Steve Wright, age 11, of Chattanooga, Tenn., for his qustion:

WHAT IS ERGOT?

Ergot is a parasitic fungus that attacks wheat, barley, rye and many wild and cultivated grasses. It most often infects rye.

Ergot attacks the grain of the plant. Long, purple structures of the fungus called sclerotia form in place of the seeds of the host plant. In the spring these sclerotia grow and produce stalks and spores. The spores ripen and are scattered by the wind to infect new plants.

Ergot infection can be prevented or reduced by rotating crops, using clean seed and cutting grasses that may harbor the disease.

A disease called ergotism in human beings and cattle can also be caused by ergot. Fortunately, this disease has now practically disappeared because of improved methods of cleaning grain.

Ergot is the source of a number of drugs, such as ergonovine, erotoxine and ergotamine. These are used to produce powerful contractions of the involuntary muscles, such as those of the blood vessels, bladder, stomach and intestines. The most common use of these drugs is to ease migraine headaches and to prevent hemorrhage after childbirth.