What to do when ornamental peach gets peach leaf curl? The prevention and control methods explained in one article

Hot summers are often when many diseases occur. In summer, the temperature is suitable for pathogens, and in some areas summer is also very humid, so before summer arrives, we often need to prepare plants for disease prevention. The editor will introduce to you the peach leaf curl of ornamental peach in summer. Friends who like ornamental peach should not miss it.

Ornamental peach

Fungal disease. The pathogen overwinters or oversummers as blastospores on the bark and bud scales, then invades the leaves in the following spring. The spores are spread by air currents and invade through stomata or the upper and lower epidermis. The pathogen's mycelium spreads beneath the host epidermis or in the intercellular spaces of the palisade tissue, stimulating the host tissue to divide massively and thickening the cell walls, causing the leaves to show symptoms of shrinkage and curling. Besides damaging leaves, this disease also harms young shoots, flowers and fruit. Infected leaves shrink and curl, turn reddish-brown in color, and become brittle in texture, finally drying up and falling off; infected young shoots have shortened internodes and some swelling, and the leaves on diseased branches are mostly clustered. In severe cases, the diseased branch tips wither and die.

Prevention and control methods: In the early stage of the disease, promptly remove diseased leaves, cut off damaged branches, and destroy them in a centralized manner to reduce the source of infection. Water and fertilize promptly and reasonably to enhance the plant's resistance and reduce the occurrence of the disease. In early spring, before peach buds swell and leaf out, spray 3-5 degrees Baume lime sulfur mixture or 1:1:160 Bordeaux mixture to prevent pathogen infection. After the peach tree sheds its leaves, spray 3% copper sulfate to kill the overwintering and oversummering spores.

How to effectively prevent and control peach leaf curl

Peach leaf curl, commonly known as swollen leaf disease, mostly occurs during rainy, low-temperature periods in spring. It occurs in peach orchards in all provinces of the country. The disease mainly harms peach, ornamental peach, cherry, apricot, plum, etc.

Prevention and control methods for peach leaf curl:

1. Do a good job in soil, fertilizer, and water management, and improve ventilation and light conditions. In severely affected peach orchards, timely topdressing and irrigation should be carried out to promote tree vigor and enhance the tree's disease resistance. Promptly remove diseased leaves and burn them in a centralized manner during the fruit tree dormant period. Spray 3-5 degrees Baume lime sulfur mixture to eliminate overwintering pathogens.

2. The key period for prevention and control is when peach flower buds show red but have not yet opened. The following agents can be sprayed: 5 degrees Baume lime sulfur mixture; 1:1:100 Bordeaux mixture; 50% sulfur suspension concentrate 600 times solution; 10% difenoconazole water-dispersible granules 2000 times solution; 70% thiophanate-methyl wettable powder 600-1000 times solution; 65% zineb wettable powder 600-800 times solution; 75% chlorothalonil wettable powder 600-800 times solution; 50% carbendazim wettable powder 600-800 times solution; 70% mancozeb wettable powder 500 times solution. This can control the occurrence of primary infection, with very good results.

Symptoms and prevention and control of peach leaf curl

Peach leaf curl is a common disease in spring. It mainly harms peach, ornamental peach, cherry, apricot, plum, etc.

PathogenCaused by fungi of the class Taphrinomycetes (Exoascomycetes).

SymptomsIt mainly harms leaves, and in severe cases can also harm flowers, young fruit and young twigs. After leafing out in spring, infected plants appear shrunken and wavy, with leaf tips and margins curling backward and the leaf surface uneven. As the leaves grow, the leaf color gradually changes from yellow-green to purplish-red, the mesophyll thickens and becomes brittle, and the unevenness increases. In late spring and early summer, a layer of white powder forms on the leaf surface, and soon the diseased leaves turn black, wither and fall off; infected young diseased branches become shortened and swollen, gray-green or yellow, with leaves clustered on the diseased branches, and in severe cases the branches die; diseased fruit develops abnormally, with the fruit surface cracking and fruit hairs falling off, but the surface is smooth.

Disease characteristicsThe pathogen overwinters as ascospores or blastospores in the crevices of bud scales or on the bark. When peach buds sprout the following spring, the blastospores produce germ tubes that directly penetrate the epidermis or enter young leaves through stomata. The ascospores and blastospores produced by diseased leaves that year mature in late spring and early summer. The disease occurs severely from April to May and is spread by wind. However, because the temperature is high at that time, it generally does not infect again, with only one infection per year. As the temperature rises, development stops, and when the temperature exceeds 30°C, the disease does not occur. Low temperature and abundant rain in spring favor the occurrence of this disease, and it also occurs frequently along rivers, lakesides and low-lying areas.

Prevention and control methods① In late autumn or early spring, promptly cut off diseased branches and leaves, remove diseased residues, or remove diseased leaves early before a white powdery layer forms on their surface to reduce the source of disease; ② In early spring, when peach buds swell but before leafing out, spray 4-5 degrees Baume lime sulfur mixture; ③ Spraying 0.1% copper sulfate solution before leafing out can also effectively prevent and control it.