This is by far the most serious of all tulip diseases, but only seems to reach serious proportions when the bulbs are grown under high forcing condition and rarely affects bulbs grown outdoors. It may be observed by the foliage turning first yellow then grey, which spreads as rapidly as a forest fire. It is similar to the Botrytis disease of tomatoes and just as destructive. There is no definite cure, but the trouble may be prevented by:
(a) Obtaining the bulbs from a reliable grower.
(b) Dipping the bulbs immediately before planting in a 2 per cent solution of formaldehyde.
(d) By using new boxes and fresh uncontaminated soil each season.
This trouble is caused by over-and poor ventilation which brings about a rotting of the base of the . Watering with a weak solution of calcium nitrate once each week will help to keep the trouble in check, though prevention is better than cure.
This is due to over-and fluctuating temperatures.
These pests often become troublesome by attacking the new shoots whilst the boxes orare in the plunge bed. Watering with the new anti-slug preparation, immediately after planting will prevent any attack.