Causes of yellowing of ginger leaves: fungal diseases, blotch and ginger blotch. Mainly harmful to leaves, the leaf spots are yellow-white, prismatic or oblong, 2-5 mm long, and the middle part of the spots becomes thinner, which is easy to break or perforate. In severe cases, the lesions are densely covered and the whole leaves are like dots, so it is also called white star disease.

The 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: spray 1 times of 5% compound thiophanate-methyl wettable powder or 6 times of 75% chlorothalonil wettable powder once every 7-1 days for 2-3 times in a row at the initial stage of the disease. Extended information

Other diseases:

1. Leaf blight: Jiang Ye blight is a fungal disease, which mainly damages leaves. The yellow-brown spots on the diseased leaves gradually spread to the whole leaf, and small black spots are produced in the diseased parts, and in severe cases, the whole leaves turn brown and die. The 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, ginger plants were sprayed with 6 times solution of 75% chlorothalonil wettable powder or 1:1:2 Boledol solution once every 7-1 days for 2-3 consecutive times.

2. Anthracnose: Colletotrichum gloeosporioides of ginger is also a fungal disease, which damages leaves. At first, spots appear from the tip or edge of leaves. At first, they are waterlogged brown jade spots, and then they expand downward or inward to oval or prismatic brown spots, with obvious or inconspicuous moire. Several diseased spots are connected into plaques, and the leaves turn brown and dry. When wet, the spots appear small black spots. The control methods are as follows:

(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 disabled materials when harvesting ginger.

(2) chemical control: at the initial stage of the disease, spray 1 times of 5% compound thiophanate-methyl wettable powder or 8 times of 8% anthrax thiram wettable powder once every 1-15 days for 2-3 consecutive times.

3. Ginger borer: Ginger borer (corn borer), also known as borer, has a variety of feeding habits, mainly damaging young stems on the ground by larvae, and can also be damaged by transplanting plants. The control method is: 52.25% Nongtianle EC or 4.5% beta-cypermethrin EC with 15-2 times solution or 1% Uranus EC with 1 times solution can be sprayed once every 1 days for 2-3 times continuously.

Reference: Baidu Encyclopedia-Ginger

Reference: Baidu Encyclopedia-Ginger.