What disease causes tomato stems to turn black? Cause analysis and control methods

Flower Cultivation Jan 1, 1970By Grace Miller 0 views

Is your tomato stem suddenly turning black as you grow it? Don't panic! This could be a disease at work! Today I'll walk you through how to treat the right cause. Symptoms of stem base rot: pale brown to dark brown patches appear at the base of the stem, which constrict after encircling the stem, later developing cobweb-like mold, and the whole plant wilts! High-risk period: prone to occur in high-temperature, high-humidity environments. Solutions

Are your tomato stems suddenly turning black as you grow them? Don't panic! This could be a disease at work! Today I'll walk you through, step by step, how to treat it according to the specific cause.

Stem Base Rot

Symptoms: pale brown→dark brown patches appear at the stem base, the stem constricts after the patch encircles it, and later a cobweb-like mold grows, and the whole plant withers!

High-risk period: it occurs easily in hot, humid environments.

Solution: 20%tolclofos-methyl emulsifiable concentrate1200-fold solution + 95%hymexazol3000-fold solution, drench300ml per plant,once every7 days1 time, for2 consecutive times!

Phytophthora Root Rot

Symptoms: dark brown sunken patches at the stem base, brown discoloration of the vascular tissue visible when the stem is cut open, rotting roots, and the plant wilting and dying!

Early stage of disease: leaves first turn yellow from the edges, then gradually dry up.

Solution:72.2%Previcur800-fold solution + 50%DT 500-fold solution + 80%thiram750-fold solution, water the soil around the roots thoroughly.

Late Blight

Symptoms: water-soaked dark brown patches appear on the stems or at the forks, covered with a white mold layer when humidity is high, and in severe cases the stem breaks and the plant falls over!

Outbreak conditions: continuous rainy weather and poor ventilation.

Solution:68%Ridomil Gold800-fold solution, spraying mainly the stems and the undersides of the leaves, once every1 week, for3 consecutive times.

Stem Blight

Symptoms: oval sunken canker patches appear on the stems, later invading the vascular bundles and causing the stems to dry-rot and shrivel!

Easily misjudged: similar to late blight; the shape of the patches must be observed to tell them apart.

Solution:50%iprodione wettable powder1000-fold solution, spray the whole plant evenly, spraying more on the affected parts!

Stripe Virus Disease

Symptoms: dark brown patches appear on the stem surface, but only the epidermis is discolored and the vascular bundles are not invaded! Leaves often show yellow-green mottling.

Source of spread: piercing-sucking pests such as aphids and whiteflies.

Solution:2%ningnanmycin aqueous solution500-fold solutionor 20%virusA wettable powder500-fold solution, spray2-3 consecutive times in the early stage of the disease.

Bacterial Disease

Symptoms: dark brown streaks on the stem; when cut open, the pith is hollow and grayish-white bacterial ooze spills out! Leaves turn yellow and wilt.

High-incidence scenarios: greenhouses with excessive watering and poor ventilation.

Solution: Xijunbiqing300-fold solution, spray once every3-4 days, for3-4 consecutive times, spraying mainly the stems and the affected patches!

Everyday Prevention

1.Before planting, treat the soil with carbendazim or lime nitrogen to kill the pathogens;

2.Keep the greenhouse/balcony well ventilated, and avoid hot, humid environments;

3.Block pests that transmit the virus; hang yellow sticky boards to trap and kill aphids and whiteflies;

What disease causes tomato stems to turn black? Cause analysis and control methods

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