Reason: If the soil for planting garlic is too hard, it is not conducive to ventilation and drainage, hindering the breathing of the roots.In addition, soil compaction will make the water and fertilizer can not penetrate into the soil well, and the roots can not absorb nutrients in time.If nutrients are not delivered in time, its leaves will begin to yellow slowly.
Measures: It is necessary to turn over the soil in time, loosen the soil, increase the softness, air permeability and drainage of the soil, so that the water and nutrients can infiltrate in time and be absorbed by the roots.
Reason: If garlic grows without nitrogen fertilizer, it will make the old leaves yellow.If there is no potash fertilizer, its branches and leaves will become dry.If there is a lack of calcium, there will be some necrotic spots on the leaves, the heart leaves will be yellowed, and the tips of the leaves will die in severe cases.
Measures: Observe the growth of garlic and apply fertilizer according to the actual situation, but not too much, especially nitrogen fertilizer.
Reason: When fertilizing too much, it is easy to burn the roots of garlic, affecting its ability to absorb nutrients, resulting in external leaves turning yellow.
Measures: In consecutive sunny days, irrigate twice with plenty of water, which can absorb the heat released by fertilizers in the soil and dilute the fertility.In addition, foliar fertilizer can also be sprayed to supplement the deficiency caused by root burns of garlic.Some functional fertilizers can also be applied to promote rooting to help the root system germinate new roots quickly.
Reason: Like leaf blight, garlic gray mold and garlic maggots, etc., can also make the leaves of garlic yellow.
Measures: Carbendazim can be sprayed to control leaf blight.Garlic gray mold can be treated with miemeiling, carbendazim and other agents.For garlic maggots, prevention and control should be more timely, you can use 90% trichlorfon 600 times solution for root irrigation treatment, every 10 to 15 days.
