Understand Lanyao (IV, agricultural streptomycin)

There is a high incidence of soft rot before and after the Qingming Festival to the moldy rainy season and around the Mid-Autumn Festival, and many Lanyou who have experienced soft rot have a headache. Soft rot is also known as bacterial soft rot, and its pathogenic bacteria are Monomonas Cartland, Eucalyptus and so on. It is a disease that harms the roots and stems of plants, which is easy to cause when it is hot and humid.

Let's get to know what bacteria are: bacteria (bacteria) belong to prokaryotes, which refer to a class of microbes whose chromosomes are made up of a single nucleic acid without an obvious nuclear membrane between the nucleus and cytoplasm. Prokaryotic microorganisms include bacteria, actinomycetes and cyanobacteria.

The damage process of bacteria to plants: bacteria mainly produce toxins, causing plant decay or tissue death, or blocking and destroying vascular bundles, forming tumors. As the prevention and control of bacteria is difficult, the best control method is to prevent the occurrence of bacteria.

The general manifestation of bacterial soft rot disease is the disease of the whole plant, which infects from the rhizome or wound, lurks after entering the catheter, and causes the disease only when the conditions are suitable. When the leaves were damaged, they were dark green and water-immersed spots, which expanded rapidly and softened and rotted in yellow-brown shape. The rotten part is leached by brown water droplets from time to time, which has a special stench, and when it is serious, the leaves turn yellow quickly. If the pseudobulb is susceptible, there will also be waterlogged spots, brown to black, which eventually make the pseudobulb soft, wrinkled and dark, and rot quickly. The disease is concealed and sudden. If it is not treated in time, it is easy to spread, and the infected plants are basically hopeless.

Using the antagonism among microorganisms, some special substances produced in the life activities of beneficial microorganisms are used to inhibit the growth and reproduction of pathogenic bacteria, which are called "antibiotics". Such as "agricultural streptomycin" can control bacterial soft rot.

Agricultural streptomycin is a metabolite produced by actinomycetes, which has a wide germicidal spectrum, especially has a good effect on a variety of bacterial diseases (also has a control effect on fungi), has internal absorption, can penetrate into the plant and transmit to other parts. Low toxicity to humans and animals, and low toxicity to fish and aquatic organisms. Mainly used for spraying, can also be used for root irrigation and seed soaking disinfection.

Problems needing attention in the application of agricultural streptomycin: the killing effect of biological pesticides is slower than that of chemical pesticides, so early prevention and control should be advocated, that is, spraying at the initial stage of the occurrence of diseases and insect pests. Most biological pesticides will decompose when exposed to strong sunlight and reduce their efficacy, so they should be sprayed in the afternoon or cloudy days and re-sprayed after rain. Strictly according to the dosage, do not increase or decrease the concentration at will.

The product name of agricultural streptomycin is usually "agricultural streptomycin sulfate", usually 72% soluble powder, the original drug is white amorphous powder powder, soluble in water, insoluble in most organic solvents. The stable storage period is more than two years under cool and dry conditions. General small packaging can be divided into 10 million units and 5 million units, weighing between 7 and 15 grams.

The control objects registered with agricultural streptomycin in the Ministry of Agriculture are: Chinese cabbage soft rot, rice bacterial blight, cotton bacterial blight, melon downy mildew and so on. It can be used in the prevention and control of orchid soft rot. During the prevention and treatment period, it is sprayed every seven to ten days for three to five times to avoid bacterial diseases. The amount of drugs used in vegetable control (72% soluble powder) is 3500, 000 times, and 2000 times is commonly used in the orchid boundary (the main parameter of the proportion is the unit of measurement of metabolites of actinomycetes). (Gao Hoi Chung)