, especially starting from the tip of the leaf to the point where the leaf meets the stem.
Tobacco leaves stomata (intercellular space, pores) are open in the sun, but those in the shade are more open. Ozone (O3) enters through the open stomata and fills the gaps. While the leaf's stomata will do their job, the leaf remains open and more stomata are filled with air. The amount of damage increases depending on the residence time of the air in the stomata. If the tobacco plant is overexposed to ozone, it closes its stomata. The first symptoms are seen physiologically within 24 hours. High levels of ozone exposure, small, dark green, water-soaked spots appear on tobacco leaves. Within 48 hours, the spots change color from brown to gray and white, pale and necrotic spots expand like a chlorotic (piebald) stain. Since it is formed on the lower and mature leaves, it dries 1-2 weeks after the symptoms appear. Often physiologically mature leaves or parts of them are susceptible to bison. They are quickly affected.
Older leaves are more sensitive. Leaves bend or become completely exhausted.
Blight occurs when the temperature is optimal, growth accelerates, and leaf tissue matures. In addition, soil moisture and rain are considered as important environmental factors and affect the formation of blight. Blight usually occurs in the field and in the intercellular spaces of the leaf after rain, floods, and fog or heavy dew.
