A, garlic disease symptoms
Garlic main harm of leaf disease, early onset in blade tip or blade central water spots, white to yellow light green edge and disease spot expanding quickly, causes the half of the blade to the blade die.3 ~ 5 days half a piece of leaf or the entire leaf wilting, rot disease spot when humidity is big, its produce sparse gray mold, stem disease Also with particular shaped decay, plants die.
Second, the garlic blight pathogen and occurrence regularity
Epidemic pathogenic fungi for onion garlic phytophthora, flagellated bacteria and fungi.Bacteria in mycelium and chlamydospore wintering in the sick body or soil, spring conditions suitable for the following year, pathogen spores by wind, rain and irrigation water, primary infection and to infect the fog.
Epidemics of garlic, bulb) and bolting ability is insufficient, which affect the yield and quality.Continuous cropping plot, the heavy clay soil, drainage, water easily, use not rotten organic fertilizer, planting density is too large, the field canopy closure, low temperature for a long time, the heavy rain.
Three, garlic epidemic factors
1, climate,
Precipitation combined with high temperature is more big, the fog times, generally in the temperature of 25 ℃ ~ 32 ℃, relative humidity above 95%, and the presence of water under the condition of heavy disease.
Stage serious the disease occurred in 4-5 months, but due to the frequent warm winter climate in recent years, increased incidents of rainfall and the rainfall is large, fog day, getting up earlier and earlier, and onset period if the morning dew is more, more severe disease.
2, variety, sowing date
The degree of disease have a certain difference between varieties.Too late sowing hazard is serious.According to the situation around the timely planting is the key link.
Early sow, early good garlic root, light disease harm;Late sowing garlic growing weak before winter, root developed, disease-resistant art ability is poor, the infectious disease in the following year.
3, water management,
Under different conditions, poor fertility of the onset of the heavier.Increase organic fertilizer, phosphate fertilizer, potash fertilizer disease, and premature nitrogen excess plot is heavier disease.
Has a great influence on soil moisture in disease also.Watering frequency, field humidity large susceptible, therefore, watering depends on soil moisture and the weather changes.
Mulch garlic field ditch is shallow, the soil moisture can't dissipate, in case of the rain weather, aggravate the disease prevalence.So, want to open a deep ditch lower underground water level.
4, planting density,
Garlic suitable density of planted 35000 plants per mu, the greater the density of the heavier disease, mainly due to the large density, field coefficient of leaf area is big, lower leaves poor ventilation pervious to light, humidity is big, combined with the field will benefit the rapid propagation of pathogenic bacteria.
