Diseases affecting garlic

Diseases affecting garlic

There garlic culture, especially with autumn sowing, has arather long cycle. In fact, it involves a stay of many months on the grounds of the garden from the planting of the cloves to the harvest period, which takes place around June-July.

Throughout this period, garlic it does not require special interventions, just scerbatura and hoeing and practically only emergency irrigation, in case of prolonged drought, because it is one of the vegetables that requires less water.

The fact that it is a simple crop to manage however, it does not mean forgetting about it until the moment of harvest: however, we must dedicate some to it inspection, aimed at verifying its development and state of health. In fact, even garlic it can be affected by harmful insects and some diseases of various kinds, which it is important to prevent or treat at the first symptoms. The different products allowed in organic farming are usually effective in solving the most common adversities. So let's review the main diseases of garlic, to recognize the symptoms and be ready to intervene if necessary.

Preventing diseases

Without a doubt, before listing the diseases, it is worth giving some useful suggestions to minimize the onset of diseases.

In organic farming, prevention is essential, in the cultivation of garlic it passes through some basic measures:

  • Respect for rotationsi, so that even in the garden every year we must always dedicate a different space to garlic, possibly not recently occupied by other lily crops (leeks, onions, asparagus);
  • The use of healthy propagation material. In this sense, the heads of garlic certified for sowing are certainly indicated, while the self-produced material is more at risk, and therefore must be well preserved and well inspected before sowing, with a strict selection. So be careful when planting garlic, you need to use healthy material.
  • Avoid excess fertilization, which favor fungal diseases;

In the most aggravated cases of the fungal diseases listed below, it makes sense treat the plants with cupric products, but always with the necessary precautions for use reported on the packaging, respecting the correct methods of distribution of the products and never exceeding the recommended doses. The discussion can be explored in the article on the use of copper as a fungicide.

Main pathologies of garlic

Here we are to list which problems can afflict a garlic crop in the garden or in the field.


The Puccinia allii mushroom is responsible for a pathology called rust because of the symptoms it creates on the leaves, which come to seem really covered with rust: they form there many small red-brown spots on a background that gradually turns yellow.

The illness, if taken in time, it does not completely compromise the internal bulb, but later on the risk is real, and the yield can be seriously reduced. If the fungus appears early, and leads to foliar drying before the bulbs form, there is the possibility that the bulbs will not form well. For this it is appropriate intervene at the first appearance of symptoms by eliminating the first affected plants.

Afterwards, we will have to remember to strictly respect the rotations and not to put garlic back on that space for about 3 years.

White rot

The pathogen responsible for the white rot of garlic covers the garlic bulbs of a whitish cottony felt, which also differentiates some small black corpicles, or the sclerotia, which are kept for several years in the soil. This disease, unlike others, manifests itself above all with cool temperatures between 10 and 20 ° C, and to a lesser extent in the heat.

Bacterial rot

Some strains of bacteria they affect the garlic starting from the outer leaf sheaths, creating them oval-shaped rotting lesions. Then the infection penetrates deeper and reaches the bulb, which eventually becomes a foul-smelling mush.

When you see the first plants affected by this adversity, we must uproot and eliminate them, and then not repeat the cultivation of garlic in that flowerbed for the next 3 years.

Mold and rot of the bulbs

Some mushrooms, including the Botrytis, cause molds and mummifications garlic, and this happens in the field but even during post-harvest storage. For this reason, it is good to make a meticulous selection of the crop to be stored, or to hang in the classic braids, and keep everything in dry and airy environments.

Dusty rot

Such mushrooms Aspergillus they are pathogens that threaten where there is already another infection in progress or in the case of storage of garlic in humid places. The garlic heads are visibly marked dto dusty masses which depending on the mushroom loops can be intense yellow or black.

Pink rot

The pathogen penetrates into the tissues of the outermost leaves and reaches the root system, which gradually takes on a pink color and finally rots. The optimal temperatures for infection are in the range of 24-28 ° C.

Edema of garlic cloves

This is one physiopathy, or an alteration that it does not depend on diseases or parasites, but it is linked to thermal imbalances when the cultivation soil is warm and humid and the outside air is cooler. The roots are subjected to osmotic pressure which causes the juice leaking from cells and tissues turn yellow.

To prevent this physiopathy, we always keep the ground was moved and ventilated where garlic is grown, avoiding water stagnation.

Video: Know how to protect your garlic crop from diseases