Apple mildew

apple mold heart disease, also known as heart rot, black heart disease, fruit rot, etc., is a compound infection of many fungi of the subfamily Hemiptera. It is pointed out that Alternaria among these fungi is the pathogen of apple mold heart symptoms, and Polyporus pink is the pathogen of apple rot symptoms. This pathogen mainly occurs in the main apple producing areas in China, such as the Bohai Sea, the old course of the Yellow River, and the northwest. In recent years, it has also shown a trend of increasing harm year by year, so it is urgent to understand and control this disease.

first, symptoms

in the early stage of apple mold heart disease, there will be brown discontinuous spots or strips in the fruit heart chamber, and then with the aggravation of the disease, these spots will continue to merge, and then form brown large patches, accompanied by black ash, dark green, white and other moldy things. In severe cases, the apple pulp will rot and deteriorate, and the fruit taste will become bitter, losing its commercial value and edible value. In addition, when this disease occurs, the fruit appearance has no obvious symptoms, so it is relatively difficult to control it in production.

II. Pathogenic regularity

The pathogen of mould heart disease parasitizes on the buds, branches, dead fruits, fallen leaves and weeds of the host in the form of hyphae. The latter overwinters on the scales of the buds in the form of spores, and the infection process begins in the second year through the media such as wind, rain and insects. Pathogens mainly invade through cracked petals, pistils, calyx, etc. First, they colonize the stigma, then start to transfer to the tissue between calyx hearts after flowering, then enter the ventricle, and start to get sick at the harvest and storage periods of fruits.

In addition to the above disease process, production experience shows that the disease is more serious in the production areas with humid weather in spring, low-lying and humid orchards and closed orchards without ventilation and light transmission; The incidence rate of different varieties is quite different: Marshal has a higher incidence rate, followed by Fuji, and Golden Crown has a very low incidence rate; There are also differences in fruit diseases in different parts: the disease incidence is lower than the central fruit, the double fruit is lower than the single fruit, and the triple fruit is lower than the double fruit; In addition, the incidence of apple mold heart disease is also related to the tree situation, and the moderate and strong trees have weak susceptibility to disease, on the contrary, the incidence of weak trees is greater.

III. Prevention and treatment measures

It has been found in the aspect of symptom identification before that the mold heart disease has no obvious external symptom characteristics, so it is difficult to identify whether this disease occurs in production. Based on this, we need to take preventive measures and cure it in advance.

1. Cultivate robust trees.

according to the characteristics of moderate and robust trees that are not susceptible to diseases, we can achieve the purpose of cultivating robust trees through a series of management measures such as reasonable balanced fertilization, increasing the amount of organic fertilizer, loosening soil and improving the growth environment of roots. In addition, some calcium nutrients, such as sugar alcohol calcium, can be sprayed on the leaves during the fruit expansion period to increase the calcium content in the tree, reduce the respiratory intensity and improve the anti-aging ability of the fruit.