You can hear the wailing from here. "Why aren't my bulbs blooming?" "There are a lot of leaves on them but not a single flower."
The overall cause of a bulb not producing a bloom is either the bud wasn't formed or it was damaged in some way. No bud equals no flower.
Here's why your bud might have been killed:
There wasn't enough sunlight last summer or you planted your bulbs in too shady an area. For the most part, spring blooming bulbs want full sunshine for at least six hours a day. If you do not give them enough sunshine, they may live but not have enough energy to produce a flower bud.
You might have cut off the foliage last year before it yellowed naturally. If you cut off the foliage before it yellows, the bulb will not be able to get enough sunlight to produce a bud. Remember Doug Green's number one rule for growing bulbs, "Grow the foliage, the flower will take care of itself." You might have tied up the foliage over top of the bulb to give yourself room to plant annuals. This is an old trick that won't go away but is still not recommended for growing good bulb leaves. (Do you think you'd grow very well if you had to hold your arms over your head all the time?)
You might have planted them too early last fall. Once the bulb had rooted and the ground was still warm, it might have started to produce a flower bud. Once that bud emerges, it either lives or dies on the soil temperature. An emerged bud that hits frozen or too-cold soil is going to die and this means there won't be another bud for the following spring.
Perhaps you overfed or overwatered those bulbs. Overwatering bulbs will most often kill them because they will rot (think of leaving an onion in a glass of water). Spring flowering bulbs have developed in areas where there is winter-cold and spring-rains but summer drought. When you water your garden in the summer to keep the annuals and perennials happy, you are making your bulbs unhappy. Too much water and the bulbs will disappear taking their flowers with them.
Perhaps the bulbs have grown up magnificently and multiplied. If so, they might simply require dividing to produce flowers again. This is not likely in a normal garden setting but possible. You can tell if there are scads of leaves all coming from the same small area if the bulbs are too crowded.
You want to know if it is a disease. The odds are that it is not. Bulb diseases either disfigure flowers or kill the bulbs. None just kill off the flower bud.
The odds are it is a cultural thing and not a disease. You just have to figure out what you need to give the bulb to make it happy. You can do this at Doug Green's flower-garden-bulbs.com website
Remember, grow those leaves to make the flowers bloom.
copyright Douglas Green 2005
Doug Green is an award winning garden writer with over 30 years experience in the horticultural industry. His bulb website is at http://www.flower-garden-bulbs.com and his garden blog is at http://www.simplegiftsfarm.com