The occurrence and control of Flaveria bidentis
F. bidentis belongs to the genus Flaveria of the Aster family, Asteraceae. It belongs to the genus Chrysanthemum and Gaillardia. It is a new type of agricultural pest introduced into China, which was listed as a national phytosanitary pest for entry into the country by Ministry of Agriculture No. 862 announcement in May 2007. Farmland phenomena such as invading millet, corn, sorghum, peanuts, and cotton have been found to be particularly serious in the management of extensive farmland. If farmland is planted as a dominant population, it will pose a serious threat to agricultural production and the ecological environment. I. The occurrence and distribution of Flaveria bidentis Bletilla is native to South America and later spread to Africa in Africa, Europe, Australia and Asia due to human factors such as introduction. In 2003, it was first discovered and reported in Nankai University and Hengshui Lake in China. Due to the remote origin of F. bidentis, the spread of bird excrement is very unlikely. It may be imported into China through imported grain seeds or test materials after analysis by experts. At present, the provinces and cities of Shandong, Hebei, and Tianjin have already occurred and reported north of the Yangtze River, with the heaviest occurrence in Hebei Province and 57 counties and cities in Hebei Province. My county first discovered in Monan Town in 2004. The route of passing my county may be related to the introduction of passenger water in Yueji Lake, but it does not rule out the possibility of cargo transportation and the spread of bird excrements. At present, our county is located in Monan and Duancun. The most serious happened. Second, the morphological characteristics and physiological habits, occurrence and propagation of Flaveria bidentis 1. Morphological characteristics and habits of Flaveria bidentis F. edulis is an annual herbaceous plant with a plant height of 20-100 cm. The plant height in the condition-adapted section can reach 180-250 cm. The stem is often purplish and has several vertical grooves. The leaves are opposite and the stems and leaves are succulent near the succulent. Inflorescences clustered on the apex, densely integrated into a crow's tail cyme, the corolla is bright and eye-catching. F. albicans has a strong physiological adaptability and evolutionary trend; it grows in a habitat rich in minerals and salt, such as wasteland, ditch, and highways. With hi, hi, halophilic habits, its rapid growth, large amount of seeds, strong seed adaptability, especially in our county saline soil content is suitable for its growth and reproduction, scattered surface seeds as a source of transmission in the coming year. 2 Relationship between Soil Temperature and Humidity and Excavation Status of Huangdingju T. edulis has a strong fertility, a large amount of seeds, and a small seed grain. A T. edodes can produce more than 600,000 seeds. The surface temperature of 5cm is stable to 14°C, soil moisture is above 75%, and the seeds of F. bidentis begin to germinate. Different environments have different germination times. Generally from the middle of April to the beginning of September, the seeds of F. bidentis can germinate. 3. Effect of Soil Depth on Excavation of Flaveria In order to understand the effect of different soil depths on the excavation of F. edulis under natural conditions, I stood in the east of Mogan and arranged 4 kinds of soils with different depths of 0cm, 0-1cm, 1-2cm and 2-5cm. Layer depth tests were conducted to investigate the seedling emergence of F. bidentis seeds at different soil depths. The soil in the test site is neutral loam. The seeds of F. bidentis were collected from the last remaining plant of F. bidentata. Through the experiment, the emergence rate of F. frondoscens was above 98%; the seedling rate of F. frondosa was 1% to 2%; the seedling rate of soil depth was 1-5 cm 0. Tests show that the seeds of F. bidentis below 5 cm in soil cannot be excavated. 4. The way and method of transmission of Flaveria bidentis There are many transmission routes of F. edulis, which makes quarantine difficult. At present, T. edulis is mainly distributed on both sides of highways and railways, along the ditch, in forests, wasteland, construction sites, abandoned areas in industrial and mining areas, and on both sides of the street. The way of transmission of F. dingpoensis remains to be further studied. From the present perspective, in addition to vehicle cargo loading and running water, high winds, bird and animal excrement, and man-made agricultural operations are also the means of spreading and spreading Huang Dingju. Third, the system monitoring and occurrence of the yellow top chrysanthemum. According to the research on the living habits of F. albicans in the past two years, there are two main methods for monitoring and forecasting F. bidentis in production control. The first is the long-term monitoring and prevention and control of the occurrence trend of F. bidentis; the second is the short-term forecast of the control period of F. bidentis. Combining with the experience of prevention and control in recent years, correctly grasping the number and distribution of seeds in the area of ​​T. fulva is the scientific basis for the occurrence of the trend. The systematic survey of the fixed-point T. scutellariae growing period in the region is a reliable method for establishing the prevention and control period. 1. Field Seed Investigating Method: In the area of ​​occurrence and fringe of F. bidentis, five sampling or checkerboard sampling methods will be adopted for random sampling in March. Each sample is 10*10*5 Crush the soil with cm and check the amount and germination of F. bidentis seeds in the soil. In order to predict the occurrence area and density of F. bidentis. 2, field fixed survey method: generally beginning in late April, in the region of yellow top flower, select different growth environment for fixed point, each point area of ​​1 square meter. Each growth environment is not less than 5 points. The investigation recorded the growth of F. albicans. Every 10 days. 3. Control standards for Flaveria bidentis: Due to the long time of excavation of F. frondosa and unearthed excavations, the standards for the control of F. bidentis are not uniform. Judging from the prevention and treatment experience in recent years, the critical period for the control of F. bidentis should be controlled at an average plant height of 30-50 cm. Fourth, control methods 1. Implement quarantine measures to control the spread of the epidemic. The areas that have already occurred will delineate or define the epidemic areas and monitoring areas according to the occurrence, and strengthen the quarantine and re-inspection work at the place of production. Each area in which it occurs will carry out strict quarantine measures for plants and their products, packaging materials, and transportation tools transferred from the epidemic areas to prevent further spread of the epidemic. 2, agricultural control measures, idle land, farmland can be used to deep plowing method. For the part of the yellow-lettered weeds entering the farmland, the field weeding was manually removed. 3. Chemical control, due to the complex environment of F. bidentis, is currently undergoing screening for pharmaceutical agents. Inactivated herbicides are generally used on idle lands. There are 20% paraquat, 200-250 ml/mu, and 41% glyphosate 350-400 ml/mu. The other herbicides in the field can be selected according to the specific conditions. disposable gloves Disposable Gloves,Protective Gloves Disposable,Catering Disposable Gloves,Breathable Disposable Gloves Shandong Haoyue Medical Technology Co., Ltd , https://www.haoyueyiliao.com