How to treat pests and diseases of red tip photinia? Detailed explanation of control methods

Red tip photinia is the collective name for hybrids of the genus Photinia in the rose family (Rosaceae), named for its bright red new shoots and young leaves. It has many cultivated varieties. Common diseases include leaf spot, anthracnose and gray mold, and common pests include aphids, scale insects and longhorn beetles. Let us take a look below at the common pest and disease control techniques for red tip photinia!

Gray mold

[Damage characteristics] Gray mold mainly damages the young twigs, young stems, leaves, flowers and fruits of red tip photinia. The lesions first appear as small water-soaked spots, then expand into large gray patches with irregular concentric rings, and finally the affected parts are covered with a gray mold layer until they become necrotic or rot.

[Control methods] Strengthen cultivation management at ordinary times, pay attention to draining standing water, reduce humidity and remove diseased plant debris. Before the rainy season arrives, spray 50% carbendazim 800x solution for prevention; during the disease period, spray 50% zineb 800x solution or thiophanate-methyl 800x solution for control.

Leaf spot

[Damage characteristics] Leaf spot mainly damages the leaves and stems. When leaves are affected, small brown spots appear first, then gradually expand into angular lesions. The lesions are reddish brown on the upper surface of the leaf and yellowish brown on the underside. When the disease is severe, the lesions may merge into patches, and even the whole plant may die.

[Control methods] In winter and spring, in combination with tending and management, sweep up fallen leaves in a concentrated way to eliminate overwintering pathogens. In March and early June, spray 1% equal-amount Bordeaux mixture once every 10-15 days for prevention; when the disease occurs, use 50% carbendazim 300-400x solution or 50% thiophanate-methyl 300-400x solution for control.

Anthracnose

[Damage characteristics] Anthracnose is a major disease that occurs in red tip photinia during cutting propagation. It is more likely to occur under conditions of high temperature, high humidity and poor ventilation, and can easily cause red tip photinia to only root without sprouting.

[Control methods] After the cuttings are finished, always pay attention to the humidity and temperature of the cutting bed, maintain good ventilation, and remove severely affected diseased leaves. In the early stage of the disease, spray 70% thiophanate-methyl wettable powder 500-1000x solution or 65% zineb wettable powder 600x solution for control, and spray again after 7-10 days.

Aphids

[Damage characteristics] Aphids, also known as greasy insects or honey insects, gather as adults or nymphs on the young buds, tender stems or tender leaves of red tip photinia, and use their needle-like piercing-sucking mouthparts to suck plant sap, causing leaves to curl and crinkle toward the underside. This directly affects the growth and ornamental value of red tip photinia, and can also cause sooty mold. Their reproductive capacity is large, and they can easily cause disasters in dry seasons.

[Control methods] Generally, when temperatures rise in spring, spray 10% omethoate emulsion 1000x solution, malathion emulsion 1000-1500x solution, or dichlorvos emulsifiable concentrate 1000x solution. During the peak aphid season from March to October, use agents such as yashijing or yashiling and spray once every 7 days to prevent adults from causing disasters.

Scale insects

[Damage characteristics] Scale insects mainly include white wheel scale, etc., and damage the terminal buds and tender twigs of red tip photinia. When the infestation is severe, they can cover the entire branches and leaves, can cause sooty mold, and affect ornamental value.

[Control methods] Before bud break in spring, spray 10%-15% diesel emulsion for prevention. When the infestation occurs, spray 40% omethoate 1000x solution, or 2.5% deltamethrin 2500x solution, 20% jusha emulsifiable concentrate 2500x solution, or 40% supusha emulsifiable concentrate 1500x solution, all of which can achieve good control results.

Longhorn beetles

[Damage characteristics] Longhorn beetles mainly bore into the branches and trunks of red tip photinia during the larval stage. The damage lasts for a relatively long time, affecting the growth and development of the plant, weakening tree vigor, leading to invasion by pathogens, and making it easy to break in the wind. When the damage is severe, the entire plant dies, seriously affecting ornamental value.

[Control methods] The control of longhorn beetles is mainly carried out through a combination of multiple measures, such as whitewashing tree trunks to repel adults from laying eggs, manually catching and killing eggs, larvae and adults, and injecting medicinal solution into insect holes in the trunk. The agents can be selected from 50% malathion emulsifiable concentrate, 50% dichlorvos emulsifiable concentrate, 40% omethoate emulsifiable concentrate, 2.5% deltamethrin emulsifiable concentrate 200x solution, etc.