1. Loose soil

Reason: if the soil for planting garlic is too hard, it is not conducive to ventilation and drainage, and hinders the respiration of the root. In addition, the hardening of the soil will make the poured water and fertilizer can not penetrate into the soil well, and the roots can not absorb nutrients in time. If the nutrition is not delivered in time, its leaves will begin to turn yellow slowly

Measures: it is necessary to turn over, loosen and loosen the soil in time to increase the softness, air permeability and drainage of the soil, so that water and nutrients can infiltrate in time and be absorbed by the roots

2. Proper topdressing

Reason: if garlic grows without nitrogen fertilizer, it will make the old leaves yellow. If it lacks potassium fertilizer, its branches and leaves will become dry. If there is a lack of calcium, some necrotic spots will appear on the leaves, the heart leaves will turn yellow, and the leaf tips will wither in severe cases

Measures: observe the growth of garlic and apply fertilizer according to the actual situation, but not too much, especially nitrogen fertilizer

3. Alleviate fertilizer damage

Reason: when fertilizing too much, it is easy to burn the root of garlic, affect its nutrient absorption capacity, and cause the external leaves to turn yellow

Measures: in continuous sunny days, watering twice with large water can absorb the heat released by the fertilizer in the soil and dilute the fertility. In addition, you can also spray foliar fertilizer to supplement the element deficiency caused by root burn of garlic. You can also apply some functional fertilizers to promote rooting to help the root system germinate new roots quickly

4. Pest control

Reason: such as leaf blight, garlic gray mold and garlic maggots, can also make the leaves of garlic turn yellow

Measures: carbendazim can be sprayed to control leaf blight. Garlic gray mold can be treated with fungicides such as mirex and carbaryl. For garlic maggots, the prevention and control should be more timely. You can use 90% trichlorfon 600 times solution for root irrigation treatment, and irrigate it every 10 to 15 days