What causes spots to appear on lettuce leaves
Lettuce is one of our everyday vegetables; it tastes good, is highly nutritious, and has a unique way of being eaten, while being simple to grow and manage. Many people grow some at home, picking and eating it fresh, but when growing it, spots appear on the lettuce leaves, and these spots can spread. What is going on here? Let's take a look at the detailed explanation below.
1. Black spot disease
The spots may be caused by black spot disease. Black spot disease first affects the outer leaves, from the bottom upward. When it strikes, yellow-brown water-soaked spots appear on the leaves, and as the disease progresses, the lesions gradually expand into circular or irregular yellow-brown dead spots. In humid conditions, a gray-black mold layer appears on the lesions, and in severe cases the lesions join together into patches, causing the leaves to yellow and wither until the entire plant dies.
2. Brown spot disease
It may also be caused by brown spot disease. When brown spot disease strikes, light yellow water-soaked spots appear on the leaves, and as the disease progresses, they gradually spread into circular or oval dead spots. In humid air conditions, a sparse gray-brown fuzzy mold appears on the leaves. In severe cases, the lesions on the leaves also join together into patches, forming large areas of necrotic spots, causing the leaves to age prematurely and wither. These two diseases are fairly similar and are hard to tell apart in the early stages, so attention is needed.
3. Leaf spot disease
Leaf spot disease starts from the leaf margins when it strikes, and as the disease progresses, the spots gradually spread, and these spots are also covered with small black granules; these granules are the pathogens of leaf spot disease. In severe cases it causes the entire plant to become infected until the plant dies, making it extremely harmful.
4. Prevention and control methods
Great importance must be attached to the prevention and control of lettuce diseases, with prevention as the priority. These diseases mostly occur during the plum rain period, when humidity is high and bacteria easily breed, so attention must be paid to drainage and dehumidification measures, along with good temperature regulation; if the temperature difference between day and night is too great, the lettuce's resistance declines, giving disease an opportunity to strike. When sowing, the seeds and soil should be disinfected, and when disease occurs, the diseased plants should be pulled out and taken out of the field, the diseased planting holes should be disinfected, and then the whole crop should be sprayed with pesticide for control.
The above is an introduction to what causes spots to appear on lettuce leaves. We hope it helps you. To learn more related knowledge, please keep following us.