Deciduous disease causes heavy losses to North American agriculture

A noteworthy news for cultivators: this year, late deciduous disease - an infectious disease that destroyed crops and caused a terrible famine due to Irish crop failure in Ireland in the 1840s - is causing tomatoes and potatoes to die mass in gardens and farms in the eastern United States. In addition, fungal diseases are affecting crops in northeastern America.

Meg McGrath, professor of plant pathology and bacterial biology, said: ' Previously, this phenomenon never happened before and spread like this.'

One of the earliest and most visible symptoms of this disease is the appearance of brown spots on the trunk. Initially, they are small and very strong. After that, they spread very quickly along with the growth of fungi in wet conditions. Finally, the stem is rotten and dead.

Typical symptoms are large spots on the leaves (smallest as well as coins), turning from yellow to brown. Along with that, the white twisted filament mushroom grows on the underside of the leaves in wet conditions (in the early morning or after the rain). Occasionally, the edges of those spots are yellow or seem to support water. These spots are initially tiny, have no fixed shape and brown. Fixed, brown spots grow on tomatoes.

The leaves are damaged due to late defoliation. (Photo: School of Agriculture and Life Sciences, Cornell University) McGrath stressed the need to act urgently to protect tomatoes and potatoes; Make sure that plants do not become germs that spread disease to farms. This should be noted because late defoliation spores are easily released by the wind.

McGrath tips for growers:

- Overall check of tomato and potato plants at least once a week to promptly detect traces of late deciduous disease

- Spray fungicides for prevention, or

- Ready to destroy plants when deciduous disease shows serious signs.

McGrath said: 'To control defoliation with fungicides, it is necessary to spray now, even before you notice the signs. And keep spraying regularly. Use a medicine containing chlorothalonil. Copper does not work well for this deciduous disease. '

Petunias (ornamental tobacco), quite close to the tomato and potato family, may also be infected with deciduous disease and also exhibit similar symptoms.

Deciduous disease has great destructive power. If left unchecked, the disease can cause plants to die faster than any other disease. It affects tomatoes, especially green fruits. Even if fungicides are used weekly, there is no guarantee, especially if there is rain. McGrath advises that growers should consider growing more vegetables this year.

Finding the origin of this disease, it was followed by traces of tomatoes originating from the South. If tomato plants germinate from northern seed, it is less likely to be infected, or at least at first it is less likely to become infected.