Apple manganese poisoning symptoms

The symptoms of apple manganese poisoning mainly occur on the branches, and the appearance is "rough skin". Generally, the front and back of the branches are smooth, and a solid dark brown rash-like small protrusion suddenly appears in the middle, which protrudes from the phloem and occurs around the lenticels, above the epidermis, and there is no living organism. Gradually spread in the later period, the lesions gradually enlarged, cracked, sag, and staggered to form a typical rough skin. Scratch the diseased skin, visible black spots and black tendons, and the heavy parts reach the xylem.

Five major hazards of manganese poisoning

1. Autumn leaves are early, and spring germination is late.

2. The leaves of the young leaves are small, the color is not fresh, and it seems to be lack of water. There are chlorosis between the veins and the margins of the leaves. In severe cases, the leaves are burnt or dead.

3. In spring, the branches are out of water, and some old trees and weak trees will flow.

4. During the growing season, symptoms such as dead twigs and weakened trees appear.

5. The apple is of poor quality, the fruit is small, the transverse diameter is large, it is oblate, and the color is poor.

Causes of apple manganese poisoning

Soil acidification. The pH value of the orchard soil is below 5.0, and the effectiveness of manganese in the soil is greatly increased. The root absorbs excess manganese and is transported to the branches. The manganese accumulation is poisonous. Soil analysis showed that the tree was susceptible to manganese poisoning when the soil effective manganese content exceeded 10 mg/kg and the leaf manganese content was higher than 150 mg/kg.

The soil organic matter content is low. The survey data showed that when the organic matter content of apple orchard was less than 0.6%, manganese poisoning was easy to occur and rough skin disease appeared.

Orchard low-lying drainage is not smooth, serious water accumulation, resulting in a large amount of manganese reduction in the soil, prone to manganese poisoning.

Apple Manganese Poisoning Solution

Taken together, there are three moves. That is to say, two coats and three sprays.

One tone: Adjust soil pH and organic matter. Including the application of organic fertilizer, balanced nutrient fertilization, iron supplementation, application of quicklime or alkaline calcium calcium magnesium fertilizer or calcium magnesium phosphate fertilizer to neutralize soil acidity, improve irrigation and drainage systems.

Second coat: Apply the affected area. Before the spring germination, the diseased branches are directly coated with “green fast (13% EDTA iron)” or “top green 6% EDDHA iron”, combined with 20 times 50% carbendazim or methyl thiophanate, once a month, Apply at least twice.

Three sprays: from late June to mid-July combined with pest control, spray "green fast" 5000 times or "top green" 6000 times. Spray even twice, the whole tree is carefully sprayed, that is, the leaves can be greened, and manganese poisoning can be prevented.