Fungal diseases
Tulip fire (grey mould) – one of the worst diseases in tulip growing. The symptoms are many small grey spots on all parts of the plant. Tulips often emerge already deformed. The disease spreads very quickly to other plants, so infected bulbs must be destroyed as soon as possible. It can be prevented with fungicide sprays and by treating the bulbs properly before planting.
Fusarium bulb rot – another fungal disease of tulips, but unlike tulip fire it affects only the bulbs. They become spotted, start to smell and turn soft. Such bulbs produce weak, spindly plants that do not look very attractive. The disease develops especially when bulbs are stored in damp rooms.
Penicillium corymbiferum – caused by fungi of the Penicillium family. Parts of the bulb become dry and hard, then soft and spongy. The disease particularly threatens bulbs damaged during lifting or handling. Prevention means choosing bulbs carefully and storing them properly.
Other, less common fungal diseases are:
- Rhizoctonia solani (Rhizoctonia rot)
- Pythium ultimum (Pythium root rot)
- Sclerotium perniciosum (stem base rot)
- Sclerotium tuliparum (grey bulb rot) Viral diseases:
- Tulip breaking virus – the hardest tulip disease to defend against. It shows as silvery or faded spots and streaks on the leaves and patches lighter than the natural colour on the flowers. The disease can be spread by aphids.
- Augusta disease – small spots first appear on the leaves, gradually enlarging and spreading to other parts of the plant. They often cause the plant to become deformed.
- Tulip mosaic – a disease little known in Poland and discovered fairly recently. It shows as variegated leaves and spots on the larger flowers. Not all tulips are susceptible, but it is not known exactly which ones are resistant.
Physiological disorders include:
- Papery flowers
- Gummosis
- Flower bud necrosis
- Stem topple
- Hard bulb tunic
- Bulb calcification
- Leaf skin cracking
These disorders can easily be prevented by following the right growing and care conditions for tulips.
Pests:
They are not diseases, of course, but they also cause plenty of trouble when growing tulips. The worst pests include:
- Common vole
- Field mouse
- Tulip bulb aphid
- Spotted snake millipede
- Bulb mite