Botrythiosis Of Gladioli

2024 Author: Gavin MacAdam | [email protected]. Last modified: 2023-12-16 13:38

Botrythiosis is an incredibly dangerous disease that leads to the mass death of gladiolus corms closer to the end of the season. This usually happens during their drying or winter storage. And the massive defeat of these attractive flowers is most often observed in the second half of summer - the humidity rises during this period, and the thermometer drops to fifteen to eighteen degrees. In order not to lose beautiful flowers, it is important to start fighting this harmful scourge as quickly as possible

A few words about the disease

The most characteristic symptom of destructive botrythiasis is mass spotting of gladiolus leaves, on which oval or rounded specks of the most varied sizes, painted in light brown tones, begin to form. And in places where harmful spores are introduced, tiny watery specks form on the perianths, which turn brown after some time. In addition, when the weather is sufficiently damp, the delicate buds of beautiful flowers begin to lick, and grayish mushroom sporulation quickly appears on them. This, in turn, leads to the development of gray rot of the necks, and as a result, the stems break and the plants die.

Further, the infection, spreading through the vessels of gladioli, gets over from their aerial parts and to the corms. Infected areas immediately turn brown, while they are quite sharply delimited from healthy tissues of flowers. The corms gradually fade, and near their tops, the appearance of a penetrating brown rot is observed. The corms of the corms are slowly completely dyed, and the corms become like bagels. They quickly turn into soft, spongy, brownish tissue, but the corm scales do not change color, and therefore they can give the impression of being healthy. Nevertheless, if you take them in your hands, the emptiness and lightness will be easily felt.

In damp storages, whole nests of rotten corms covered with grayish fungal sporulation can sometimes form. And even if the areas of rot on them are insignificant, such corms will still be unsuitable for planting, since strongly weakened and rather quickly dying shoots always develop from them.

The causative agent of botrytosis is the microscopic fungus Botrytis gifdioli, belonging to the genus Botrytis. This ubiquitous fungus is capable of forming long-lasting sclerotia in the soil, which, under favorable conditions, actively develop on decaying plant debris. The result of such vigorous activity is the formation of spores, carried by the wind over great distances. Together with moisture, the formed spores settle on the leaves and stems with flowers, where they begin to actively germinate, penetrating into the tissues of beautiful plants. The spread of infection always occurs from top to bottom, that is, from leaves with stalks, the pathogen gradually descends to the corms.

How to fight

In order to prevent botrythiasis, it is recommended to strictly observe the rules of crop rotation and to eliminate all plant residues from the site. And the corms intended for planting, on which signs of rot are found, must be discarded and immediately destroyed. In addition, the planting material should not be exposed to mechanical damage.

During the growing season, and in the second half of summer in particular, every ten to fifteen days it is necessary to carry out salvage prophylactic spraying with a copper-soap mixture (20 g of green soap and 1 g of copper sulfate) or Bordeaux liquid at a concentration of 1-1.5%.

Corms should be harvested as early as possible. After cleaning, they should be washed, and then treated with a solution of "Fundazole" (0.2%) and immediately dried for five to seven days at a temperature of twenty five to thirty degrees. It is impossible to leave corms at room temperature - botrytosis in this case can begin to progress and quickly destroy them. And it is necessary to store dried corms in dry rooms.