Bacterin1B1ight was first discovered in Brazil in 1960, and it began to appear in the Hawaiian region in 1971. It gradually spread in some regions that produced Anthurium in the 1980s. With the rapid development of the flower industry, the scale of planting red-flowered cut flowers and potted plants in China has gradually expanded, and the disease has also quietly entered China. Red leaf bacterial leaf spot is an extremely dangerous Anthrax bacterial disease. In the 1990s, the disease nearly destroyed the flamingo flower industry in Hawaii. In the Netherlands, companies that specialize in the breeding and cultivation of Anthurium have also suffered heavy losses due to poor prevention. Like the quarantine perforation nematode on the red palm, red leaf bacterial leaf spot disease has become a deadly killer of Anthurium, which should cause widespread concern and attention in the industry of Anthurium flower industry in China. First, the infection and its symptoms The bacteria has two infections. The first type of infection begins on the leaf and is called leaf infection. Leaf infestation usually begins at the margins of leaves and in the lower part of the leaves. In the initial stage, water-soaked spots were visible on the back of the leaves, brown spots appeared on the leaf margins at the late stage, and yellow halo was found on the edges. The second type of infestation begins on the stem and quickly spreads throughout the plant through the vascular bundle system, called systemic infestation (or vascular invasion). Systemic infections can be detected by yellowing leaves, and the new leaf color is dark at the beginning of bacterial infection. In the vascular bundle, due to the blocking of bacteria, the flow of water in the body and transportation of nutrients to the leaves are hindered, so that the leaves are dark and the leaves are yellow. In a short period of time, this type of infestation can cause the peduncle and leaves to fall off from the plant, the point of growth decays rapidly, and there is a strong gush of bacteria. When the juice carries bacteria to the leaves, water-soaked spots appear in the leaves, similar to leaf infections, except that water-soaked spots mostly appear near the main veins in the middle of the leaves. Systemic infections are irreversible. Second, the pathogen The pathogen is called Xanthomonas xanthium, which is a rod of bacteria, the size of 0.7-1.80.4-0.7 microns. Gram-negative, arousal with unipolar flagella, good tour. The main single, suitable for growth temperature 25-30 °C. Third, the host range In addition to Anthurium's crops, the pathogen can almost all plants of Araceae, such as Dieffenbachia genus (Dieffdnbachiaspp.), Synechium spp. (Syngonium spp.), Philodendrons genus (Philodendronspp.) Some of the plants in the genus are their hosts. IV. Transmission and Infection Pathways The pathogens can be forced into the plants through wounds on stems and leaves, or through stomata and leaflet spiting holes in the plants. Moisture is the main medium for transmission and invasion of germs. It takes more than 20 minutes to invade the surface of the leaf, and it mainly infects young tissues at a certain developmental stage (the formation of stomata is more, and the open type and the medium size are larger). In addition to the disease through contact with the plant or the surface of the plant with bacteria dripping on the surface of the plant, the staff of the contaminated hands, clothing, tools to cut leaves, splashing rain, contaminated irrigation water, carriers of bacteria and bacteria with the Shoes, wheels, etc. are the means of transmission. V. Prevention and control measures 1. Strengthen prevention and prevent the entry of bacteria into the park 1 Requires planting clean, pathogen-free, tissue-cultured healthy seedlings. When choosing to introduce domestic and foreign radix seedlings, it is imperative to select healthy seedlings produced by regular seedling producers with health quarantine certificates. 2 Disinfection tanks are placed at the entrance of the production area, and disinfectant is added daily. All personnel entering and leaving the greenhouse must disinfect the shoes. Persons entering the greenhouse must wear a white coat that can be used for disinfection and are regularly changed and disinfected. Minimize the replacement and flow of personnel in production areas. 3 Reduce the flow of operational tools in production areas and prevent ward tools from entering the park. Cut flowers and leaves are used as partitions for regular disinfection. 4 Avoid arbitrarily introducing host plants (such as Araceae) to the disease in Anthurium production area. 2. Comprehensive prevention and control to prevent the spread of germs in the area If the disease has already occurred in the park to prevent the spread of germs in the park, the following tasks must be done: (1) Strengthen the health measures in the production area, as mentioned earlier The health measures arrived are still very important. (2) Regularly check and remove the infected leaf (infested by leaf) as soon as possible, and put it into a closed plastic bag to bring it out of the park for destruction. Or the whole plant is removed (infected by the system), and the adjacent plants and substrates are also removed. All operations must be in the advanced clean area to enter the contaminated area. In and out of the greenhouse, you must wash your hands with a disinfectant (85% alcohol available). (3) In order to prevent diseases from being cut by cutting flowers and cutting leaves between plants, the cutting tools should be disinfected after each use, that is, disinfection can use 85% alcohol each time each use is disinfected. It is best to use at least two more knives so that when one is used, the other can be placed in disinfectant for disinfection. (4) Moisture is conducive to the spread of bacteria. Use the proper environmental conditions to keep the plants dry as much as possible. (5) The level of ammonium nitrogen and nitrate nitrogen should be reduced as much as possible in the fertilization, and the ammonium nitrogen in the original fertilizer formula should be removed, and the potassium element should maintain the original required level. (6) Weakly growing plants are more likely to be infected by bacteria. Therefore, adverse environmental conditions and high temperatures should be avoided as much as possible. The ideal temperature for bacterial growth is around 30°C. Bacterial diseases develop faster at higher temperatures. . (7) Rational use of pesticides. At the same time as the above-mentioned control methods, it is necessary to apply scientific and rational pesticides. The concentration of 72% of streptomycin sulfate 4000 times, neomycin toxin 5000 times, 10% of mongovanine wettable powder 1000-1300 times, 20% of thiazole wettable powder 1000-1200 times can be used. Prevent pathogens from developing resistance and spray once a week. Due to the toxic effects of copper preparations on the Anthurium plant, 50% of the copper phthalate (DT) WP wettable powder 500-800 times, Garethon WP 500-800 times and other copper pesticides should be carefully selected.
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