What are the common pests and diseases of goji berry? How should they be prevented and controlled?

Goji berry is a common health food and is currently loved by many health-conscious people. Everyone talks about “soaking goji berries in a thermos”, so more and more people are growing goji berries. So what are the common pests and diseases of goji berry? How should they be prevented and controlled?

1. Goji berry anthracnose

Goji berry anthracnose, also known as black fruit disease, has a diseased plant rate of 15%-20%, and in severe cases up to 70%. It is a fungal disease and is a major disease in goji berry production.

1. Symptoms

The disease mainly damages the fruit, and also infects young branches, leaves and flowers. In the early stage of disease on green fruit, pinhead-sized brown small round spots appear on the fruit surface, which later expand into irregular lesions. The lesions are sunken and softened, and turn black. When the climate is dry, the fruit shrivels. On the surface of the lesions, small black dots arranged in nearly concentric rings grow. When humid, orange-red spore masses appear on the surface of diseased fruit. When young branches, leaf tips and leaf margins are infected, semicircular brown spots appear, and when field humidity is high they become wet rot-like, with orange-red slimy dots appearing on the surface. After flowers and flower buds are infected, they turn black and cannot bloom or bear fruit.

2. Disease occurrence pattern

The pathogen overwinters on diseased fruit and diseased branches. Wind and rain are the main transmission media. The disease can occur throughout the growing period. The pathogen continuously causes reinfection in the field. With more rainfall and high humidity, the disease spreads rapidly. The peak incidence period is July—August

3. Control methods

Strengthen field management. In combination with winter pruning and shaping, remove diseased branches, thoroughly clean up dead branches and fallen leaves in the field, and burn them in a centralized manner. In the rainy season from May—June, spray 1:1:100 Bordeaux mixture once, and spray again after 15 d. In the early stage of disease, spray 3-5 times with 50% mancozeb 600-fold solution or 70% thiophanate-methyl 500-fold solution. Use the two agents alternately, spraying once every 7-10 d. If rain occurs, supplement the spray in time.

2. Goji berry gray leaf spot

Goji berry gray leaf spot is a fungal disease. It mainly damages leaves and also infects fruit. The annual incidence rate is 30%, and losses are 20%-30%.

1. Symptoms

The lesions on leaves are round, grayish white to light brown in the center, with a slightly darker edge, and the diseased part is sunken. In the later stage, the lesions turn brown and dry up, and light black mold-like substances grow on the back of the leaves. Light black mold-like substances also appear on diseased fruit

2. Disease occurrence pattern

The pathogen overwinters on dead branches, fallen leaves and diseased fruit, or overwinters in the soil as diseased plant residues. The following year it is spread by wind and rain to cause initial infection. During the growing season, multiple reinfections can occur in the field. High temperature and high humidity in summer, and foggy and dewy weather, are conducive to disease occurrence and spread, and the damage is more severe.

3. Control methods

In winter, in combination with pruning, thoroughly remove dead branches, fallen leaves and diseased fruit from the field, and burn them in a centralized manner. Strengthen field management, increase the application of phosphorus and calcium fertilizers, and enhance plant disease resistance. Before disease onset, spray 1:1:150 Bordeaux mixture to prevent disease occurrence. In the early stage of disease, spray 70% thiophanate-methyl 600-fold solution or 50% carbendazim wettable powder 500-fold solution. Spray once every 10-15 d, for 3-4 consecutive sprays.

3. Goji berry powdery mildew

Goji berry powdery mildew is a fungal disease. It mainly damages leaves, with an annual incidence rate of 20%, and also infects young fruit.

1. Symptoms

On diseased leaves, white powdery mold layers appear on both the front and back sides. Affected leaves often shrink and curl, and in the later stage the diseased leaves turn yellow, necrose, and grow small black dots, and the leaves fall off early.

2. Disease occurrence pattern

The pathogen overwinters in diseased tissues and winter buds on diseased branch tips. The following spring, disease begins to occur, and the incidence rate is high during the young fruit stage. The pathogen is spread by wind to infect and cause disease. It continuously causes reinfection. Dry climate causes more severe disease than rainy conditions, and large day-night temperature differences are conducive to disease occurrence. Late July to early August is the peak incidence period.

3. Control methods

In winter, remove diseased leaves and branches from the field and burn them, reducing pathogens in the field. In early March, before branches sprout, spray 1:1:100 Bordeaux mixture once. In the early stage of disease, choose 25% triadimefon 800-fold solution or 50% carbendazim 500-fold solution, and spray 2—3 times depending on the condition, once every 10-15 d.

4. Goji berry aphids

Goji berry aphids are one of the more common pests causing damage. They can cause a yield reduction of 20%-30%.

1. Characteristics

They mainly use adult aphids and nymphs to gather on tender leaves, tender buds and young fruit to pierce and suck sap, causing tender shoots to become brown and withered, stunting new shoot growth, and deforming fruit. When the infestation is severe, leaves are covered with oily secretions, affecting photosynthesis and causing early leaf fall. The tree vigor weakens, and yield and quality decline.

2. Disease occurrence pattern

Aphids show overlapping generations. They overwinter as eggs in goji berry branches, axillary buds and trunk crevices. The following spring, before hatching, they reproduce parthenogenetically and damage tender buds. Late May to early June is the peak damage period. After mid-to-late July, insect 1:1 density decreases and damage lessens. In September, damage begins to rise again, and bisexual aphids occur and cause damage. After laying eggs, they overwinter as eggs

3. Control methods

In autumn and winter, prune branches with aphids and burn them in a centralized manner to eliminate overwintering eggs. During the growing season, promptly prune excessive vegetative branches and take them out of the field to burn. Eliminate aphids clustered on tender parts and reduce field pest population density. In the early stage of damage, spray pesticide in time. You can use 50% mieyajing 3000-fold solution or 10% imidacloprid wettable powder 1500-fold solution for comprehensive control.