During peach cultivation, many people often encounter the problem of black spots appearing on the fruit skin. This not only affects the appearance of the peaches but may also reduce their taste and market value. So what disease causes black spots on peaches? Let's find out below.
What disease causes black spots on peaches?
Black spots on peaches are usually caused by peach scab, also known as peach black spot disease. This disease is one of the most common and serious diseases affecting peach trees and occurs in all peach-producing areas of my country.
How can we effectively prevent and control peach scab?
1. Symptoms
Peach black spot is a fungal disease caused by Cladosporium flavum, which mainly affects the fruit. After the fruit is infected, small dark green round spots appear in the early stage, which expand into black mole-like spots, and later become rough purplish-black patches. The diseased fruit eventually withers and cracks.
2. Disease pattern
The pathogen overwinters in lesions on one-year-old branches and spreads as spores the following spring. The incubation period is relatively long, with fruit infection occurring 40-70 days later. Rainfall in spring and early summer is the primary factor determining whether the disease will become widespread.
3. Causes of the disease
The occurrence of peach scab is related to climate, orchard topography, and variety. Rainfall in spring and early summer, especially during the fruit's near-ripe period, is a crucial factor influencing the disease's occurrence and spread. High humidity and rain during these periods increase the risk of disease. Low-lying orchards , dense planting, poor ventilation and light penetration, and high humidity exacerbate the disease.
4. Prevention and control measures
(1) Agricultural control: Select disease-resistant or early-maturing varieties, prune and remove diseased branches in winter to reduce the source of disease, pay attention to drainage after rain in the peach orchard, prune properly to ensure good ventilation and light penetration in the peach orchard, and bag the fruit after fruit set to prevent pathogen infection.
(2) Chemical control: Before flowering, spray lime sulfur mixture with sodium pentachlorophenate or crystalline lime sulfur mixture. Half a month after flowering, spray mancozeb and other agents. Apply the agent once every 10-15 days, for a total of 3-4 times, to reduce the occurrence of diseases.
