Tomato Fusarium Wilt: Symptom Identification and Control Methods

Tomato Fusarium wilt is very likely to occur during tomato cultivation. Once this disease strikes, it affects tomato yield and market quality, so it must be prevented in time. So what are the symptoms of tomato Fusarium wilt? How is it controlled?

1. What are the symptoms of tomato Fusarium wilt?

In the early stage of Fusarium wilt, symptoms mainly appear on the leaves closer to the ground. The leaves first turn yellow, then become brown and dry up, but the dead leaves do not fall off and remain attached to the stem. These withered yellow leaves sometimes appear only on one side of the stem, while the leaves on the other side remain normal, or one side of a single leaf turns yellow while the other side remains normal. The appearance of diseased leaves develops from the bottom upward. Apart from a few leaves at the top, in the later stage all the leaves of the whole plant die, and the vascular bundles of the stem near the ground, the petioles and the fruit stalks all turn brown. When the weather is humid, pink mold often forms at the base of the stem. From the first appearance of symptoms to the wilting of the whole plant takes about half a month to one month. The speed at which diseased plants die varies with climate and environmental conditions. After spring tomatoes are infected with Fusarium wilt, the disease gradually intensifies as temperatures rise. After autumn tomatoes are infected at the seedling stage, because temperatures gradually drop, the disease tends to ease, but the diseased plants are markedly stunted and bear fewer fruits, which also affects yield to varying degrees. The symptoms of tomato Fusarium wilt and bacterial wilt are somewhat similar, so they are easily confused when diagnosing.

2. How is tomato Fusarium wilt controlled?

1. Before transplanting or after harvest, clear weeds from the field and its surroundings, and burn them in a centralized pile or compost them; plow the soil deeply to destroy stubble and sun the soil to promote the decomposition of diseased residues and reduce sources of disease and pests.

2. The nutrient soil for raising seedlings should be sterile soil, and it should be sunned for more than 3 weeks before use.

3. Practice crop rotation. In heavily diseased fields, carry out a 3-5 year rotation with cruciferous vegetables, cucurbits, and onions and garlic and similar vegetables. If cucumbers are to be planted, they must be grafted onto black-seeded squash.

4. Choose disease-resistant varieties and use disease-free, coated seeds. If the seeds are not coated, they must be sterilized with a seed dressing agent or seed soaking agent.

5. Raise seedlings and transplant them, cover the seeds with medicated soil after sowing, and spray an insecticidal and sterilizing agent once before transplanting. This is the key to disease prevention.

6. Choose fields with convenient irrigation and drainage, dig drainage ditches well, lower the groundwater level, and ensure there is no standing water after rain stops; after heavy rain, clear the ditch system in time to prevent moisture from lingering and reduce field humidity. This is an important measure for disease prevention.

7. In fields with many soil-borne pathogens or severe underground pests, broadcast or apply in furrows a sterilizing and insecticidal medicated soil before sowing.

8. Apply compost fermented with effective microorganisms or fully decomposed organic fertilizer. Do not use pathogen-carrying fertilizer, and the organic fertilizer applied must not contain diseased residues of crops in the same family.

9. Deeply plow and sun the soil, and increase the application of organic fertilizer and phosphorus and potassium fertilizer to promote robust crop growth and improve disease resistance.

10. Control pests in time to reduce plant wounds and reduce the routes of pathogen spread; when disease occurs, promptly remove diseased leaves and diseased plants and carry them out of the field to be burned, and apply pesticide or quicklime to the diseased planting holes.

11. Grafting for disease prevention: use wild water eggplant, poisonous eggplant or red eggplant as rootstock and cultivated eggplant as scion, and adopt the cleft grafting method. This is indeed effective.