Wheat powdery mildew occurs in all wheat areas in China and is one of the common diseases in wheat production. [Symptoms and Occurrence] Wheat powdery mildew mainly damages the leaves, and in severe cases, sheaths, stems and panicles also occur. At the beginning of diseased leaves, brownish-green dots appeared, which gradually enlarged into round or oval lesions. There was a layer of white powdery mildew on the upper part of the diseased leaf, and it turned grayish or gray-brown later, and many small black particles were born. When the disease is severe, the leaves are covered with moldy layers and the leaves die, causing premature plant failure, empty grains, and affecting yield. The powdery mildew germs spread over the summer and winter in the sick and the air flow. The disease can occur at 5 to 25°C, with the fastest onset at 20°C, and the higher humidity favors the onset. Generally, the occurrence of wheat fields that are poorly shaded, over dense, poorly ventilated, lack of light, or lodging in wheat fields and long-term droughts are severe. There is a significant difference in disease resistance among varieties. [Control method] 1. Selection of disease-resistant varieties At present, there are many disease-resistant varieties that have been selected from various regions, and each wheat area can choose appropriate varieties for planting according to actual conditions. 2. Strengthen the cultivation and management of reasonable close planting, fertilization and irrigation to promote ventilation and light transmission, prevent lodging, make wheat plants grow robustly and enhance resistance. 3. Drugs can prevent and control rust and scab on the early stage of disease. The following agents were sprayed 100 kg per acre. (1) Baume 0.5 degree lime sulfur spray. (2) 70% thiophanate-methyl wettable powder 1000 times spray. (3) 50% ethyl thiophanate WP 1000 times spray. (4) 50% methicillin zinc wettable powder 300 to 500 times liquid spray. (5) 50% Tuzet WP 1000 times spray. (6) 40% sterilization Dan WP 800 to 1000 times spray. (7) 25% carbendazim WP 500 times spray. (8) 25% triadimefon wettable powder sprayed with 16 grams per mu, 60 kg spray, the effect of control up to 84%, residual period of 30 days.
Roundness Tester
Roundness tester is a length measuring tool for measuring roundness using the rotary axis method. The roundness meter is a measuring tool for measuring the roundness error of the workpiece using the rotary axis method. Roundness tester is divided into two types: sensor rotary type and workbench rotary type. During measurement, the measured part is installed concentrically with the precision shaft system, and the precision shaft is attached with an inductive length sensor or a workbench for precise circular motion. It is composed of sensor, amplifier, filter and output device of the instrument. If the instrument is equipped with a computer, the computer is also included in the system.Roundness Tester
The principle of the roundness meter is the same as that of the coordinate measuring machine. In fact, its working principle is very simple. The coordinate measuring machine is a point acquisition tool. Its principle is to collect points first, and then form a line from points, and then form a three-dimensional model from lines. CMM is a kind of measuring equipment that has a guiding mechanism, a length measuring element, a digital display device in three mutually perpendicular directions, and a worktable that can place the workpiece (not necessarily large or huge). The measuring head can be moved to the measured point easily by manual or motorized means, and the coordinate value of the measured point is displayed by the reading device and the digital display device. Obviously, this is the simplest and most primitive measuring machine. With this measuring machine, the coordinate value of any point in the measured volume can be displayed through the reading device and digital display device.
Roundness Measuring Instruments ,Roundness Measuring Machine,Instrument Used To Measure Roundness,Roundness Tester,Gear profile measuring instrument
Zhejiang dexun instrument technology co., ltd , https://www.dexunmeasuring.com