What are the symptoms of garlic leaf blight, prevention and cure of garlic leaf blight

Garlic leaf blight often occur large area, causing big garlic leaf die, light person young garlic shoot small, poor quality;The person that weigh can't afford the moss, affect production, and even failures, seriously restrict the development of garlic.This article introduced the garlic leaf blight for everybody condition of symptom, pathogen, pathogenesis and prevention method, for everybody reference.

1, the symptoms

The disease is mainly blade.Leaf disease, early flowers white dots, and starting from the tip.Disease spot after expanding irregular shape, pale, wet disease spot on the black mould material, and the gray into beige.Disease spot starting from the tip, top-down extension, light along the tip when dry, serious when whole leaf and even whole plants die.Pedicel infected from disease break easily, the last in the disease department sends out a lot of small black point, harm serious when not bolting.

2, pathogen

Sexual and asexual stages of the disease pathogen, all can infect garlic, give priority to with asexual phase of infection.Sexual stage for leaves spore cavity bacteria, fungi belonging to ascomycotina.Asexual stage for stomach handle mould, belong to half known bacteria and fungi.Conidium gray or dark brown, solitary, ovate to elliptic or broadly elliptic.Perithecia spread or dispersion, globose or oblate, orifice.Ascospore tan, spindle or elliptic.

3, disease conditions,

3.1 soil and fertilizer

The premise condition of soil is the disease occurrence and heavy.The disease by mycelium or perithecia with sick body overwintering in the soil, soil moisture in winter is moderate, pathogen survival, the following the onset of heavy;Soil dry wet, are unfavorable to bacteria for the winter, the onset of light in the following year.Soil is fertile and the sick body, high organic matter content, bacteria easy survival;Low soil nutrients, organic matter content less, go against disease.Too much nitrogen fertilization, pale green leaf growth, or lack of potash, susceptible.

3.2 host plants

In addition to the harm of garlic, the germs in the local also serious harm green class, second only to garlic, also harm the lettuce.

3.3 the temperature

The disease occurs in the spring, when the spring day after the start when the average temperature of 12 ℃, 18 ℃ disease spot, the optimum temperature for the onset of 15 ~ 25 ℃, the temperature is below 8 ℃, 34 ℃ or more rarely incidence.

3.4 garlic varieties

The garlic varieties resistance difference is bigger, heavier of local varieties for many years.

3.5 the cultivation management

Fine management plots in the onset of light, the use of chemical weed control plots in the onset of light;Weeds, management extensive field heavy disease.The roadside fields, river bank field.The bacteria is a weak parasitic bacteria, if other serious diseases, or insect pests, the disease is heavy.

4, infection cycle

The bacteria mainly hypha or perithecia with sick body left overwintering in the soil.Primary infection source is wintering in the soil of ascospore produced on the sick body.Ascospore infection after the blade, cause disease, the disease of conidium.Conidium caused to infect infect other blades.Field spread mainly by air, rain, intrusive way for wound, porosity.The bacteria is a weak parasitic bacteria, often accompanied by downy mildew or purple spot mix.

5, prevention and cure

5.1 clean the pastoral

Garlic harvested, in a timely manner to the field of disease leaves, stems, such as the sick body to clear, before the turners soil on the soil surface with straw, rice straw on fire and burned