Summary of control methods for 7 common diseases and 2 major pests of ginger

As the saying goes, eat radish in winter and ginger in summer. Ginger is currently one of the indispensable seasonings for people. If you want a good harvest of ginger, the prevention and control of pests and diseases cannot be ignored. Below, let us look at the control methods for 7 common diseases and 2 major pests of ginger.

1. The 7 common diseases of ginger

1. Ginger soft-foot disease

Commonly known as ginger plague. This disease has its peak occurrence period from Xiaoman to Dashu. It is a root and rhizome disease caused by bacteria, also called rot disease or soft rot disease.

It is mainly spread through irrigation water and underground pests. It can occur from the sprouting and emergence of seed ginger to before ginger harvest. The disease mostly occurs in high-temperature, frequent-shower, waterlogged fields. It occurs in all ginger-producing areas in northern and southern China and is a major disease in ginger-producing areas, especially severe in continuously cropped land. In the early stage of the disease, stems and leaves wilt, then turn bright yellow, leaves shrink, and roots become water-soaked. A cross-section of the ginger stem about 3 cm from the tuberous root appears light black, and soon a milky white mucus flows out. If not pulled out, within a few days the wilted stems and leaves will rot and stink and spread to other plants. Ginger soft-foot disease is a bacterial disease, mainly transmitted through soil, water, and ginger seeds. Therefore, preventive work must be done well.

The control methods are:

(1) Choose soil free of pathogens or plots that have previously grown rice for planting;

(2) Select seeds from disease-free areas

(3) Prevent water accumulation and waterlogging at the ginger roots;

(4) Once disease occurs, promptly pull out the affected plants and disinfect the soil with 50% chlorobromoisocyanuric acid at 300 times dilution or 5% lime water.

2. Ginger rot disease

The symptoms spread from the skin rot toward the center (ginger blast disease, by contrast, spreads from the center rot toward the skin). Water accumulation or application of undecomposed manure easily triggers this disease.

The main preventive methods are: do not allow water to accumulate in the ginger field; farmyard manure used must be thoroughly composted. If disease has already occurred, apply Bordeaux mixture as a drench, or disinfect the soil according to the method for preventing soft-foot disease.

3. Ginger leaf spot disease

It is a fungal disease. It mainly damages leaves. Leaf spots are yellowish white, spindle-shaped or oblong, small, 2-5 cm long, with the center of the spot becoming thin and easily rupturing or perforating. When severe, the spots are densely distributed, and the whole leaf looks speckled, hence the name white star disease. The conidia of the pathogen causing ginger leaf spot disease serve as the source of primary infection and reinfection and spread by rain splash. Warm and humid conditions, closed plant spacing, high field humidity, or continuous cropping plots all favor the occurrence of this disease.

Control methods: Avoid continuous cropping and implement crop rotation of more than 2-3 years. Choose plots with convenient irrigation and drainage for planting, and do not plant in low-lying land. Pay attention to the balanced application of nitrogen, phosphorus, and potassium fertilizers, and do not apply excessive nitrogen fertilizer. At the initial stage of disease, spray the leaves with 50% chlorobromoisocyanuric acid or thiophanate-methyl, once every 7-10 days, for 2-3 consecutive sprays.

4. Ginger anthracnose

Fungal disease. It mainly damages leaves, with lesions first appearing at leaf tips and leaf margins. The lesions are initially water-soaked brown small spots, then expand inward into elliptical or spindle-shaped to irregular brown spots, with or without obvious concentric rings. Several lesions connect into diseased patches, causing leaves to turn brown and dry up; when humid, small black dots appear on the diseased surface. It spreads by rain splash or insect activity. Besides damaging ginger, the pathogen can also infect many ginger family or nightshade family crops. The pathogen spreads and causes damage alternately on host crops in the field, with no obvious overwintering period. Continuous cropping, excessive plant growth, high field humidity, and excessive nitrogen application all favor the occurrence of this disease.

Control methods: Implement crop rotation and avoid continuous ginger cropping. At harvest, thoroughly remove diseased residues, gather and burn them, and take them out of the field. Increase the application of farmyard manure, pay attention to the balanced application of nitrogen, phosphorus, and potassium to enhance plant disease resistance; strictly prohibit excessive nitrogen application to avoid excessive plant growth. Strictly prohibit water accumulation in the field, and promptly carry out ditch clearing and drainage. Spray with chlorobromoisocyanuric acid or copper oxychloride, applying to the leaves at the initial stage of disease, once every 10-15 days, for 2-3 consecutive sprays.

5. Ginger sheath blight:

(1) Before sowing or transplanting, or after harvest, clear weeds in and around the field, gather and burn them or compost them; deep plow the land to destroy stubble, promote the decomposition of diseased residues, and reduce pathogens and pest sources.

(2) Rotate with non-grass-family crops; rice-upland rotation is best.

(3) Select disease-resistant varieties, and choose disease-free, coated seeds; if uncoated, seeds must be sterilized with a seed dressing agent or seed soaking agent.

(4) Cover with medicated soil after raising seedlings for transplanting or after sowing, and spray an insecticidal and sterilizing agent once before transplanting. This is key to disease prevention.

(5) Choose fields with convenient irrigation and drainage, dig drainage ditches well, lower the groundwater level, and achieve no water accumulation after rain stops; after heavy rain, promptly clear the ditch system to prevent moisture retention and reduce field humidity. This is an important measure for disease prevention.

(6) For fields with many soil pathogens or severe underground pests, broadcast or apply in furrows medicated soil for sterilization and insect killing before sowing.

6. Ginger white star disease

(1) Choose relatively high, dry, fertile soil plots for planting. Low flat land should be cultivated with high ridges or high beds, and deep ditches should be made for drainage.

(2) Apply sufficient decomposed manure and topdress timely and appropriately. Do not use too much nitrogen fertilizer, and pay attention to increasing phosphorus and potassium fertilizers, especially potassium fertilizer.

(3) Irrigate scientifically and drain after rain to reduce field humidity.

(4) It is not advisable to work in the field after rain or when dew has not dried, so as to reduce opportunities for disease transmission and lessen disease occurrence.

(5) At the initial stage of disease, promptly spray chemicals for control. Optional chemicals include 50% chlorobromoisocyanuric acid at 1000 times dilution, or 30% copper succinate-glutarate wettable powder at 400 times dilution, or 80% captafol wettable powder at 500 times dilution.

7. Ginger soft rot disease

Also called rot disease or ginger blast disease. Its occurrence is fast, widespread, and highly damaging. The disease generally first occurs at the stem base near the ground and the upper half of the underground rhizome. In the early stage of ginger soft rot disease, yellow-brown lesions appear on stems and leaves, the aboveground stems and leaves turn yellow, wilt, and then die, and the underground tubers become soft-rotted when infected, losing edible value. It should be noted that the pathogen spreads and expands rapidly with wind and rain. If measures are not taken in time, it can result in basically no harvest.

Control methods: These can be summarized as prevention first and integrated management. In seed selection, do well in selecting healthy seeds, disinfecting ginger, implementing crop rotation, and improving cultivation techniques. In addition, treatment should target the causes of ginger diseases. Since soft rot disease is caused by infection by Pythium fungi, chemical selection should be targeted. You can use 50% chlorobromoisocyanuric acid at 1000 times dilution, or 64% oxadixyl mancozeb wettable powder at 500 times dilution, 69% dimethomorph mancozeb wettable powder at 600 times dilution, 72% cymoxanil wettable powder at 600 times dilution, or 80% fosetyl-aluminum wettable powder at 400 times dilution to soak seeds plus sealed seed treatment (sealed with nylon film) for 1 hour each, then dry and sow; after emergence and up to the initial disease stage, irrigate again with the above chemicals, and irrigate once more after 10 days.

2. The 2 common pests of ginger

1. Ginger stem borer

Farmers call it the heart-boring worm. This pest uses its larvae to bore into and feed on ginger seedlings, causing their leaves to turn yellow and wither, and in severe cases can cause the death of the whole plant.

Control methods: Eliminate adult ginger stem borers early, remove larvae by hand, or apply pesticide to kill them during the first and second instar larval stages. Larvae can be seen causing damage from early May, with the peak period in July and August when ginger seedlings branch vigorously. Control is more effective when pesticide is applied during the young larval stage. During the larval stage, spray 20% tebufenozide suspension concentrate at 1500 times dilution onto the heart leaves of ginger seedlings in the evening; when the solution flows to the stem, it can kill the ginger stem borer larvae.

2. Ginger maggot

It is a major pest during ginger storage. The larvae are commonly called ginger maggots, and they also damage seed ginger in the field, causing a certain impact on ginger yield and quality. Ginger maggot larvae have moisture-seeking and concealment habits. Newly hatched larvae bore into the ginger skin to feed. Those feeding at the "round head" area cover themselves with a silk web mixed with insect feces and debris, and the larvae hide within. The larvae are active, and at damaged ginger sites only the epidermis, coarse fibers, and granular insect feces remain; they can also cause ginger to rot. Ginger maggots are not strict about environmental conditions and can occur year-round. Especially when temperatures rise around Qingming, damage intensifies. Field surveys show the rate of damaged ginger reaches 20-25%.

Control methods: Carefully select ginger seeds, immediately discard seed ginger found to be damaged, or soak seed ginger in 1.80% abamectin emulsifiable concentrate at 1000 times dilution for 5-10 minutes to prevent pests from spreading from the ginger cellar to the field. Before putting ginger into the cellar, thoroughly clean the ginger cellar and spray the cellar with 80% dichlorvos at 1000 times dilution. You can also place several open small bottles containing undiluted dichlorvos in the ginger pile when storing ginger, or after the ginger is placed, heat undiluted dichlorvos for fumigation. In the field, pay attention to carefully selecting ginger seeds, discarding damaged seed ginger, and soaking seed ginger in 80% dichlorvos at 1000 times dilution for 5-10 minutes before sowing to kill pests inside the ginger.