PREVENTING CHILI LEAF CURL DISEASE 02/06/2022

In Vietnam, chili leaf curl disease is very common in areas that have grown chili for many years, especially the disease is often severe in areas with hot, arid climates and where many crops are also host to the virus. The disease has significantly reduced the yield and quality of chili peppers. Gardens that are infected early when the plants are young may not yield. However, up to now, many garden owners still do not know the cause and how to fix it.

Pathogens: Leaf curl disease is caused by a number of viruses. These viruses are parasitic on a number of plants. Examples: tobacco (with TMV virus), cucurbit family (CMV), potato (PVY) and chili pepper virus (PMMV)...

Mode of transmission and source of disease: The causative agent is a virus, so there must be intermediates (vectors) that carry and transmit the disease to spread the disease. Vectors such as aphids (Aphid), white flies (Bemisia tabaci), thrips (Thrips)… Insects carry viruses from diseased plants and then spread them to healthy plants. Humans cause mechanical wounds on plants when planting and tending, allowing viruses to penetrate. In nature, the virus still exists in many host plants such as weed and wild plants... Some viruses have the ability to survive for decades in the dried debris of diseased plants, so the source of the disease is in nature. However, it is very large, so the possibility of spreading the epidemic is always permanent.

Disease symptoms: Depending on the virus species, the chili variety, the weather and the stage of the infected plant, the time of disease onset and symptoms will be different. Normally, when infected with a virus, the plant is often dwarfed, growth and development are poor, leaves are not uniform in color, may be small, wrinkled, deformed, or only have leaf veins... If a plant is infected with many virus species, the symptoms are mixed and complicated. Many times the symptoms on the leaves are similar to those of weeds or micronutrient deficiencies.

Harm: Small plant stage, if infected with virus earlier, the incubation period is shorter, and the plant develops disease earlier. When grown plants are infected, due to higher resistance, the disease occurs later, or no disease occurs. The sooner the plant develops the disease, the greater the damage, even if it does not yield. Diseased plants are often dwarfed and their leaves are deformed, so photosynthesis is reduced, fruits are reduced, thus yield and quality are reduced.

Prevention: The disease is caused by a virus, so there is no specific product to treat it. However, we can effectively manage the disease by managing the way it is spread. To manage the disease, we must apply many measures simultaneously to achieve the desired results. Those measures are:

Sanitize remnants of previous crops, especially those that are host to viruses such as tobacco, cucurbits, potatoes, tomatoes, etc. Avoid planting near fields where the above-mentioned crops are at an advanced stage. growing period, especially the period about to harvest. Sanitize weeds and weeds around the border (including nurseries).

Should be planted early.

Use cultivars that are resistant to sucking pests, and resistant to viruses.

Uproot and destroy diseased plants, do not throw diseased plants indiscriminately.

Limit damage to trees when planting and caring.

Avoid over-fertilizing nitrogen fertilizers, enhance micronutrients by using foliar fertilizer Poly Feed 19-19-19 to increase the resistance of plants.

Closely monitor the density of sucking pests, especially aphids and whiteflies, for timely prevention, focusing on preventing sucking pests from the time the plant has just sprouted until 25-30 days later (because This is the stage that determines the rate of diseased plants and how severe or mild the disease is. Currently, a popular and effective product for sucking insects is SK Enspray 99EC mineral oil. This product is completely non-toxic to humans and animals. To increase the effectiveness of killing suckers, chewing worms and harmful spiders, fellow farmers often combine with some biologically-based products such as Comda Gold 5WG to prevent.