Explore key diseases that cause yellowing in wheat and discover how to recognize and distinguish their symptoms in the field. Perfect for farmers, students, and agriculture enthusiasts looking to enhance their crop health knowledge.
A farmer notices yellow stripes running lengthwise along wheat leaves early in the season. Which disease is most likely responsible for this symptom?
Explanation: Stripe rust causes yellow to orange, stripe-like lesions along the length of wheat leaves, especially in cool, moist conditions. Loose smut primarily affects spikes and does not produce yellow stripes. Head blight impacts wheat heads rather than leaves, and crown rot usually results in browning at the base, not stripes on leaves.
What soil-borne fungal disease often causes yellowing and stunted growth in wheat, especially in patches across a field?
Explanation: Take-all is a root disease leading to yellowing leaves and stunted patches because infected roots can't absorb water and nutrients. Powdery mildew appears as white fungal growth rather than just yellowing. Leaf rust and stem rust produce distinct rust-colored pustules on leaves or stems, not mainly yellowing in patches.
If wheat fields in wet conditions show lower leaves yellowing with water-soaked lesions progressing to brown, which disease is most likely present?
Explanation: Septoria tritici blotch typically starts as yellowing with water-soaked lesions on lower leaves during wet weather, later turning brown. Barley yellow dwarf mainly causes uniform yellowing and stunting, not lesions. Karnal bunt and ergot affect heads and grains, not leaves, so these are less consistent with described symptoms.
Which virus transmitted by aphids causes widespread yellowing and stunting of wheat plants, often forming irregular patches?
Explanation: Barley yellow dwarf virus, spread by aphids, leads to irregular patches of yellowing and stunted growth in wheat. Tan spot causes lesions, not largely systemic yellowing. Snow mold affects fields under snow cover, showing as dead patches, and glume blotch targets the heads and glumes, not widespread yellowing.
Which wheat disease is commonly confused with nitrogen deficiency due to general yellowing of lower leaves but is actually caused by a fungus?
Explanation: Spot blotch initially causes diffuse yellowing of lower leaves, resembling nitrogen deficiency before dark lesions appear. Leaf rust and powdery mildew both produce characteristic pustules or powdery covering, while Fusarium foot rot usually causes browning or drying at the base of the stem rather than yellowing of leaves.