Cervical rot of garlic– a disease of garlic and onion caused by the fungus Botrytis (Botritis allii). The disease causes garlic and onions the most significant damage during storage.
The Botrytis fungus develops in onions, shallots, leeks, garlic, wild onions, and also on rotten residues of such crops as cereals, peas and beans.
There are around 361 types of fungus Botrytis. It’s believed that the greatest damage to the crops of garlic and onions is caused by three of them:
- Botrytis allii
- Botrytis aclada
- Botrytis porri
Name of the disease Cervical rot of garlic in other languages
- Spanish: de pudrición en el cuello de ajo, Botrytis porri
- Russian: Шейковая гниль чеснока
Cervical rot of garlic – infection
Common pathways of infection
- From a sick planting material
- From overwintered in the soil of the mushroom sclerotia (compact mass of mycelium)
What increases the risk of infection
- Late harvest garlic in rainy weather
- Landing on heavy loamy soils (the most favorable soil for the development of the fungus Botrytis allii)
- Infection with peronosporosis (downy mildew) increases the risk of cervical rot
- High doses of nitrogen fertilizers at the end of vegetation worsen the storage of garlic and reduce its resistance to infection of the disease of garlic – cervical rot
The characteristics and development cervical rot of garlic
As a rule, caused by this fungus, a disease of garlic, does not manifest itself in the field and immediately after harvesting garlic.
The mold rot of garlic begins to appear during the storage, after about 1-1.5 months.
Rot usually occurs in the neck of the bulb, but it can also occur in other places, where there has been physical damage and where the infection has come from.
The neck of the bulb softens and becomes mucous, then covered with a gray or blackish fluffy coating – sporulation of the fungus.
On the cloves are formed spots with a gray-brown coating. Later the plaque becomes rotten and small black dots are formed in it – sclerotia of fungi, which can be combined into a single black crust.
With further storage, the cervical (neck) rot of garlic can spread to the bottom and other areas of the bulb.
For a month or two the bulb rotates and infects healthy ones.
The most intense cervical rot (neck) of garlic develops at a temperature of 15-20 ° C.
How to deal with cervical rot of garlic
- Observance of a four-year crop rotation.
- Timely harvesting and drying of the bulbs until the leaves dry before storage.
- In the case of wet weather during the harvest is to apply a forced drying at 30 ° C.
- The introduction of phosphorus fertilizers (ie, the sufficiency of phosphorus for the plant) contributes to the enhancement of the stability of garlic to the development of cervical rot.
- In case of cutting a false stalk of garlic before digging out – harvest garlic from the field for the first 48 hours.
- Sorting garlic during storage, culling the damaged.
- Observance of the optimal storage regime (temperature 0, -2 ° C and relative humidity not more than 70%).
- The correct mode of fertilization: nitrogen is introduced in the initial period of vegetation, the dose of phosphorus and potassium increases in the second half of growth. High levels of nitrogen fertilizers during the growing season can lead to delayed maturity.
- In order to avoid the transfer of spores of the fungus Botrytis allii by wind, the fields of garlic should be separated from the onion fields for considerable distances.
Etching of planting material
- Maxim XL, the production of Syngenta Switzerland. The active substance of 25 g/l was Fludioxonil 10 g/l metalaxyl–M (from seed molding, Fusarium root rot, downy mildew, disease).
Treatment during the growing season
- Custodia, the production of Adam, Israel. Active substance tebuconazole 200 g/l + AZOXYSTROBIN, 120 g/l
- Switch, the production of Syngenta, Switzerland. The active ingredient 375 g/l Cyprodinil 250 g/l was Fludioxonil.
- Uniform, the production of Syngenta, Switzerland. The active substance is 322 g/l AZOXYSTROBIN 124 g/l metalaxyl–M.
- Ridomil gold the production of Syngenta, Switzerland. The active substance of 640 g/K MANCOZEB 40 g/kg metalaxyl–M.
- Contortionist the production of BASF, Germany. The active substance of 90 g/kg Dimethomorph and 600 g/kg MANCOZEB.
On the video – the mold of the fungus Botrytis allii affects a young shoot of onions
The authors of the photo:
- Steven B. Johnson
- Cynthia M. Ocamb
- Howard F. Schwartz, Colorado State University
- Lindsey du Toit, Washington State University
Information was prepared by – Andrey Marchenko
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