The Latest Causes of Continuous Cropping Obstacles in Garlic and Control Measures

Continuous cropping of garlic increases garlic pests and diseases, leading to a decline in the yield and quality of garlic bulbs and garlic scapes, and severely restricting the development of the garlic industry. Therefore, understanding the causes of continuous cropping obstacles in garlic and control measures is extremely important for the sustainable development of garlic. Let's learn about it together with the editor below.

I. Harm of Continuous Cropping

With continuous planting year after year, the area affected by garlic diseases has gradually risen. According to surveys of the harm of continuous cropping in garlic, disease occurrence is severe in plots where garlic has been continuously cropped for more than 15 years. Continuous cropping obstacles in garlic are not a single disease but a comprehensive manifestation of a series of physiological diseases and infectious diseases. Disease generally begins in March, with main symptoms including leaves losing green color and turning yellow, drying up, and dying; as well as poor root development, root discs turning brown and rotting, and in severe cases root death; garlic plants are short and stunted, garlic bulbs are thin and small, and in severe cases scapes cannot be produced, generally resulting in a yield reduction of about 30-40%.

II. Causes of Continuous Cropping Obstacles

1. Influence of pathogenic organisms

Due to many years of continuous cropping, garlic pathogens and microorganisms remain in the soil. After planting, they parasitize garlic and multiply in large numbers, with their numbers rising year by year. Moreover, under continuous cropping cultivation, seedlings have weak resistance and are highly susceptible to disease. For example, root-knot nematodes multiply exponentially in the soil year by year, damaging the garlic root system and affecting the normal development of garlic, causing diseases to worsen year by year.

2. Nutrient imbalance

Garlic growth absorbs various nutrient elements from the soil. If slight carelessness is taken in the application of organic fertilizer and microelement fertilizer during fertilization, it will lead to an imbalance of the nutrients required by garlic, resulting in poor growth and development of garlic, decreased stress resistance, weakened growth, and the appearance of nutrient deficiency-type physiological diseases.

3. Soil

Excessive application of chemical fertilizers will cause the oxygen content of the soil to continuously increase, aggravating soil salinization. The accumulation of soil salts will increase soil permeability. Garlic roots have weak absorption capacity, and it will also cause certain antagonistic effects among elements, affecting the absorption of certain elements by garlic, hindering garlic growth, and also affecting the survival, reproduction, and activity of beneficial microorganisms, causing beneficial microorganisms to run rampant. In addition, excessive use of chemical fertilizers will cause soil compaction, leading to poor soil permeability and causing root suffocation.

III. Control Measures

1. Crop rotation and changing plots

Crop rotation and changing plots is the best method to solve the harm of continuous cropping obstacles. Compared with other vegetables, garlic requires a longer rotation period, generally requiring 3-5 years of crop rotation and plot change; otherwise, it is difficult to eliminate continuous cropping obstacles. In addition, it cannot be continuously cropped with other scallion and garlic vegetables such as Welsh onion, small scallion, onion, and Chinese chives. During rotation, scallion and garlic crops should be avoided.

2. Fertilization

Increase the application of organic fertilizer, improve soil structure, increase soil organic matter content, maintain good air permeability, and promote root growth. The fertilization principle should combine organic, inorganic, and microelement fertilizers, with organic fertilizer as the main component and chemical fertilizer as a supplement; base fertilizer as the main component and topdressing as a supplement; and chemical fertilizer mainly based on high nitrogen and high potassium.

The above is an introduction to the causes of continuous cropping obstacles in garlic and control measures. We hope it can help you. To learn more related knowledge, please stay tuned to us.