What disease causes yellow leaves on peppers? Latest analysis of the causes
Peppers are an essential seasoning and side vegetable in the daily life of people in several provinces such as Hunan and Sichuan, and peppers hold a fairly high place in our lives. The scale of pepper cultivation is also very large, and although there are many varieties of peppers, they all share the same pests and diseases. Moreover, some pests and diseases harm the leaves, causing them to turn yellow, which reduces the plant's photosynthesis and affects its growth and development. So what diseases can cause yellow leaves? How should they be prevented and controlled? Let's take a look below!
1. Leaf mold
Symptoms: Leaf mold generally starts on the lower leaves of the plant and then spreads upward. It is most severe during the fruit-swelling stage. In the early stage, light-colored irregular patches appear on the leaves, and small white mold spots appear on the underside of the leaves at the patches. The color then gradually darkens, and many growers mistake it for a nutrient deficiency or cold damage. But later, as the damage becomes more extensive, the entire leaf becomes covered with patches, then turns yellow and dies, severely hindering plant growth; the fruit lacks nutrients and yields drop.
Control methods: Strengthen vegetable garden management. In the early stage of the disease, sprays such as thiophanate-methyl can be used for control. After each harvest, clean up the garden once, collect diseased plant debris, fallen leaves, flowers and fruit, and carry them out of the garden for disposal. Avoid continuous cropping to reduce the disease incidence.
2. Whiteflies
Symptoms: Many growers, for convenience or to save on cultivation costs, do not put film on their greenhouses, but this actually makes later management more difficult. In hot, dry environments, whiteflies are most likely to occur, and whiteflies have extremely strong reproductive capacity, making whitefly control even more difficult. Whiteflies generally lay eggs on the underside of leaves, and after the larvae hatch they directly suck the leaf sap, causing the leaves to turn yellow.
Control methods: Control the humidity in the vegetable garden well to avoid drought, and do a good job of disinfecting the garden to reduce eggs. If pests are found, sprays such as dichlorvos or buprofezin can be used to kill them.
3. Viral disease
Symptoms: Like whiteflies, viral disease mainly occurs in hot, dry environments. Leaves affected by viral disease mainly start at the top, and light green patches appear on the leaves, or patches of alternating light and dark green. The diseased leaves then begin to turn yellow, and later the diseased leaves directly yellow, die and fall off, causing a very serious impact on plant growth. The spread of viral disease mainly relies on pests such as aphids.
Control methods: As just mentioned, the spread of viral disease mainly relies on pests, so we should focus on controlling aphids; for aphid control, agents such as trichlorfon can be used to kill them. To control viral disease, triacontanol can be used. Promptly remove fallen leaves and fruit from the orchard to reduce pathogens and lower the disease incidence.
The above are several diseases that cause yellow leaves on peppers. In fact, it is not only diseases that cause yellow leaves; drought and nutrient deficiency can also cause these problems in peppers. If drought is the cause, water promptly and pay attention to the amount, then check which element is lacking that is causing the yellow leaves and apply the corresponding supplement. That is all for today's introduction. This article is for reference only, and we hope it is helpful to everyone.