Chapter 14

Enemies and Diseases.

The gladiolus has almost no enemies, and the same may be said of diseases. The bulb has a very unpleasant taste, and is somewhat poisonous. It is not eaten by mice or grubs. The black aster beetle is fond of the flowers, and is quite a pest when very abundant. These insects have a preference among colors, and attack the red flowers first, especially a scarlet sort named Bertha. They will single out the spikes of this variety in a field of mixed colors, and devour the very buds as soon as the red comes in sight. They are especially troublesome when the weather is hot and dry, as they can then fly readily. When it is cool and damp, if jarred from the spikes they fall to the ground, and are slow in regaining their places. The grower of flowers, either amateur or commercial, finds in these insects an enemy hard to contend with, but the grower of bulbs pays no attention to them, as they do him no harm.

In regard to diseases, bulbs sometimes become scabby, but this seems rather an accident than a disease. It is apparently due to conditions, and is not perpetuated by heredity. Perfectly sound bulbs may produce scabby ones, and vice versa. If healthy bulbs are planted in a place that is too wet, or that is subject to frequent overflow, or if they come in contact with barnyard manure in the ground, or if the foliage is seriously injured in the growing season, the product is liable to be scabby. Some years ago I had a field of gladioli, one end of which proved to be a runway for dogs, and the plants that came in their way were broken, or partly broken. As a consequence, many of the bulbs in that part of the field were scabby, but these planted in a different place, produced smooth ones the next season. If bulbs are taken up and cured immediately after the tops have been injured, by wind or otherwise, they will be sound and in good condition for the next year, even though not half grown; but to be deprived of their foliage, or a large portion of it, while the roots remain undisturbed, appears to destroy the balance, and cause bad results.

In some localities the gladiolus is affected by rust, which turns the tips of the leaves brown in the growing season. If this is a disease, the remedy does not seem to have been discovered, but in numerous instances careful observation will show that it is due to local causes. The foliage is sensitive to atmospheric conditions, and cannot be successfully grown where it is subject to poisonous gases. Smoke from a pottery carried over the bed by prevailing winds is almost sure to be fatal. Salt is thrown into the kilns to glaze the ware, and the chlorine set free is deadly to many plants. Even smoke from factories is more or less injurious, and many cases of rust can be traced to some such source.

Taken all in all, the gladiolus is one of the most reliable of crops. (See Note.)

Note:--There are three well defined diseases affecting gladiolus bulbs during growth and in storage, soft rot, hard rot, and scab. There is no cure for the two former, but they may be controlled by discarding all affected bulbs and planting in fresh soil free from animal manures. Scab may be greatly reduced by soaking all diseased or suspected bulbs, after removing the outer coatings, for twenty minutes in a solution of bichloride of mercury, fifteen grains to each gallon of water, or for same time in solution of formalin, one pint to thirty gallons of water.