The causes of yellowing of ginger leaves are fungal diseases, spot disease and ginger leaf blight. Mainly harmful to leaves, the leaf spots are yellow-white, prismatic or rectangular, 2-5 mm long, and the middle of the spots are thin, easy to break or perforate. In severe cases, the lesions are densely covered and the whole leaves are punctate, so it is also called white star disease.

Prevention and control methods are:

(1) agricultural measures: avoid continuous cropping and partial application of nitrogen fertilizer, and pay attention to increasing the application of phosphorus, potassium fertilizer and decomposed organic fertilizer.

(2) Chemical control: At the initial stage of the disease, spray 1000 times of 50% compound thiophanate-methyl wettable powder or 600 times of 75% chlorothalonil wettable powder 1 time every 7 7- 10/day for 2-3 consecutive times.

Extended data of other diseases:

1, leaf blight: Leaf blight of ginger is a fungal disease, which mainly harms leaves. The original yellow-brown spots on the diseased leaves gradually spread to the whole leaves, and small black spots were produced in the diseased parts. In severe cases, the whole leaf turns yellow and dies. Prevention and control methods are:

(1) agricultural measures: rotation with Gramineae or non-solanaceae crops for more than 3 years; Apply fully decomposed organic fertilizer.

(2) Chemical control: At the initial stage of the disease, 75% chlorothalonil wettable powder with 600 times solution or 1: 1:200 Boleduo solution was sprayed 1 time every 7- 10 days for 2-3 consecutive times.

2. Anthracnose: Anthracnose of ginger is also a fungal disease, which damages leaves. At first, the lesion appeared at the tip or edge of the leaf. At first, it is waterlogged brown jade spot, and then it expands downward or inward into oval or prismatic brown spot, and the moire on the spot surface is obvious or not. Several diseased spots become patches, and the leaves turn brown and dry. When wet, small black spots will appear on the spots. Prevention and control methods are:

(1) agricultural measures: avoid continuous cropping and partial application of nitrogen fertilizer, pay attention to increasing the application of phosphorus, potassium fertilizer and decomposed organic fertilizer, and thoroughly remove sick and residual materials when ginger is harvested.

(2) Chemical control: At the initial stage of the disease, spray 10- 15 days with 50% compound thiophanate-methyl wettable powder or 800 times 80% thiram anthrax wettable powder 1 time for 2-3 consecutive times.

3. Ginger borer: Ginger borer (corn borer), also known as borer, has a variety of eating habits, mainly harming young stems on the ground with larvae, and also harming plants by transplanting. The control method is: 52.25% Agrocybe aegerita EC or 4.5% beta-cypermethrin EC 1500-2000 times, or 100% Uranus EC 1000 times, every 10 day/time.

References:

Baidu encyclopedia-ginger

References:

Baidu encyclopedia-ginger