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Kiwi tree in the spring when the flow of -red water phenomenon, what causes, how to control?
Apr 19, 2017

Kiwi tree in the spring when the flow of "red water" phenomenon, what causes, how to control?

Kiwi ulcer disease is a bacterial disease

Kiwi ulcer disease is a bacterial disease, the main harm to the trunk, branches, serious cause plants, branches dead, but also harm the leaves and buds, 1980 in the United States, California and Japan Shenzhou Shizuoka first discovered. China from 1986, Shandong Dongshan Peak Forest Farm has confirmed the occurrence of ulcer disease, there have been a number of provinces and autonomous regions reported the occurrence of the disease, a serious place caused many orchards were destroyed. As the ulcer disease has hidden, explosive and devastating characteristics, in China kiwi producing areas have gradually increased the trend, has become the most serious threat to kiwi disease.


 Hazardous Symptoms Kiwi ulcer disease is caused by Pseudomonas theophylla kiwi pathogen (Pseudomonas yingaepv.actinidiae) caused by bacterial diseases, the main harm to the trunk, branches, serious cause plants, branches dead, but also harm the leaves and buds.


 Susceptible plants from the initial site of the buds, leaf marks, lenticels, small wounds, etc. spilled milky white mucus bacteria pus, scratched cortex visible phloem began to become dark gray rot. Department of cortical tissue gradually softened into a water-like subsidence, trunk or large branches can appear on the vertical cracks. Plant into the injury period, the sick part of the bacteria pus and wound fluid mixed from the wound overflow, was rust red. Lesion spread around the stem after a week leading to the incidence of branches above the necrosis, will also be extended to the lower part of the ground causing death or death. Leaves when the incidence of fresh leaves on the leaves appear small green, water-like, after the development of 1 to 3 mm irregular or polygonal brown lesions, the edge of a clear light yellow halo, humidity, And milky white bacteria pus overflow. High temperature conditions, the lesion was red, in continuous rainy low temperature conditions, the lesion spread quickly, and sometimes do not produce yellow halo. Many small lesions on the leaves are fused with each other to form a freckle, and the leaves are rolled up and are not easy to fall off. The autumn leaves are dark purple or dark brown and are easy to fall off. Buds can not be exposed after the damage, brown dead; new shoots after the onset of black dead.


 Pathogenesis


The incidence of law in Shaanxi Guanzhong kiwi producing areas generally in early February to early March in the field began to ulcer disease symptoms, individual years in late December when the winter began to appear when the symptoms of pruning, the main outcome of the mother branch, the main vine or trunk. Susceptible plants from the initial site of the buds, leaf marks, lenticels, small wounds, etc. spilled milky white mucus bacteria pus, cortical visible phloem began to become dark gray necrosis. Department of cortical tissue gradually softened into a water-like subsidence, trunk or large branches can also appear on the vertical cracks. Plant into the bleeding period, the Department of the disease pus and wound fluid mixed from the wound overflow, was rust red, out of the bacteria pus to other parts of the source of infection. Lesion spread around the stem after a week leading to the incidence of branches above the necrosis, will also lead to the expansion of the whole plant death. After entering May with the temperature rise, the disease on the branches of the development of slow and even basically stable. In mid-September the condition again picked up, there was a small peak, the main hazard leaves.







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