Prevention and treatment of bacterial bacterial perforation
Symptoms Plum bacterial perforation mainly damages the leaves. At the beginning of the leaf vein near the veins produced a small brown water spots like spots, water spots around the lesions yellow halo. At the end of the disease, there was a crack in the junction, and a perforation was formed. The edges of the hole were not neat.
The pathogen Xanthomona campestris (Smith) Dovosen, called Xanthomonas oryzae, is a bacterium. The cells are short-barreled, 0.3-0.80.8-1.1 micron in size, both ends are round, with a single flagellum, no spores, no decidua, and Gram-negative staining. Germ development temperature 24-28 °C, the highest 38 °C, the lowest 7 °C, lethal temperature 51 °C. The pathogen can survive for 10-13 days under dry conditions. It can survive for more than 1 year in the branch ulcer tissue.
Pathogens and Pathogens The pathogenic bacteria in the damaged twigs overwintered and the bacterium in the Hunch disease tissue began to move. Before and after plum blossom, pathogens overflowed from the diseased tissue and spread through wind and rain or insects, invading through the stomata and shoots of the leaves. The incubation period is 7-14 days. In the spring, the ulcer spots are easy to dry and the surrounding healthy tissues are easily healed. Therefore, the bacteria in the ulcer spots die in dry conditions for 10-13 days. Temperature 19-28 °C, relative humidity 70-90 °C conducive to disease. The disease usually occurs between May and July and August.
The occurrence of the disease is related to climate, tree vigor, management level and variety. Suitable temperature, frequent rain or fog, heavy fog season conducive to the reproduction and infestation of pathogens, disease severity. Bacteria are easily washed into the ground during heavy rains, which is unfavorable for their reproduction and infestation. In general, during the spring and autumn rainy season, the disease spreads rapidly, and during the summer drought, it expands slowly. The incubation period of the disease is related to temperature: temperature 25-26 °C incubation period 4-5 days, 20 °C 9 days, 19 °C 16 days. The tree vigor is light and late, and the tree vigor is early and heavy.
Control methods
(1) Strengthen management and increase tree vigor. Pay attention to drainage, increase organic fertilizer, avoid partial application of nitrogen fertilizer, and reasonably prune, so that plum garden ventilation and light transmission, in order to enhance tree vigor and improve tree disease resistance.
(2) Remove the source of overwintering bacteria. Combine pruning in winter, cut off diseased branches, remove fallen leaves, and burn them together.
(3) spray protection. Spray 5 parts of lime sulfur before germination or 40% of crystal lime sulfur or 1:1:100 of Bordeaux mixture. After germination, spray 72% of agricultural streptomycin soluble powder 3000 times or streptomycin sulfate. 4000 times liquid or oil emulsion: mancozeb: water = 10:1:500, in addition to effective bacterial perforation, but also control aphids, scale insects, leafhoppers and so on.
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