Why does a tomato stem grow bumps, is it a disease?
Don't ignore lumps appearing on tomato stems - only timely treatment can secure a good harvest! Today I've put together the common causes and solutions, easy enough for beginners to handle.
Aerial-root type lumps (physiological reaction)
Symptoms: white/pale green soft lumps on the stems, like"small aerial roots"
Cause: overwatering, compacted soil, or fertilizer burn of the roots; once the roots lack oxygen, the plant"rescues itself"by growing aerial roots.
Treatment: reduce watering and let the soil dry, loosen the soil to improve aeration; drench with rooting agent+soil conditioner to build roots; for root rot, spray kasugamycin for control.
Bacterial disease lumps (urgent intervention)
Symptoms: dense hard lumps on the middle and upper stems, the vascular bundles inside turn brown, leaves become brittle and curled, and the plant wilts.
Cause: wounds infected by bacterial pith necrosis, canker, etc.; a high-humidity environment speeds up the spread.
Treatment: prune diseased branches and disinfect the tools, spray the whole plant with kasugamycin/quinolone (once every 3 days1 time, spray 2-3 times in a row); control humidity and improve ventilation to prevent spread.
Physiological nutrient-deficiency lumps (nutritional imbalance)
Symptoms: small lumps scattered over the whole plant, along with yellowing, curling leaves and slow growth, but no rotting or browning.
Cause: deficiency of potassium/sulfur, or compacted soil causing poor root uptake.
Treatment: apply more compound fertilizer containing potassium and sulfur, spray the leaves with monopotassium phosphate+micronutrient fertilizer; loosen the soil to improve its aeration.
Key points for routine care
1.Watering"dry-wet cycle"
2.After pruning, disinfect the wounds promptly, and improve ventilation on humid days;
3.Diseased plants should be isolated; when lumps come with dark brown lesions/root rot, treat it as a disease first.
In short, follow these methods and your tomatoes will grow healthy and set fruit.